Repro Chapter 1 Part 2 Flashcards Preview

Physio II > Repro Chapter 1 Part 2 > Flashcards

Flashcards in Repro Chapter 1 Part 2 Deck (76):
1

What are the two gonadotropins?

Follicle Stimulating Hormone (FSH)

Lutenizing Hormone (LH)

2

What is the function of gonadotropins?

stimulate gonads in both males and females

3

Where are gonadotropins secreted?

Secreted by the same gonadotroph or by two different gonadotrophs in the anterior pituitary gland

4

Gonadotropins are what type of proteins?

glycoproteins

5

Which gonadotropin subunit confers specificity to each hormone?

beta subunit

6

Which gonadotropin subunit is identical in LH, FSH, TSH, and human chorionic gonadotropin (hCG)?

alpha subunit

7

What control LH synthesis and secretion?

GnRH

8

What is the half life of LH?

10 minutes

9

LH can be measured in serum to determine gonadal function. True or false?

True

10

Measuring LH in serum can serve as an indicator of what?

GnRH release

11

What is the half life of hCG?

48 hours

12

What are the direct physiological effects of LH in females?

ovulation

theca cells produce testosterone

corpus luteum developemnt and progesterone production

13

What are the indirect physiological effects of LH in females?

estrogen production

maintenance of pregnancy - progesterone

14

What are the direct physiological effects of LH in males?

Leydig cells and steroid production

15

What are the indirect physiological effects of LH in males?

spermatogenesis

male repro tract

accessory sex glands

16

How does osteocalcin induce testosterone production by Leydig cells?

LH independent mechanism

17

What is osteocalcin?

A protein synthesize by osteoblasts by precursor (preproosterocalcin)

18

How many AAs is osteocalcin?

46-50

19

What is the half life of FSH?

40 hours

20

What is the function of FSH and what controls its production?

to stimulate follicle growth in ovaries; under control of GnRH

21

Which is more heavily glycosylated, FSH or LH?

FSH

22

What is PMSG?

PMSG=FSH

23

What are the physiological effects of FSH in females?

follicle development, growth, and maturation

estradiol synthesis during follicular phase

superovulation

24

Wtf is superovulation?

development of more than the usual number of mature follicles

25

What are the physiological effects of FSH in males?

sertoli cells affected

initiation/ re-initiation of spermatogenesis

spermiation

26

How are sertoli cells affects by FSH?

synthesis of ABP
synthesis of inhibin
synthesis of estradiol

27

Which feedback loop is more complex, LH or FSH?

FSH

28

Activin stimulates ______ synthesis. Synthesis of _______ is constitutive in anterior pituitary and gonads.

FSH; activin

29

What inhibits FSH synthesis?

inhibin and follistatin

30

What makes up inhibin A and B?

inhibin A= activin A & alpha inhibin
inhibin B = activin B & alpha inhibin

31

What type of hormone is prolactin?

peptide hormone

32

What synthesizes and secretes prolactin?

lactotrophs in the anterior pituitary gland, brain, immune cells, and deciduas

33

Prolactin is synthesized as a pro-hormone to what?

signal peptide and mature prolactin hormone

34

How many AAs is prolactin?

194-199

35

What is the half life of prolactin?

10 minutes

36

Prolactin is glycosylated. True or false?

True; and this increases the half life.

37

What are the physiological effects of prolactin in females?

mammary gland development and milk production

non-lactational aspects (maintenance of corpora lutea)

social behavior (nest building, retrieval of scattered young ones)

38

What are the physiological effects of prolactin in males?

It is unknown, but overproductionc auses hypogonadism.

39

What is involved in the negative regulation of prolactin?

dopamine - the major PIF
GnRH Associated Protein (GAP)

40

What is involved in the positive regulation of prolactin?

PRH
TRH
GnRH
VIP
Estrogen
Spinal Reflex (stimulation of teats)

41

What are the physiological effects of prolactin in females?

stimulation of milk ejection

stimulation of uterine smooth muscle contraction

establishment of maternal behavior

induction of PGF2a synthesis in uterus

42

Which physiological effect of prolactin in females in species dependent?

induction of PGF2a synthesis in uterus

43

What are the physiological effects of prolactin in males?

facilitation of sperm transport

acts on myoid pertubular cells - for sperm transport in the seminiferous tubules

44

What controls oxytocin secretion?

tactile stimulation of the teat
sex steroid hormones
acute stress

45

How does tactile stimulation of the teat promote oxytocin release?

The stimulation sends a neurosignal to the hypothalamus to release oxytocin from the posterior pituitary gland

46

How do sex steroid hormones affect oxytocin?

Burst of oxytocin at time of parturition is triggered by a decline in plasma progesterone

47

How does acute stress affect oxytocin?

Stress releases catecholamines which inhibit oxytocin release

48

How does inhibin inhibit FSH synthesis?

Alpha inhibin binds to activin A or B

49

Describe the structure of relaxin.

6k Dalton protein consisting of two (34 & 29 aa) chains held together by S-S bonds

50

The half life of relaxin is ________ and depends upon ______ and ___________.

variable; species; gestation time

51

Where is relaxin synthesized?

CL, placenta, heart atria, prostate in males

52

Why is relaxin called relaxin?

Impure preparation from CL of pregnant sow in 1926; because it relaxed the pubic ligament of the oestrogen primed guinea-pig, it was named relaxin

53

What are the (4) physiological effects of relaxin?

prep of the the endometrium for implantation

inhibition of uterine activity in early pregnancy

remodeling of the uterine stroma during pregnancy

softening of cervix and the initiation of parturition for rapid and safe delivery

54

What causes the physiological effects of relaxin?

Due to induction of collagen biosynthesis to facilitate remodeling of the CT in target organs

55

Steroid hormones are _______ derivatives.

cholesterol

56

Where do we get cholesterol?

It is synthesized by the liver from acetate or absorbed from the diet.

57

Where are steroids hormones synthesized and what is required for synthesis?

gonads and adrenal glands

oxidative enzymes in mitochondria and smooth ER

58

What is the rate-limiting step in steroid hormones production?

cholesterol to pregnenolone by desmolase (CYP11A1)

59

What immediate steroid precursor shuffles back and forth between mitochondria and the SER?

pregnenolone

60

Steroid hormones are stored in the liver. True or false?

False; steroid hormones are not stored

61

Steroid hormones are lipophillic and hence limited solubility in aqueous solutions. True or false?

True

62

What do steroid hormones bind to?

carrier proteins

63

In the target tissue, there is more bound than free steroid hormone. True or false?

False; there is an equilibrium between bound and free steroid hormones in target tissue

64

Progesterone is a C-__ steroid hormone.

21

65

What is the primary progestogen?

progesterone

66

Progesterone is the intermediate for the synthesis of which two hormones?

androgen and estrogen

67

What produces progesterone?

corpus luteum, placenta, and adrenal gland

68

Estrogen is a C-__ steroid hormone.

18

69

What produces estrogens?

granulosa cells and sertoli cells

70

What is the primary estrogen?

estradiol-17b

71

Estradiol in human males is due to what?

Expression of aromatase in adipose tissue

72

Androgens are C-__ steroid hormones.

19

73

What are 17-ketosteroids?

Androgens when -OH is replaced with a =O at the C-17 position.

74

What produces androgens?

Leydig cells, theca cells, and limited amounts produced by adrenal glands

75

Testosterone is converted to DHT by __________ in ______ and ________.

5a reductase; sertoli cells; accessory sex glands

76

Testosterone is converted to estradiol in ________ and _______.

sertoli cells; granulosa cells