Physiology Flashcards
Covers - Puberty - Reproductive Endocrinology and Regulation - Gametogenesis & Spermatogenesis - Oogenesis - Reproductive Cycle Phases - Ruminant/Porcine Cycles - Small Animal Cycles - Equine Cycles - Fertilization - Genetics - Placentation - Maternal Recognition of Pregnancy
1
Q
What is gametogenesis?
A
(Production of gametes from haploid precursor cells)
2
Q
(T/F) Mitosis results in a diploid daughter cell that is genetically identical to the diploid parent cell.
A
(T)
3
Q
(T/F) Meiosis optimally results in 4 haploid daughter cells that are genetically distinct from their diploid parent cell.
A
(T)
4
Q
How many functional spermatozoa are formed from one spermatocyte?
A
(4)
5
Q
How many functional gametes are formed from one oocyte?
A
(1 and two nonfunctional polar bodies)
6
Q
Why does spermatogenesis produce four potentially functional gametes per original spermatocyte but oogenesis only produces one?
A
(Bc the cytokinesis that occurs with oogenesis is unequal so one cell gets a majority of the cytoplasm and the other does not, forming a polar body; cytokinesis is equal in spermatogenesis)
7
Q
What is the term for the release of fully-formed sperm into the lumen of the seminiferous tubules?
A
(Spermiation)
8
Q
What is spermatogenesis?
A
(Production of sperm from a primordial germ cell)
9
Q
What cells of the testes provide the blood-testis barrier (BTB) whose purpose is to protect developing germ cells from external insults and the immune system?
A
(The sertoli aka sustentacular cells)
10
Q
What does the androgen binding protein that is produced by sertoli cells do?
A
(Binds large amounts of testosterone, which is necessary to stimulate spermatogenesis)
11
Q
What do sertoli cells do with the large amounts of testosterone that they bind?
A
(Form estradiol which then ‘directs’ spermatogenesis)
12
Q
What do the interstitial/leydig cells produce testosterone in response to?
A
(Luteinizing hormone)
13
Q
(T/F) By the time sperm reaches the epididymis, the spermatozoa are fully mature.
A
(F, full maturation takes place once the sperm reaches the epididymis)
14
Q
What is the term for the temporary remnant of the cytoplasmic bridges between developing spermatids that are now singular spermatozoa?
A
(Cytoplasmic droplet)
15
Q
Where within the epididymis do spermatozoa both morphologically (removal of the cytoplasmic droplet) and physiologically (acquiring motility and penetrability) mature?
A
(The body)
16
Q
Where within the epididymis are fully mature spermatozoa stored?
A
(The tail)
17
Q
(T/F) Fetal primary oocytes complete meiosis I and then enter meiosis II but then arrest development until puberty.
A
(F, development arrests after they enter into meiosis I)
18
Q
What are formed from primary oocytes that resume development and complete meiosis I?
A
(Secondary oocytes)
19
Q
Where within the body do primary oocytes complete meiosis I and become secondary oocytes (in all species but the bitch)?
A
(The ovaries)
20
Q
Secondary oocytes do not complete meiosis II unless what event takes place?
A
(Fertilization)
21
Q
How can you tell microscopically if a secondary oocyte was fertilized and completed meiosis II?
A
(There will be two polar bodies present instead of just one)
22
Q
What is the term for an arrested primary oocyte surrounded by a simple squamous layer of ovarian (follicular) cells?
A
(Primordial follicle)
23
Q
What is the term for an arrested primary oocyte surrounded by a cuboidal layer of granulosa cells?
A
(Primary follicle)
24
Q
What distinguishes a primary follicle from a secondary follicle in terms of the granulosa cells?
A
(Primary - one layer of cuboidal granulosa cells; secondary - multiple layers of granulosa cells)
25
What distinguishes a primary follicle from a secondary follicle in terms of the theca layer?
(Primary - theca is forming, not split into interna and externa; secondary - theca has specialized into interna and externa)
26
What is the defining feature of a mature aka graafian follicle?
(The ‘giant’ antrum; granulosa cells will be restricted to a relatively thin stratified cuboidal layer at the periphery of the large antrum)
27
At what approximate age do male canines reach puberty?
(9 months → very breed dependent tho)
28
At what approximate age do female canines reach puberty?
(12 months → very breed dependent tho)
29
At what approximate age do male felines reach puberty?
(9 months)
30
At what approximate age do female felines reach puberty?
(8 months; range is 4-12 months d/t seasonal effects but average is 8 months)
31
At what approximate age do male equids reach puberty?
(14 months)
32
At what approximate age do female equids reach puberty?
(18 months)
33
At what approximate age do male pigs reach puberty?
(7 months)
34
At what approximate age do female pigs reach puberty?
(6 months)
35
At what approximate age do male sheep/goats reach puberty?
(7 months)
36
At what approximate age do female sheep/goats reach puberty?
(7 months; range is 4-14 months d/t seasonal effects but average is 7 months)
37
At what approximate age do female cows reach puberty?
(11 months)
38
At what approximate age do male cows reach puberty?
(11 months)
39
Which sex has a surge center?
(Females)
40
What hormone is necessary to defeminize the male surge center?
(Estradiol; testosterone crosses the BBB in males and is converted into estradiol in the brain, this does not occur in females)
41
(T/F) After female puberty, their basal level of GnRH released from the tonic center is higher than the basal level was in the prepubertal stage.
(T)
42
What is the surge center of the hypothalamus responsible for in females who have reached puberty?
(Preovulatory surge of GnRH (and subsequently LH))
43
What percentage of an animal's mature body weight do they typically need to be to reach puberty?
(40-50% of their mature body weight)
44
(T/F) Female cows born to male cattle with a larger scrotum will reach puberty faster than females cows born to male cattle with a smaller scrotum.
(T)
45
Do heifers born in the fall or spring reach puberty earlier?
(Heifers born in the fall)
46
Do spring or fall born lambs come into puberty earlier?
(Spring, they will come into puberty the fall of the same year they were born whereas fall born lambs will not come into puberty until the next fall a year later)
47
The increase in photoperiods in January/February prompts the onset of puberty in which species?
(Cats)
48
The HPG axis (hypothalamus-pituitary-gonad axis) is considered mature when it becomes responsive to which hormone?
(Estrogen)
49
Where is follicular stimulating hormone produce?
(Anterior pituitary)
50
Primary follicles slightly increase in size and cells proliferate around them which indicates when they become secondary follicles, what type of cells are the ones that proliferate around the follicle?
(Granulosa cells)
51
FSH stimulates the granulosa cells of secondary follicles to release follicular fluid, what does this process form (hint: another stage of follicle)?
(Antral follicles)
52
Which of the cell layers of the antral follicles (granulosa cells, theca interna, or theca externa) are responsible for production of androgens under the influence of luteinizing hormone?
(Theca interna)
53
Besides the follicular fluid that led to the development of secondary follicles into antral follicles, what else does the granulosa cell layer produce (hint: both answers are hormones)? Two answers.
(Estrogen and inhibin)
54
What occurs to dominate follicles if there are high levels of progesterone in the system?
(They will undergo atresia)
55
What type of hormones are cholesterol based, and therefore production of them is dependent on diet?
(Steroid hormones)
56
All hormone receptors are what type of molecule?
(Proteins)
57
Where are steroid hormone receptors located in relation to the target cell?
(Cytoplasm or nucleus)
58
What cells of the gonads, male and female, produce estrogen?
Female - granulosa cells; male - sertoli cells
59
Where is estrogen produced in the body? Two answers.
(Gonads (specifically the granulosa cells of the follicle and the sertoli cells of the testis) and the placenta; Dr. Cecere also mentioned the adrenals so that is also a correct answer)
60
Where is progesterone produced in the body? Two answers.
(Corpus luteum and placenta)
61
Where is testosterone produced in a male versus female?
(Male - leydig cells; female - theca interna of follicle)
62
Where are peptide-protein hormone receptors located in relation to the target cell?
(Cell surface/transmembrane)
63
Which cells of the testes are responsive to FSH and secrete inhibin?
(Sertoli cells)
64
Which cells of the testes are responsive to LH and secrete testosterone?
(Leydig cells)
65
What gonadal hormone is secreted by the corpus luteum?
(Progesterone)
66
Do high or low levels of estrogen have a positive feedback on GnRH, FSH, and LH secretion from the hypothalamus/pituitary?
(Low levels of estrogen)
67
What hormone does inhibin have a negative feedback on?
(FSH)
68
Does progesterone have negative or positive feedback on GnRH, FSH, and LH?
(Negative)
69
(T/F) High levels of gonadotropins indicates a lack of gonad.
(T, due to a lack of feedback from the gonads being present)
70
What is the primary action of prostaglandin F2a?
(Luteolysis aka starts the cycle over again when not pregnant)
71
What effect does the administration of prostaglandin have on the length of the estrous cycle?
(It shortens it)
72
What stage of the estrous cycle is prolonged by successful fertilization and pregnancy?
(Diestrus)
73
What is occurring to the corpus luteum during proestrus?
(It is regressing → progesterone levels fall below 1 ng/ml)
74
What is occurring to estrogen levels during proestrus?
(They are rising)
75
The dominant follicle produces the maximum amount of estrogen it can during estrus, what effect does this have on luteinizing hormone production?
(High levels of estrogen induces an LH surge which then triggers ovulation)
76
Once ovulation has occurred, what hormone stimulates the transition of granulosa and theca cells of the dominant follicle into luteal cells?
(Luteinizing hormone)
77
What is the purpose of the increase in follicle stimulating hormone that occurs following ovulation of a dominant follicle?
(To stimulate a new wave of follicular development)
78
What is the dominant hormone of diestrus?
(Progesterone)
79
Cows are monestrous/polyestrous/seasonally polyestrous (choose one) and have a _____ day estrous cycle.
(Polyestrous, 21 day estrous cycle)
80
(T/F) Metestral bleeding is normal in cows and occurs the day after ovulation.
(T)
81
Listed below are different behaviors/physiologic characteristics that change in a cow when she is in estrus; give the change in those behaviors/physiologic characteristics that you would expect to occur.
- Locomotive activity
- Feed intake and milk yield
- Body temperature
- Locomotive activity (Increase, 2-5 fold)
- Feed intake and milk yield (Decrease slightly, this is not a consistent finding)
- Body temperature (Increase, expected increase is half a degree in C)
82
What season do mares experience anestrus naturally?
(Winter, typically November - February/March)
83
Is the length of estrus for mares longer or shorter later in spring?
(Shorter, will start longer in the early spring and decrease in length as spring progresses)
84
Ewes and does are short/long day breeders.
(Short, experience anestrus during the summer months)
85
How do the lengths of the estrous cycle of ewes and does compare?
(Ewes → 17 days; does - 21 days)
86
(T/F) Female dogs ovulate primary oocytes while other species ovulate secondary oocytes.
(T)
87
What is the cardinal behavioral sign of estrus in cows?
(Standing to be mounted)
88
What is the normal estrous cycle length for a cow?
(21 days)
89
What is the dominant hormone of proestrus in a cow?
(Estrogen)
90
What is the dominant hormone of estrus in a cow?
(Estrogen)
91
What stage of estrous starts after ovulation in a cow?
(Metestrus)
92
On what day of a cow’s estrous cycle will the uterus release PGF to lyse the corpus luteum?
(Day 16)
93
The corpus luteum is not responsive to PGF prior to what day of a cow’s estrous cycle?
(Day 5)
94
What is the dominant hormone in a bitch who is in proestrus?
(Estrogen)
95
What are the physical changes associated with proestrus in a bitch? Two answers.
(Turgid swelling of the vulva and hemorrhagic vulvar discharge)
96
Will a bitch be positively responsive to a dog during proestrus?
(No)
97
When a bitch is in estrus, estrogen is decreasing/increasing while progesterone is decreasing/increasing.
(Estrogen is decreasing while progesterone is increasing)
98
When do progesterone levels peak during diestrus and after ovulation in a bitch?
(25-35 days, ~ halfway through diestrus)
99
What hormone takes over for progesterone in the second half of diestrus that is necessary to maintain the corpus luteum for both bitches and queens?
(Prolactin)
100
What is the minimum and maximum time period for the interestrus interval in a bitch?
(Minimum is 4 months and maximum is 12 months)
101
What effect does melatonin have on the release of GnRH that results in horses being long day breeders?
(Melatonin blocks release of GnRH so when there is more melatonin in the system during shorter days (i.e. the winter), GnRH is blocked and mares are in anestrus)
102
What feedback (positive or negative) does progesterone have on luteinizing hormone?
(Negative feedback)
103
What is the uterine and cervical tone during diestrus in a mare?
(Firm; there is also no uterine edema)
104
Does LH peak before or after ovulation in mares?
(After)
105
What is the uterine and cervical tone during estrus in a mare?
(Uterine - moderately firm d/t edema; cervical - soft/relaxed)
106
What estrous cycle related events indicate the beginning and end of diestrus in a mare?
(Beginning is ovulation, end is luteolysis)
107
Dominant follicles release estrogen which has positive/negative (choose one) feedback on LH and positive/negative (choose one) feedback on FSH.
(Positive feedback on LH, negative feedback on FSH)
108
Beside estrogen, what hormone is released by dominant follicles that has a negative feedback on FSH?
(Inhibin)
109
What estrous cycle related events indicate the beginning and end of estrus in a mare?
(Beginning is luteolysis (release of prostaglandin, decrease in progesterone) and end is ovulation)
110
What is the dominant structure on the ovary during estrus?
(Dominant follicle)
111
What is the dominant structure on the ovary during diestrus?
(Corpus luteum)
112
How many days should you wait to administer PGF/ a PGF analog to a mare who was accidentally exposed to a stallion?
(At least 14 days)
113
What is deslorelin/sucromate and what is its purpose?
(GnRH analog, purpose is to induce ovulation)
114
Where (anatomical location) is semen deposited in ruminants and cats?
(The vagina)
115
Where (anatomical location) is semen deposited in pigs?
(Cervix)
116
Where (anatomical location) is semen deposited in dogs and equids?
(Uterus)
117
Once in the uterus, estrogen induces peristaltic waves that transport sperm to accumulate where within the female reproductive tract?
(At the UTJ/uterotubal junction; sperm then binds to the epithelium there and are slowly released to the oviduct)
118
Where does sperm capacitation occur?
(Sperm capacitation cannot occur until the sperm is within the female reproductive tract (besides in vitro))
119
What does sperm capacitation do to the lifespan of a sperm?
(It dramatically shortens it)
120
What does sperm capacitation do to the motility of a sperm?
(Progresses it, they become hypermotile)
121
What occurs to the caltrin, which is a protein that is added to sperm by vesicular secretions to block calcium transport, during sperm capacitation?
(It is removed; sperm is now able to bring calcium into itself)
122
When do capacitated sperm undergo their acrosome reaction?
(When they bind to the zona pellucida of an oocyte)
123
What is the purpose of exposing the acrosin within the sperm cell?
(The acrosin digests a pathway through the zona pellucida to allow for sperm penetration into the oocyte)
124
What effect do the proteases released by the cortical granules of the oocyte (which is the cortical reaction) have on the zona pellucida?
(Renders the zona resistant to acrosin digestion (which is the zona reaction), purpose is to block polyspermy)
125
What triggers the cortical reaction, which is the exocytosis of oocyte cortical granules, resulting in a polyspermy block?
(An influx of cytoplasmic calcium that is triggered upon sperm-egg binding)
126
What is the term for when the male and female pronuclei reach the center of the ovum and their pronuclear envelopes disappear allowing the two genomes to become one?
(Syngamy)
127
What is the term for the structure that results from the blastomeres producing cell adhesion molecules on their surface that occurs at some point between the 8 and 16 cell embryo stage (depending on species)?
(A morula)
128
What’s the difference between hereditary and congenital traits?
(Hereditary - something that is passed generation to generation; congenital - a trait that is present at birth, this could be something that has no relation to genetics)
129
What is the term for the environmental influence on how genes are expressed?
(Epigenetics)
130
(T/F) Carriers of recessive genes (Aa) are much more common than recessive homozygotes (aa).
(T)
131
How many phenotypes are associated with incomplete dominance of a gene?
(Three; AA is equal to one thing, aa is equal to one thing, and Aa is equal to a mixture of the phenotypes for AA and aa)
132
What is a good example of codominance (at least in the human population)?
(Blood type; codominance is full express of each allele so for the example of blood type, type ABs have both A and B receptors on their blood cells so both A and B genes are fully expressed)
133
What is the term for a genotype at one locus masking the expression of a second locus?
(Epistasis; the gene that is masking the other is the epistatic gene while the gene being masked is the hypostatic gene)
134
What type of genetic mutations shift the reading frame of the genome, which can invalidate transcription of the entire genome?
(Deletions or insertions)
135
What is the difference between missense and nonsense point mutations?
(Missense - transcripts the wrong amino acids; nonsense - transcripts a stop codon)
136
How does inbreeding (breeding first degree relatives; parent to offspring or siblings) affect the following:
- Tends to make things homozygous or heterozygous
- Increases or decreases predictability
- Increases or decreases viability
- Tends to make things homozygous or heterozygous (Homozygous)
- Increases or decreases predictability (Increases)
- Increases or decreases viability (Decreases)
137
How does outbreeding and crossbreeding (mating unrelated animals within a single breed/mating between breeds) affect the following:
- Tends to make things homozygous or heterozygous
- Increases or decreases predictability
- Increases or decreases viability
- Tends to make things homozygous or heterozygous (Heterozygous)
- Increases or decreases predictability (Decreases)
- Increases or decreases viability (Increases; ‘crossbreeding depression’ is a thing in future generations)
138
What is the term for the process by which the embryo becomes completely embedded within the endometrial connective tissue, which occurs in rodents and primates?
(Implantation)
139
(T/F) Except in carnivores, placentation is non-invasive in domestic animals.
(T)
140
(T/F) Normally, fetal and maternal blood never mix, regardless of species.
(T)
141
What is the purpose of the yolk sac?
(To provide nutrition very early in the life of an embryo; it regresses and is mostly a remnant in mammals by early gestation)
142
Which of the following is not one of the purposes of the amnion and its contained amniotic fluid?
A. Cushions the embryo
B. Prevents the embryo/fetus from sticking to the amniotic wall
C. Provides nutrition early in the embryos life
D. Provides medium from free movement
(C)
143
What is the term for the membrane that immediately surrounds the embryo/fetus and which contains fluid within it?
(Amnion, fluid contained is amniotic fluid)
144
Of the species listed below, which rely primarily on placenta progesterone? (Dr. Faux q)
Mare
Cow
Sow
Bitch
Ewe
Queen
Doe
(Mare and ewe)
145
Of the species listed below, which rely primarily on CL progesterone? (Dr. Faux q)
Mare
Cow
Sow
Bitch
Ewe
Queen
Doe
(Doe and sow)
146
Of the species listed below, which rely on placental and CL progesterone?
Mare
Cow
Sow
Bitch
Ewe
Queen
Doe
(Cow, bitch, and queen)
147
What hormone released from the placenta promotes endometrial growth, suppresses myometrial contraction, and promotes mammary alveolar development?
(Progesterone)
148
What is the purpose of equine chorionic gonadotropin, which is secreted from endometrial cups that develop in mares around 35 days into gestation?
(Play a role in preventing rejection of the fetus by the mare’s immune system)
149
What hormones released from the placenta promote myometrial growth, uterine vascular proliferation, and mammary ductal growth?
(Placental estrogens)
150
Give the gestation length for the species listed below in approximate months.
Cow
Mare
Ewe
Sow
Bitch/queen
Cow (9 months)
Mare (11 months)
Ewe (5 months)
Sow (3 months)
Bitch/queen (2 months)
151
What is the primary purpose of maternal recognition of a fetus?
(To prevent the body from lysing the CL which is releasing progesterone which is important for the pregnancy)
152
In the cow, the conceptus enters the uterus at approximately day 5/6 and maternal recognition of pregnancy occurs around day 15-18, what protein is used for MRP?
(Bovine interferon tau)
153
A hormonal signal has not been identified for maternal recognition in mares. What instead indicates when the embryo becomes fixed (and this is, I guess, considered successful maternal recognition)?
(Embryo motility; will be very motile from days 11-16 and then become fixed on day 16)
154
At maternal recognition of pregnancy in a sow, how many embryos need to be in each uterine horn?
(4 total embryos, 2 in each uterine horn)
155
What hormone is used to send the signal from the embryo in sows for maternal recognition?
(Estradiol; causes PGF to be released intraluminally instead of intravenously)
156
Are LH levels low or high during pregnancy?
(Low)
157
Of the species listed below which are luteal independent and which are luteal dependent for their source of progesterone throughout pregnancy?
Cow
Queen
Doe
Mare
Sow
Ewe
Bitch
(Luteal independent - cow, ewe, and mare; luteal dependent - doe, sow, bitch, and queen)
158
What is the purpose of the equine chorionic gonadotropin that is released from the endometrial cups in mares?
(To make secondary corpus lutea to produce progesterone, eCG has ‘LH like’ effects in the mare)
159
What cells of the gonads, male and female, produce estrogen?
Female - granulosa cells; male - sertoli cells
160
What are produced from haploid precursor cells in gametogenesis?
Gametes
161
What is the term for the process by which gametes are formed from haploid precursor cells?
Gametogenesis
162
What is spermiation?
The release of fully-formed sperm into the lumen of the seminiferous tubules
