male physiology - Tanner stages Flashcards
types of androgens
- testosterone
- dihydrotestosterone (DTH)
- androstenedione
androgens - source
DHT and testosterone –> testis
androstenedione –> adrenals
androgens - potency of each (in order)
- DHT
- Testosterone
- androstenedione
testosterone action
- differentiation of internal genitalia except prostate (epididymis, vas deferens, seminal vesicles)
- Growth spurt (penis, seminal vesivels, sperm, muscles, RBCs
- deeping voice
- Closing of epiphyseal plates (via estrogen converted from testosterone)
- libido
hormones- ephipheseal plates closing in males
estrogen bia testosterone conversion
dihydrotestosterone (DTH) action
early –> differentiation of penis, scrotum prostate
late –> prostate growth, balding, sebaceous gland activity
testosterone is converted to DHT by …., which is inhibited by
5-a reductase
inhibited by finasteride
production of estrogens in males
androgens are converted to estrogen by cytochrome P-450 aroatase (adipose tissue and testis)
exogenous testosterone action on axon
inhibition of hypothalamic-pituitary-gonadal axis –> decreased intratesticular testosterone –>decreased testicular size –> azoospermia
azoospermia
absence of motile (and hence viable) sperm in the semen.
spermatogenesis increases at … with ….
puberty with spermatogonia
spermatogenesis - full development takes (time)
2 months
gametes - types/definition/origin
types: 1. Oocytes 2. Spermatozoa
they are descendants of primordial germ cells that originate in the wall of yolk sac of the embryo –> migrate into the gonadal cells
spermatogenesis - location
seminiferous tubules
phases of spermatogenesis
- Spermatocytogenesis
- Meiosis
- Spermiogenesis
spermatogenesis - spernaticytogenesis?
primordial cells (2N,2C) yolk sac to testis (wk 6th) –> spermatogonium (2N, 2C) -> remain dormant until puberty
spermatogenesis - meiosis
at puberty –> through Blood testis barrier –> meiosis –> 1ry spermatocytes (2N,4C) (46 sister chromatids X-X, Y-Y) –> 2ry spermatocytes (23 sister chromatids, X-X or Y-Y)
–> meiosis II –> spermatid (1N,1C)
spermatogenesis - spermiogenesis
spermatid –> mature spermatozoon
loss of cytoplasmic contains, gain of acrosomal cap
spermatogenesis - all cells and DNA status
primordial cells (2N,2C) –> spermatogonia (2N,2C) –> type B spermatogonia (2N,2C) –> 1ry spermatocytes (2N,4C) –> 2ry spermatocytes (1N,2C) –> spermatids (1N,2C)
mature spermatozoon dna status and structure
- 1N,1C
- Head with acrosome, and nucleus in head
- neck, and then middle piece and tail
impaired tail motility - seen in/results
seen in ciliary dyskinesia/kartegener
infertility
Tanner stages is a
a scale of physical development in children, adolescents and adults.
Tanner stages is assigned independently to
independently to: 1. genitalia 2. pubic hair 3. breast (person can have Tanner 2 genitalia, Tunner stage 3 pubic hair
Tanner stages - stage I (male and female)
PRE-pubertal
female: no sexual hair, flat appearing chest with raised nipple
male: no sexual hair
Tanner stages - stage II (male and female)
female: pubic hair appears (pubarche), Breast bub forms (thelarche)
male: pubic hair appears (pubarche), testicular enlargement
Tanner stages - stage III (male and female)
female: coarsening of pubic hair, breast enlarges, mound forms
male: coarsening of pubic hair, increase penis size/length
Tanner stages - stage IV (male and female)
female: Coarse hair across pubis, sparing thigh, breast enlarges, raised areola, mound on mound
male: Coarse hair across pubis, sparing thigh, increase penis width/glans
Tanner stages - stage V (male and female)
female: Coarse hair across pubis and medial thigh, adult breast contour, areola flattens
male: Coarse hair across pubis and medial thigh, penis and testis enlarge to adult size
Thelarche?
onset of female breast development
Pubarche?
the first appearance of pubic hair in a child
Prostate - lymph drainage
Internal iliac
