Reproductive Physiology

Question 1

Where does LH act in the males and what does this produce?

Answer 1

Leydig cells - testosterone

Question 2

Where does FSH act in the males and what does this produce?

Answer 2

Sertoli cells - androgen binding protein (ABP)

Question 3

In males, what are the two mechanisms of negative feedback? State where these are produced

Answer 3

Inhibin (Sertoli cells)

Testosterone (Leydig cells)

Question 4

Where are the two hormones secreted into?

Answer 4

The seminiferous tubule

Question 5

List the names of the sperm in the stages of spermatogenesis

Answer 5

Primordial germ cell
Spermatogonium
Primary spermatocyte
Secondary spermatocyte
Spermatids
Mature sperm

Question 6

What do you call the sperm which undergoes mitotic division, and what does it become?

Answer 6

Spermatogonium -> primary spermatocyte (diploid, 44+XY)

Question 7

What do you call the sperm which undergoes first meiotic division, and what does it become?

Answer 7

Primary spermatocyte -> secondary spermatocyte

Question 8

What do you call the sperm which undergoes second meiotic division, and what does it become?

Answer 8

Secondary spermatocyte -> spermatid

Question 9

What is a spermatid?

Answer 9

The product of second meiotic division, just before maturing to become sperm

Question 10

What happens to sperm as men age?

Answer 10

Sperm quantity and quality decreases

Question 11

In females, besides ovarian follicle development, what is the role of FSH?

Answer 11

Stimulation of 17beta-oestradiol synthesis

Question 12

Which hormone does LH stimulate in females?

Answer 12

Progesterone production

Question 13

Give another name for GnRH and describe the release of this hormone

Answer 13

LHRH

Pulsatile

Question 14

Describe the effect of oestradiol on the HPA during the follicular cycle

Answer 14

Follicular phase - negative feedback

Midcycle (ovulation) - positive feedback

Question 15

Describe the effect of progesterone on the HPA during the follicular cycle

Answer 15

Luteal phase - negative feedback

Question 16

What do you call days 0 to 14 of the ovarian cycle?

Answer 16

Follicular phase

Question 17

What do you call days 14 to 28 of the ovarian cycle?

Answer 17

Luteal phase

Question 18

Describe the peaks and troughs of hormones from the HPA during the ovarian cycle

Answer 18

Follicular phase: 
LH and FSH levels rise minimally
Midcycle:
Both peak 
Luteal phase: 
Both fall

Question 19

Describe the peaks and troughs of hormones from the ovaries during the ovarian cycle

Answer 19

Follicular phase:
Progesterone levels stay low
17b oestradiol levels rise and peak just before midcycle
Luteal phase:
Progesterone levels rise greater than oestradiol
Oestradiol levels rise but not so much as in the follicular phase

Question 20

What causes endometrial shedding?

Answer 20

Declining progesterone levels

Question 21

What initially causes thickening of the endometrium during the menstrual cycle?

Answer 21

Oestrogen

Question 22

What causes further thickening of the endometrium during the luteal phase?

Answer 22

Oestrogen and progesterone from corpus luteum

Question 23

Describe folliculogenesis in the baby

Answer 23

Primordia follicle grows to become antrum, which undergoes meiosis 1, producing a diploid primary oocyte.

Question 24

At which stage has the oocyte released during ovulation been arrested?

Answer 24

Metaphase 2

Question 25

Is the oocyte diploid or haploid?

Answer 25

Diploid 2n

Question 26

What happens to the primary oocyte after fertilisation?

Answer 26

It continues with meiosis to produce a PRONUCLEUS ovum and a second polar body

Question 27

How long does it take to move a resting oocyte into ovulation?

Answer 27

3 cycles i.e. 3 months

Question 28

What happens to the sperm following fertilisation?

Answer 28

Sperm chromosomes condense to form pronucleus

Question 29

Is the pronucleus haploid or diploid?

Answer 29

23 chromatids (haploid)

Question 30

What happens to the male and female pronucleus once they’ve formed following fertilisation?

Answer 30

They bind together, duplicate, align on mitotic spindles and separate to form two identical cells

Question 31

What do you call the creation of the first two identical cells following fertilisation?

Answer 31

1st cleavage division

Question 32

What do you call the death of developing follicles?

Answer 32

Atresia

Question 33

Which cells of the developing follicle are responsible for production of oestrogens?

Answer 33

Thecal cells

Question 34

Which cells of the developing follicle take over hormone production during the second stage of the cycle, and what do they produce?

Answer 34

Granulosa-luteal cells produce oestrogens and progesterone

Question 35

Which nerve takes afferent tactile info from the penis?

Answer 35

Pudendal nerve

Question 36

What initiates the changes during erection?

Answer 36

Increased PNS activity to SM of pudendal artery

Question 37

What induces dilatation of the arterial smooth muscle?

Answer 37

Increased nitric oxide synthase activity, therefore increased nitric oxide and downstream cGMP

Question 38

What other changes occur during erection?

Answer 38

Increased blood flow to corpus cavernosum (cave of blood)

Compression of dorsal vein (restricting blood outflow)

Question 39

What protects the urethra from increased pressure during erection?

Answer 39

Corpus spongiosum (protective sponge)

Question 40

What is the target of Viagra?

Answer 40

Phosphodiesterase inhibitor; therefore prevents deactivation of cGMP

Question 41

Which pathways regulate fertility and planning?

Answer 41

Neuroendocrine pathways

Question 42

Which pathways in the brain regulate sexual movements?

Answer 42

Nigrostriatal tract