Reproduction

Question 1

What is the function of FSH? LH? Prolactin?

Answer 1

FSH - Gametogenesis
LH - Secretion of estrogen, progesterone , and testosterone
Prolactin - Lactation and development of the ovary during pregnancy

Question 2

When does the hypophysis respond to hormonal influences?

Answer 2

D6 in male and D12 in female

Question 3

When does ovarian follicle development begin? When does it mature? How is this correlated with signs of sexual maturity?

Answer 3

Begins at 3 weeks, matures by 30 days, and occurs concurrently with signs of sexual maturity.

Question 4

When does puberty occur in the female? What changes are noted? How does this compare to onset of puberty in the male?

Answer 4

Estrogen-dependent changes in the female (cornification of the vagina) occur at 24-28 days. Puberty up to 2 weeks later in males.

Question 5

Describe the mouse estrous cycle.

Answer 5

Polyestrous with 4-5day cycle

Question 6

What visual signs signal proestrus and estrus?

Answer 6

Patency of vaginal orifice and swelling of the vuvla.

Question 7

When does postpartum estrus occur? What is the comparative fertility, and why?

Answer 7

14-24 hours post birth. Less fertile and cornification of vagina not complete

Question 8

Describe ovulation in mice.

Answer 8

Spontaneous, do not ovulate every estrus.

Question 9

Why don’t mice ovulate every estrus?

Answer 9

Estrus is dependent on gonadal hormones, ovulation responds to gonadotropins.

Question 10

What controls the cyclicity of estrus and ovulation?

Answer 10

Diurnal rhythm of photoperiod

Question 11

How quickly does the Whitten effect take effect?

Answer 11

Estrus within 3 days of exposure to male/male urine.

Question 12

What is the vaginal plug consist of? What area of tissue does it fill?

Answer 12

Mix of vesicular and coagulating glands. Fills cervix to vulva.

Question 13

What is the result of physical stimulation of the cervix/vagina during mating?

Answer 13

Physical stimulation results in prolactin release. Prolactin causes CL to produce progesterone which causes a pseudopregnancy for 13 days. If pregnant, the placenta will take over progesterone production at 13 days.

Question 14

Where and when does fertilization occur?

Answer 14

Ampulla, within 10-12 hours

Question 15

How does lactation affect implantation and gestation?

Answer 15

Lactation can delay implantation, prolonging gestation by 12-13 days.

Question 16

When are female breeders typically retired?

Answer 16

6 months

Question 17

How does maternal care impact neonate body weight?

Answer 17

Accounts for up to 70% of variation in neonatal body weight.

Question 18

Describe lactation length.

Answer 18

Occurs for 3 weeks, peaks at day 12.

Question 19

What is the function of oxytocin?

Answer 19

Needed for nursing, not parturition or reproductive behavior.

Question 20

How do neonates receive antibodies? When does maternal immunity begin to wane?

Answer 20

Majority through colostrum. Ab are secreted in milk throughout lactation. Decay of maternal immunity several months after weaning.

Question 21

During proestrus, what is present on vaginal smear, in the uterus, and in the ovary and oviduct?

Answer 21

Smear - Epithelial to epithelial-cornified or epithelial-cornified cells; leukocytes to epithelial cells
Uterus - Increasing hyperemia and distension, active mitoses in epithelium, few leukocytes
Ovary/OD - Follicles enlarged and distended with liquor folliculi, few mitoses in germinal epithelium and follicular cells

Question 22

During estrus, what is present on vaginal smear, in the uterus, and in the ovary and oviduct?

Answer 22

Smear - Epithelial-cornified to cornified + cells
Uterus - Max distension and activity, then decrease. No leukocytes
Ovary/OD - Ovulation, followed by distension of upper end of oviduct. Active mitoses in germinal epithelium and follicular cells

Question 23

During metestrus, what is present on vaginal smear, in the uterus, and in the ovary and oviduct?

Answer 23

Smear - Cornified ++ cells, epithelial cells, leukocytes ++
Uterus - Decreased distension. Leukocytes in epithelium. Walls collapsed. epithelium degenerates. Mitoses rare
Ovary/OD - Follicles undergo atresia. Growing CL. Eggs in oviduct. Few mitoses in germinal epithelium and follicular cells

Question 24

During dieestrus, what is present on vaginal smear, in the uterus, and in the ovary and oviduct?

Answer 24

Smear - Epithelial cells, leukocytes, more or less mucus.
Uterus - Pale, walls collapsed. Epithelium healthy with many leukocytes. Some secretion by uterine glands.
Ovary/OD - Follicles begin rapid growth towards end of period.