Reproductive Endocrinology Flashcards Preview

Theriogenology > Reproductive Endocrinology > Flashcards

Flashcards in Reproductive Endocrinology Deck (54):
1

What is a simple neural reflex?

Nerves that release simple neurotransmitters directly onto the target tissue.

2

What is a neuroendocrine reflex?

Needs a neurohormone to enter blood and act at a remote location.

3

What is the neural control center for repro hormones?

Hypothalamus/pituitary

4

What organ deposits neurohormones directly into circulation?

Posterior pituitary

5

What regulates GnRH?

Male: Tonic center
Female: Tonic and Surge centers

6

What quantity of repro hormones do you need?

Small quanitities

7

How long are repro hormone half-lives?

Short

8

Where does GnRH come from?

Hypothalamic nuclei

9

Where do FSH, LH and prolactin come from?

Anterior Pituitary

10

Where does Oxytocin come from?

Posterior pituitary

11

Which repro hormones are a peptide?

GnRH

12

Which repro hormones are a glycoprotein?

FSH
LH
Inhibin

13

Which repro hormones are steroids?

Progesterone
Testosterone
Estradiol

14

What does PGF2a do?

Lyses the corpus luteum

15

What does PGE2 do?

Relaxes the cervix

16

How do protein hormones cause their actions?

Bind to plasma membrane bound receptors

17

How do steroid hormones cause their actions?

Travel freely through the plasma membrane into the cytoplasm and bind to the specific nuclear receptors

18

What does binding of hormones result in?

New protein synthesis

19

What are two functions of pheromones?

Influence the onset of puberty
Lets the male know who is in heat

20

What 4 things affect the strength of a hormone?

Pattern and duration of secretion
Half-life
Receptor density (this is really important)
Receptor-hormone affinity

NOTE: We can play with receptor-hormone affinity to make synthetic hormones that bind better than the natural hormone.

21

What are3 different patterns and duration of secretion?

Episodic
Basal
Sustained

22

What is Episodic secretion?

Burst or pulse

NOTE: generally associated with hormones under nervous control.

23

What is Basal secretion?

Secretion stays low, but fluctuates with low amplitude pulses.

24

What is Sustained secretion?

Hormone remains elevated, but in a steady fashion for a long period.

NOTE: Steroids tend to be secreted this way.

25

Where are steroids metabolized and excreted?

Metabolized: Liver
Excreted: Urine and feces

26

What organ is usually larger in high producing dairy cows?

Livers

27

Why can pregnancy tests be a urine test?

Because the protein hormones (eg. hCG) are metabolized in the liver and excreted by the kidneys.

28

What is estrus?

"Heat" or secual receptivity

29

What is estrous?

Length of the estrous cycle

30

What is an estrous cycle?

The period between one estrus and the next.

31

What is anestrus?

Not cycling

32

What does estrual mean?

Something related to estrus.

33

What 3 species are polyestrus?

Cattle
Swine
Rodents

34

What 4 species are seasonally polyestrus short-day breeders?

Sheep
Goats
Deer
Elk

35

What species is seasonally polyestrus long-day breeders?

Horses

36

What 3 species are monestrus?

Dogs
Wolves
Bears

37

What is the follicular phase?

Follicles are dominant structure

38

What hormone is dominant during the follicular phase?

Estrogen

39

What is the luteal phase?

Corpora lutea are dominant structure.

40

What hormone is dominant during the follicular phase?

Progesterone

41

What are the 4 stages of the estrous cycle?

Proestrus
Estrus
Metestrus
Diestrus

42

What 2 stages of the estrous cycle are in the follicular phase?

Proestrus
Estrus

43

What 2 stages of the estrous cycle are in the luteal phase

Metestrus
Diestrus

44

During what stage of the estrous cycle does estrogen secretion begin?

Proestrus

45

During what stage of the estrous cycle does estrogen secretion peak?

Estrus

46

During what stage of the estrous cycle does prostaglandin secretion being?

Metestrus

47

During what stage of the estrous cycle is progesterone secretion sustained at high levels?

Diestrus

48

Why do you need to watch progesterone levels in dogs?

Because they have a longer period of receptivity.

49

What is important to remember about diestrus in the bithc?

It is always 2 months no matter what.

50

What is important to remember about cats?

They are induced ovulators.

51

What are 5 conditions that would result in anestrus?

Pregnancy
Lactation
Seasons
Stress
Pathology

52

What are 3 factors that might cause a true anestrus?

Nutrition
Stresses
Pathology

53

What are 2 causes of apparent anestrus?

Failure to detect estrus
Failure to know that she is pregnant

54

What species are induced ovulators?

Llamas and Queens