Reproductive system Flashcards
(21 cards)
What are the main structures of the male reproductive system?
A pair of testes in the scrotum, the penis, ducts connecting the testes and penis, and accessory glands.
What is the male reproductive system adapted for?
The creation of the male gamete (spermatozoa) and sexual reproduction.
What are the main structures of the female reproductive system?
Two ovaries. Oocytes mature in follicles which develop from cells in the germinal epithelium.
Where does spermatogenesis occur?
In the seminiferous tubules of the testes.
What do interstitial cells between seminiferous tubules secrete?
Testosterone to stimulate spermatogenesis.
Where does oogenesis take place and when?
In an ovary, up to the secondary oocyte stage before birth.
How are primary oocytes formed?
Diploid germinal epithelium cells divide by mitosis to make oogonia that grow into primary oocytes.
What is capacitation in fertilisation?
A process that increases the permeability of the sperm membrane in front of the acrosome.
What happens during the acrosome reaction?
Proteases digest the corona radiata and hydrolase enzymes digest the zona pellucida.
What is the cortical reaction?
Cortical granules fuse with the membrane, modifying the zona pellucida to prevent polyspermy.
What completes meiosis II in the oocyte?
Fusion of the sperm and secondary oocyte membranes, forming the ovum and second polar body.
What is the result of the sperm and ovum nuclei fusing?
A diploid zygote nucleus is formed.
What is cleavage in early development?
Mitotic divisions of the zygote forming a blastocyst.
Where does the blastocyst implant?
In the endometrial lining of the uterus.
What hormone does the blastocyst secrete and why?
HCG, to maintain the corpus luteum which produces progesterone.
What is the function of progesterone in early pregnancy?
Maintains endometrium, inhibits FSH and LH, suppresses uterine contractions.
What are the roles of the placenta?
Links mother and foetus for exchange of gases, nutrients, and waste.
What hormonal change occurs just before birth?
Oestrogen increases and progesterone decreases, allowing uterine contractions.
What hormone triggers uterine contractions?
Oxytocin from the posterior pituitary gland.
What is the effect of oxytocin during birth?
It causes uterine contractions and is involved in positive feedback.
What hormone stimulates milk production?
Prolactin from the anterior pituitary gland.
