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Flashcards in Repro - Female 1 Deck (85):
1

What is the primary site of steroid AND protein synthesis?

follicles

2

Follicles are classified in an ________ progression.

ascending

3

What are the layers of the Graafian follicle?

theca externa, theca interna, granulosa cells

4

What do follicles house?

ova

5

What is the difference between oogenesis and folliculogenesis?

Oogenesis is the prenatal phase.

Folliculogenesis is the prepubertal phase.

6

When are folliculogenesis and oogenesis both occurring?

During differentiation in the pubertal phase.

7

What is oogenesis?

the process by which female gametes are generated

8

Oogenesis occurs independently of folliculogenesis. True or false?

True

9

How is the product of oogenesis different than spermatogenesis (besides the obvious)?

Oogenesis leads to formation of haploid cell that builds up a store of enzymes, mRNAs, organelles, and metabolic substrates

10

Ovum is non-motile. True or false?

True

11

When are oogonia referred to as oocytes?

Upon entering meiotic division.

12

When are oocytes arrested?

Prenatal phase

At the diplotene stage, also known as dictyate stage of meiosis

13

What are primordial follicles?

spindle-shaped epithelial cells that surround oocytes

14

How many oocytes are in the canine, bovine, and porcine ovaries at birth?

bovine- 150,000

porcine & canine- 700,000

15

Folliculogenesis occurs during the ________ phase.

prepubertal

16

Few follicles grow during prepubertal phase, these follicles do not undergo ______ and become ______.

ovulation; atretic

17

After birth, oocytes continue to ___.

die

18

How do the number of oocytes change as a dog ages?

decrease; 700k at birth to 33k at 5 years, to 500 at 10 years

19

What initiates transition from primordial to primary follicles?

kit ligand (KL)

leukaemia inhib. factor (LIF)
bone morphogenic proteins (BMPs)

keratinocyte growth factor (KGF)

basic fibroblast growth factor (bFGF)

20

What has a negative impact on the transition from primordial to primary follicles?

Anti-Mullerian hormone (AMH)

21

How many follicles begin to grow?

unknown

22

Do all growing follicles become Graafian follicles?

No

23

What happens to follicles that do not become Graafian follicles?

They undergo atresia

24

When does follicular atresia occur?

Any step during folliculogenesis

25

What signals atresia to occur?

lack of support signal

26

More than ___% of follicles and oocytes degenerate during germ cell development.

60

27

What follicles constitute the higher proportion of follicles that undergo atresia?

antral follicles

28

What follicle stages are FSH independent?

primordial, primary, and secondary follicles


29

What follicle stages are FSH-responsive?

preantral to antral

30

What follicle stages are FSH-dependent?

mature

31

Gonadotropin dependent follicles have a high rate of atresia in the ewe. True or false?

True

32

What are the two patterns of follicular development?

dominant, ovulatory-size follicles develop throughout the estrous cycle

dominant ovulatory-size follicles develop only during follicular phase

33

Which animals only have follicular development during the follicular phase?

pigs

34

Which animals have follicular development throughout estrus?

cattle, sheep, horses

35

What is the basis of selection of dominant follicle?

intrafollicular mechanisms

36

What are the intrafollicular mechanisms in cattle?

Free IGF-I and estradiol levels
+
LH receptor number on granulosa cells

37

What are the intrafollicular mechanisms in horses?

Free IGF-1, Estradiol, inhibin-A, and activin-A are the deciding factors for the selection of dominant follicle

38

What about growth and maturation of oocytes?

Oocytes have contact with granulosa cells and are completly dependent on them for growth.

39

How do oocytes and granulosa cells communicate?

cytoplasmic connections transfer metabolic substances

40

What is the cAMP Theory for Oocyte Maturation and Ovulation?

cAMP is transferred from the follicular granulosa cells to the oocyte

41

High levels of cAMP in the oocyte ____ oocyte maturation.

inhibit

42

Low levels of cAMP in the oocyte ______ oocyte maturation.

stimulate

43

LH surge prior to ______ stimulates synthesis of ________ in the granulosa cells.

ovulation; hylauronic acid

44

What disrupts the contact between granulosa cells and the oocyte? What does this result in?

hylauronic acid; no more transfer of cAMP frm granulosa cells to oocyte

45

Why are low levels of cAMP critical?

critical for resumption of meiosis

46

After LH surge, _______ occurs and _______ oocyte at MII is released.

ovulation; secondary

47

What is the exception to cAMP theory?

Dog, fox- at the time of ovulation, primary oocyte at metaphase I is released

After ovulation, primary oocyte at M1 rapidly completes its 1st meiotic division

48

What is the end result of the cAMP theory?

Germinal vesicle breaks down and first meiotic division is complete and first polar body is released.

49

The first polar body has an excess of cytoplasm. True or false?

False- very little cytoplasm

50

Where does ovulation take place in most mammals?

At random locations over the surface of either ovary.

51

In what species do ovulations occur more frequently from the left ovary? The right?

left- pig and camel
right- cow

52

In what animal is the ovulation site restricted to a depression in the ovary called the fossa?

horse

53

What is the half life of FSH?

40 hours

54

When are androgens synthesized?

follicular phase

55

When are estrogens synthesized?

follicular phase

56

When are progeterones synthesized?

luteal phase

57

In which female do dominant antral follicles develop and undergo ovulation only in follicular phase?
A. Sow
B. Cow
C. Ewe
D. Mare

A) sow

58

As follicular maturation progresses, the ability of granulosa cells to aromatize androgens _____.

increases

59

What are the physiological effects of low levels of estrogen?

positive feeback on FSH and LH secretion

60

What are the physiological effects of high levels of estrodiol?

positive feedback on LH secretion; LH surge

61

What are the physiological effects of VERY high levels of estradiol?

negative feeback on FSH and LH secretion

62

Etradiol regulates timing of uterine ____ secretion in what species?

PGF; cows and sheep

63

Estrogen causes growth and development of _____ for gamete transport.

oviducts

64

When does estrogen production increase in the follicle and when is it highest?

increase in pre-ovulatory phase

highest at the time of LH/FSH surge

65

How does estrogen effect oxytocin?

increases oxytocin receptor number in endometrium

66

How does estrogen affect prostaglandin?

increases it

67

Estrogen does not effect development of mamary glands. True or false?

False

68

Progesterone is synthesized and secreted by what?

corpus luteum

69

Preovulatory surge of LH results in what? (related to progesterone synthesis and secretion)

luteinization of granulosa and theca cells

70

What are the postive effects of luteinization of granulosa and theca cells?

increase synthesis of DESMOLASE and 3b-HYDROXYSTEROID DEHYDROGENASE

71

What are the inhibitory effects of luteinization of granulosa and theca cells?

Decrease synthesis of 17a-HYDROXYLASE

72

Why is the bitch unique in regards to progesterone?

1. progesterone produces before ovulation because lutenization occurs before ovulation

2. pseudopregnany because functional corpus luteum persists in unmated animals and after infertile mating

73

In what species is the diestrus phase the same as the gestation period? How long is it?

dog; 60-70 days

74

What is clinical pseudopregnancy?

exaggeration of normal physiological PP

75

Lactating PP bitches are under the influence of _______.

prolactin

76

Progesterone inhibits ________ contraction and prevents ________.

uterine; estrus

77

Where does progesterone primarily act? What hormones does progesteron inhibit?

the hypothalamus; LH/FSH

78

Decreasing levels of progesterone has a positive feedback on ___ and ___ from the AP after the end of _____.

FSH; LH; diestrus

79

When does corpus luteum regress?

Only when CL acquires the capacity for luteal regression.

80

What is luteolysis?

regression of CL

81

Can a CL undergo lysis at any time?

No.

It is acquired on day 7 in cows and day 13 in pigs (post ovulation)

82

What is the purpose of PGR2a?

It will cause luteolysis of the CL

83

How is PGR2a used in cats and dogs?

It is ineffective in cats and has limited efficacy in dogs

84

What is the mechanism of luteolysis?

termination of CL by the luteolytic agent, PGF2a, of uterine origin

85

PGF2a only works if the animal is not pregnant. True or false?

True