physiology

Question 1

Oogenesis

Answer 1

Oogonia divide (mitosis) from the second to the seventh month of gestation to form roughly 7 million germ cells

after 7th month, most die and rest enter first meiotic division- primary oocytes
o progress through the first meiotic prophase until the diplotene stage, at which point they are maintained until puberty

At birth, 2 million primary oocytes of which 400 mature and ovulate

everyone month, group of oocytes recruited of which one goes through development into secondary oocyte capable of fertilization.

Question 2

HPO axis

Answer 2

• FSH (follicle stimulating hormone), LH (Luteinising hormone) – anterior pituitary

Question 3

LH

Answer 3

♣ maintains dominant follicle, induce follicular maturation and ovulation, stimulate CL function

Question 4

FSH

Answer 4

stimulates follicular recruitment and development

Question 5

Oestradiol

Answer 5

granulosa cells supports female secondary sexual characteristics and reproductive organs, negative feedback control of LH and GnRH
♣ Except for late follicular phase - positive control of LH surge, stimulates proliferative endometrium, negative control of FSH
Progesterone from CL maintain secretory endometrium, negative feedback control of HPO

Question 6

targets of oestrogens

Answer 6

systemic:
protein metabolism
carbohydrate"
lipid"
water& electrolyte balance
blood clotting

CNS
Uterus
Bone maturation and turnover
Mammary gland
Fat distribution

Question 7

Sperm production, storage and transport

Answer 7

o Production takes 75 days in seminiferous tubules
o Storage 15 days in epididymis where sperm gains motility
o Capacitation occurs only in the female genital tract – functional maturation (physiological change) which renders the sperm able to fertilise an oocyte

Question 8

Testis

Answer 8

seminiferous tubule- 80cm long
join at rete testis
epididymis-5m

Question 9

ejaculation

Answer 9

seminal vesicles (60% of fluid)
prostate (30%)
bulbourethral (5%)
20-200 millions sperm

Question 10

sertoli cells

Answer 10

form blood testis barrier
Isolate haploid 2o spermatocytes, spermatids, spermatozoa from immune system
♣ Provision of nutrients to sperm, removal of waste
♣ Removal of excess cytoplasm following cell divisions
♣ Support for spermiation – mature spermatids (imp) released from the Sertoli cells
♣ Secrete activins and inhibins which regulate FSH secretion

Question 11

leydig cells-

Answer 11

produce testeoterone

Question 12

Counter current heat exchange

Answer 12

arterial blood, dense network of capillaries coming from testis and epididymis before reaching spermatic cord
arterial blood is cooled by venous blood which helps maintain testicular pressure

Question 13

spermatogenesis

Answer 13

testis temperature
endocrine
loss of blood testis barrier
immunological
environment
medication

Question 14

testoterone effects

Answer 14

systemic
deepening voice
male body hair
increased sebaceous gland activity
protein anabolism

CNS
hypothalamus
penis
striated muscle
prostate seminal vesicle
testis