Reproduction in Mammals

Question 1

What are the two phases of follicular development? Where do they take place?

Answer 1

Follicular phase - in the ovary

Luteal phase - in the uterus

Question 2

What are the three parts of the HPG axis, and what hormones do they secrete?

Answer 2

Hypothalamus - GnRH
Pituitary - FSH, LH
Gonads (Ovaries and testes) - Progesterone, testosterone, estradiol

Question 3

What are the two manifestations of ovulation in mammals? What happens to the endometrium in each of them?

Answer 3

Estrous - endometrium is reabsorbed

Menstrual cycle - endometrium sheds through vagina

Question 4

List the 4 stages of follicular development

Answer 4

Primordial follicle
Primary follicle
Secondary follicle
Mature follicle

Question 5

What are the two groups of cells that differentiate in the follicular phase, and what do they do?

Answer 5

Theca cells - LH stimulates progesterone production and conversion to testosterone
Granulosa cells - FSH stimulates testosterone conversion to estradiol

Question 6

What hormone stimulates ovulation

Answer 6

Luteinizing hormone (LH)

Question 7

What hormones down-regulate the HPG axis?

Answer 7

Progesterone
Estradiol
Inhibin

Question 8

What are the stages of endometrial development?

Answer 8

Menstrual phase
Proliferative phase - follicular phase
Secretory phase - Luteal phase

Question 9

How long does the corpus luteum last?

Answer 9

14 days

Question 10

What are the two types of cells in testes, and what do they produce?

Answer 10

Leydig cells - testosterone for development of spermatogonia

Sertoli cells - production of sperm, and compounds to nourish them

Question 11

Where do sperm mature? Where are they stored?

Answer 11

Mature in testes

Stored in epididymis and vas deferens

Question 12

What neurotransmitter is involved in erections? What does it increase levels of?

Answer 12

Nitric oxide (NO)
Increases c-GMP levels

Question 13

What type of muscle contracts in an orgasm? Where does it stem from in males AND females?

Answer 13

Smooth muscle contraction of pelvis muscle and:
Vas deferens in males
Uterus and vagina in females

Question 14

What is the outer most layer of the egg called? How do sperm get through the granulosa layer of the egg? How many sperm fuse to the oocyte?

Answer 14

Zona pellucida
Use of enzymes released from sperm
One sperm fuses

Question 15

What are the two lines of the blastocyst and what do they form?

Answer 15

Embryonic - forms embryo

Trophoblastic - forms the placenta

Question 16

What sustains the corpus luteum and progesterone secretion?

Answer 16

Chorion releases chorionic gonadotropin

Question 17

What replaces the corpus luteum as main source of P4?

Answer 17

The placenta

Question 18

What stimulates contractions for delivery?

Answer 18

Oxytocin release from posterior pituitary

Question 19

What stimulates milk production and what stimulates milk ejection?

Answer 19

Production - Prolactin from anterior pituitary

Ejection - Oxytocin from posterior pituitary