Basic, Male & Female Reproduction

Question 1

How is sperm produced and how is it hormonally controlled?

Answer 1

Spermatagonia develop into primary spermatocytes. First meiotic division into two haploid secondary spermatocytes. Second meiotic division to produce two spermatids.

Spermiogenesis: They develop flagella and become mature sperm.

Occurs in the wall of the seminiferous tubules over 75days. Stored for 15days in epididymis

Testosterone activate the inactive cells and produce sperm

Question 2

What factors affect spermatogenesis?

Answer 2

Lifestyle, dietary deficiencies, occupational work, Hypoxia, toxins, environment, diabetes and other pathologies, variocele, cryptorchidism, steroids

Anything which affects hormonal control or site of production

Question 3

What are the major actions of sex steroids in the male?

Answer 3

Testosterone
- hair growth, increase protein eg muscle strength and volume, also serum protein synthesis, penile growth, spermatogenesis, prostate growth and function, libido, mood, erythropoietin production, stem cells, increase linear growth, closure of epiphyses

Question 4

What is the process of oogenesis?

Answer 4

Production of female gametes - Primary oocyte begins first meiotic division then arrests. Before birth.

Puberty. Finishes division in follicle. Gives rise to secondary oocyte and smaller polar body. Secondary meiotic division begins. Arrests. Will not finish unless fertilised - released from ovary at this stage.

Question 5

What are the major actions of sex steroids in the female?

Answer 5

GnRH - stimulates LH and FSH from anterior pituitary
FAH - stimulates follicle recruitment and development
LH - maintain dominant follicle, induce follicular maturation and ovulation, stimulate CL
Oestradiol - supports female secondary sex characteristics and reproductive organs, negative feedback control of LH and GnRH expect in late follicular stage (positive LH), stimulates proliferation endometrium, negative control of FSH
Progesterone - maintainsnsecretory endometrium, negative feedback control of HPO

Question 6

How do hormones control the ovarian and the menstrual cycle?

Answer 6

Beginning of menses (0-7d):
Inhibit B levels high, estogren moderate. The uterus lining breaking down. Low LH and FSH.

Proliferation (7-14d):
Spike of estrogen levels to stimulate LH to release egg from ovum. Endometrium building back up.

Secretory (14-28d):
High levels of progesterone to maintain endometrial lining due to corpus luteum, oestrogen and inhibin

Ovarian cycle:
- follicular stage (0-14d) = follicle stimulated to mature due to slowly increasing levels of FSH and LH (from GnRH) releasing oestradiol, and FSH decreases. Oestradiol peaks, alongside LH which stimulates to produce egg from follicle.

• luteal phase (14-28d) = dominant follicle transforms into corpus luteum. This release progesterone. CL degenerates into corpus albicans.

Question 7

What factors affect oogenesis?

Answer 7

Hormonal control eg genetic, tumours, medications, functional

Site of production eg genetic, cancer treatment induced, surgery, trauma, infections