Reproduction Flashcards
1
Q
Where does the reproductive tract originate from
A
The embryonic mesoderm
2
Q
What does the kidney originate from
A
The metanephric diverticulum (from the mesonephros)
3
Q
What hormone destroys the Müllerian duct and what produces it
A
Anti-Mullerian hormone, produced under influence of the SRY gene on the Y chromosome
4
Q
What is the gubernaculum
A
A cord that extends from the testicle into the inguinal canal
5
Q
Which layers of fascia make up the vaginal tunic
A
The visceral and parietal peritoneum
6
Q
What does the gubernaculum become after testicles have descended through the inguinal canal
A
- The proper ligament of the testicle
- The ligament of the tail of the epididymis
- The scrotal ligament
7
Q
In the genetic female, germ cells become ___
In the genetic male, germ cells become ___
A
Female: oogonia
Male: spermatogonia
8
Q
Which cells direct male development
A
Seritoli cells
9
Q
Which cells direct female development
A
Granulosa cells
10
Q
Which class of hormone drives penis developement
A
Androgens
11
Q
Which class of hormone drives vulva development
A
Estrogens
12
Q
What are the 3 lobes of the pituitary gland
A
- Anterior lobe
- Posterior lobe
- Intermediate lobe
13
Q
Where does the hypothalamus sit
A
Between the midbrain and forebrain
14
Q
Which lobe of the pituitary is connected to the hypothalamus via axons of neurons
A
The posterior lobe
15
Q
How does the hypothalamus communicate with the anterior lobe of the pituitary
A
Via a vascular network
16
Q
Which reproductive hormones are produced by the hypothalamus
A
GnRH and oxytocin
17
Q
Which reproductive hormones are produced by the pituitary gland
A
LH, FSH and prolactin
18
Q
GnRH: function
A
Stimulates the synthesis and secretion of FSH and LH
19
Q
LH: funtion
A
Triggers ovulation and CL development in females
Stimulates testosterone production from Leydig cells in males
20
Q
FSH: function
A
Stimulates estradiol production in granulosa cells
Acts on Sertoli cells to stimulate sperm production
21
Q
Oxytocin: function
A
Stimulates uterine contractions and milk let down
22
Q
Prolactin: function
A
Stimulates milk production in the mammary gland and inhibits GnRH production (and thus FSH and LH production)
23
Q
How does GnRH control the release of FSH and LH from the anterior pituitary
A
When GnRH pulse frequency is high, LH is released
When GnRH pulse frequency is low, FSH is released
24
Q
How do FSH and LH inhibit GnRH production
A
They stimulate the production of steroid hormones (testosterone, estradiol and progesterone) that inhibit GnRH production
25
Which cells in the anterior pituitary secrete FSH and LH
Gonadotroph cells
26
Where is oxytocin stored
In the pituitary gland
27
Which cells in the anterior pituitary produce prolactin
Lactotroph cells
28
Explain the difference in how oxytocin and prolactin are produced
Oxytocin is produced via positive feedback from itself
Prolactin is only produced when the 'brakes' come off (main break is dopamine)
29
Define puberty in the female
The age at which the female can support a pregnancy
30
Define puberty in the male
The age at which ejaculate contains enough sperm to fertilize
31
Explain the gonadostat theory of puberty
Before puberty, the hypothalamus is very sensitive to negative feedback from gonadal steroids, so there is very low levels of GnRH produced (and no LH surge)
At puberty, the hypothalamus is much less sensitive so there is increased GnRH and gonadotropin release
32
Explain the maturation of the hypothalamic-pituitary-gonadal axis theory
GnRH inhibition is independent of gonadal steroid feedback until puberty, and an increase in GnRH pulsatility as the structures mature is the trigger for puberty
33
List 4 factors influencing puberty
1. Age & Bodyweight
2. Nutrition
3. Social & Environmental
4. Genetics
34
Where does the proliferation stage of spermatogenesis occur
In the basal compartment of the seminiferous tubule
35
Where does the meiotic stage of spermatogenesis occur
In the adluminal compartment of the seminiferous tubule
36
Which stage of spermatogenesis ends with primary spermatocytes
Proliferation (first)
37
Which stage of spermatogenesis ends with spermatids
Meiosis (second)
38
List 4 changes that occur in the final differentiation stage of spermatogenesis
1. Formation of acrosome
2. Nuclear condensation
3. Flagellar development
4. Phagocytosis of unwanted cytoplasm
39
Where does the final maturation stage of spermatogenesis occur
The epididymis
40
What forms the blood:testis barrier
The tight junctions between Sertoli cells that divide the tubule lumen in the basal and adluminal compartments
41
What is the role of the blood:testis barrier
It prevents spermatozoa from leaking into circulation because the body's immune system is intolerant to spermatozoa antigens and helps keeps the lumen environment optimal for sperm development
42
Which piece of the sperm flagellum contains the mitochondria
The midpiece
43
Which piece of the sperm flagellum contains a fibrous sheath that provides support and the beat
The principal piece
44
How long does spermatogenesis take
~60 days
45
Where do ovarian follicles develop
Within the cortical tissue
46
Describe a primordial follicle
Immature oocyte surrounded by a single layer of cells
47
Describe a primary follicle
A slightly more advanced form of a primordial follicle, it will either go on further of degenerate
48
Describe a secondary follicle
An oocyte surrounded by two or more layers of cells, but with no antrum or cavity
49
Describe a tertiary follicle
An oocyte surrounded by a number of cells layers, with a cell cavity/antrum filled with follicular fluid
50
What forms the zona pellucida in the primordial follicular growth phase
Glycoproteins secreted from the immature oocyte
51
What is the zona pellucida
A 'shell' that separates the oocyte from surrounding granulosa cells
52
Where do theca cells originate from
From the condensation of ovarian stromal cells
53
At which stage of follicular growth are follicles dependent on hormonal control
The antral stage
54
Describe the sequence of hormone release/action in the antral stage of follicular growth
1. FSH is released and acts on granulosa cells
2. Granulosa cells are activated and convert the androgens produced by theca cells into estradiol
3. More estradiol is produced and stimulates LH receptors to appear on granulosa cells
55
What event needs to happen for a follicle to enter the preovulatory stage of development
An LH surge (coinciding with the appearance of LH receptors on granulosa cells)
56
List 3 effects of LH on a follicle
1. Rapid expansion of granulosa and thecal cells
2. Rapid increase in follicular fluid
3. Increase in blood flow to the follicle
57
Define spontaneous ovulation
Ovulation occurs regardless of mating
58
Define induced ovulation
Ovulation occurs in response to mating, pheromones or sperm derived factors
59
What does the ovarian follicle become after ovulation (release of the oocyte)
Corpus hemorrhagicum
60
When the follicular BM breaks down after ovulation, granulosa cells become ___
Large luteal cells
61
When the follicular BM breaks down after ovulation, theca cells become ___
Small luteal cells
62
What is the main hormone produced by the corpus luteum
Progesterone
63
List 3 luteolytic hormones
1. LH
2. Prostaglandin E2
3. Prolactin
64
List the principal luteolytic hormone
Prostaglandin F2a
65
What produces prostaglandin F2a
The uterus
66
Which follicular cells have FSH receptors
Granulosa cells
67
What are the 3 stages of reproductive behavior in the male
1. Precopulatory
2. Copulatory
3. Postcopulatory
68
What are the 3 stages of reproductive behavior in the female
1. Attractivity
2. Proceptivity
3. Receptivity
69
When do females tend to display sexual behaviour
During the follicular phase when estradiol is high
70
List 5 steps in how reproductive behavior is controlled by the CNS
1. Sensory input
2. Hypothalamic neurons release peptides in response to increased E2
3. Peptides act on midbrain to speed up the signal
4. Signal synapses with the medulla to integrate a postural response
5. Signal is sent to the body for lordosis and mounting
71
What happens first in the process of an erection
The relaxation of cavernosal smooth muscle and increased blood flow to cavernosal spaces
72
List 3 things that stimulate the ejaculation reflex
1. Pressure
2. Tactile sensation
3. Temperature (in the bull)
73
What is vesiculization
The fusion of the plasma membrane of the egg and acrosomal membrane of the sperm - this creates pores in the plasma membrane and allows acrosomal enzymes to pass through
74
Define syngamy
The fusion of male and female nuclei to form a zygote
75
What are the 4 concentric layers of the female reproductive tract from outermost to innermost
1. Serosa
2. Muscularis
3. Submucosa
4. Mucosa
76
What makes up the broad ligament of the uterus
Mesovarium, mesosalpinx and mesometrium
77
What is the name of the female reproductive system common to both the urinary and reproductive tract
The vestibule (part of the caudal vagina)
78
What is different about the ovary in a mare
The structure is reversed, with the cortex in the center of the ovary and medulla surrounding it
79
What are the 4 steps of implantation
1. Hatching of the blastocyst
2. Apposition next to the endometrium
3. Adhesion
4. Attachment/Invasion
80
When is the viability of an embryo strongly influenced by maternal factors
From implantation onwards
81
Where does the blastocyst implant in litter bearing species
Evenly spaced throughout the uterine horns
82
Where does the blastocyst implant in ruminants
In the ipsilateral horn of the ovulated follicle
The second migrates to the contralateral horn (in sheep)
83
Where does the blastocyst implant in horses
It will migrate between both horns
84
Which species have a diffuse placenta
Horses and pigs
85
Which species have a cotyledonary placenta
Ruminants
86
Which species have a zonary placenta
Carnivores (including dogs)
87
Which species have a discoid placenta
Primates and rodents
88
What is a placentome
The cotyledon-caruncle complex associated with a cotyledonary placenta
89
What is the fetal portion of the allantochorin in cotyledonary placenta
The cotyledons
90
What is the maternal portion of the allantochorin in cotyledonary placenta
Caruncles
91
Describe a epitheliochorial placenta
Fetal chorion and uterine endometrial epithelium are in direct contact
92
Describe a synepithelialchorial placenta
Fetal chorion and uterine endometrial epithelium are in direct contact and the fetal trophoblasts fuse with endometrial cells to form binucleate cells
93
Describe a endothelialchorial placenta
The chorion is in direct contact with endothelium of the blood vessels of the dam
94
Describe a hemochorial placenta
Fetal vessels and chorion are invaginated into pools of maternal blood
95
List 5 functions of the placenta
1. Provide oxygen and nutrients
2. Provide hormones
3. Remove waste
4. Thermo-regulation
5. Confer passive immunity
96
What forms the yolk sac
The endodermal cells that separated from the embryonic disc and line the cavity containing the blastocyst
97
What forms the chorion
The amniotic folds (caused by the yolk sac growing upwards) fusing with the trophoblast layer (initial layer lining the blastocyst)
98
What forms the allantois
An outgrowth from the primitive gut
99
What forms the aminon
Trophectoderm and mesoderm layers, left after the amniotic folds fuse
100
What forms the chorioallantoic placenta
The fusion of the allantois and chorion
101
How does the ruminant conceptus prevent luteolysis in order for the pregnancy to continue
By producing interferon tau (IFNt), which binds to oxytocin receptors, blocking oxytocin from stimulating the endometrium to produce PGF2a
102
How does the equine conceptus prevent luteolysis in order for the pregnancy to continue
High mobility of the embryo acts as an anti-luteolysis signal
103
What are the 3 mechanisms of placental exchange
1. Simple diffusion
2. Facilitated diffusion
3. Active transport
104
What 2 things does the oxygen supply to the fetus depend on
1. Blood oxygen content and flow rate in the uterine and umbilical arteries
2. The diffusing capacity of the placenta
105
Why is the fetus so good at using less oxygen
Their hemoglobin concentration is 50% higher, and it has a greater oxygen carrying capacity
106
Which species acquire passive immunity from the placenta
Primates and rodents
107
How can IgG be transferred across the mammalian placenta
By binding to the FCrN receptor on the surface of syncytiotrophoblasts
108
Define fetal programming
The concept that events occur during critical points during pregnancy that can cause long term effects on the fetus and offspring after birth
109
What are the 3 stages of parturition
1. Initiation of myometrial contractions
2. Expulsion of the fetus
3. Expulsion of the fetal membranes
110
What hormones are involved in the first stage of parturition, the initiation of myometrial contractions, and what does each one do
E2: indirect removal of P4 block and activates contractions
Oxytocin: initiate myometrial contractions
PGF2a: regresses CL and activates contractions
111
What hormones are involved in the second stage of parturition, expulsion of the fetus, and what does each one do
E2: provides mucus and lubrication
PGF: stimulates relaxin
112
List 3 events (in order) that occur in the third step of parturition, expulsion of the fetal membranes
1. Vasoconstriction to dislodge chorionic villi from the maternal side
2. Contractions for physical expulsion of the placenta
3. Maternal immune response against fetal membranes
113
What is the name of the discharge containing remnants of fetal and maternal tissue a few days after birth
Iochia
114
List 2 things that happen to the uterus following birth
1. Uterine involution
2. Endometrial regeneration
115
What is uterine involution
The return of the uterus to its normal size
116
List 5 factors affecting the resumption of ovarian cyclycity
1. BCS
2. Energy balance
3. Retained fetal membranes
4. Endometritis
5. Mastitis/lameness
117
List 5 common postpartum disorders in mammals
1. Retained placenta
2. Milk fever
3. Negative energy balance
4. Mastitis
5. Endometritis
