exam 2 Flashcards
(99 cards)
1
Q
Neuroendocrinology
A
Interaction between nervous system and endocrine glands
2
Q
what do neuron produce
A
impulses
3
Q
what do neuroendocrine cells produce
A
neurohormones
4
Q
what do endocrine cells produce
A
hormones
5
Q
what is the blood supply between the hypothalamus and AP
A
hypothalamo-hypophyseal portal system
6
Q
function of GnRH
A
causes release of FSH and LH
7
Q
what is GnRH used for
A
treatment of cystic ovaries, prepubertal and anestrous animals to being cycles
8
Q
Trade name for GnRH
A
Cystorelin
9
Q
function of prolactin-releasing factor (PRH or PRF)
A
releases prolactin from AP
10
Q
function of prolactin inhibiting factor ( PIF) aka dopamine
A
inhibits prolactin release from AP
11
Q
function of corticotropin-releasing hormone (CRH)
A
stimulates release of ACTH from AP
12
Q
neuroHormones that affect Posterior pituitary
A
Oxytocin
13
Q
site of production of oxytocin (OT)
A
paraventricular and supraoptic nuclei cells of the hypothalamus, CL of cow, ewe, and human
14
Q
Where is oxytocin stored
A
Posterior Pituitary
15
Q
what are supraoptic paraventricular nuclei
A
body of nerve cells in hypothalamus in relation to PP
16
Q
functions of Oxytocin
A
milk let down, stimulates uterine contractions during sperm and egg transport and parturition, may play a role in CL function (luteolytic in cow, ewe, and goat)
17
Q
what enhances responsiveness of smooth muscle to OT
A
estrogen
18
Q
uses of OT
A
induces milk let down, the expulsion of retained placenta, aids delivery of young when labor is extended
19
Q
what is a negative feedback
A
one hormone inhibits release of another hormone
20
Q
examples of negative feedback
A
-Increasing concentrations of progesterone, estrogen, or testosterone inhibits the release of GnRH, FSH, and LH
-Increasing concentrations of inhibin inhibits FSH from AP
21
Q
what is positive feedback
A
where one hormone stimulates the release of another
22
Q
example of Positive feedback
A
increasing concentrations of estrogen stimulate release of GnRH, LH, FSH, and Prolactin
23
Q
condition of being first capable of reproducing
A
puberty
24
Q
what does puberty mean for the male
A
ability to copulate and ejaculate mature spermatozoa
25
what does puberty mean for the female
onset of regular estrous cycles with ovulation of female gametes
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condition of producing the maximum number of gametes
sexual maturity
27
genetic factors that affect age at puberty
body weight and nutrition (BCS and growth)
28
environmental factors that affect age at puberty
photoperiod, temperature, and social factors
29
progressive accomplishment of alterations in genital tract; characteristic of estrus, metestrus, diestrus and proestrus produced by changes in ovarian hormones
estrous (period from beginning of estrus to beginning of next estrus)
30
where does estrous occur
non-primate females
31
period of sexual receptivity in females also called "heat"
estrus
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estrous
adjective- cycle as a whole
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estrus
noun- specific phase
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days of proestrus
17-21
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what happens during proestrus
ovarian follicles are growing rapidly, increase in estrogen from growing follicles, decrease in progesterone from CL, mucosal layers of vagina and uterus multiply
36
days of estrus
1
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what happens during estrus
period of sexual receptivity, surges of FSH and LH from AP, sow, ewe, and mare ovulate
38
days of metestrus
2-4
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what happens during metestrus
cow ovulates, beginning of luteal phase, short trasitional phase after ovulation with decreasing estrogen and increasing progesterone, recently ruptured follicle in reorganizing into CL
40
what happens during metestrus
cow ovulates, beginning of luteal phase, short transitional phase after ovulation with decreasing estrogen and increasing progesterone, recently ruptured follicle in reorganizing into CL
41
days of diestrus
5-16
42
what happens during diestrus
continuation of luteal phase in species with long estrous cycles (absent in animals with short cycles) , CL becomes fully developed and progesterone exerts a dominant influence on oviducts, uterus, vagina, pituitary, and hypothalamus, CL remains functional for about 13 days in ewe and 15-17 days in sow cow and mare, CL regresses at the end of diestrus
43
anestrous
period between diestrus and proestrus in monoestrous and seasonal polyestrous animals. characterized by quiescence of repro tract
44
when is anestrous
nonbreeding season of ewe and mare varies in length, ends when proestrus begins
45
when is anestrous
nonbreeding season of ewe and mare varies in length, and ends when proestrus begins
46
two phases of the menstrual cycle
luteal and follicular
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how long is each phase and what separates them
2 weeks, ovulation
48
occurs in rabbits and other induced ovulators, LH release is induced by mating, ovulation occurs every 8-12 hrs after mating
continuous estrous
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Occurs in bears, wolves, foxes, and some dogs, only one estrous cycle per year, long anestrous separates each cycle
monoestrous
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true polyestrous cycles, 2 or more estrous cycles per year unless interrupted by pregnancy, composed of proestrus, estrus, metestrus, and diestrus merging into proestrus
polyestrous
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difference between seasonal polyestrous and polyestrous
last diestrus of breeding season would proceed into anestrous ( ewe and mare)
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mechanism
- retina of the eye is a sensor for light signals
-impulses travel by way of the optic nerve to the pineal gland
-pineal gland relases melatonin
-melatonin serves as a mediator between photoreceptors, hypothalamus and/or AP
-episodic surges of LH occur as breeding season begins
53
how long are short estrous cycles
4-6 days
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what animals have short cycles
rat, mouse, hamster, and gerbil
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what happens if mating does not occur? and if sterile mating occurs.
becomes follicular cycles. if sterile mating occurs, pseudopregnancy begins and lasts about 2 weeks
56
what is needed to induce functional activity of CL ( progesterone secretion)
mating
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how long are long estrous cycels
15-16 days or longer
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animals with long cycles
cow, ewe, sow, mare, and guinea pig
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does not require mating to produce functional CL, sterile mating does not shorten or lengthen cycle
long estrous cycles
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two phases of long estrous cycles
follicular ( proestrus and estrus; follicles growing and estrogenic phase) and luteal (metestrus and diestrus; secretory phase of CL, progestational phase)
61
estrus that occurs within a few days after parturition, rarely observed in ewes and cows
post-partum estrus
62
post-partum estrus in sow
occurs every 3-10 days after farrowing, ovulation rarely occurs, non-fertile estrus
63
post-partum estrus in mare
called foal heat, begins 5-15 days after foaling and lasts 1-10 days, mare usually ovulates but fertility may be lowered if abnormal tract exists
64
absence of psychological behavior of estrus, occurs in all farm animals, ovulation occurs
silent estrus or quiet ovulation
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initial estrus interrupted by a period of non-receptivity followed by another period of estrus, frequently seen in mares and occasionally in cows
split estrus
66
estrus without ovulation, occurs in all farm animals, best example is postpartum estrus in sows
anovulatory estrus
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the continuous psychological desire to mate, ovulation rarely occurs, most common in cows, less common in mares, rare in ewe or sow, cystic ovaries usually accompany nymphomaniac condition
nymphomania
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spontaneous ovulation
repeated ovulation at regular intervals except during pregnancy, LH release is cyclic and independent of mating stimulus, LH release is triggered by increasing concentrations of estrogen
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what animals have spontaneous ovulation
cow, ewe, sow, mare, rat, hamster and guinea pig
70
induced ovulation
ovulation occurs after stimulation of vagina and/or cervix, LH release only after mating stimulus, estrus persists for a variable length of time
71
what animals have induced ovulation
rabbit, cat, mink, and llama
72
what hormone does the hypothalamus secrete into blood vessels connecting to the AP
GnRH
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what does GnRH release from the AP
FSH and LH
74
where does FSH go once secreted
circulation, transported to ovary and stimulates follicular developement (granulosa cells to produce estrogen)
75
where does LH go once secreted
circulation and acts synergistically with FSH to stimulate secretion of estrogen by follicle
76
what are peak concentrations of LH and FSH responsible for
estrogen, which has positive and negative feedback on the hypothalamus and AP to control release of FSH and LH
77
what else are the peak concentrations responsible for
rupture of follicle and release of ovum (ovulation)
78
what does LH do after ovulation
transforms the follicle into a CL which secretes progesterone ( stimulated by LH)
79
what kind of feedback does progesterone have on the hypothalamus and AP
negative feedback; to decrease FSH and LH secretion
80
when do follicles grow
at all times of the cycle
81
what happens to the granulosa and theca cells during the cycle
granulosa cells increase in numbers and layers of theca cells grow and encompass periphery of follicle
82
two types of theca cells
theca externa and theca interna
83
theca externa
connective tissue surrounding entire follicle
84
theca interna
inner layer of thecal cells next to the basement membrane
85
what do the theca intera do
synthesize androgens (T) under influence of LH
86
what happens to the androgens once they are produced
pass across the basement membrane to granulosa cells where they are converted to estrogen under influence of FSH
87
what happens to follicles right before estrus
undergo rapid maturation
88
what happens to estrogen during the follicular phase
increases
89
when is the concentration of estrogen the highest
beginning of estrus
90
when does estrous behavior occur
follicular phase
91
what is estrus a result of
local effect of estrogen on central nervous system
92
relationship between progesterone and estrogen
progesterone has a synergistic action with estrogen in inducing sexual receptivity
93
feedback of increasing estrogen on hypothalamo-hypophyseal axis
positive feedback; causes surge of LH and FSH during estrus
94
what does LH do during estrus
activates enzymes that digest connective tissue in wall of follicle, resulting in ovulation
95
when does ovulation occur in most domestic animals
after LH peak
96
what happens during the luteal phase
1. granulosa and theca cells differentiate into luteal cells
2. CL secretes progesterone under influence of LH (luteotropic effect)
97
when does CL reach maximum function and size
mid-luteal phase
98
what causes CL regression
increased concentrations of prostaglandin (produced by endometrium during late luteal phase)
99
mechanism of CL regression in ewe and cow
1. mid to late diestrus: non-ovulatory follicles secrete increasing concentrations of estrogen
2. endometrial cells stimulated by estrogen to synthesize oxytocin receptors
3. oxytocin from CL (or PP) binds to OT receptors and stimulates the secretion of arachidonic acid and prostaglandin synthetase by endometrium
4. arachidonic acid converted by prostaglandin synthetase to prostaglandin
5. prostaglandin secreted into uterine veins and lyses the CL
