Quiz 4 Flashcards Preview

Animal Reproduction > Quiz 4 > Flashcards

Flashcards in Quiz 4 Deck (78)
Loading flashcards...
1
Q

3 Steps of Parturition

A
  1. Preparatory
  2. Expulsion
  3. Cleaning
2
Q

In step one of Parturition (preparatory), what is happening?

A
  • E2 increases
  • P4 decreases
  • Relaxation of cervix
  • Contractions
  • Lubrication increases
    • Oxytocin increases
3
Q

In step two of Parturition (expulsion), what is happening?

A
  • Strong, rhythmic contractions
  • Chorio-allantoic rupture - ends with fetus in birth canal
  • Amnion rupture
4
Q

In step three of Parturition (cleaning), what is happening?

A
  • Accommodates delivery
  • Detachment/expulsion of placenta/membranes
5
Q

Descrive post-partum.

A
  • Involution (not highly correlated to fertility)
  • “Gets things back to normal”
6
Q

Mice have a _____ pregnancy - meaning they are practically pregnant again during their _____.

A

21 day; involution

7
Q

What does dystocia mean?

A

“Difficult birth”

8
Q

What are common causes of dystocia?

A
  • Size of the fetus
  • Placement/Orientation
  • *Higher incidence in twins
9
Q

What is a freemartin pregnancy?

A
  • When a cow gives birth to twins (M & F) and the M affects the F
  • (Ex: Twin F born without ovaries –> infertile)
10
Q

Why is a C-section termed Caesarian?

A

Caesar thought his kin was too good to be born vaginally

11
Q

A cow and sow need ______ for majority of pregnancy.

A

Corpus luteum

12
Q

Human placenta starts to produce _____

A

CRH

13
Q

What are surfactants?

A

Premature babies that need to be given cortisol

14
Q

Secreted by the ovary and/or placenta depending on the species

A

Relaxin

15
Q

Neuro-endocrine H/P/A complex (FETAL)

A

Hypothalamus

to (CRH)

Anterior Pituitary

to (ACTH)

Adrenal

to (Cortisol)

Placenta

(Increase PGF2alpha and E2, Decrease P4)

16
Q

Gonadostat Hypothesis - year proposed?

A

1930

17
Q

What does the gonadostat hypothesis propose?

A

Puberty occurs due to a resetting of H/P/G and how feedback occurs

18
Q

When you castrate, what hormone accumulates/increases?

A

LH

19
Q

Surge and Pulse are controlled by different parts of the _____.

A

Hypothalamus

20
Q

Pulse frequency refers to _____, while pulse amplitude refers to _____.

A

Pulse frequency - time

Pulse amplitude - height

21
Q

Bull puberty =

A

38 weeks

22
Q

Young animals will have _____ as they are developing.

A

Increase in LH

23
Q

Radioimmunoassays:

Antibody?

Antigen?

A

Antibody - LHAb

Antigen - LH-Iodine I^125

Can measure how much is in the blood using radio wave markings

24
Q

Before puberty (males), testosterone is produced but…

A

Not enough to have spermatogenesis

25
Q

In males, there is a stronger (-) feedback until _____. Then feedback _____.

A

Until puberty

Then feedback amount relaxes

26
Q

H/P/G of Female

A

Hypothalamus

to (GnRH) (+)

Pituitary

to (FSH, LH) (+)

Follicle

E2 (-) Feedback goes back to both Pit and Hyp

27
Q

H/P/G of Male

A

Hypothalamus

to (GnRH) (+)

Pituitary

to (FSH, LH) (+)

Testis

Testosterone (-) Feedback goes back to both Pit and Hyp

28
Q

Gonadal Maturation

A

Seminiferous tubules produce sperm

29
Q

Behavioral Maturation

A

In the brain

*Progression, not one specific event

30
Q

What are permissive signals?

A

Metabolic status, photoperiod, demographics, sex ratios

31
Q

Developmental clock

A

H/P/G Axis maturation

32
Q

Heifer puberty?

A

10-12 mo

33
Q

In a heifer, if there is high grain intake, then puberty occurs _____. Around what age?

A

Earlier

8 months

34
Q

In a heifer, if there is low grain intake, then puberty occurs _____. Around what age?

A

Later

14 months

35
Q

What is the developmental clock?

A
  • Changing of the H/P/G Axis
  • Change in sensitivity to feedback
  • Pre-puberty some estradiol or testosterone has a high effect
  • Hypothalamus: surge center
    • Responds to LH surge to cause ovulation (females only)
  • Tonic center: pulsatile LH - estrus cycle
    • Male & female
    • Pulse frequency and amplitude
36
Q

Pulse amplitude and frequency are controlled by _____ at hypothalamus.

A

GnRH

37
Q

Pulse GnRH leads to…

A

Pulse LH

38
Q

Types of permissive signals

A
  1. Metabolic: Heifers/Body weight
  2. Social grouping: Can influence time of puberty
  3. Pheromones
  4. Photoperiod: Affects time its going to breed
39
Q

Tonic Center

A

Pulse Frequency

Pulse Amplitude

40
Q

During the cycle, estradiol has a modest affect on _____.

A

Amplitude

41
Q

Progesterone has a high/large affect on _____.

A

Frequency

42
Q

In anestrus

E2 and P4

A

Both have a strong affect on frequency

Decrease pulse frequency

43
Q

Photoperiod

A

Stimulation to light receptors in the retina

44
Q

Sex Determination (3)

A

1) Chromosome

Humans: 44 autosomes, 2 sex chromosomes; 46 total

2) Temperature

Crocodile and some fish

3) Sex Change

Fish, snail, clam: Dominant is female, rest are male

45
Q

XXY

A

Klinefelters

Extra X chromosome

Most common proble, reduced fertility, hypogonads

46
Q

XXX

A

Trisomy X

Reproductive, not normally diagnosed

47
Q

XYY

A

Not normally diagnosed

48
Q

XO

A
  • Turner’s Syndrome
  • Sterile and lots of problems
49
Q

Alpha-fetoprotein

A

Prevents estridiol from entering the brain

Would be masculinized if entered

50
Q

Day 0

A

Genetic cells

not differentiated

Y present or not

51
Q

Day 17/18

A

Rudimentary Nervous System

Rudimentary GI Tract

Rudimentary Cardiovascular System

Rudimentary Urinary Tract

Undifferentiated gonad

52
Q

Day 28

A

Gonadal Migration

Male: Wollfrian Ducts

Female: Mullerian Ducts

Differentiated, sex specific

53
Q

Day 55

A

Male: Vas defferines and seminierous tubules

Female: Oviduct and uterus

In abdominal cavity

54
Q

Day 80

A

Testis still in abdominal cavity but moving lower

55
Q

External Genitalia

A

Indifferent/ Bipotential

1) Genital Fold
2) Genital Swelling
3) Genital Tubercle

56
Q

In males, Sry is considered the testis dominating factor. Sry will activate…

A

SF1

57
Q

During sexual differentiation in males, fetal leydig cells secrete testosterone. This testosterone induces degeneration of the Mullerian ducts. T or F

A

F

58
Q

Name the 3 components that make up the indifferent external genitalia.

A
  1. Genital swelling
  2. Genital tubercle
  3. Genital fold
59
Q

Puberty occurs in gilts around _____.

A

28 weeks of age

60
Q

If no males are present in a gilt herd, when will they reach puberty?

A

32 weeks of age

61
Q

Name two permissive signals that can affect the onset of puberty in female swine.

A
  1. Presence of male
  2. Metabolic changes
62
Q

In social groupings, if you have 10 gilts at what age will they reach puberty?

A

28 weeks

63
Q

In social groupings, if you have 3 gilts at what age will they reach puberty?

A

32 weeks

64
Q

In social groupings, if you have males present at what age will they reach puberty?

A

24 weeks

65
Q

What is the gestation of a ewe?

A

Ewe (short day breeders) - Gestation 147 days / 5 months

66
Q

In the ewe, parturition occurs in response to activation of the maternal hypothalamic/pituitary/gonadal axis. T or F

A

False

67
Q

At parturition in the ewe, what causes the release of oxytocin from the maternal posterior pituitary?

A

Pressure sensors in the cervix

68
Q

Puberty in the ewe lamb can occur as early as 5-6 mo of age. Farmer Bob in southern KY had his ewes lamb last October. When should he expect these ewe lambs to reach puberty?

A

These ewe lambs should reach puberty this October. This is because they missed the photoperiod the October they were born so they did not go into puberty since they would not be breeding.

Short-day breeders: need photoperiod

11-12 months of age; next breeding period

69
Q

What gland produces the hormone melatonin?

A

Pineal gland

Retina –> Superior cervical ganglion –> Pineal gland –> melatonin –> hypothalamus –> GnRH

70
Q

Farmer Bob’s cousin Billy decided to raise swine. He purchased 20 infant gilts and one mature boar to start his operation. They were all housed in close proximity to each other. Puberty typically occurs in gilts around 28 weeks of age. At what age should Billy expect his 20 gilts to reach puberty?

A

24 weeks of age due to the presence of the mature boar

71
Q

In the ewe, estradiol and progesterone exert negative feedback on the H/P/G axis. During periods of anestrus, what is the effect of:

a. ) estradiol
b. ) progesterone

on the pattern of secretion (pulse amplitude and/or pulse frequency) of LH?

A

E2 and P4 decrease pulse frequency during anestrus.

72
Q

During estrus cycle, what effect does estradiol and progesterone have on the pattern of secretion (pulse amplitude and/or pulse frequency) of LH?

A

During the cycle, estradiol affects pulse amplitude. Progesterone affects pulse frequency.

73
Q

In males, SRY is considered the testis determining factor. Sry will activate:

A

SF1

74
Q

Men typically have 44 autosomes plus 2 sex chromosomes (XY). When a male is born with an additional Y chromosome (ex: XYY, a sex chromosome aneuploidy), it is expected that he will be of normal fertility. T or F

A

True

75
Q

During sexual differentiation in males, fetal leydig cells secrete testosterone. This testosterone induces degeneration of the Mullerian ducts. T or F

A

False - Wolferian

76
Q

During sexual differentiation, what cells produce anti-mullerian hormone?

A

Sertoli cell

77
Q

The male prenatal brain is masculinized by _____.

A

Estradiol

78
Q

Describe the role of alpha-fetoprotein with respect to prenatal brain development.

A

Alpha-fetoprotein prevents estradiol from reaching the brain in a female. If estradiol was to reach the brain, the brain would be masculinized.