Endocrinology Flashcards
1
Q
What are Endocrine glands?
A
They secrete hormones (chemical messengers) to the blood or lymph and have no ducts
2
Q
Function of the hypothalamus ?
A
Sexual behavior and production and release of hormones
3
Q
What are hormones that activate the reproductive system?
A
- Gonadotropin Releasing Hormone (GnRH) –> LH FSH release
- Thyrotropin Releasing Hormone (TRH) –> TSH Prolactin release
4
Q
Anterior Pituitary hormones?
A
Gonadotropins:
- FSH
- LH
- Prolactin
5
Q
Posterior Pituitart hormones?
A
- Oxytocin (contracts smooth muscles)
- Anti Diuretic Hormone _ADH
6
Q
What are 2 Gonadal polypeptide hormones?
A
- Relaxin: produced during pregnancy
- Inhibin: diminishes FSH release
7
Q
Where are Gonadal steriod hormones found in the body?
A
Ovary, testis, adrenal gland
8
Q
Types of steriod production?
A
-Androgens (testosterone)
- Estrogens (estadiol)
- Progestines (progesterone)
9
Q
Estrus cycle
A
When female is sexually receptive (in heat) and ovulation
- includes follicular phase and luteal phase
10
Q
What is the main hormone during estrus cycle in the Follicular phase?
A
Estrogen
11
Q
What is the main hormone during estrus cycle in the Luteal phase?
A
structure- Corpus luteum
- Progesterone
12
Q
What are the 3 phases of Menstrual cycle?
A
- 4-6 days of mestruation (peeking of endometrium)
- Follicular: 8-10 days - follicules produce estradiol - endometrium thickens
- Luteal: 14 days - CL produces progesterone and estrogen - continued thickening of the endometrium
13
Q
What is Polyestrus?
A
having more than one period of estrus per year
(Cows, queen (cats), sow (pig))
14
Q
what is seasonally polyestrus?
A
Those animals with estrous cycles occurring only during certain seasons of the year, due to the amount of daylight
such as horses (Long day breeders- spring) and ewe (sheep- short day breeders - autumn)
15
Q
What is monoestrus?
A
having one estrous cycle per year.
such a dogs, wolves, and bears
16
Q
What are the two phases in the Follicular phase during estrus cycle?
A
- Proestrus - formation of an ovulatin follicule & increased estradiol secretion
- Estrus - peak estradiol secretion induces receptive behavior and ovulation
17
Q
What are the two phases in Luteal phase during estrus cycle?
A
- Metestrus - formation of corpus lutem from folicular cells & beginning of progesterone secertion
- Diestrus - prolonged luteal secretion of high progesterone levels
18
Q
What happens during proestrus?
A
- preovulatory follicle grows
- Estradiol levesl rise
- Endometrial glands grow
- Peak estrogen
19
Q
What happens during estrus?
A
- enables the male to breed
- estrogen levels decrease
- Ovulation 24- 48 hrs after peak LH
- increases mucus in cervix
20
Q
What happens during Metaestrus?
A
- low estrogen levels
- ovulation in the cow and other similar species
- Formation of Corpus hemorrhagicum
- FSH levels increase (formation and growth of follicles)
- contractions in the uterus
21
Q
What happens during Diestrus?
A
- high progesterone levels
- FSH rises at a certain point to enable the ovulating follicle to grow
- Contractions stop in the uterus
- small corpus luteum at end of period if not pregnant - due to release of PGF
22
Q
Canine estrus cycle:
Anestrus - __Months
(Follicular phase)
Proestrus - __ days
Estrus - ___ days
(Luteal phase)
Diestrus - ___ months
A
Anestrus - 5 Months
(Follicular phase)
Proestrus - 9 days
Estrus - 9 days
(Luteal phase)
Diestrus - 2 months
23
Q
What is anestrus?
A
Anestrus refers to the phase when the sexual cycle rests. This is typically a seasonal event and controlled by light exposure through the pineal gland that releases melatonin
24
Q
Amenorrhea in women
A
the absence of menstruation during the reproductive years of a woman’s life
- prolonged reproductive cycle , seen in athletes and during lacation
25
What are gonadotropin hormones?
FSH, LH, and Prolactic
26
What is the Placenta hormone produced in mares called and its use?
Equine Chorionic Gonadotropin - formation of accessory Corpus Luteum and pregnancy maintence
27
What is the job of Prostaglandin hormone PGF2a?
contracts blood vessels, corpus luteum breakdown, sperm motility, parturition (act of giving birth)
28
What is the job of Prostaglandin hormone PGE2a?
Expands blood vessels, ovulation, corpus luteum maintenance, fetal implantation
29
What does puberty begin with?
begins with the ability of sepcific hypothalamic neurons to provide enough GnRH to promote and support gametogensis
30
When is considered female puberty?
- age at 1st estrus cycle
- age at first ovulation
- age @ which the female can keep a pregnancy **
31
When is considered male puberty?
- age at which male behavior begin to be expressed
- age of first ejaculation
- age at which sperm is first seen in the ejaculate
- age at which sperm is first seen
- age at which sperm is first seen in the urine
- age at which there is a threshold number of sperm in the ejaculate
32
Age of puberty in Bovine
Male and Female - 11 months
33
Age of puberty in Ovine (sheep)
Male and Female at 7 months
34
Age of puberty in Equine
Male 14 months and Female 18 months
- horses are seasonal cycle - a large range because sexual maturity is in the spring (those born in the fall are sexually mature only in the following spring
35
What effects puberty?
hormones, genetics, environment, nutrition
36
What hormone determines the time of puberty?
GnRH
37
What are potential inspectors of GnRH pulses during puberty?
- development of surge center
- change in feedback sensitivity to estradiol
38
When is puberty in birds?
at 2 months of age (zebra finch, japanese quail)
- Song birds and parrots at one year
- larger birds around 3 years
- males later then females
39
When is puberty in rodents such as ferret?
Females - 8-12 months
Males - 4-12 months
Seasonal Breeders - long day!
40
Monoestrus
cycle once or twice a year
In Bitches cycle twice a year
In Wolves once a year
41
Polyestrus
cycle many times during the year
such as Sows, sheep, cats
42
Types of cyles in Cow, sheep, sow, & mare
type of cycle - long
Follicle development - spontaneous
Ovulation & CL formation - spontaneous
Cl function - spontaneous
43
Type of cycle in Rats, mice, hamsters
type of cycle - short
follicle development - spontaneous
Ovulation and CL formation - spontaneous
CL function - Induced (prolactin)
44
Type of cycle in Rabbit, queen, mink, ferret, alpaca
type of cycle- Induced
follicle development - spontaneous
Ovulation and CL formation - Induced (peak LH)
Cl function - induced
45
Type of reproductive cycle:
Alpaca -
Bitch -
Cow -
Sheep-
Llama -
Mare -
Queen -
Sow -
Alpaca - polyestrus
Bitch - monoestrus (6 months)
Cow - polyestrus (21 days)
Sheep- Seasonal polyestrus (short day)
Llama - polyestrus
Mare - seasonal polyestrus (long day)21
Queen - seasonal polyestrus (long day) 17
Sow - polyestrus 21 days
46
High or Low Melatonin levels during Long days/Short nights
low melatonin levels
47
High or Low melatonin levels during Shory days/Long night
High melatonin levels
48
Animals lacking placenta
reptiles, birds, fish, marsupials
49
What are the 4 stages in polyestrus in cows, sheeps, and goats?
estrus, metestrus, diestrus, and proestrus
50
What are the 3 stages of polyestrus in sows?
proestrus, estrus, diestrus
51
what are the 4 stages of monoestrus in female dogs?
proestrus, estrus, diestrus, anetrus
52
what are the 5 stages of seasonal polyestrus in felines?
proestrus, estrus, interestrus, diestrus, anetrus
53
What does the follicular phase include?
Proestrus and estrus
54
What does the Luteal phase include?
metestrus and diestrus
55
What events occur in the follicular phase?
- Rise in level of gonadotropin release from the anterior putitary
- Follicle development/preperation for ovulation
- Ovulation
56
High or low levels of estrogen and progesteron during estrus?
High estrogen levels
Low progesterone levels
57
What does estrogen cause?
- blood flow enhancment
- swelling of genitalia
- rise in WBC
- rise in mucoid secretions
- rise in uterine musculature tonus
58
During the follicular phase, what happens in the tonic center?
Releases small amplitude pulses of GnRH that stimulate release of FSH and LH from anterior pituitary
- Causes growth and development of follicales in the ovary - follicles produce estrogen
59
During the follicular phase, what happens in the surge center?
Responds in positive feedback to increase levels of estrogen (produced by follicle) in absence of progesterone to release LARGE quantities of GnRH which causes release of LH- ovulation
60
During the follicular phase what do the rise in FSH levels cause?
Recruitment of new follicles
61
What are the 4 follicle dynamics?
Recruitment
Selection
Dominance
Atresia (degenerative process)
62
What is the process of recruitment in follicle dynamics?
Process of recruitment of primordial follicles from the ovarian stores
63
What is the process of Selection in follicle dynamics?
Follicles chosen from the stores become atretic or continue to ovulate
64
What is the process of Dominance during follicle dynamics?
- Follicles that do not undergo atresia
- Produce large quantities of estrogen
- Progress to ovulation
65
What are the hormonal dynamics in recruitment?
High FSH --> antral follicle growth
Low LH
No inhibin
66
What are the hormonal dynamics of Selection?
Low FSH
Moderate LH
low inhibin (inhibit FSH secretion)
67
What are the hormonal dynamics of Dominance?
Low FSH (cause other antral follcile to undergo atresia)
High LH (release from preovulatory center)
High inhibin (secreted by dominant follicle)
68
Oogenesis
the process of the formation of a mature ovum from the oogonia in females. It takes place in the ovaries. During oogenesis, a diploid oogonium or egg mother cell increases in size and gets transformed into a diploid primary oocyte
69
The female dog ovulates how long post LH surge?
2 days!
70
What happens to a follicule that ovulated?
Shrinks, fills with blood, and corpus hemorrhagicum
71
what is corpus hemorrhagicum?
("bleeding corpus luteum") is a temporary structure formed immediately after ovulation from the ovarian follicle as it collapses and is filled with blood that quickly clots
72
How many follicular waves in Cow?
2-3 cycle
73
How many follicular waves in sheep?
4-5 cycle
74
How many follicular waves in Sow?
one wave cycle
75
How many follicular waves in Mares?
2 wave cycles
76
What animal ovulates a primary oocyte?
Dogs
77
What is Luteolysis?
is the structural and functional degradation of the corpus luteum, which occurs at the end of the luteal phase of both the estrous and menstrual cycles in the absence of pregnancy.
- Dramatic decline is porgesterone levels
- Release of negative feedback of progesterone on the hypothalamus and hypohysis
- PGF2a is the luteolytic substance in domestic animals (endometrium)
- NO luteolysis in female dogs
78
What is Leutinization?
the change of Theca and Granulosa cells to become functional luteal cells
Granulosa --> Large luteal cells
Theca interna --> small luteal cells
79
Comparison between estrus and menstrual cycles
estrous cycle is the reproductive cycle of females of non-primate mammals in which the endometrium is reabsorbed by the walls of the uterus while menstrual cycle is the reproductive cycle of females of primate mammals in which endometrium is shed via bleeding
80
Length of estrus in cows
12 -24 hours
81
length of estrus in sow
4-36 hours
82
length of estrus in mare
4 days
83
length of estrus in sheep
24 hours
84
Sexual behavior of the female cow
- increased walking
- increased vocalization
- circle and tail lift
- licking and increased cleaning
- mount other females
85
sexual behavior in mare
- increased walking
- tail "flagging"
- urination stance or in front of male
- exposure of the clitoris
- vuvar "winking"
86
sexual behavior in female sheep
- short period of restlessness
- "search" of a male
- urination in front of male
- stand stil
- tail flagging
87
sexual behavior of female goat
- more "talkative"
- tail waiving, wag, becomes sticky
- milking goats five less milk
- mount other females
- urination
- courts the male
88
sexual behavior of the sow
- mild discomfort
- stand still
89
sexual behavior of female dog
- wandering
- stand still
- "flagging"
- urination in front of male
-rubbing head fondly
90
sexual behavior of female cat - queen
- vocalization
- bending, rubbing head, rolling
- lordosis
-presentation of vulva
-tail flagging
91
What is the Flehmen response
curling back of upper lip exposing its front teeth
- females produce pheromones
- males : 3 alpha androstenol
92
What animal has short time mating of 1-3 seconds?
Ox and sheep, cow
93
What animal has continuous mating 5-20 seconds?
boar
94
what animal has intermediate mating 20-60 seconds?
stallion
95
Which animals use artificial vagina for semen collection?
stallion, goat, bull, dog, tomcat, sheep
96
which animals use electroejaculation for semen collection?
boar, sheep, bull, stallion,camal, cat
97
Which animals use manual semen collection?
swine, dog, sometimes cats
98
Azoospermia
no sperm in ejaculate
99
oligospermia
very low numbers of sperms in the ejaculate
100
teratospermia
high number of defective sperms in the ejaculate
