Male reproduction physiology Flashcards
(27 cards)
The bulbourethral gland contributes how much of the seminal fluid?
5%
The prostate gland contributes how much of the seminal fluid?
30%
The Seminal vesicle contributes how much of the seminal fluid?
60%
How many sperm per ml are there?
20-200million sperm/ml
How much in ml of semen is there usually in a single ejaculation?
2-5ml
What is involved in the male reproduction jigsaw?
1) Hormones
2) Testis
3) Sperm production
4) Sperm travel pathway
Where is GnRH (Gonadotrophin releasing hormone) released?
Hypothalamus
Where are gonadotrophin released?
FSH and LH are released from the anterior pituitary
Where is testosterone produced?
The leydig cells of the testis
What produces inhibin?
The Sertoli cells
What produces sperm?
The germ cells (Sertoli cells)
What makes the leydig cells different from the adrenal cortex allowing testosterone production?
They do not contain 21B-hydroxylase or 11B-hydroxylase in contrast to the adrenal cortex.
Therefore, they do not synthesis glucocorticoids or mineralocorticoids
What is the role of LH in a man?
In parallel to the action on the adrenal cortex, LH increases testosterone production by stimulating cholesterol desmolase.
Which enzyme does LH stimulate allowing an increase in testosterone production?
Cholesterol desmolase within Leydig cells of the testis
What is the action of the prostate in hormone production?
The prostate contains 5alpha-redutase which converts testosterone to the more active, dihydrotestosterone.
What is the role of FSH in men?
Stimulates the Sertoli cells (spermatogenia) of the Seminiferous tubules to produce sperm, spermatogenesis
How does sperm travel from the testis to the urethra?
Throughout the vas deferens
where is semen produced?
In the Seminal vesicles and prostate
What has to occur to allow a spermatogonium to become a mature sperm cell?
1) Two rounds of meiosis to produce spermatids, then:
2) Spermatogenesis
How many sperm are produced each day?
30 million
How long does it take to produce sperm?
60-75 days
How long does it take to transport sperm to the epididymis?
10-14 days
What can affect spermatogenesis?
1) Hormonal control (Genetic, tumours, medication, functional)
2) Problem at the site of production (Genetic, cancer treatment induced, surgical, trauma, infections)
What is the negative feedback control of testosterone?
Inhibits LH release by:
1) Inhibiting the release of GnRH form the hypothalamus
2) Inhibiting the release of LH form the anterior pituitary
