Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/53

Click to flip

53 Cards in this Set

  • Front
  • Back
Puberty
›The period of time during which physical
development changes from that of a child to
full adult reproductive capacity (secondary
sexual development)
›Puberty is a biological event
›Puberty is the major hormonal transition in life
(others are pregnancy, menopause, andropause)
"arche
- the begining
Adolescence
›Encompasses both the physical and psychosocial
aspects of growth and development
›Spans a greater time period than puberty –
adolescence is the second decade of life (10-19
years)
›Youth is 12-24 years and includes young adulthood
›Puberty almost certainly adds to the complexities of
adolescence
›Puberty, unlike adolescence, has a clear endpoint
Human puberty differs from other animals
›Growth spurt
›Adrenarche (except a few primates)
›The length of time between the completion of puberty
and optimal reproductive age (the human head is soo big compartively, thus need the extra time to be-able to birth a child)
›Delay in brain maturation compared to other physical
growth
Important events of puberty
1. Height growth
2. Weight growth – lean mass (muscle & bone) and fat mass
3. Body composition change
4. Bone mass accretion
5. Gonadal steroid production (testosterone and oestradiol) & attainment of reproductive capacity
Pubertal Growth Rates
› In about 2.5 years, boys gain 30cm and 30kg and girls gain 20 cm and 20kg, second only to ›Growth in utero, an average of 70cm/year
End points of Puberty
1. Epiphyseal (bone growth plate) fusion
2. Near adult bone mass
3. Full secondary sexual development (as described by
Tanner staging)
4. Menstruation with ovulation/mature spermatogenesis
Main Pubertal Hormones
Puberty Part of a continuum
we are born to go through puberty immediately but the brakes are always put on
- girl babies have breast development
- boys get testies enlarged then receed
we are born to go through puberty immediately but the brakes are always put on
- girl babies have breast development
- boys get testies enlarged then receed
Initiation of Puberty
› Gonadotrophin hormone releasing hormone (GnRH) neurons in the hypothalamus have widespread
projections
› Kisspeptin activation of GPR 54(gprotein receptor) is important for the activation of these neurons at puberty
› Their activation results in an increase in frequency and amplitude of GnRH secretion - initially at night which is detected clinically by nocturnal LH surges in the blood
Kisspeptin
› Kisspeptin neurones in the arcuate
nucleus also produce
- neurokinin B (TAC 3) required
for the onset of puberty
- dynorphin which inhibits GnRH
production
› Glial (non-neuronal) factors may
also facilitate puberty onset
Timing of puberty
›Normal range for onset 8 - 13 F and 9-14 M
›Normal range for duration 2 - 5 years
›Because of this variability chronological age does not define developmental stage
Bone Age
›Descriptor of developmental stage
›Uses X Ray of hand/wrist
›A better descriptor of developmental stage
than chronological age.
›Two grading systems where the individual XRay
is compared with radiographic pictures
-Greulich Pile
- Tanner Whitehouse

- EXAMPLE: average bone age for a female at menarche is 13.5 yrs
Height growth in females
›Mean peak growth velocity 8-9 cm/year in
females
›Growth spurt in the female is an early puberty
event and is initiated and maintained by
- Ovarian oestradiol (low levels) plus
- Pituitary growth hormone (increase in frequency
and size of nocturnal peaks) / IGF1 which act
synergistically
› 20 cm average gain
›Halted by epiphyseal closure
- oestradiol (high levels) - THEREFORE THERE IS A PROBLEM WITH EARLY OCP USE
Height growth in males
›Mean peak growth velocity 9-11.5 cm/year in males
›Growth spurt in the male is a late puberty event and is initiated and maintained by
- Testicular testosterone (higher levels) plus
- Pituitary growth hormone (increase in frequency
and size of nocturnal peaks) / IGF1 which act
synergistically
› 30 cm average gain
›Halted by epiphyseal closure
- High level oestradiol (aromatisation from testosterone)
Growth curves for males and females
boys on average 10-12cm taller
boys on average 10-12cm taller
Weight Gain
Males
› 30kg average gain
› Increase in lean body mass &
› Decrease in fat mass under the influence of testosterone
› Weight gain is a late pubertal event – height first and then
bulking up
Females
› 20 kg average gain (50% in peri-menarchal year)
› Increase in lean body mass
› Relatively greater increase in fat mass in oestrogen
dependent areas (breast, thighs, buttocks)
› Initiated and maintained by GH/IGF1 and oestradiol
Increase in Bone Mass
›Accumulated during growth spurt and beyond
›Peak bone mass nearly achieved by end of second decade
›Pubertal growth abnormalities may inhibit
accumulation of bone mass and result in risk
of future osteoporosis/fracture
› The increase in bone mass is initiated and maintained by GH/IGF-1, oestradiol or testosterone, adequate dietary calcium and Vitamin D, and physical activity
Tanners Staging: Breast
Tanners Female Hair Development
Tanners Male Hair Development
Tanner Genital Stages Male
› 1 Pre-pubertal – testes < 3ml
› 2 Testicular enlargement - 4-8ml; penis ~
6cm
› 3 Testicular enlargement and penile
lengthening 10-12ml
› 4 Testicular enlargement 15ml +; penis
lengthens and widens
› 5 Adult – testicles 20-25ml; penis ~ 12.5cm
Secondary sexual characteristics - M
› Voice breaks (G3/4)
- Vocal cords lengthen
- Larynx & cricothyroid cartilage increase in size
- Laryngeal muscles enlarge
› Body and facial hair (G4/5)
- Later development (as is muscle bulk)
- Amount of hair genetically determined by sensitivity of androgen
receptor
› Acne (G4/5)
- Result of increasing testosterone
- Usually resolves despite continuing adult testosterone levels
Changes leading to capacity for
menstruation and ovulation
›Cervix and uterine muscle and uterine lining
(endometrium) growth under the influence of
oestradiol
› Fluctuation in oestradiol levels causes a
withdrawal bleed (shedding of endometrium)
as menarche – early cycles are usually
anovulatory
›High oestradiol levels produce a positive
feedback on LH with pre-ovulatory surge in the
more mature menstrual cycle and
progesterone production from the ovary in the
second half of the cycle

progesterone is the painful part of mensturation and thus first few arent painful
- dont reach menarch until have enough bosy weight
Menarche - the first menstruation
›A certain percentage of body fat is required
›Generally anovulatory (no egg produced)
›Mean age 12.3 years in Australia
›95% height growth completed
› 6-12 months to establish the cycle
›Secular trends - (Age of menarche has been falling
over the past century in Westernised countries but
now stabilising)
Hormonal Changes of Male Puberty
› Slow increase in testosterone levels in childhood- most
assays not sensitive enough to detect (same for
oestradiol in females)
› Increased frequency and size of LH pulses
from pituitary (via GnRH)
- Leydig cells stimulated to produce
testosterone
› Increased frequency and size of FSH pulses
from pituitary (via GnRH)
- growth of seminiferous tubules and Sertoli
cells – increase in testicular size
LL
LH
Leydig cells
SSS
FSH
Sertoli cells
Seminiferous tubules
Sperm
Changes leading to capacity for spermatogenesis & ejaculation
›Growth of seminiferous tubules
›Mitoses and maturation of the Sertoli cells LEADS TO
testicular enlargement
›Seminal vesicle and prostate enlargement
› Increase in testicular blood flow
›Penile growth
›Sperm production from 13.5 years
›Secular trend for earlier onset of testicle enlargement over last 30 years
Other important hormones of puberty
› Increase in growth hormone production by anterior pituitary which causes an increase in Insulin-like Growth Factor 1(IGF1) from liver and in tissues
› Transient insulin resistance (secondary to GH
increase)
› Increase in leptin production (early) - which decreases later in males only – permissive role, measure of energy stores
› Increase in adrenal androgen production which is not dependent on GnRH
Adrenarche
 Independent of gonadal
maturation and clinically
detected as pubic hair (pubarche) ;
also acne, seborrhoea, body odour
 Commences before gonadal
maturation; adrenal androgens start to
rise soon in early childhood (DHEA,
DHEAS & andro...
 Independent of gonadal
maturation and clinically
detected as pubic hair (pubarche) ;
also acne, seborrhoea, body odour
 Commences before gonadal
maturation; adrenal androgens start to
rise soon in early childhood (DHEA,
DHEAS & androstenedione)
 Trigger is unknown - No good evidence
for anything other than pituitary
ACTH (adrenocorticotrophic hormone)
and no clear reason as to why
adrenarche might be an advantage
Variation in timing of the onset of puberty
› Genetic – normal distribution curve – (describes
40-70% of variance)
› Birth - small for dates, prematurity, post-term
(earlier)
› Obesity earlier in girls; ?later in boys
›Malnutrition or excessive exercise:
intentional/unintentional later/delayed
› Chronic illness later/delayed
› Visually impaired earlier (role of melatonin and sleep training?)
› Overseas adoptees earlier
Potential environmental effects on puberty timing
›Chemical pollutants (endocrine disruptors)
- Mostly as a result of localised pollution
- Delay or advancement of puberty
- Increasing prevalence of hypospadias & lower sperm counts
›Westernised environments earlier
- Changes in nutrition and physical activity with changes in body composition
›Reduced childhood infections earlier
›Absent biological fathers earlier in girls
- ? phaeromones
Delayed/absent/halted puberty
› Maturational delay (delayed puberty) will ultimately
spontaneously correct
› Defined as no signs of puberty by 13 (F) and 14 (M)
› It may be difficult to differentiate extreme delay from absent
puberty
› Both medical and social pressures dictate management
which is the use of low dose oestradiol (F) or low dose
testosterone (M)
› The longer the delay the more likely it is to be
absent
›An interruption in puberty development or a
reduction in the pace of change may be pathological
Puberty and long term health
›Early menarche: increased incidence of
- Breast cancer
- Eating disorders
- Depression
›Late onset of puberty: increased incidence
of
-Osteopaenia and fracture risk in later life
- Anxiety disorders
Male puberty - gynaecomastia
›Occurs in over 80% of normal males in
Tanner stage Genital 3/4
›Varying size; unilateral or bilateral
›Generally resolves with no treatment, but may
require surgical removal**
› If prolonged and marked consider secondary
cause
- Klinefelter syndrome (47XXY)
- Drugs; marijhuana, cimetidine, aldactone
- Thyrotoxicosis
- Feminising tumours – extremely rare
Female puberty - unequal breast development
›Early puberty - breast bud maybe unilateral
›By the end of puberty minor breast inequality
very common
›Small % of women have noticeable difference
in breast size
- not a hormone abnormality
- due to local growth factors or
- rarely previous trauma to breast bud
› Therapy is non medical
Female puberty - body hair
› Increase in limb and eyebrow hair occurs in puberty as
well as the development of secondary sexual hair
› Hirsutism = increase in terminal hair
- increased androgen sensitivity (familial)
- polycystic ovaries (especially if menstrual
disturbance & acne)
- disorders of the adrenal gland
- late onset congenital adrenal hyperplasia
- Cushing syndrome
Premature adrenarche
› More frequent in low birth weight children
› Present with
- Secondary sexual hair (pubic, axillary)
- Acne, seborrhoea
- Increased body odour
› May have
- Slight advancement of bone age
- Mild increase in plasma adrenal androgens
› Exclude
- Congenital adrenal hyperplasia, androgen producing tumours
› Treatment
- Generally expectant but associated with later polycystic ovaries
in females
Premature thelarche - female
›Present with breast development, but no other
pubertal signs
› To make diagnosis must have pre-pubertal
oestradiol levels
›Exclude
- exogenous oestrogen source
- true precocious puberty with advanced bone age & elevated oestradiol
› Treatment
- expectant
Pathological Puberty Problems
- Primary gonadal dysfunction
- Pituitary dysfunction (secondary gonadal dysfunction)
- Hypothalamic dysfunction (tertiary gonadal dysfunction)
- Adrenal malfunction with the excessive production of
testosterone/oestradiol or related hormones as the adrenal
has similar steroid hormone production pathways
- Androgens or oestrogens (similar to testosterone or
oestradiol) from other sources
Absent puberty in the female 1o
›Primary gonadal failure: high FSH & LH, low
oestradiol
- Turner syndrome 45XO (and other karyotype variants)
- Premature menopause - auto immune
- Chemotherapy
- Galactosaemia inadequately treated (rare metabolic disorder)
- Torsion (bilateral)
- Surgical removal
- Irradiation as part of cancer therapy
Hormone replacement therapy is required to initiate puberty – oral
preparations mainly
Turner syndrome

can be held negligent if you dont do a genetic test in a female with 1. ______________
Short stature
Low set ears and hairline
Ptosis
Neck webbing
Shield chest
Increased carrying angle
Partial or absent secondary sexual development
Primary amenorrhoea
Congenital cardiac valve lesions
Absent or horseshoe kidney
Conduction deafness
Scoliosis
Learning difficulties
Absent puberty in the male 1o
›Primary gonadal failure: high FSH & LH, low
testosterone
- Klinefelter syndrome 47XXY
- Chemotherapy
- Trauma & torsion (bilateral)
- Cryptorchidism (undescended testicles)
- Radiation damage (cancer therapy)
- Infection (mumps)
Klinefelter Syndrome
Small testicles
Tall stature
Eunuchoid (long limbed) - not enough E to fuse the bones
Gynaecomastia
Failure to enter puberty
Scoliosis
Learning difficulties
In less severe forms infertility may be the only symptom (azospermia)


have normal pubic hair because no problem with adrenal androgen production
Absent Puberty Male and Female 2o
›Secondary gonadal failure – pituitary
disorders; low FSH, LH and low oestradiol (F)
or testosterone (M)
- Genetic pituitary deficiency
- Tumour replacing normal pituitary tissue
- Trauma, especially to pituitary stalk
- Radiotherapy damage (cancer therapy)
- Surgery (often to remove tumour)
Usually associated with other hormone deficiencies
Hormone replacement is required to initiate and maintain
pubertal change. Use oestradiol and testosterone (LH and FSH
can only be given by injection)
Absent Puberty Male and Female 3o
› Tertiary gonadal failure – hypothalamic
disorders; low FSH, LH and low oestradiol (F)
or testosterone (M); indistinguishable on blood tests from
secondary gonadal failure (GnRH not detectable in periphery)
- As a result of chronic disease and debility (functional –
GnRH suppression )
- Isolated GnRH deficiency (Kallman syndrome anosmia)
- Head trauma
- Iron deposition (iron overload states such as thalassemia major
if inadequate chelation with hypertransfusion)
- Tumours
- Irradiation therapy for tumours
Usually associated with other hormone deficiencies
Hormone replacement to initiate and maintain pubertal change,
same as 1o and 2o gonadal failure; GnRH is injection only
Damage to the hypothalamus
› Craniopharyngioma
› Glioma,meningioma
› Teratoma,germ cell tumour
› Tumour metastases
› Aneurysm (artery)
› Surgery,radiotherapy
› Syndromes (Prader Willi)
and result in
› Pituitary hormone deficiency & in
some but not all situations
hyperphagia, reduced physical
activity, sleep disturbances, rage
and emotion control disorders
Primary Amenorrhoea – no menarche
1. Hypothalamic - pituitary disorder/disease
2. Ovarian disease/disorder
3. Mullerian agenesis * with absent
- uterus
- fallopian tubes
- upper 2/3 vagina
4. Imperforate hymen* thye get normal BREAST DEVELOPMENT (DDx); get a complete block thus build up of blood (present to ED with abdominal pain)
5. Androgen insensitivity syndrome *
- XY karyotype
- feminised with endogenous oestradiol from testosterone
Androgen insensitivity syndrome
• 46XY
• High testosterone
(which is aromatised to
oestradiol)
•Non-functioning
androgen receptor
•tall stature
•female phenotype
•little body hair
• inguinal gonads (testes)
•lower 1/3 vagina only

tall, strong women that can compete with women
Precocious puberty
Precocious puberty is very different to the secular change in menarche. It is the abnormally early activation of the normal puberty hormone sequence

earliest mother 6yrs old

True, central, GnRH dependent; increased LH, FSH
and oestradiol or testosterone following a normal
puberty pattern but appearing too early
Pseudo-precocious puberty Isosexual
GnRH independent Isosexual (same sex
puberty change); low FSH and LH with high
oestradiol (F) or testosterone (M)

- McCune - Albright Syndrome in females (ovarian
autonomy) via intrinsic hyper-function of FSH receptor
- Testotoxicosis in males (often familial) - via intrinsic
hyper-function of LH receptor
- Exogenous oestrogen/androgens**
- Ovarian/testicular tumours**
- Adrenal tumours**
Pseudo-precocious puberty Contrasexual
GnRH independent contrasexual (opposite
sex puberty change) with low FSH and LH and high
oestradiol (M) or testosterone (F)
Females – virilisation; acne, deep voice, loss of body fat,
clitoromegaly
- Congenital adrenal hyperplasia - enzyme defect with over production of
testosterone and other androgens
- Adrenal or ovarian tumour producing predominantly testosterone and
other androgens
- Exogenous androgen exposure
Males – feminisation; breast development, loss of muscle
- Adrenal or ovarian tumour producing predominantly oestradiol and other
oestrogens
- Exogenous oestrogen exposure