Reproductive physiology

Question 1

Define biological sex

Answer 1

Gender Male= XY and Female =XX

Question 2

How does sexual reproduction differ from other form of reproduction (eg asexual)

Answer 2

Sexual reproduction requires intercourse and it produces offspring that is genetically different from both parents.

Question 3

What system is part of the pleasure and reward system associated with sexual intercourse.

Answer 3

Mesolimbic dopaminergic system

Question 4

What is the most important sexual organ and why

Answer 4

The brain as activation of pleasure pathways keeps humans procreating and ensure human life. Also gametogenesis is regulated by the HPG axis. (CNS also involved in physical arousal).

Question 5

What enzyme inhibits penile erection.

Answer 5

phosodiesterase deactivates cyclic GMP. Note Viagra inhibits this enzyme.

Question 6

Which nerve forms the afferent pathway involved in penile erection

Answer 6

pudendal nerve

Question 7

What role does the parasympathetic system play in arousal?

Answer 7

Vasodilation, mediated by NO, of the pudendal artery causing an erection.

Question 8

Where does spermatogenesis occur?

Answer 8

Seminiferous tubules in the testes

Question 9

What endocrine role do leydig cells have?

Answer 9

They produce testosterone when stimulated by LH. This encourages the differentiation of sperm.

Question 10

What is the role of Sertoli cells?

Answer 10

Sertoli cells provide physical and nutritional support to developing sperm. They are FSH responsive.

Question 11

What is the path of sperm during ejaculation?

Answer 11

Sperm are stored prior to ejacualtion in the epididymis,then are released into the vas deferens, during which time various secretions are mixed with the sperm to become seminal fluid. The ejaculate leaves via the urethra.

Question 12

Draw a diagram of an ovary

Answer 12

please google, I’m cheap.

Question 13

What is the role of the fallopian tube in reproduction

Answer 13

It transports the oocyte from the ovary to the uterus. The medial third is often the sit of fertilisation.

Question 14

Which cells in the ovary produce which hormones

Answer 14

Granulosa cells produce Oestrogen and inhibin ( stimulated by FSH)
Thecal cells produce progesterone (stimulated by LH) in

May need to edit.

Question 15

Follicular phase and luteal phase are part of which cycle?

Answer 15

Ovarian cycle.
Follicular=14 days
Ovaulation
luteal= 14 days

Question 16

What are the phases of the endometrial cycle and their lengths?

Answer 16

menstrual phase= 1-5 day (5)
Repair and proliferative= day 5-14 (9)
secretory phase= day 15-28 (13)

Question 17

What obseration changes at ovulation

Answer 17

increased body temperature.

Question 18

What endocrinological change stimulates ovulation?

Answer 18

continual high levels of oestrogen cause a change to postive feedback on LH causing an LH surge in the late follicular phase.

Question 19

Draw the hormone graph

Answer 19

google

Question 20

which phase is controlled by an increase in progesterone?

Answer 20

The secretory phase. Progesterone from the corpus luteum stimulates production of nutrients, epithelial gland thickening, increased vascularisation.

Question 21

What is different between the genders for gametogensis?

Answer 21

Females are born with total number primordial follicles they will ever have. The quality of of oocytes decreases at 45 years old and menopause indicates no more eggs. Eggs at ovulation are at the 2n meiosis metaphase II (previously paused at meiosis prophase I. where as males can produce sperm their whole life although they may decrease in quality.

Question 22

What causes capacitation and what are its effects?

Answer 22

Progesterone released from the oocyte.

It increases sperm motility and acts to increase chemotaxis

Question 23

What reaction prevents polyspermy?

Answer 23

Acrosome reaction

Question 24

What does calcium influx cause during fertilisation?

Answer 24

Resuming of meiosis for the oocyte and completion of oogenesis releasing the 2nd polar body.