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416 Cards in this Set

  • Front
  • Back
Anatomy
the structure of the body
Physiology
the processes or functions of living things
Homeostasis
existence and maintenance of a relatively constant environment within the body
Normal Range
body temperature increases and decreases slightly around the set point (ideal value)
Tissue;
Types? (4)
a group of similar cells and the materials surrounding them

4 Types: Epithelial, Connective, Muscle, and Nervous
Organ
Organs are composed of two or more tissue types that together perform one or more common functions.
Organ System;
Types?
a group of organs classified as a unit because of a common function or set of functions

Types: integumentary, skeletal, muscular, lymphatic, respiratory, digestive, nervous, endocrine, cardiovascular, urinary, and reproductive
Name the Primary Bones in the Skeletal System

Purpose?
Provides protection and support, allows body movements, produces blood cells, and stores minerals and fat. Consists of bones, associated cartilages, ligaments, and joints.
Name the Primary Components of the Integumentary System

Purpose?
Provides protection, regulates temperature, prevents water loss, and helps produce vitamin D. Consists of skin, hair, nails, and sweat glands.
Name the Primary Muscles involved in the Muscular System

Purpose?
Produces body movements, maintains, posture, and produces body heat. Consists of muscles attached to the skeleton by tendons.
Name the primary systems involved in the Lymphatic System

Purpose?
Removes foreign substances from the blood and lymph, combats disease, maintains tissue fluid balance, and absorbs fats from the digestive tract. Consists of the lymphatic vessels, lymph nodes, and other lymphatic organs.
Name the primary organs in the respiratory system

Purpose?
Exchanges oxygen and carbon dioxide between the blood and air and regulates blood pH. consists of the lungs and respiratory passages.
Name the primary organs involved in the digestive system

Purpose?
Performs the mechanical and chemical processes of digestion, absorption of nutrients, and elimination of wastes. Consists of the mouth, esophagus, stomach, intestines, and accessory organs.
Name the main organs involved in the Nervous System

Purpose?
A major regulatory system that detects sensations and controls movements, physiological processes, and intellectual functions. Consists of the brain, spinal cord, nerves, and sensory receptors.
Name the primary organs in the Endocrine System

Purpose?
A major regulatory system that influences metabolism, growth, reproduction, and many other functions. Consists of glands, such as the pituitary, that secrete hormones.
Name the primary organs involved in the cardiovascular system

Purpose?
Transports nutrients, waste products, gases, and hormones throughout the body; plays a role in the immune response and the regulation of body temperature. Consists of the heart, blood vessels, and blood.
Name the primary organs involved in the Urinary System

Purpose?
Removes Waste products from the blood and regulates blood pH, ion balance, and water balance. Consists of the kidneys, urinary bladder, and ducts that carry urine.
Name the primary organs involved in the FEMALE reproductive system.

Purpose?
Produces oocytes and is the site of fertilization and fetal development; produces milk for the newborn; produces hormones that influence sexual function and behaviors. Consists of the ovaries, vagina, uterus, mammary glands, and uterine tube.
Name the primary organs involved in the MALE reproductive system.

Purpose?
Produces and transfers sperm cells to the female and produces hormones that influence sexual functions and behaviors. Consists of the testes, ductus deferens, seminal vesicle, prostate gland, epididymis, and penis.
Negative Feedback
Negative feedback maintains homeostasis by resisting any deviation from set point and returning the body to a normal range.
1) A receptor monitors the value of a variable - blood pressure
2) Control center establishes the set point around the variable - brain
3) An effector changes the value of the variable to maintain homeostasis - heart

Example: Blood Pressure
Positive Feedback
Less Common than Negative Feedback

When a value deviates from normal values, the system's response is to make the deviation even greater

Ex: inadequate delivery of blood to cardiac (heart) muscle
Ex: hemorrhage = blood pressure goes decreases because of losing blood, heart can’t work properly (heart beats even slower), thus causing blood pressure to decrease even further, etc.
Ex: Estrogen surge during menstrual cycle, release of estrogen causes more release of estrogen
Negative feedback is much more common than positive feedback
Ion Chemical Significance?
Ca 2+
Calcium
Part of bones and teeth; functions in blood clotting, muscle contraction, release of neurotransmitters
Ion Chemical Significance?
Na +
Sodium
Membrane potentials, water balance
Ion Chemical Significance?
K +
Potassium
Membrane potentials
Ion Chemical Significance?
H +
Hydrogen
Acid-base balance
Ion Chemical Significance?
OH
Hydroxide
Acid-base balance
Ion Chemical Significance?
C l-
Chloride
Water balance
Ion Chemical Significance?
HCO3 -
Bicarbonate
Acid-base balance
Ion Chemical Significance?
NH4 +
Ammonium
Acid-base balance
Ion Chemical Significance?
PO4 3-
Phosphate
Part of bones and teeth; functions in energy exchange, acid-base balance
Ion Chemical Significance?
Fe 2+
Iron
Red blood cell function
Ion Chemical Significance?
Mg 2+
Magnesium
Necessary for enzymes
Ion Chemical Significance?
I -
Iodide
Present in thyroid hormones
ATP
Adenosine Triphosphate
Provides energy as a result of breakdown from ATP → ADP
Neutral Solution
number H + = number OH -
Acidic Solution
number of H + > number of OH -
Basic (Alkaline) Solution
number of H + < number of OH -
Buffer
a chemical that resists changes in pH when either an acid or a base is added to a solution
ECF
Extracellular Fluid, makes up about 1/3 of the body's water
ICF
Intracellular Fluid, makes up about 2/3 of the body's water
Interstitial Fluid
Fluid that bathes the outside of cells, plasma leaks fluid into the interstitial space primarily through capillaries
Capillaries
the smallest of a body's blood vessels
Plasma
fluid part of the blood (extracellular)
Fluid Mosaic Model
Phospholipids form a double layer of molecules, a barrier between the inside and outside of the cell, gives it a liquid quality. Cholesterol within offers strength and flexibility. Proteins "float" freely throughout the membrane and are sometimes modified by carbohydrates. Proteins function as membrane channels carrying molecules.
Cation? Anion?
positive charged ion
Major Cations and Anions in ECF? Major Cations and Anions in ICF?
Extracellular fluid =
Cations: Sodium, Potassium, Calcium
Anions: Chloride, Hydrogen Carbonate

Intracellular fluid =
Cations: Potassium
Anions: Hydrogen Phosphate
How are ion concentration differences maintained between the ECF and ICF?
Leaky pores and the sodium-potassium pumps.

Potassium tends to be INSIDE the cell
Sodium tends to be OUTSIDE the cell
Phospholipid structure?
Tails make up most of the lipids, which are made up of hydrocarbons
Tend to be Hydrophilic (water loving)
Lipids like being with other lipids
Lipids assemble together with tails pointed towards each other
Cell membranes
Tend to be lipophilic (water fearing or hydrophobic)
Hydrophilic
water loving
Hydrophobic
water fearing, lipophilic
diffuse easily across the cell membrane
Lipophilic
water fearing, hydrophobic
diffuse easily across the cell membrane
Diffusion? Basics?
solutes move from a place of higher concentration to a place of lower concentration of that solute in solution.
Diffusion is random!
Ex: perfume in a room
WITH gradient

Examples: Oxygen, carbon dioxide, chloride ions, urea

Hydrophobic molecules diffuse easily across the cell membrane.
Like diffuses like.
Steroids are made of cholesterol (which is a lipid) therefore it diffuses across cell membranes.
Ions DO NOT cross cell membranes
Net Diffusion?
solutes move from a place of higher concentration to a place of lower concentration of that solute in solution.

Net Diffusion is HIGH → LOW
Ex: More in "A" than in "B"
Osmosis
Osmosis can be thought of as the diffusion of water from an area of high water concentration to an area of low water concentration. Water wants to move where it has more stuff to dissolve.
Isotonic
water plus salt (or a substance)
Hypotonic
it has more solute inside the cell than outside
Hypertonic
it has more solute outside of the cell than inside
Facilitated diffusion
Facilitated Diffusion utilizes a protein in the cell membrane to transport solutes down their concentration gradients.
Ex: glucose
WITH gradient
no energy needed
Primary Active Transport
Primary Active Transport utilizes a protein to pump solutes against their concentration gradients. It moves low to high and requires additional energy (ATP).
Ex: Sodium out, Potassium in, ATP used up
AGAINST gradient
Ex: sodium, potassium, calcium, and hydrogen; amino acids
Secondary Active Transport
Secondary Active Transport involves the coupled transport of 2 or more solutes.
It requires indirect energy, which comes from the primary active transport. Something is always moving in the gradient and something is always moving against the gradient; usually sodium is moving down.
AGAINST gradient by carriers
EX: Glucose, amino acids
Major Molecules in Cell Membrane?
Phospholipids and proteins.

Lesser: cholesterol and carbohydrates.
Cell Membrane diffusion easy? What substances are found in the cell membrane?
small water-soluble molecules diffuse easily across, others must pass through membrane channels
molecules that are lipid-soluble, such as Oxygen, carbon dioxide, and steroids, pass through the phospholipids.

enzymes, glycogen, and potassium ions are found inside the cell.
sodium, calcium ,and chlorine are found outside the cell
Which direction is sodium pumped? Potassium?
Why is this important?
Sodium moves Up
Potassium moves Down
Results in a higher concentration of sodium extracellularly and a higher concentration of potassium intracellularly. This is essential in maintaining membrane potential.
Histology
microscopic study of tissue structure
Epithelium
covers internal and external surfaces throughout the body. it also forms most glands.

No blood vessels in the epithelial tissue. Gets blood from the basement membrane.

Purpose: protection, selective barrier, secretion, absorption, propulsion

Identification: Open space
Basement Membrane
Secreted partly by epithelial cells and partly by the cells of the underlying tissues. It consists of a meshwork of protein molecules with other molecules bound to them.

Has blood vessels

Purpose: filter and barrier
ex: prevent metastasis (moving of disease)

Made of collagen and adhesives; acellular
Cilia
propel materials along the free surface of cells. The nasal cavity and trachea are lined with pseudostratified columnar ciliated epithelium.

Require energy cuz they are constantly beating
Microvilli
cylindrical extensions of the cell membrane that increase the free surface area. Normally many microvilli cover the free surface of each cell involved in absorption or secretion, such as the cells lining the small intestine or kidneys.
Tight Junctions
bind adjacent cells together and form permeability barriers. Tight junctions prevent the passage of materials between epithelial cells because they completely surround each cell, similar to the way a belt surrounds the waist. materials must pass through the cells, so they're regulators.
Gap Junctions
Small channels that allow small molecules and ions to pass from one epithelial cell to another. Most epithelial cells are connected to one another by gap junctions, and researchers believe that molecules or ions moving through the gap junctions act as communication signals to coordinate the activities of cells.
Simple Squamous Epithelium
Location: air sacs (alveoli) of lungs and inner linings of the heart and blood vessels

Purpose: Diffusion and Filtration - It is found lining surfaces of passive transport or gasses.
Simple Cuboidal Epithelium
Location: Kidney tubules, thyroid gland, liver, and ducts of salivary glands

Function: Secretion, excretion, absorption
Simple Columnar Epithelium
Location: Anywhere that requires absorption.
Nonciliated: uterus, stomach, and intestines.
Ciliated: Uterine tubes

Function: Protection, Secretion, and Absoption
Pseudostratified Columnar Epithelium
Location: Linings of the Upper respiratory tubes

Function: trap and move pollutants to the mouth where they are swallowed
Stratified Squamous Epithelium
Location: Keratinized - Epidermis of the skin
Nonkeratinized - linings of the oral cavity, esophagus, vagina, and anal canal
Transitional Epithelium
Location: Line the urinary bladder, ureters, and part of the urethra

Function: distention or fluctuation
Goblet Cells
modified columnar epithelial cells that synthesize and secrete mucous
Endocrine Glands
No ducts
Empty secretions into the blood (Hormones)

Includes: Thyroid gland and insulin-secreting portions of the pancreas
Connective Tissue
found throughout body.

It is usually characterized by large amounts of extracellular material that separates cells from one another (Extracellular Matrix)

Functions:
Enclosing tissues, Support and movement, Energy storage, Cushioning and insulation, Protection
Extracellular Matrix
Extracellular material that separates cells (connective Tissue).

Major Components: protein fibers, ground substance consisting of nonfibrous protein and other molecules and fluid
Exocrine Glands
Have Ducts
simple or compound or tubular

Includes: sweat glands and sebaceous glands
Collagen
Resemble microscopic ropes, flexible but resist stretching
Ground Substance
Shapeless background against which cells and collagen fibers can be seen
Elastin
have a structure similar to that of coiled metal bed springs; after being stretched, they can recoil to their original shape
Proteoglycans
resemble the limbs of pine trees, with proteins forming the branches

(top is tropocollagen)
-blasts
produce matrix
-cytes
maintain matrix
-clasts
break down matrix for remodeling
macrophages
immune; white blood cells (phagocytes) that eat
mast cells
immune; allergy preventers, release histamine and heparin
Areolar Connective
Location: around body organs

Function: binds skin to deeper organs
Makes up membranes
Loose packing support, and nourishment for the structures with which it is associates
Adipose Connective
Locations: subcutaneous layer; around kidneys and heart; yellow bone marrow; breasts

Function: Packing material, thermal insulator, energy storage, and protection of organs against injury from being bumped or jarred
Reticular Connective
Location: spleen; thymus; lymph nodes; red bone marrow

Function: forms a soft skeleton to support lymphatic organs, also holds adipose tissue together
Dense Regular Connective
Location: Ligaments and Tendons

Functions: Withstanding great pulling forces exerted in the direction of fiber orientation due to great tensile strength and stretch resistance
Dense Irregular Connective
Location: Dermis, Heart Valves (AEORTA), periosteum on bone

Function: strength and stretch resistance
Elastic Connective
Locations: larger artery walls; vocal cords; ligaments between vertebrae

Function: Capable of Stretching and recoiling like a rubber band with strength in the direction of fiber orientation
Hyaline Cartilage
Locations: Nasal Septum, larynx, costal cartilage, ends of long bones, fetal skeleton

Functions: Allows growth of long bones; provides rigidity with some flexibility in the trachea, bronchi, ribs and nose; forms rugged, smooth yet somewhat articulated surfaces; forms the embryonic skeleton
Fibrocartilage
Locations: between vertebrae; between pubic bones; pads (meniscus) in knee

Functions: More collagen than hyaline; somewhat flexible and capable of withstanding considerable pressure, connects structures subjected to great pressure
Elastic Cartilage
Locations: outer ear; epiglottis

functions: contains elastin and collagen and proteoglycans; provides rigidity with even more flexibility than hyaline cartilage because elastic fibers return to their original shape after being stretched
Compact Bone
Locations: Bone Shafts (Sides of Bones), beneath periosteum

Functions: provides great strength and support and protects internal organs such as the brain, bone also provides attachment sites for muscles and ligaments
Spongy (Cancellous) Bone
locations: ends of long bones; inside flat and irregular bones

Functions; holds marrow, provides strength and support
Blood (Liquid) Connective
Locations: Lumens of blood vessels; heart chambers

Functions: Transports oxygen, carbon dioxide, hormones, nutrients, waste products, and other substances protects the body from infection and is involved in temperature regulation.
Do blood vessels extend into epithelium? How does epithelial tissue exchange gasses, nutrients and wastes?
Blood vessels do not extend from the underlying tissues into epithelium, so gases and nutrients that reach the epithelium must diffuse across the basement membrane from the underlying tissues, where blood vessels are abundant. Waste products produced diffuse across the basement membrane to blood vessels.
Describe the changes which occur to epithelium lining the respiratory tract in long-term smokers. How does this lead to smoker's cough?
Delicate pseudostratified columnar epithelium, which performs a cleaning function by moving mucus and debris from the passageways, is replaced by stratified squamous epithelium, which is more resistant to irritation but does not perform a cleaning function. also, lung cancer most often results from changes in epithelial cells in the lung passageways of smokers. Changes are used to identify cancer. Smokers often cough because they have to in order to get rid of mucous and debris that used to be removed by cilia.
Are blood vessels present in connective tissue?
yes, erythrocytes are generally present in connective tissue.
How does collagen fiber help tissues?
it provides added strength and durability.
Muscle Tissue
Characterized by elongated cells, often called muscle fibers, that can contract to create movements

Attached to skeleton, but also components of internal organs

Generates body heat through movement
Skeletal Muscle Tissue
Voluntary Control, Striated

Locations: Attached to bones via tendons, tongue, facial muscles, and voluntary sphincters

Functions: body movement, maintaining posture, breathing, speaking, controlling waste eliminations, and protection
Smooth Muscle Tissue
Involuntary, non-striated

Locations: visceral organs, the iris, blood vessels, respiratory tubes, attached to hair follicles

Functions: visceral organs, controlling pupil size, blood flow, and airflow, and creating "goose bumps" if we are too cold or frieghtened
Cardiac Muscle Tissue
Involuntary, Striated

Locations: Only in heart wall

Functions: Pumping Blood
Neurons
Contain a cell body with the nucleus and most of the cytoplasm, and cellular processes that extend from the cell body

Cellular processes include one to many dendrites and a single axon (nerve fiber)

Functions: Considered excitable cells because they can exhibit signals called action potentials (nerve impulses) along the neuron to another neuron or a muscle or gland
Neuroglia
Glial Cells

More abundant than neurons
Cannot conduct nerve impulses

Functions: they have important supportive and protective functions for neurons
Integumentary System
Consists of the skin and accessory structures, such as hair, glands, and nails

Functions: Protection, sensation, vitamin d production, temperature, regulation, excretion
Epidermis
most superficial layer of skin, layer of epithelial on the dermis, prevents water loss and resists abrasion, stratified squamous epithelium, new cells produced by mitosis.
Dermis
layer of dense connective tissue, on average the dermis is 10-20 times thicker than the epidermis, responsible for structural strength of skin, rests on hypodermis which connects skin to muscle
Subcutaneous Fat
a fat layer found in the hypodermis, the base layer of skin. It is connective tissue to muscle.
Keratinization
as new cells form, they push older cells to the surface, where they slough, or flake off. The outermost cells protect the cells underneath, and the deeper, replicating cells replace cells lost from the surface. During their movement, the cells change shape and chemical composition. The cells are filled with the protein keratin, which makes them hard. As keratinization proceeds, epithelial cells eventually die and produce an outer layer of dead, hard cells that resists abrasion and forms a permeability barrier.
Stratum Corneum
The most superficial stratum of the epidermis. it consists of dead squamous cells filled with keratin. Keratin gives the stratum corneum its structural strength. The stratum corneum cells are also coated and surrounded by lipids, which help prevent fluid loss through the skin. It consists of 25 or more layers of dead squamous cells joined by desmosomes. Excessive stratum corneum cells sloughed from the surface of the scalp are called dandruff. in skin subjected to friction, the number of layers in the stratum corneum greatly increases, producing a thickened area called a callus.

keratinocytes
Apical Layer
Stratum basale
deepest stratum, consists of cuboidal or columnar cells that undergo mitotic divisions about every 19 days. one daughter cell becomes a new stratum basale cell and can divide again. The other daughter cell is pushed toward the surface, a journey that takes about 40-56 days. As cells move to the surface, changes in the cells produce intermediate strata.
Made of cuboidal or columnar tissue. Takes almost 3 months to have all knew skin (reach surface)

keratinocytes
"Germinativum"
Basal Layer
Mitosis
when a eukaryotic cell undergoes self division into two different cells
Dermal Papillae
Contain many blood vessels that supply the overlying epidermis with nutrients, remove waste products, and help regulate body temperature. The dermal papillae int he palms of the hands, the soles of the feet and the tips of the digits are arranged in parallel, curving ridges that shape the overlying epidermis into fingerprints and footprints. The ridges increase friction and improve the grip of the hands and feet.
Cleavage lines
collagen fibers of the dermis are oriented in many different directions and can resist stretch. However, more collagen fibers are oriented in some directions than in others. This produces cleavage lines, or tension lines, in the skin, and the skin is most resistant to stretch along these lines. it is important for surgeons to be aware of cleavage lines. An incision made across the cleavage lines is likely to gap and produce considerable scar tissue, but an incision made parallel with the lines tends to gap less and produce less scar tissue.
Melanocytes
melanin is produced by melanocytes, which are irregularly shaped cells with many long processes that extend between the epithelial cells of the deep part of the epidermis.
Melanin
"black", group of pigments primarily responsible for skin, hair, and eye color. Most melanin molecules are brown to black pigments, but some are yellowish or reddish. Melanin provides protection against ultraviolet light from the sun. Large amounts of melanin form freckles or moles in some regions of the skin, as well as darkened areas in the genitalia, the nipples and the circular areas around the nipples. Other areas, such as the lips, palms of the hands, and soles of the feet, contain less melanin. melanin production is determined by genetic factors exposure to light, and hormones.
Albinism
recessive genetic train that causes a deficiency or an absence of melanin. Albinos have fair skin, white hair, and unpigmented irises in the eyes.
Hair follicle
hair arises from a hair follicle, an extension of the epidermis that originates deep in the dermis. The shaft of hair protrudes above the surface of the skin, whereas the root and hair bulb are below the surface.
Hair Bulb
below the surface. hair is produced in the hair bulb, which rests on a dermal papilla. Blood vessels within the papilla supply the hair bulb with the nourishment needed to produce the hair. Hair is produced in cycles.
Male pattern Baldness
alothough many of the hair follicles are lost, some remain and produce a very short, transparent hair, which for practical purposes is invisible. These changes occur when male sex hormones act on the hair follicles of men who have the genetic predisposition for pattern baldness.
Sabaceous glands
simple, branched acinar glands. Most are connected by a duct to the superficial part of the hair follicle.
Sebum
an oily, white substance rich in lipids. The sebum lubricates the hair and the surface of the skin, which prevents drying and protects against some bacteria.

Exocrine
Apocrine Sweat Glands
Simple, coiled, tubular glands, that produce a thick secretion rich in organic substances. They open into hair follicles, but only in the armpits and genitalia. Apocrine sweat glands become active at puberty because of the influence of sex hormones. The organic secretion, which is essentially odorless when released is quickly broken down by bacteria into substances responsible for what is commonly known as body odor.

Exocrine
Eccrine Sweat Glands
simple, coiled, tubular glands located in almost every part of the skin but most numerous in the palms and soles. They produce a secretion that is mostly water with a few salts. Eccrine sweat glands have ducts that open onto the surface of the skin through sweat pores. When the body temperature starts to rise above normal levels, the sweat glands produce sweat, which evaporates and cools the body. Sweat can also be released in the palms, sole, armpits, and other replaces because of emotional stress. Emotional sweating is used in lie detector tests because sweat gland activity usually increases when a person tells a lie. Such tests can detect even small amounts of sweat because the salt solution conducts electricity and lowers the electrical resistance of the skin.
Vitamin D
formed when exposed to ultraviolet light. The vitamin is carried by the blood to the liver, where it is modified and then to the kidneys, where it is modified further to form active vitamin d. If exposed to enough ultraviolet light, humans can produce all the vitamin d they need. However many people need to ingest vitamin d as well because clothing and indoor living reduce their exposure to UV Light. Fatty fish and vitamin d fortified milk are the best sources. Vitamin d stimulates the intestines to absorb calcium and phosphate, the substance necessary for normal bone growth and normal muscle function.
Edema
Swelling
Malignant Melanoma
rare form of skin cancer that arises from melanocytes, usually in a preexisting mole. A mole is an aggregation, or "nest" of melanocytes. The melanoma can appear as a large, flat, spreading lesion or as a deeply pigmented nodule. Metastasis is common, and unless diagnosed and treated early in development, this cancer is often fatal.
1st, 2nd, and 3rd degree burns
1. Involve only the epidermis and are red and painful. Slight edema or swelling, may be present. Heals in a week.
2. Damages both the epidermis and the dermis. if dermal damage is minimal symptoms include redness, pain, edema, and blisters. healing takes 2 weeks. if deep in the dermis, may appear red, tan or white; can take several months to heal and might scar.
3. Epidermis and the dermis are completely destroyed, and recovery occurs from the edges of the burn wound. Third degree are often surrounded by areas of first and second. Although first and second areas are painful the region of third is usually painless because sensory receptors in the epidermis and dermis have been destroyed. may appear white, tan, brown, black or deep cherry red. Doctors may use skin grafting to heal.
What are the major functions of the integumentary system?
Protection
Sensation
Vitamin D Production
Temperature Regulation
Excretion
What function is the epidermis best adapted for? The dermis?
epidermis prevents water loss and resists abrasion.

dermis is responsible for most of the skin's structural strength. (collagen and elastic fibers)
Describe how skin grows? Which layers are involved? What is the role of keratinization?
New cells are produced by mitosis. As new cells form, they push older cells tot he surface, where they slough, or flake off. The outermost cells underneath, and the deeper, replicating cells replace cells lost from the surface. During their movement, the cells change shape and chemical composition. The cells are filled with the protein keratin (keratinization), which makes them hard. As keratinization proceeds, epithelial cells eventualy die and produce an outer layer of dead, hard cells that resist abrasion and form a permeability barrier. Specific layers of strata are involved (Stratum Basale to Stratum Corneum).
What kinds of substances could easily pass through the skin by diffusion?
Lipophilic or Hydrophobic
What kind of tissue is the dermis? What structures and cell types are present within the dermis? Are blood vessels present?
The dermis is composed of dense collagenous connectie tissue containing fibroblasts, fat cells, and macrophages. nerves, hair follicles, smooth muscles, glands, and lymphatic vessels extend into the dermis Collagen and elastic fibers are responsible for the structural strength of the dermis.
Blood vessels are present.
With respect to cleavage line orientation, which direction would be best for making an incision? Why?
An incision made across the cleavage lines is likely to gap and produce cinsiderable scar tissue, but an incision made parallel with the lines tends to gap less and produce less scar tissue.
How do epithelial cells in the skin acquire melanin? What factors account for skin color? Which of these increase melanin production?
Factors that determine skin color include pigments in the skin, blood circulating through the skin, and the thickness of the stratum corneum. Melanin is the group of pigments primarily responsible for skin, hair, and eye color. melanin is produced by melanocytes which are irregularly shaped cells with many long processes that extend between the epithelial cells of the deep part of the epidermis. The Golgi apparatuses of the melanocytes package melanin into vesicles called malanosomes which move into the cell process of the melanocytes. Epithelial cells phagocytize the tips of the melanocyte cell processes, thereby acquiring melanosomes.
Melanin production is determined by genetic factors exposure to the light, and hormones. Exposure to ultraviolet light in sunlight stimulates melanocytes to increase melanin production. The result is a tan.
What type of tissue is hair composed of? How does it grow? What is responsible for male pattern baldness?
Hair is produced in the hair bulb, which rests on a dermal papilla. Blood vessels within the papilla supply the hair bulb with the nourishment needed to produce the hair. Hair is produced in cycles. During the growth stage it is formed by epithelial cells within the hair bulb. These cells, like the cells of the stratum basale in the skin, divide and undergo keratinization. The hair grows longer as these cells are added to the base of the hair within the hair bulb. During the resting stage, growth stops. when the next growth stage begins, a new hair is formed and the old hair falls out. Eyelashes 30 days, rest for 105 days. Scalp 3 years, rest for 1-2 years.
In baldness, some hair remains and produce a very short, transparent hair, which for practical purposes is invisible. These changes occur when male sex hormones act on the hair follicles of men who have the genetic predisposition for pattern baldness. DHT may destroy hair follicles (a converted form of testosterone). Finasteride inhibits DHT synthesis.
What is the role of the skin in vitamin D synthesis? Give one example why having adequate levels of vitamin D in the body is important.
Adequate levels of vitamin D are necessary because vitamin D stimulates the intestines to absorb calcium and phosphate, the substances necessary for normal bone growth and normal muscle function.
How is body temperature homeostasis regulated by blood flow in the skin?
Normal body temperature is maintained at = 37 C

Regulation of body temperature is important because the rate of chemical reactions within the body can be increased or decreased by changes in the body temperature. Even slight changes in temperature can make enzymes operate less efficiently and disrupt the normal rates of chemical changes in the body.
To cool, blood vessesl in the dermis dilate and enabel more blood to flow within the skin, thus transferring heat from deeper tissues to the skin where the heat is lost by radiation (infrared energy), convection (air movement), or conduction (direct contact with an object). Sweat that spreads over the surface of the skin and evaporates also carries away heat and reduces body temperature.
To heat, constriction of dermal blood vessels reduce blood flow to the skin. Thus less heat is transferred from deeper structures to the skin, and heat loss is reduced. however with smaller amounts of warm blood flowing through the skin, the skin temperature decreases. if the skin temperature drops below 15 C, dermal blood vessels dilate.
Explain how extensive burns can be immediately life-threatening.
Increased permeability of capillaries results in fluid and ions from the burn wound traveling into tissue spaces. The loss of fluid decreases blood volume, which decreases the heart's ability to pump blood. The resulting decrease in blood delivery to tissues can cause tissue damage, shock and even death. infections are the major cause of death for burn victims. Depression of the immune system during the first or second week after injury contributes the high infection rate. Venous thrombosis can also form as another complication. Clots occur regularly at damaged tissue, but can occur also in the veins halting blood flow.
Hypodermis
Subcutaneous fat, makes up about 1/2 body fat, used to estimate % body fat, It's fatty connective tissue

Areolar + Adipose Tissue
Vitiligo
may result from autoimmune destruction of melanocytes
What can you do if you do not have the correct amount of melanin for your geographical location?
D3 supplements, diet
or Shading and sunscreens
Ringworm
Fungal infection that produces patchy scaling and inflammatory response in the skin
Eczema and Dermatitis
Inflammatory conditions of the skin caused by allergy, infection, poor circulation, or exposure to chemical or environmental factors
Psoriasis
Chronic skin disease characterized by thicker than normal epidermal layer (stratum corneum) that sloughs to produce large, silvery scales; bleeding may occur if the scales are scraped away
Impetigo - Bacterial Infection
Small blisters containing pus; easily rupture to forma thick, yellowish crust; usually affects children
Decubitus ulcers (Bedsores or Pressure sores) - Bacterial Infection
Develop in people who are bedridden or confined to a wheelchair; compression of tissue and reduced circulation result in destruction of the hypodermis and skin, which later become infected by bacteria, forming ulcers.
Rubeola (measles) - Viral Infections
Skin lesions; caused by a virus contracted through the respiratory tract; may develop into pneumonia or infect the brain causing damage.
Rubella (German Measles) - Viral Infections
Skin lesions; usually mild viral disease contracted through the respiratory tract; may be dangerous if contracted during pregnancy because the virus can cross the placenta and damage the fetus.
Varicella (Chicken Pox) - Viral Infections
Skin lesions; usually mild viral disease contracted through the respiratory tract
Shingles - Viral Infections
Painful skin lesions that can recur when the dormant virus is activated by trauma, stress, or another illness; caused by the chickenpox virus after childhood infection.
Cold Sores - Viral Infections
Skin lesions; caused by herpes simplex I virus; transmitted by oral or respiratory routes; lesions recur
Genital Herpes - Viral Infections
Genital lesions; caused by herpes simplex II Virus; transmitted by sexual contact
Hydroxyapatite
Hydroxyapatite – Most of the mineral in bone is in the form of calcium phosphate

Hydroxyapatite = concrete
Collagen = flexible rebar
Diaphysis
Diaphysis = central shaft of the bone
Epiphysis
Epiphysis = ends of bone
Epiphyseal plate/line
Epiphyseal plate/line = growth plate, composed of cartilage, between each epiphysis and the diaphysis. This is where the bone grows in length. When bone growth stops, the cartilage of each epiphyseal plate is replaced by bone and becomes an epiphyseal line.
Red Marrow and Yellow Marrow
Red marrow and Yellow Marrow – resides in medullary cavity in the diaphysis, and smaller cavities in the epiphyses of long bones.

Red marrow consists of blood-forming cells and is the only site of blood formation in adults. Children have more red marrow than adults (growth).

Yellow marrow replaces red, it contains mostly adipose tissue.
Periosteum
Periosteum – Most of the outer surface of bone is covered by dense connective tissue which is HIGHLY vascularized (blood vessels) and lots of nerves; outer layer is tougher
Endosteum
Endosteum – the surface of the medullary cavity is lined with a thinner connective tissue membrane; not vascularized
Compact Bone
Compact bone – blood vessels in bone matrix (osteons) are only found in compact bone; forms most of the diaphysis of long bones and the thinner surfaces of all other bones.
Osteoblasts
The periosteum and endosteum contain osteoblasts, which function in the formation of bone, as well as in the repair and remodeling of bone. When osteoblasts become surrounded by matrix, they are referred to as osteocytes.
Osteocytes
When osteoblasts become surrounded by matrix, they are referred to as Osteocytes.
Lamellae
Bone is formed in thin sheets of extracellular matrix called lamellae, which osteocytes located between the lamellae within spaces called lacunae.
Canaliculi
Cell processes extend from the osteocytes across the extracellular matrix of the lamellae within tiny canals called canaliculi.
Spongy Bone (cancellous)
consists of a lacy network of bone with many small marrow-filled spaces.
It is located mainly in the epiphyses of long bones. It forms the interior of all other bones. Spongy bone consists of delicate interconnecting rods or plates of bone call trabeculae, which resemble scaffolding, the trabeculae add strength to a bone without the added weight that would be present if the bone were solid mineralized matrix. The spaces between are filled with marrow.
Central Canal (Haversian Canal)
Blood vessels that run parallel to the long axis of the bone are contained within the central canals. Each central canal, with the lamellae and osteocytes surrounding it, is called an osteon, or haversian system. Most of the lamellae of compact bone are organized into sets of concentric rings, with each set surrounding a central canal.
Osteon
Each central canal, with the lamellae and osteocytes surround it, is called an osteon or haversian system. Each osteon, seen in cross section, looks like a microscopic target, with the central canal as the "bull's eye". Osteocytes, located in lacunae, are connected to one another by cell processes in canaliculi. The canaliculi give the osteon the appearance of having tiny cracks within the lamellae.
Trabeculae
delicate interconnecting rods or plates of bone, resmble the beams or scaffolding of a building. The trabeculae add strength to a bone without the added weight. Spaces are filled with marrow. Each trabecula consists of several lamellae with osteocytes between them. No blood vessels penetrate and no canals.
Ossification
Ossification is the formation of bone by osteoblasts. After an osteoblast becomes completely surrounded by bone matrix, it becomes a mature bone cell, or osteocyte. Bone formation that occurs within connective tissue membranes its called intramembranous ossification, and bone formation that occurs inside cartilage is called endochondral ossification.
Intramembranous Ossification
Intramembranous ossification occurs when osteoblasts begin to produce bone in connective tissue membranes. This occurs primarily in the bones of the skull. Osteoblasts line up on the surface of connective tissue fibers and begin depositing bone matrix to form trabeculae. Process begins in "ossification centers"; usually two or more centers exist in each flat skull bone, and the skull bones result from fusion as they enlarge.

Mostly found in Fetal Skulls
Endochondral Ossification
The bones at the base of the skull and most of the remaining skeletal system develop through the process of endochondral ossification from cartilage models. The cartilage models have the general shape of the mature bone. During endochondral ossification, cartilage cells, called chondrocytes, increase in number, enlarge, and die. Then the cartilage matrix becomes calcified. As this process is occurring in the center of the cartilage model, blood vessels accumulate in the perichondrium. The presence of blood vessels in the outer surface of future bone causes some the unspecified connective tissue cells on the surface to become osteoblasts.
Chondrocytes
During endochondral ossification, cartilage cells, called chondrocytes, increase in number, enlarge, and die. Then the cartilage matrix becomes calcified.
Bone Collar
As the osteoblasts are laying down bone on either the calcified cartilage or old existing bone they form the first outer layer of new bone called the bone collar, which is then filled in.
Bone Remodeling
Bone remodeling involves the removal of existing bone by osteoclasts and the deposition of new bone by osteoblasts. Bone remodeling occurs in all bone. Remodeling is responsible for changes in bone shape, the adjustment of bone to stress, bone repair, and calcium ion regulation in the body fluids. Remodeling is also involved in bone growth when newly formed spongy bone in the epiphyseal plate forms compact bone. A long bone increasses in length and diameter as new bone is deposited on the outer surface and growth occurs at the epiphyseal plate. At the same time, bone is removed from the inner, medullary surface of the bone. As the bone diameter increases, the thickness of the compact bone relative to the medullary cavity tends to remain fairly constant. If the size of the medullary cavity did not also increase as bone size increases, the compact bone of the diaphysis would become thick and very heavy.
Calcium is regulated by; removal from bones when blood calcium levels decrease, and it is deposited when dietary calcium is adequate. This is controlled by hormones.
Bone Remodeling
Bone remodeling involves the removal of existing bone by osteoclasts and the deposition of new bone by osteoblasts. Bone remodeling occurs in all bone. Remodeling is responsible for changes in bone shape, the adjustment of bone to stress, bone repair, and calcium ion regulation in the body fluids. Remodeling is also involved in bone growth when newly formed spongy bone in the epiphyseal plate forms compact bone. A long bone increases in length and diameter as new bone is deposited on the outer surface and growth occurs at the epiphyseal plate. At the same time, bone is removed from the inner, medullary surface of the bone. As the bone diameter increases, the thickness of the compact bone relative to the medullary cavity tends to remain fairly constant. If the size of the medullary cavity did not also increase as bone size increases, the compact bone of the diaphysis would become thick and very heavy.
Calcium is regulated by; removal from bones when blood calcium levels decrease, and it is deposited when dietary calcium is adequate. This is controlled by hormones.
Parathyroid Hormone
PTH is secreted from the parathydoid glands when blood calcium levels are too low, stimulates increased bone breakdown and increased blood calcium levels by indirectly stimulating osteoclast activity. PTH increases calcium uptake from the urine in the kidney. Additionally, PTH stimulate the kidneys to form active vitamin D, which increases calcium absorption from the small intestine. Decreasing blood calcium levels stimulate PTH secretion.
Synovial Fluid
A complex mixture of polysaccharides, proteins, fat, and cells. Synovial fluid forms a thin, lubricating film covering the surfaces of the joint. In certain synovial joints, the synovial membrane many extend as a pocket or sac called a bursa.
Osteoporosis
Osteoporosis, or porous bone, results from reduction in the overall quantity of bone matrix. It occurs when the rate of bone reabsorption exceeds the rate of bone formation. The loss of bone mass makes bones so porous and weakened that they become deformed and prone to fracture.
In postmenopausal women, decreased production of the female sex hormone estrogen can cause osteoporosis. The degeneration occurs mostly in spongy bone, especially in the vertebrae of the spine and the bones of the forearm.
Finally, osteoporosis can result from inadequate exercise or disuse caused by fractures or paralysis.

Increased dietary calcium and vitamin D can increase calcium uptake and promote bone formation. Exercise helps, or estrogen replacement therapy decreases osteoclast activity, which reduces bone loss.


Dual-emission X-ray absorptiometry (DXA, previously DEXA) is a means of measuring bone mineral density (BMD). Two X-ray beams with differing energy levels are aimed at the patient's bones. When soft tissue absorption is subtracted out, the BMD can be determined from the absorption of each beam by bone. Dual-energy X-ray absorptiometry is the most widely used and most thoroughly studied bone density measurement technology (Wikipedia).
What are the major functions of the skeletal system?
Support
Protection
Movement
Storage
Blood Cell Production
What type of tissue is bone tissue? Describe the composition of the bone matrix. What would it be like if all of the mineral were removed? What if all of the collagen were removed?
Bone is made up of either compact or spongy Bone. But mostly it consists of an extracellular Matrix.


Hydroxyapatite: bone mineral composed of calcium phosphate crystals (This is like the concrete)
Collagen (like the flexible rebar)

If all the mineral were removed it would be super flexible
If all the collagen were removed it would be really rigid.
Describe how a long bone, such as the femur, would differ between a young person and an adult.
Young:
Mostly Spongy Bone
Tons of Red Marrow (for blood cell productions)
Epiphyseal plates are not closed yet - still growing

Adults;
Mostly Compact (though there is Spongy)
Mostly yellow marrow (used to hold fatty marow, for minerals)
Epiphyseal Plates have closed now called the Epiphyseal Lines
Describe the major histological features of compact and spongy bone.
The periosteum and endosteum contain osteoblasts, which function in the formation of bone. When they are surrounded by matrix they are referred to as osteocytes.
Bone is formed in thin sheets of extracellular matrix called lamellae, with osteocytes located between the lamellae within spaces called lucunae. Cell processes extend from the osteocytes across the extracellular matrix of the lamellae within tiny canals called canaliculi.
There are two major types:
Compact bone is mostly solid matrix and cells. Compact bone has osteons or haversian systems with a central canal at the center. These osteons are built around blood vessels that run parallel to the axis and can provide nutrients.
Spongy bone consists of a lacy network of bone with many small marrow-filled spaces. The interconnecting plates of spongy bone is called trabeculae, and trabeculae do not have blood vessels penetrating it. Marrow fills the spaces between the trabeculae.
Briefly outline the steps involved in intramembranous and endochondral ossification, respectively.
Intramembranous Ossification - Mostly in fetal skull
Osteoblasts produce trabecular matrix between connective tissue membranes
Several ossification centers

Endochondral Ossification - Ossification from cartilage models
Blood supply required
Osteoblasts produce bone collar
Primary ossification center in diaphysis (also where it gets longer); osteoclasts remove calcified cartilage; osteoblasts produce new matrix
Secondary ossification centers in epiphyses:
New cartilage produced on epiphyseal side.
Chondrocytes mature, enlarge and die.
Matrix calcified.
Surface for bone formation by osteoblasts.
How do growth hormone, estrogen and testosterone respectively affect bone growth?
Growth Hormone stimulates lengthening of bone, endochondral ossification. It also stimulates bone widening. If you have an excess of growth hormone, as a child your bones would become taller, as an adult your bones would become wider (because your epiphyseal plates are closed).

Testosterone is needed to close the epiphyseal plates.

Estrogen prevents bone resorption.
What are the functions of bone remodeling?
Constant removal (osteoclasts) and formation (osteoblasts) of bone
Simultaneously within same bone
Adjustments to stress; new bone is stronger
Bone repair, conversion of spongy to compact and calcium homeostasis
What are the steps in bone repair?

Why is complete joint immobilization only recommended in the early phase of bone repair?
When a bone is broken a clot forms in the damaged area.
Blood vessels and cells invade the clot and produce a network of fibers and cartilage called a callus.
Osteoblasts enter the callus and form spongy bone.
Most of the spongy bone is lowly remodeled to form compact bone and the repair is complete.

Your bones need stress in order to stimulate bone remodeling.
What important role does bone play in Ca homeostasis? How do parathyroid hormone and vitamin D affect Ca homeostasis?
Bone is the major storage site for calcium int he body, and movement of calcium into and out of bone helps determine blood calcium levels, which is critical for normal muscle and nervous system function. Calcium moves into bone as osteoblasts build new bone and out of bone as osteoclasts break down bone. When blood calcium levels are too low, osteoclast activity increases, releasing calcium into blood. If blood calcium is too high, osteoclast activity decreases.

Parathyroid hormone (PTH) is released when calcium levels are too low in the blood. It stimulates bone breakdown and increased blood calcium levels by indirectly stimulating osteoclast activity. PTH also increases calcium uptake from the urine int he kidney. Additionally, PTH stimulates the kidneys to form active vitamin D, which increases calcium absorption from the small intestine. Decreasing blood calcium levels stimulate PTH secretion.
Calcitonin is the hormone that decreases osteoclast activity.

Calcium is important for muscle tissue and nervous tissue.
Why are postmenopausal women particularly at risk for osteoporosis? What are other risk factors?
Estrogen declines a ton!!
Loss of sex hormones; menopause in women
Hip and vertebral fractures serious in elderly
Risk factors: advanced age, females, alcohol, smoking, soda, sedentary lifestyle and vitamin D deficiency
Bone density scan , vitamin D supplementation , HRT and bisphosphonate drugs

Estrogen prevents bone resorption. So your bone breaks down MUCH faster after menopause.
How do the three types of articulations differ? Provide an example for each.
Fibrous: little or no movement; fetal skull

Cartilaginous: united by cartilage; epiphyseal plates, costal cartilage and intervertebral discs

Synovial: free movement; joints of appendicular skeleton; filled with synovial fluid
Tumors
May be malignant or benign and cause a range of bone defects
Gigantism
abnormally increased body size due to excessive growth at the epiphyseal plates
dwarfism
abnormally small body size due to improper growth at the epiphyseal plates
osteogenesis imperfecta
brittle bones that fracture easily due to insufficient or abnormal collagen
rickets
growth retardation due to nutritional deficiencies in minerals or vitamin D; results in bones that are soft, weak, and easily broken
osteomyelitis
bone inflammation often due to a bacterial infection that may lead to complete destruction of th ebone
tuberculosis
typically, a lung bacterium that can also affect bone
osteomalacia
softening of adult bones due to calcium depletion; often caused by vitamin D deficiency
osteoporosis
reduction in overall quantity of bone tissue; see systems pathology
arthritis
inflammation of joint; causes include infectious agents, metabolic disorders, trauma and immune disorders
rheumatoid arthritis
general connective tissue autoimmune disease
degenerative joint disease
gradual degeneration of a joint with advancing age; can be delayed with exercise
gout
increased production and accumulation of uric acid crystals in tissues, including joint capsules
bursitis
inflammation of a bursa
bunion
busitis over the joint at the base of the great toe; irritated by tight shoes
Fasciculi
A muscle is composed of numerous visible bundles called muscle fasiculi, which are surrounded by loose connective tissue called the perimysium.
Muscle Fiber
A fasciculus is composed of several muscle cells, which are called muscle fibers. Each muscle fiber is surrounded by loose connective tissue called endomysium.
Transverse Tubules
Along the suface of the sarcolemma are many tublike invaginations, called transverse tubules, or T tubules, which occur at regular intervals along the muscle fiber and extend inward into it. The T Tubules are associated with a highly organized smooth endoplasmic reticulum called the sarcoplasmic reticulum.
Sarcolemma
The cell membrane of the muscle fiber is called the sarcolemma. The multiple nuclei of the muscle fiber are located just deep tot he sarcolemma.
Sarcoplasmic Reticulum
The T Tubules are associated with a highly organized smooth endoplasmic reticulum. T tubules connect the sarcolemma to the sarcoplasmic reticulum. The sarcoplasmic reticulum has a relatively high concentration of Ca, which play a major role in muscle contraction.
Sarcomere
The actin and myosin myofilaments are arranged into highly ordered, repeating units along the myofibril called sarcomeres.
Actin
Actin myofilaments, or thin filaments, are made up of three components; actin, troponin, and tropomyosin. The actin myofilaments, which resemble two minute strands of pearls twisted together, have attachment sites for the myosin myofilaments.
Myosin
Myosin myofilaments, or thick myofilaments, resemble bundles of minute golf clubs. The parts of the myosin molecule that resemble golf club heads are referred to as myosin heads. The myosin heads have three important properties; The heads can bind to attachment sites on the actin myofilaments; they can bend and traighten during contraction; and they can break down ATP, releasing energy.
Troponin
Troponin molecules are attached at specific intervals along the actin myofilaments. These molecules have binding sites for Ca.
Tropomyosin
Tropomyosin filaments are located along the groove between the twisted strands of actin myofilament subunits. The tropomyosin filaments block the myosin myofilament binding sites on the actin myofilaments in an unstimulated muscle.
Sliding Filament Model
Contraction of skeletal muscle tissue occurs as actin and myosin myofilaments slide past one another, causing the sarcomeres to shorten. Many sarcomeres joined end to end form myofibrils. Shortening of the sarcomeres causes myfibrils to shorten, thereby causing the entire muscle to shorten. This is referred to as the sliding filament model.

During contraction, neither the actin nor the myosin fibers shorten. The H zones and I bands shorten during contraction, but the A bands do not change in length. During muscle relaxation, sarcomeres lengthen. This lengthening requires an opposing force, such as that produced by other muscles or by gravity.
Cross-Bridge Cycling
During contraction of a muscle, Ca bind to troponin molecules, causing tropomyosin molecules to move, which exposes myosin attachment sites on actin myofilaments.
The myosin heads bind tot he exposed attachment sites on the actin myofilaments to form cross-bridges, and phosphates are released from the myosin heads.
Energy stored in the myosin heads is used to move the myosin heads, causing the actin myofilament to slide past the myosin myofilament, and ADP molecules are released from the myosin heads.
ATP molecules bind to the myosin heads.
As ATP is broken down to ADP and phosphates, the myosin heads release from the actin attachment sites.
The heads of the myosin molecules return to their resting position, and enrgy is stored in the ehads of the myosin molecules. If Ca are still attached to troponin, cross-bridge formation and movement are repeated. This cycle occurs many times during a muscle contraction. Not all cross-bridges form and release simultaneously.
Resting Membrane Potential
The inside of most cell membranes is negatively charged compared to the outside of the cell membrane; in other words, the cell membrane is polarized. The charge difference, called the resting membrane potential, occurs because there is an uneven distribution of ions across the cell membrane. The resting membrane potential develops for three reasons; the concentration of K inside the cell membrane is higher than outside the cell membrane; the concentration of Na outside the cell membrane is higher than inside the cell membrane; and the cell membrane is more permeable to K than it is to Na.
Action Potential
The rapid depolarization and repolarization of the cell membrane is called an action potential. In a muscle fiber, an action potential results in muscle contraction.
Depolarization & Repolarization
Resting membrane potential = Na channels and some, but not all, K channels are closed. A few K diffuse down their concentration gradient through the open K channels, making the inside of the cell membrane negatively charged compared to the outside.
Depolarization = Na channels are open. A few Na diffuse down their concentration gradient through the open Na channels, making the inside of the cell membrane positively charged compared to the outside.
Repolarization = Na channels are closed, and Na movement into the cells stops. More K channels open. K movement out of the cell increases, making the inside of the cell membrane negatively charged compared to the outside once again.
Motor Neurons
Motor neurons are specialized nerve cells that stimulate muscles to contract. Motor neurons generate action potentials that travel to skeletal muscle fibers. Axons of these neurons enter muscles and send out branches to several muscle fibers.
Neuromuscular Junction
Axons of motor neurons enter muscles and send out branches to several muscle fibers. Each branch forms a junction with a muscle fiber, called a neuromuscular junction. A more general term, synapse, refers to the cell-to-cell junction between a nerve cell and either another nerve cell or an effector cell, such as a muscle or gland cell. Neuromuscular junctions are located near the center of a muscle fiber.
Motor Unit
A single motor neuron and all the skeletal muscle fibers it innervates constitute a motor unit. The fewer fiber there are in the motor units of a muscle, the greater control you have over that muscle. Many muscle units constitute a single muscle.
Myasthenia Gravis
Myasthenia gravis is an autoimmune disorder in which antibodies are formed against acteylcholine receptors. As a result, acetylcholine receptors in the postsynaptic membranes of skeletal muscles are destroyed. With fewere receptors, acetylcholine is less likely to stimulate muscle contraction, resulting in muscle weakness and fatigue.


autoimmune condition, your antibodies bind to receptors, causing muscle disfunction
Very critical with diaphragm
Rigor Mortis
After a person dies, ATP is no longer available, and the cross bridges that have formed are not released, causing the muscles to become rigid.

stiffness of death
Dead people don’t make atp, so they are locked
Creatine Phosphate
Creatine Phosphate provides a means of storing energy that can be used rapidly to help maintain an adequate amount of ATP in a contracting muscle fiber. During periods of inactivity, as excess ATP is produced in the muscle fiber, the energy contained in the ATP is used to synthesize creatine phosphate. During periods of activity, the small reserves of ATP in the cell are used first. Then the energy stored in creatine phsophate is accessed quickly to produce ATP, which is used in muscle contraction and to restore ATP reserves.
Myoglobin
Myoglobin can continue to release oxygen in a muscle even when a sustained contraction has interrupted the continuous flow of blood.

Myo - muscle, globin - oxygen
Hypertrophy
Muscle fibers are enlargening
Duchenne's Muscular Dystrophy
Duchenne’s muscular dystrophy is the most common childhood form of MD

Etiology
Dystrophin mutation
X-linked
(Anchors sarcomeres to cell membrane
Protects fibers against mechanical stress)
If not functioning properly the muscle fibers actually die and are replaced with fat

Clinical course
Diagnosed by age 3
Progressive muscle weakness and atrophy
Life expectancy: late teens to mid 20s

Incidence
1 in 3,000 boys *(because of only x chromosone, since it acts on x)
Rarely girls
Dystrophin
a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane

mutation in genes causes Duchenne's Muscular Dystrophy
Smooth Muscle Fibers
Involuntary Control

Locations
Walls of hollow organs
Vasculature
Bronchioles
Iris and ciliary body in eyes
Functions
Under involuntary control
Autonomic nervous system
Produce motility
Propel food in the GI tract
Maintain tension
Vascular tone
Unitary Smooth Muscle
Unitary smooth muscle
Gap junctions
Coordinated contraction
Gastrointestinal tract, bladder, and ureters
Spontaneous activity
Multiunit Smooth Muscle
Multiunit smooth muscle
Each fiber behaves as a separate motor unit
Fine motor control
Iris, ciliary muscles of lens, and vas deferens
Motor Unit
A single motor neuron and all the skeletal muscle fibers it innervates constitute a motor unit.
Muscle Twitch
A muscle twitch is the contraction of a muscle fiber in response to a stimulus. Because most muscle fibers are grouped into motor units, a muscle twitch usually involves all the muscle fibers in a motor unit.

A muscle twitch has three phases:
Lag phase - the time between the application of a stimulus and the beginning of contraction
Contraction phase - the time during which the muscle contracts
Relaxation phase - the time during which the muscle relaxes
Tetanus
Tetanus is a sustained contraction that occurs when the frequency of stimulation is so rapid that no relaxation occurs. The increased force of contraction produced in summation and tetanus occurs because Ca build up in myofibrils, which promotes cross-bridge formation and cycling. The buildup of Ca occurs because the rapid production of action potentials in muscle fibers causes Ca to be released from the sarcoplasmic reticulum faster than they are actively transported back into the sarcoplasmic reticulum.
Recruitment
In recruitment, the number of muscle fibers contracting is increased by increasing the number of motor units stimulated, and the muscle contracts with more force. When only a few motor units are stimulated, a small force of contraction is produced because only a small number of muscle fibers are contracting. As the number of motor units stimulated increases, more muscle fibers are stimulated to contract, and the force of contraction increases. Maximum force of contraction is produced in a given muscle when all the motor units of that muscle are stimulated (recruitment).

If all the motor units in a muscle could be stimulated simultaneously, the resulting motion would be quick and jerky. However, because the motor units are recruited gradually, some are stimulated and held in tetanus while additional motor units are recruited; thus, contractions are slow, smooth, and sustained. In the same way, smooth relaxation of muscle occurs because some motor units are held in tetanus while other motor units relax.
Summation
In summation, the force of contraction of individual muscle fibers is increased by rapidly stimulating them. When stimulus frequency, which is the number of times a motor neuron is stimulated per second, is low, there is time for complete relaxation of muscle fibers between muscle twitches. As stimulus frequency increases there is not enough time between contraction for muscle fibers to relax completely. Thus one contraction summates, or is added onto, a previous contraction. As a result, the overall force of contraction increases.
Major functions of the muscular system?
Movement
Posture
Respiration
Heat production
Organ/vessel constriction
Heart contraction
Describe how muscle fibers are organized within muscle tissue
Muscle Fiber cells and organelles....
nuclei - near surface, create proteins
mitochondria - many
T Tubules - reach across and connect sarcoplasmic reticulum to cell membrane (here is where action potential)
Sarcoplasmic reticulum - houses lots of calcium (which open calcium channels and allow for cross bridge cycling to take place)
Myofilament Structure - describe how it contracts
Describe how flow of ions lead to the resting membrane potential and the generation of action potentials
Briefly describe the steps involved in synaptic transmission of an action potential across the neuromuscular junction
Each presynaptic terminal (axon) contains many small vesicles, called synaptic vesicles. These vesicles contain acetylcholine, or ACh, which functions as a neurotransmitter, a molecule released by a presynaptic nerve cell that stimulates or inhibits a prostynaptic cell. When an action potential reaches the presynaptic terminal, it causes Ca channels to open. Ca enter the presynaptic terminal ancd cause several synaptic vesicles to release acetylcholine into the synaptic cleft by exocytosis. The acetylcholine diffuses across the synaptic cleft and binds to acetylcholine receptor sites on the Na channels in the muscle fiber cell membrane. The combination of acetylcholine with its receptor opens Na channels and therefore makes the cell membrane more permeable to Na. The resulting movement of Na into the muscle fiber initiates an action potential, which travels along the length of the muscle fiber and causes it to contract. The acetylcholine released into the synaptic cleft between the neuron and muscle fiber is rapidly broken down by an enzyme, acetylcholinesterase. This enzymatic breakdown ensures that one action potential in the neuron yields only one action potential in the skeletal muscle fibers of that motor unit and only one contraction of each muscle fiber.
What occurs when an action potential migrates down the T tubule of a muscle fiber? Why is this important?
How does an increase in intracellular Ca initiate cross-bridge cycling? What role does ATP play in cross-bridge cycling?
How does muscle fiber relaxation occur?
Muscle fiber relaxation occurs with a lack of motor neuron stimulation.

Ca2+ is pumped back into the sarcoplasmic reticulum and intracellular levels decrease.
Why do some muscles contain smaller motor units while other contain larger motor units? Provide an example for both circumstances.
Smaller Motor Units = fine motor control, such as the eyes

Larger Motor Units = gross motor control, such as the legs
Why does tetanus produce not only prolonged contraction but a greater force of contraction?
Continuous Action Potential

It happens so fast that the Calcium channels in the Sarcoplasmic Reticulum remain open so that Ca can continue to flow.

This causes more cross bridge cycling = tension
What mechanism ensures that muscle contractions are slow and sustained rather than rapid and jerky? Explain.
Recruitment controls the amount of stimulus, so that motor units are gradually held in tetanus while other are recruited (some are in tetanus while other motor units are relaxing)
Contrast how a muscle would obtain energy while at rest versus while intensely exercising. Why do these differences occur?
Resting or moderate=
Aerobic respiration
Creatine phosphate storage at rest
Fatty acids most important source
Most Efficient
Breaking down Fuel in the presence of Oxygen to make ATP

Intense exercise=
Anaerobic respiration
ATP reserves quickly consumed (not enough)
Glycogenolysis (use up all your glucose stores)
Lactic acid buildup
Limited by glucose
Breaking down energy WITHOUT Oxygen (less efficient)
Contrast Slow and Fast Twitch Fibers
Slow Twitch = Endurance
Many Mitochondria
Aerobic Metabolism
High Fatigue Resistance
High Myoglobin Content
Low Glycogen Content

Fast Twitch = Strength
Few Mitochondria
Anaerobic Metabolism
Low Fatigue Resistance
Low Myoglobin Content
High Glycogen Content
Where is smooth muscle found in the body? What are its functions?
Locations
Walls of hollow organs
Vasculature
Bronchioles
Iris and ciliary body in eyes
Around Arteries and Blood vessels

Functions
Under involuntary control
Autonomic nervous system
Produce motility
Propel food in the GI tract
Maintain tension
Vascular tone
Helps maintain blood pressure (like sitting and standing)
Contrast the functions of unitary and multiunit smooth muscle.
Unitary smooth muscle
Gap junctions
Coordinated contraction
Gastrointestinal tract, bladder, and ureters
Spontaneous activity

Multiunit smooth muscle
Each fiber behaves as a separate motor unit
Fine motor control
Iris, ciliary muscles of lens, and vas deferens
Cramps
Pianful, spastic contractions of a muscle; usually due to a buildup of lactic acid
Fibromyalgia
Non-life-threatening, chronic, widespread pain in muscles with no known cure; also known as chronic muscle pain syndrome
Hypertrophy
Enlargement of a muscle due to an increased number of myfibrils, as occurs with increased muscle use
Atrophy
Decrease in muscle size due to a decreased number of myofilaments; can occur due to disuse of a muscle, as in paralysis
Tendinitis
Inflammation of a tendon or its attachment point due to overuse of the muscle
Inferior (Caudal)
Below
The neck is inferior to the head
Anterior (Ventral)
Closer to front of body
The lips are anterior to the teeth
Posterior (Dorsal)
Closer to back of body
The teeth are posterior to the lips
Medial
Closer to midline of body
The nose is medial to the eyes
Lateral
Farther from midline of body
The eyes are lateral to the nose
Intermediate
Between two structures
The elbow is intermediate between the shoulder and the wrist
Ipsilateral
On same side of body
The right arm and right leg are ipsilateral
Contralateral (Peripheral)
On opposite sides of body
The right arm and left arm are contralateral
Proximal
Nearer to point of attachment of limb to trunk
The elbow is proximal to the wrist
Distal
Farther from point of attachment of limb to trunk
The wrist is distal to the elbow
Superficial
Closer to surface of body
The skin is superficial to the muscles
Deep
Farther from surface of body
The muscles are deep to the skin
Cervical
neck
Thoracic
chest
Pectoral
breast
Sternal
breast bone
Abdominal
abdomen
Umbilical
navel
Coxal
hip
Pelvic
pelvis
Pubic
genital area
Dorsal
back
Scapular
shoulder blade region
Vertebral
spinal column
Lumbar
the area of the back between the lowest rib and buttocks
Acromial
highest point of the shoulder
Axillary
armpit
Brachial
arm
Cubital
elbow
Antecubital
Anterior surface of the elbow
Olecranal
posterior surface of the elbow
Antebracial
forearm
Carpal
wrist
Manual
hand
Palmer
palm of the hand
Digital
digits
Inguinal
grown where the thigh attaches to the pelvis
Gluteal
buttocks
Femoral
thigh
Patellar
anterior surface of the knee
Popliteal
posterior surface of the knee
Crural
anterior surface of the leg
Sural
posterior surface of the leg
Fibular
lateral side of the leg
Tarsal
ankle
Pedal
foot
Calcaneal
heel
Plantar
sole of foot
Parietal ....
Outer wall or lining
Visceral ....
Inner wall or lining
Pericardial Cavity
the cavity surrounding the heart
Pleural cavity
the cavity surrounding the lungs
Simple Squamous Epithelium
Simple Cuboidal Epithelium
Simple Columnar Epithelium
Pseudostratified Columnar Ciliated Epithelium
Stratified Squamous Epithelium
Transitional Epithelium
Areolar Tissue
Adipose Connective Tissue
Dense Regular Connective
Dense Irregular Connective
Elastic Connective
Spongy or Cancellous Bone Tissue
Axial
Pertaining to the central part of the body, the head and trunk
Appendicular
Pertaining to the extremities or limbs
Cephalic
head
Facial
face
Frontal
forehead
Orbital
eye
Otic
ear
Buccal
cheek
Oral
mouth
Cranial
pertaining to the portion of the skull surrounding the brain
Occipital
the back of the head
Tuberosity
rough projection or elevation
Ex: tibia
Crest
Ridgelike
Ex: hip bone
Epicondyle
superior to condyle
Ex: femur
Line
slightly raised ridge
Ex: femur
Process
prominent
Ex: vertebra
Protuberance
outgrowth
Ex: skull
Ramus
extension
Ex: hip bone
Spine
sharp slender, thornlike
Ex: scapula
Trochanter
large blunt shape
Ex: femur
Tubercle
knoblike
Ex: humerus
Condyle
rounded process
Ex: skull
Facet
nearly flat
Ex: vertebra
Head
Expanded end
Ex: femur
Lacrimal
2

Lacrimal fossa (tear ducts)
Vomer
1
divides nostrals at nose end
Maxilla
2

Alveoli
Palatine Process

(cleft palate)
Inferior Nasal Concha
2

Help with cleaning in the nose
Palatine
2
Zygomatic
2
Auditory Ossicles
SMALLEST bones in the body

contains the
Malleus
Incus
Stapes
Sinuses purpose?
lessen the tension on our heads and necks.
4
found in frontal, maxillary, ethmoid and sphenoid
Vertebral Column
26 bones

Vertebra
Intervertebral Discs
Cervical
Thoracic
Lumbar
Sacrum
Coccyx
Vertebra & Intervertebral Discs
Body
Vertebral Foramen
Intervertebral Foramen
Superior & Inferior Articular Facets
Transverse Process
Spinous Process (C7)
Cervical Vertebra
7

Atlas (C1) - No body
Axis (C2) - Dens
C1-C6:
"Triangular" Foramen
(Bifurcated) Spinous Process
Transverse Foramen
Transverse Process
Vertebral Foramen
Lamina
Pedicle
Superior Articular Process
Inferior Vertebral Notch
Body
Spinous Process (C7)
Atlas (C1)
Transverse Process
Transverse Foramen
Vertebral Foramen
Axis (C2)
Body
Dens
Facet that articulates with occipital condyle
Spinous Process
Superior articular fact
transverse process
transverse foramen
vertebral foramen
Thoracic Vertebra
T1-T12

(Heart shaped) body
inferior vertebral notch
lamina
pedicle
Spinous process
Superior articulared process
transverse (oval) foramen
transverse process
vertebral foramen
demifacets on body articulate with head of rib
facets on transverse process articulate with tubercle of rib
Lumbar Vertebra
L1-L5

Body
Inferior vertebral notch
lamina
pedicle
(hatchet shaped) spinous process
superior articular process
transverse foramen
transverse process
vertebral foramen
It is the largest
Sacrum
5 fused

Sacral crest
Ala
Sacral Canal
Sacral Promontory
Auricular Surface
Anterior sacral foramen
Posterior sacral foramen
Sacral Hiatus
Superior Articular Process
Coccyx
3-5 fused
Thoracic Cage
Sternum
Ribs
Sternum
3 bones

Manubrium
- Jugular Notch
- Sternal Angle (opposite 2nd rib)
Body of Sternum
Xiphoid (this is cartilage, ossifys completely by age 40)
Ribs
12 pairs

True Ribs (7) - Costal Hyaline Cartilage connected
False Ribs (5) - last 2 pairs are called floating

Markings
head - to demifacets on body
neck
Tubercle - to facet on transverse process
Body
Appendicular
126 bones in all

Pectoral Girdle
Forelimb
Wrist
Palm
Digits
Pelvic Girdle
Ankle
Sole
Toes
Pectoral Girdle
Clavicle
Scapula
Clavicle
2

Sternal end
Acromial End

Breaks most often
Scapula
2

Spine
Acromion (highest point of your shoulder)
Caracoid Process (named after crow)
Glenoid Cavity
Inferior Angle
infraspinous fossa
lateral border
supraspinous fossa

Breaks least often
Forelimb
Humerus
Radius
Ulna
Humerus
2

Head
Anatomical Neck
Surgical Neck
Greater & lesser Tubercle
Intertubercular sulcus
deltoid tuberosity
medial & lateral epicondyle
coronoid fossa
capitulum (little head)
olecranon fossa
trochlea
Radius
2

Head
Styloid Process of Radius
Radial Tuberosity
Ulna
2

Olecranon
Trochlear notch
coronoid process
Radial notch of ulna
Ulnear notch of radius
Head of ulna
Ribs
12 pairs

True Ribs (7) - Costal Hyaline Cartilage connected
False Ribs (5) - last 2 pairs are called floating

Markings
head - to demifacets on body
neck
Tubercle - to facet on transverse process
Body
Appendicular
126 bones in all

Pectoral Girdle
Forelimb
Wrist
Palm
Digits
Pelvic Girdle
Ankle
Sole
Toes
Pectoral Girdle
Clavicle
Scapula
Clavicle
2

Sternal end
Acromial End

Breaks most often
Scapula
2

Spine
Acromion (highest point of your shoulder)
Caracoid Process (named after crow)
Glenoid Cavity
Inferior Angle
infraspinous fossa
lateral border
supraspinous fossa

Breaks least often
Forelimb
Humerus
Radius
Ulna
Humerus
2

Head
Anatomical Neck
Surgical Neck
Greater & lesser Tubercle
Intertubercular sulcus
deltoid tuberosity
medial & lateral epicondyle
coronoid fossa
capitulum (little head)
olecranon fossa
trochlea
Radius
2

Head
Styloid Process of Radius
Radial Tuberosity
Ulna
2

Olecranon
Trochlear notch
coronoid process
Radial notch of ulna
Ulnear notch of radius
Head of ulna
Ribs
12 pairs

True Ribs (7) - Costal Hyaline Cartilage connected
False Ribs (5) - last 2 pairs are called floating

Markings
head - to demifacets on body
neck
Tubercle - to facet on transverse process
Body
Appendicular
126 bones in all

Pectoral Girdle
Forelimb
Wrist
Palm
Digits
Pelvic Girdle
Ankle
Sole
Toes
Pectoral Girdle
Clavicle
Scapula
Clavicle
2

Sternal end
Acromial End

Breaks most often
Scapula
2

Spine
Acromion (highest point of your shoulder)
Caracoid Process (named after crow)
Glenoid Cavity
Inferior Angle
infraspinous fossa
lateral border
supraspinous fossa

Breaks least often
Carpals (16)
So long top part her comes the thumb

Scaphoid (Largest Carpal)
Lunate (Crescent Moon shaped)
Triquetrum
Pisiform (small pea)
Hamate (hook)
Capitate (head)
Trapezoid
Trapezium
Metacarpals (10) & Phalanges (28)
Metacarpals
Middle
Distal
Proximal
Coxal Bone
2

Pelvic Brim
True Pelvis
False Pelvis
Obturator Foramen (Largest Foramen in the body)
Acetabulum
Ilium
2

Iliac Crest (this is where you rest your hands on your hips)
Greater Sciatic Notch
Spine
Ischium
2

Ischial Tuberosity (that's what you sit on)
Spine
Pubis
2

Pubic Symphasis
Spine
Femur
2

head
neck
Fovea Capitis
Greater and lesser Trochanter (only found in femurs)
Gluteal Tuberosity
Linea Aspera (feels like a ridge on posterior side)
Lateral and Medial epicondyle
lateral and medial condyle
shaft

(Old people break their Femur not their hips)
Patella
2

largest sesamoid bone
Tibia
2

Medial and lateral condyles
tibial tuberosity
anterior crest
medial malleolus
anterior border


makes up the knee
Fibula
2

head (triangular)
Lateral Malleolus
distal tibiofibular joint

Makes up the larger part of the ankle
Tarsals (14)
Calcaneous (heel bone)
Talus (2nd largest bone)
Cuboid (cube shaped)
Navicular (looks like the hull of a ship)
Lateral, Intermediate & medial Cuneiforms (these make up the ankle bones
Sole has Metatarsals (10) & Phalanges (28)
metatarsals
proximal
middle
distal
Hyoid Bone
The only bone that does not articulate with any other bone

Attachment for tongue and holds Trachea.
When strangled this bone is broken.
Age a skull
Sutures to look at:
Lambdoidal Suture
Point between Lambdoidal and Sagittal
Sagittal Suture mid and top
point between sagittal and coronal
Coronal Suture Mid and end

0 = open
1 = minimal closure
2 = significant closure
3 = completely obliterated
Sex the Skull
handout....
2D:4D
Women tend to be 1:1
Men tend to be <1:1
because testosterone affects the their 4th digit

Athletes tend to have more compressed digits cuz of wear