Quiz 4 Flashcards
(78 cards)
1
Q
3 Steps of Parturition
A
- Preparatory
- Expulsion
- 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
In males, there is a stronger (-) feedback until \_\_\_\_\_. Then feedback \_\_\_\_\_.
Until puberty
Then feedback amount relaxes
26
H/P/G of Female
**Hypothalamus**
to (GnRH) (+)
**Pituitary**
to (FSH, LH) (+)
**Follicle**
E2 (-) Feedback goes back to both Pit and Hyp
27
H/P/G of Male
**Hypothalamus**
to (GnRH) (+)
**Pituitary**
to (FSH, LH) (+)
**Testis**
Testosterone (-) Feedback goes back to both Pit and Hyp
28
Gonadal Maturation
Seminiferous tubules produce sperm
29
Behavioral Maturation
In the brain
\*Progression, not one specific event
30
What are permissive signals?
Metabolic status, photoperiod, demographics, sex ratios
31
Developmental clock
H/P/G Axis maturation
32
Heifer puberty?
10-12 mo
33
In a heifer, if there is high grain intake, then puberty occurs \_\_\_\_\_. Around what age?
Earlier
8 months
34
In a heifer, if there is low grain intake, then puberty occurs \_\_\_\_\_. Around what age?
Later
14 months
35
What is the developmental clock?
* 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
Pulse amplitude and frequency are controlled by _____ at hypothalamus.
GnRH
37
Pulse GnRH leads to...
Pulse LH
38
Types of permissive signals
1. Metabolic: Heifers/Body weight
2. Social grouping: Can influence time of puberty
3. Pheromones
4. Photoperiod: Affects time its going to breed
39
Tonic Center
Pulse Frequency
Pulse Amplitude
40
During the cycle, estradiol has a modest affect on \_\_\_\_\_.
Amplitude
41
Progesterone has a high/large affect on \_\_\_\_\_.
Frequency
42
In anestrus
E2 and P4
Both have a strong affect on frequency
Decrease pulse frequency
43
Photoperiod
Stimulation to light receptors in the retina
44
Sex Determination (3)
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
XXY
Klinefelters
Extra X chromosome
Most common proble, reduced fertility, hypogonads
46
XXX
Trisomy X
Reproductive, not normally diagnosed
47
XYY
Not normally diagnosed
48
XO
* Turner's Syndrome
* Sterile and lots of problems
49
Alpha-fetoprotein
Prevents estridiol from entering the brain
Would be masculinized if entered
50
Day 0
Genetic cells
not differentiated
Y present or not
51
Day 17/18
Rudimentary Nervous System
Rudimentary GI Tract
Rudimentary Cardiovascular System
Rudimentary Urinary Tract
Undifferentiated gonad
52
Day 28
Gonadal Migration
Male: Wollfrian Ducts
Female: Mullerian Ducts
Differentiated, sex specific
53
Day 55
Male: Vas defferines and seminierous tubules
Female: Oviduct and uterus
In abdominal cavity
54
Day 80
Testis still in abdominal cavity but moving lower
55
External Genitalia
Indifferent/ Bipotential
1) Genital Fold
2) Genital Swelling
3) Genital Tubercle
56
In males, Sry is considered the testis dominating factor. Sry will activate...
SF1
57
During sexual differentiation in males, fetal leydig cells secrete testosterone. This testosterone induces degeneration of the Mullerian ducts. T or F
F
58
Name the 3 components that make up the indifferent external genitalia.
1. Genital swelling
2. Genital tubercle
3. Genital fold
59
Puberty occurs in gilts around \_\_\_\_\_.
28 weeks of age
60
If no males are present in a gilt herd, when will they reach puberty?
32 weeks of age
61
Name two permissive signals that can affect the onset of puberty in female swine.
1. Presence of male
2. Metabolic changes
62
In social groupings, if you have 10 gilts at what age will they reach puberty?
28 weeks
63
In social groupings, if you have 3 gilts at what age will they reach puberty?
32 weeks
64
In social groupings, if you have males present at what age will they reach puberty?
24 weeks
65
What is the gestation of a ewe?
Ewe (short day breeders) - Gestation 147 days / 5 months
66
In the ewe, parturition occurs in response to activation of the maternal hypothalamic/pituitary/gonadal axis. T or F
False
67
At parturition in the ewe, what causes the release of oxytocin from the maternal posterior pituitary?
Pressure sensors in the cervix
68
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?
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
What gland produces the hormone melatonin?
Pineal gland
Retina --\> Superior cervical ganglion --\> Pineal gland --\> melatonin --\> hypothalamus --\> GnRH
70
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?
24 weeks of age due to the presence of the mature boar
71
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?
E2 and P4 _decrease_ pulse frequency during anestrus.
72
During estrus cycle, what effect does estradiol and progesterone have on the pattern of secretion (pulse amplitude and/or pulse frequency) of LH?
During the cycle, estradiol affects pulse amplitude. Progesterone affects pulse frequency.
73
In males, SRY is considered the testis determining factor. Sry will activate:
SF1
74
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
True
75
During sexual differentiation in males, fetal leydig cells secrete testosterone. This testosterone induces degeneration of the Mullerian ducts. T or F
False - Wolferian
76
During sexual differentiation, what cells produce anti-mullerian hormone?
Sertoli cell
77
The male prenatal brain is masculinized by \_\_\_\_\_.
Estradiol
78
Describe the role of alpha-fetoprotein with respect to prenatal brain development.
Alpha-fetoprotein prevents estradiol from reaching the brain in a female. If estradiol was to reach the brain, the brain would be masculinized.
