Chapter 9

Question 1

What three phases does the luteal phase consist of?

Answer 1

1) luteinization (formation of the CL)
2) synthesis and secretion of large quantities of progesterone
3) luteolysis

Question 2

How long is the luteal phase?

Answer 2

ovulation to luteolysis of the CL

Question 3

What phases does the luteal phase consist of?

Answer 3

diestrus and metestrus

Question 4

What is the dominant ovarian hormone of the luteal phase?

Answer 4

progesterone

Question 5

Trend of progesterone during luteal phase?

Answer 5

ovulation -> progesterone begins to rise -> reaches maximum secretion in diestrus -> decrease in luteolysis

Question 6

What is the bloody hemorrhagic appearance in the ovary that happens to rupture at ovulation?

Answer 6

corpus hemorrhagicum

Question 7

Progesterone secretion and CL size align together in diestrus?

Answer 7

yes

Question 8

What does a regressed corpus luteum become?

Answer 8

corpus albicans (white body)

Question 9

What does the luteal phase immediately begin after?

Answer 9

ovulation

Question 10

What does the corpus luteum originate from?

Answer 10

An ovulatory follicle

Question 11

What two things are involved in luteinization transformation?

Answer 11

theca interna and granulosal cells

Question 12

What is the luteinization process?

Answer 12

where cells of the ovulatory follicle are transformed into luteal tissue

Question 13

What is the luteal tissue formation governed?

Answer 13

LH

Question 14

What is the process of luteinization?

Answer 14

1) no more separation of cells
2) mixing together of cells

Question 15

What is the exception of mixing cells together in?

Answer 15

women and where the mixing is actually distinct islets.

Question 16

Large luteal cells originate from what?

Answer 16

granulosal cells

Question 17

Small luteal cells originate from what?

Answer 17

theca interna cells

Question 18

What do large luteal cells contain?

Answer 18

secretory granules that have oxytocin and relaxin

Question 19

What are small and large luteal cells called?

Answer 19

steroidogenic (produce steroids -> progesterone)

Question 20

What animal is it hard to tell is the CL is present?

Answer 20

Mare

Question 21

What is luteolytic agent to induce estrus and ovulation?

Answer 21

F2a

Question 22

What can an increase in size and weight of the corpus luteam be related too?

Answer 22

increase in volume (3x) of large luteal cells and increase in number (5x) of small luteal cells

Question 23

What is it when large luteal cells increase in size?

Answer 23

hypertrophy

Question 24

What is it when small luteal cells increase in cells number?

Answer 24

hyperplasia

Question 25

What does the vigor of the corpus luteum depend on?

Answer 25

the number of luteal cells and degree to which the CL becomes vascularized

Question 26

Insufficient luteal function means what?

Answer 26

poor progesterone synthesis and secretion

Question 27

What are the primary target organs for the progesterone?

Answer 27

hypothalamus, uterus, and mammary gland

Question 28

What are the two uterus target components?

Answer 28

glandular endometrium and muscular myometrium

Question 29

After the conceptrus enters the uterine lumen, what is it called?

Answer 29

free-floating

Question 30

What glands does progesterone stimulate secretion?

Answer 30

endometrial glands

Question 31

What is an important inhibitory role of progesterone?

Answer 31

reduce motility (contractions) of the myometrium

Question 32

What still happens in mares in terms of contractions?

Answer 32

contraction of the myometrium to transport conceptus around uterine lumen

Question 33

What does progesterone secretion require?

Answer 33

Cholesterol and LH

Question 34

What does progesterone exert?

Answer 34

negative feedback on the hypothalamus (GnRH secretion)

Question 35

What does this progesterone negative feedback do?

Answer 35

reduces pulse frequency in the tonic center of GnRH

Question 36

Progesterone is an inhibitor because?

Answer 36

1) it reduces GnRH pulse frequency 2) prevents behavioral estrus 3) stops the preovulatory LH surge 4) reduces myometrial tone (not in mare)

Question 37

What hormone is inducing luteolysis?

Answer 37

PGF2a

Question 38

Luteolysis is what?

Answer 38

Loss of progesterone secretion by the CL and structural integrity

Question 39

What is PGF2a secreted by?

Answer 39

uterine endometrium

Question 40

What inhibits GnRH secretion?

Answer 40

progesterone

Question 41

What is uterectomy?

Answer 41

removal of the uterus to sustain CL for longer period of time (148 days period)

Question 42

What positive influence is progesterone exerted on?

Answer 42

endometrium of the uterus

Question 43

Why is the uterus required?

Answer 43

for successful luteolysis

Question 44

What must the uterine be near?

Answer 44

the ovary

Question 45

What allows for PGF2a to be transported?

Answer 45

a vascular countercurrent transport system (exchange mechanism) to the ovary

Question 46

Does the systemic circulation have dilute?

Answer 46

no

Question 47

How is the PGF2a transported?

Answer 47

across the wall of the utero-ovarian vein and into the blood of the ovarian artery with help of a prostaglandin transport protein

Question 48

What is not present in the mare?

Answer 48

the countercurrent transport system cause the mare doesn't metabolize PGF2a as rapidly as other species and the CL is also more sensitive to PGF2a

Question 49

What type of levels does PGF2a have compared to progesterone during late diestrus and proestrus?

Answer 49

the opposite

Question 50

What would happen if there was not a vacular countercurrent exchange system?

Answer 50

most PGF2a would get denatured during 1 circulatory pass in the pulmonary system

Question 51

What are the requirements for luteolysis?

Answer 51

1) presence of oxytocin receptors on endometrial cells 2) presence of a critical level of oxytocin 3) PGF2a synthesis by the endometrium

Question 52

What does progesterone block at first?

Answer 52

formation of oxytocin receptors in the uterus

Question 53

What does progesterone prevent from being secreted?

Answer 53

PGF2a

Question 54

How long in the estrous cycle does progesterone prevent PGF2a after exposure from being secreted

Answer 54

12-14 days

Question 55

When does PGF2a start being secreted in the estrous cycle?

Answer 55

days 15-17

Question 56

What starts forming after progesterone loses it blocking capability?

Answer 56

oxytocin receptors (binding)

Question 57

What type of relationship do oxytocin and PGF2a have?

Answer 57

positive feedback (one occurs and then the other occurs)

Question 58

What is also increasing as progesterone decreases?

Answer 58

estrogen

Question 59

What initiates PGF2a secretion?

Answer 59

oxytocin binding

Question 60

What do immune cells secrete?

Answer 60

cytokines (ex. interferons)

Question 61

What do cytokines trigger?

Answer 61

apoptosis

Question 62

Do uterectomy in women influence cyclicity?

Answer 62

no

Question 63

Administration of progesterone can do what?

Answer 63

align estrus cycles of large groups of females for fertility (higher pregnancy rates), in women it is intended to block ovulation and minimize pregnancy chance

Question 64

CIDR is what?

Answer 64

Controlled Internal Drug Release for progesterone via intravaginal

Question 65

Figure 9-13 page 196

Answer 65

yes

Question 66

What are two methods to synchronize ovulation in cows?

Answer 66

Ovsynch and Presynch

Question 67

How long is elephants estrous and gestation cycles?

Answer 67

16 weeks and 22 months

Question 68

What species CL does not develop if copulation does not occur?

Answer 68

rodents

Question 69

What animals luteal phase is longer than pregnancy?

Answer 69

Kangaroo