Mammalian Reproduction

Question 1

puberty

Answer 1

period during which secondary sex characteristics begin to develop and the capability of sexual reproduction is attained

Question 2

is puberty the start or end of growth?

Answer 2

in terms of height, end of growth
long bone growth stops, estrogen stimulates epiphyses to close

Question 3

puberty in rats/mice

Answer 3

at onset, weight is half of adult weight
testes descend into the scrotum of the male
behavioral changes (aggressiveness)
vocal changes (male voice deepens)
change in phenotypic appearance

Question 4

estrous cycle

Answer 4

female’s reproductive cycle, similar to menstrual cycle

Question 5

polyestrous

Answer 5

multiple/continuous cycles (rats and mice)
cycle from puberty until old age, average cycle is 4-5 days

Question 6

proestrus

Answer 6

1 day (mice/rats)
FSH levels increase
follicles stimulated, start producing estrogen

Question 7

FSH

Answer 7

follicle stimulating hormone
produced in anterior pituitary gland

Question 8

follicles

Answer 8

egg cells on ovary

Question 9

estrus/heat

Answer 9

12-24 hours (mice/rats)
only time male and female will mate
high levels of FSH, estrogen
low level of progesterone
LH surge

Question 10

LH

Answer 10

luteinizing hormone
produced in anterior pituitary gland
causes follicles to rupture and release egg cell (ovulation)

Question 11

metestrus

Answer 11

ovulation
12 hours (rats/mice)
follicle opens and releases ovum

Question 12

diestrus

Answer 12

period before next proestrus, 2 days (rats/mice)
corpus luteum forms in ruptured follicle, secretes progesterone
if no pregnancy, prostaglandin causes CL regression

Question 13

progesterone

Answer 13

secreted by corpus luteum
signals to uterus to prepare for pregnancy
maintains pregnancy

Question 14

draw the chart for FSH, estrogen, LH, progesterone levels

Question 15

spontaneous ovulation

Answer 15

rats/mice

Question 16

induced ovulation

Answer 16

stimulus induces ovulation
still cycle
rabbit/hare

Question 17

rat mating behavior

Answer 17

nocturnal breeders
may mate 12-20 times with multiple males in 12 hour period

Question 18

parturition

Answer 18

act of giving birth
rodents: pupping, 4 hours

Question 19

postpartum estrus

Answer 19

rats/mice immediately start new estrus cycle after giving birth

Question 20

lactation for rats/mice

Answer 20

3 weeks

Question 21

average litter size for mice, rats

Answer 21

mice: 4-7
rats: 6-10

Question 22

estrogen

Answer 22

produced by cells in the follicle
necessary for development of secondary sex characteristics in female
stimulates estrus (heat)

Question 23

prostaglandin

Answer 23

destroys corpus luteum
stimulates production of relaxin

Question 24

oxytocin

Answer 24

produced by posterior pituitary
causes uterine contractions, stimulates parturition
stimulates maternal behavior

Question 25

relaxin

Answer 25

relaxes cervix, pelvic bones

Question 26

prolactin

Answer 26

stimulates milk release, secretion after parturition
stimulates maternal behavior

Question 27

main structures of male reproductive system

Answer 27

testes: manufacturing/production of sperm
epididymis: sperm storage
accessory sex glands: add fluid/nutrients to sperm
penis: delivery

Question 28

spermatogenesis

Answer 28

stem cells, continually divide and renew themselves

Question 29

do birds have an epididymis?

Answer 29

yes

Question 30

male reproductive hormones

Answer 30

testosterone: stimulates testes to produce sperm
LH: acts on cells in testes to stimulate testosterone production
FSH: stimulates testes to produce sperm