Chapter 7 Flashcards
1
Q
Estrous cycle vs. Menstrual Cycle
A
Estrous cycle= mammals
Menstrual cycle= primates
2
Q
What does cycle mean?
A
series of predictable events
3
Q
Define Estrous
A
Start with estrus and ends with start of the next estrus
Period of one estrus (heat) and the next
4
Q
Define Menstrual
A
start at beginning of menstrual period and end with start of next menses
5
Q
Define Estrus
A
period of sexual receptivity
6
Q
What is lordosis
A
the visual mating (standing) posture in females
arching of the back in preparation to be mounted
7
Q
What is seasonal breeding
A
Several estrous cycles during a cetain season
Mare= spring
Ewe= fall
8
Q
What are the 3 patterns of cycle?
A
polyestrus
Seasons polyestrus
Monoestrus
9
Q
Define Polyestrus
A
many cycles per year
10
Q
Define Seasons Polyestrus
A
multiple cycles within a season
long day vs. short day breeders
11
Q
Define Monoestrus
A
one cycle per year
12
Q
How many phase happen each cycle? What are they?
A
two
Follicular (20%) and Luteal (80%)
13
Q
What is designated as day 0?
A
Estrus
14
Q
High E2 results in what behavior?
A
Estrus
15
Q
What structure develops post ovulation? What hormone does it produce?
A
Corpus Hemorragicum then CL
CL produces Progesterone
16
Q
What happens on day 16 of cycle?
A
Lysis of CL
17
Q
What happens to P4 after lysis of CL? Then What?
A
Progesterone decreases, negative feedback on GnRH decrease, so the cycle can start over
18
Q
Where does prostaglandin come from?
A
Uterus
19
Q
What is the dominant structure during the follicular phase?
A
Large Antral follicles (results FSH and LH) and Estrogens (E2)
20
Q
What is the sexual receptivity during the follicular phase?
A
standing to be mounted by the male
21
Q
What structures occur during the Luteal phase?
A
Corpora lutea (CL) and P4 (progesterone)
22
Q
What are the 4 STAGES of the Estrous Cycle.
*stages and phases are two different categories that overlap**
A
- proestrus
- Estrus
- Metestrus
- Diestrus
23
Q
What is Proestrus stage?
A
development of ovulatory follicles= increase in E2 (15% of cycle)
24
Q
What is Estrus Stage?
A
sexual receptivity, peak E2 (day 0) (5%, shortest)
25
What is the Metestrus stage?
CL formation and increasing P4 (20%)
26
What is the Diestrus stage?
mix CL size and peak P4 (longest 60%)
27
How do the phases and stages interact?
Follicular phase= proestrus+ estrus
| Luteal phase= metestrus+ diestrus
28
Proestrus is characterized by a significant rise in _____ by maturing follicule.
E2
29
T or F. When E2 reaches a certain level, the female shows behavioral estrus and then ovulate.
True
30
T or F. Following ovulation, cells of the follicle are transformed into luteal cells and for the corpus Hemorragicum during metestrus.
False, corpus luteum
31
T or F. diestrus is characterized by a fully function CL and low progesterone (P4)
False, high progesterone (P4)
32
What is the primary function of estrogen during the follicular phase?
sexual receptivity
33
What parts of the brain help induce puberty
```
Tonic= high frequency
Surge= amplitude of GnRH
```
34
T or F. the bitch is monoestru
True, 17.5 month= one cylce, 3 cycles in 2 years
35
What are the unique phases of the bitch?
Long anestus= 5 months
Proestrus= 9 days
Estrus= 9 days
Diestrus= 2 months
36
Why does the bitch have a long time without cyclicity?
Long anestrus period
37
When does ovulation occur in the bitch?
2-3 days post LH surge
38
When is fertilization in a bitch?
within the 2-3 days of ovulation
39
What is superfecundation?
Can have multiple sires in one litter
40
What is seasonality primarily caused by?*
Photoperiod
41
How long is Diestrus?
2 months long
42
T or F. both bred and open dogs are considered to be in diestrus
True
43
A dog that is not pregnant is called?
pseudopregnant
44
How long is the gestation period of the dog?
same length as diestrus. 2 months
45
What is the reproductive cycle of the Queen?
```
Proestrus
estrus
postestrus
diestrus
anestrus
```
46
What is polyestrus?
BUT copulation required for ovulation "induced ovulators"
- No CL, continual follicular phase
- Estrus every several weeks
47
How long is the gestation period for the Queen?
60 days
48
T or F. Lactational anestrus do occur in the queen
False, does not occur
49
T or F. The queen will show estrus while lactating
True
50
Define Anestrus
without estrus (cyclicity)
51
What causes Anestrus?
Pregnancy, lactation, presence of offspring, season of the year, Nutrition, Stress, Pathology
52
True vs. apparent anestrus
Apparent anestrus= pregnancy or failure to recognize estrus
| True= insufficient GnRH, no follicular growth
53
What is Gestational anestrus?
Normal, High P4 inhibits GnRH= inhibits hormonal cascade
54
What species have seasonal anestrus?
Horse (short day)
| Sheep (long day)
55
What are the two components of photoperiod?
1. Photoreception pathway, eye to pineal gland (secretes melatonin)
2. Nueronal pathways (kisspeptin neurons)
56
What neuron does melatonin act on?
RFRP
57
RFRP neurons secretes __________ which acts on _________ neurons
RFRP-3
| kisspeptins
58
What kisspeptin is secreted during photoperiod?
kisspeptin 10 (kiss-10)
59
What does kiss 10 affect?
Kiss 10 increases GnRH therefore FSH and LH
60
What happens with long photoperiod?
decreases melatonin
61
What happens with short photoperiod?
high melatonin release
62
what does high melatonin inhibit?
RFRP neurons
63
Describe the long day breeder cyclicity.
* decrease melatonin secretion by the pineal gland
* results in increase firing of RFRP neurons, increasing RFRP-3 which then...
* stimulates firing of kisspeptin neurons, increasing kiss-10 release (stimulates GnRH release, stimulate FSH and LH)
64
Describe the Short Day breeder cyclicity
* short days elevates secretion of melatonin
* results in decrease rate of firing RFRP neurons, therefore decrease of RFRP-3 secretion (which is inhibitory to kisspeptin neurons)
* RFRP-3 decrease removes inhibition of kisspeptin neurons, allowing kisspeptin neurons to fire (increasing levels of kiss-10)
* Kiss-10 increases GnRH therefore FSH and LH
65
In short what is long days?
decrease of melatonin, increasing RFRP secretion, this stimulates kisspeptin neurons
66
In short what is short days?
increase melatonin, reduced RFRP secretion (RFRP-3 inhibits kiss10), the reduced inhibition by RFRP results in increase kiss10 therefore GnRH
67
A queen that is not pregnant does not have corpora lutea. The reason for this is:
She does not ovulate and therefore cannot have corpora lutea.
she is an induced ovulator. If she cannot copulate, she will not ovulate.
She has a period of postestrus following an estrus period.
68
Typically, the shortest stage of the estrous cycle is ___________
Estrus
69
Starting at metestrus, what are the next three sequential stages of the estrous cycle?
1. diestrus
2. Proestrus
3. Estrus
70
A litter of puppies that consists of multiple breeds is called ___________
Superfecundation
71
The most important environmental factor regulating seasonal cyclicity is:
Photoperiod
72
Long photoperiods cause a decrease in the pineal hormone, ___________
Melatonin
73
The follicular phase consists of ________ and estrus
Proestrus
74
The estrous cycle of the bitch starts at the beginning of:
Proestrus
75
The longest stage of the estrous cycle is
Diestrus
76
What is the proposed physiological difference in the "long day" and "short day" breeder?
Kisspeptin neurons respond differently to RFRP-3?
77
The dominant hormone during the luteal phase is ___________
Progesterone
78
After menstruation in women, the uterine equivalent of the follicular phase is called the _____________
Proliferative Phase?
79
The luteal phase typically occupies about what percentage of the estrous cycle?
80%
80
The two phases of the estrous cycle are the _________ phase and _______ phase
Follicular
| Luteal
81
Which best describes metestrus?
formation of a corpus luteum from the ovulatory follicle
82
Failure to detect estrus can be misinterpreted as females being in anestrus. The proper term to describe this is
Apparent Anestrus
83
Which of the following sentences is INCORRECT for useage of the words estrous and estrus?
The visible sign that indicates that a bitch will soon be in estrous is a blood-tinged vaginal discharge.
84
T or F. Sexual receptivity and ovulation characterize estrus
True
85
Which best describes the menstrual cycle when compared to the estrous cycle?
Edometrial sloughing, no defined period of sexual receptivity, begins at the onset of menstruation
86
In a cycling queen that has not been mated, a unique stage of the cycle is called_________
Postestrus
87
The luteal phase consists of ________ and _________
metestrus
| diestrus
88
The dominant hormone during the follicular phase is __________
Estrogen
89
The dominant ovarian structure(s) during diestrus are ____________
CL
90
In women, the menstrual cycle equivalent of anestrus is _______
Amenorrhea
91
Which of the following stimuli likely contribute to lactational anestrus?
Mammary stimulation, sight of the neonate, smells of the neonate
92
Which best describes a queen that DOES NOT mate with a tom?
No ovulation, No CL, no luteal phase
93
What are the three categories of estrous cycles according to their frequencies throughout the year?
polyestrus, seasonal polyestrus, monoestrus
94
The most important ovarian structures during the follicular phase are:
Large antral follicles
95
What is the proper sequence?
Melatonin, RFRP neurons, kisspeptin neurons, Kiss10, GnRH neurons
96
Typically, the bitch has only three estrous cycles in two years. What is the most likely reason for this?
A long anestrous plus a long diestrus
97
What causes lactation anestrus?
suckling, vision, olfactory, auditory, nursing by an alien calf ("breaks" anestrus)
98
Why is the menstrual cycle estrus cycle?
no defined period of sexual receptivity, endometrial sloughing, begins and ends with menses
99
In women the follicular phase is equivalent to?
mense and proliferative phase (14 days)
100
In women the luteal phase is equivalent to?
secretory phase (14 days)
