Exam 3 Flashcards
(152 cards)
1
Q
In female birds, elevation of serum _____ above a threshold level causes a GnRH surge, leading to an ___ surge, and ovulation.
A
- Progesterone
- LH
2
Q
What is the source of progesterone that can cause ovulation in birds when it is above a threshold level?
A
-F1 follicle
3
Q
What two things does FSH doe in mammals and birds?
A
- Stimulate granulosal cells
2. Promote follicular development
4
Q
What does LH do in mammals and birds?
A
- Stimulates thecal cells
- When granulosa cells of a preovulatory follicle acquire LH receptors, ovulation will occur in response to the LH surge
5
Q
In female mammals, granulosa cells convert ____ to _____ and are the primary source of follicular _____. Thecal cells are the primary source of ______.
A
- Androgen
- Estrogen
- Estrogen
- Androgen
6
Q
True or False: the chicken follicle has no antrum and no follicular fluid.
A
True
7
Q
What is the chicken follicle filled with?
A
Yolky oocyte
8
Q
What is ovulation in the bird?
A
The release of the ovum with yolk from the follicle
9
Q
The interval from the LH surge to ovulation is ___ - ____ hours. The interval from ovulation to oviposition is ______ hours. The interval from oviposition to the next ovulation is _____ hours. Under what condition is this not true?
A
- 4-8
- 24
- .5
- If it is the last egg in the clutch
10
Q
What occurs to the post-ovulatory follicle of the bird?
A
-It will become inactive and be reabsorbed
11
Q
Atresia occurs in ___% of primordial and growing follicles of the laying hen.
A
90
12
Q
The _____ receives the ovulated oocyte and the yolk. What other two things occur here?
A
- Infundibulum
1. Fertilization occurs here from sperm stored in storage tubules
2. Chalazae formed here
13
Q
Describe the chaliziferous layer.
A
-Fibrous layer of the albumen that covers the entire yolk. It is twisted at both ends of the yolk to form thick rope-like structures that allow the yolk to rotate and keep it in the center of the egg. It is formed in the infundibulum.
14
Q
The egg spends ________ in the infundibulum, ______ in the magnum, ________ in the isthmus, ______ in the shell gland, and ______ in the vagina.
A
- 15 minutes
- 3 hours
- 1 hour 15 minutes
- 18-25 hours
- 1 minute
15
Q
In the ______ the albumen is secreted. What does it do? What are the two layers?
A
-Magnum
-Surrounds and protects the yolk and blastoderm that gives rise to the embryo
-Inner layer: Thick albumen
Outer Layer: Thin Albumen
16
Q
The _____ is where the soft shell membrane is added around the albumen.
A
-Isthmus
17
Q
What occurs in the shell gland?
A
-The hard shell is added
18
Q
Where is the primary site of sperm storage tubules? What is their purpose?
A
- Utero-vaginal junction
- To protect sperm from the hen’s immune system, preserve energy, and prolong the sperm’s life span
19
Q
What occurs in the vagina of the hen?
A
-The mucin coating is added to the egg
20
Q
The _____ inverts for oviposition.
A
Cloaca
21
Q
Why does the yolk of the egg have light and dark layers?
A
- When the hen eats, she adds more fat, creating dark yellow layers
- When the hen is not eating, she adds more protein, adding light white layers
22
Q
A ____ is consecutive days over which eggs are laid.
A
-Clutch
23
Q
What three things does optimal spermatogenesis require?
A
- Adequate secretion of GnRH from the hypothalamus
- FSH and LH secretion from the anterior pituitary
- Secretion of gonadal steroids such as testosterone
24
Q
What are tonic GnRH secretion patterns like? What are LH and FSH secretion patterns like?
A
- GnRH: Frequent, intermitten pulses lasting several minutes
- LH and FSH: Follow GnRH pulses with 4-8 pulses per day. FSH is lower in amplitude and longer in duration than LH.
25
Why are patterns of FSH and LH secretion different?
1. Inhibit inhibits only FSH, so FSH amplitude is lower
| 2. FSH has a longer half-life. so duration is longer
26
Describe the testosterone secretion patterns and why the patterns are pulsatile.
- Follow LH pulses
- If LH levels were continuously high, superstimulation would occur and lead to desensitizing of the LH receptors. This way, LH stimulates a burst of testosterone and then the testes can relax and respond to the next burst.
27
_____ concentrations of androgens withing the _____ _______ are essential for optimal spermatogenesis
- High
| - Seminiferous Tubules
28
Androgens such as testosterone and dihydrogentestosterone are produced by ____ cells. What is their job?
- Leydig
| - To maintain spermatogenesis by decreasing germ cell degeneration to increase the number of sperm cells produced
29
___ from the anterior pituitary stimulates leydig cells to produce _____.
- LH
| - Androgen
30
____ from the anterior pituitary stimulates sertoli cells to increase the production of _____ ______ _____.
- FSH
| - Androgen binding protein.
31
LH stimulates ____ cells, while FSH stimulates _____ cells.
- Leydig
| - Sertoli
32
Sertoli cells make androgen binding protein. What two other things doe they produce?
1. Inhibin for negative feedback
| 2. Estrogen
33
What does androgen binding protein do and why?
Binds androgen to concentrate it within the seminiferous tubules for optimal spermatogenesis
34
What does androgen inhibit?
The hypothalamus and anterior pituitary for decreased GnRH, FSH, and LH. Decreased LH leads to decreased androgen production.
35
What does estrogen inhibit?
Gonadotropin secretion at the hypothalamus and anterior pituitary
36
Inhibin is produced by ____ cells and inhibits _____ at the ____ ____.
- Sertoli
- FSH
- Anterior Pituitary
37
____ cells, also called nurse cells, reach from the basement membrane of seminiferous tubules to the lumen. What doe they do? What three things do they secrete?
- Sertoli
- Help sperm develop and mature
- 1. Fluid for sperm transport
2. Androgen binding protein
3. Inhibin
38
What is the spermatogenic cell lineage?
Spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids, spermatozoa
39
____ are primitive germ cells resting on the basement membrane. They are ___n and replicate by ___.
- Spermatogonia
- 2
- Mitosis
40
____ ______are larger, rounded cells derived form spermatogonia that move away from the basement membrane. They are ___n and will undergo _____.
- Primary spermatocytes
- 2
- meiosis
41
______ _____ result from the first meiotic division of primary spermatocytes. They are ___n.
- Secondary spermatocytes
| - 1
42
_____ result from the second meiotic division. They are _____n and are the smallest cells that are close to the lumen.
- Spermatids
| - 1
43
_____ result from the morphological development of spermatids, in which the head and tail are visible.
-Spermatozoa
44
In males, you get ____ spermatids from ____ primary spermatocyte. In females, you get ___ polar bodies and ____ ovum from one primary ooctye.
- 4
- 1
- 2
- 1
45
Mitotic divisions result in _____ of spermatogonia. As they divide, ____ changes occur.
- proliferation
| - Maturational
46
During meiosis, a primary spermatocyte becomes ___ spermatids.
-4
47
What occurs during differentiation of sperm?
- Spermatids mature into spermatozoa
| - Changes include condensation of nuclear chromatin, formation of flagellum, and development of the acrosome.
48
The _____ is a balloon of enzymes over top of the sperm head that is acquired during differentiation.
Acrosome
49
True or False: Blood and lymph penetrate the seminiferous tubules
False, because of the blood-testis barrier
50
What are the components of the blood-testis barrier?
- Peritubular cells surrounding seminiferous tubules
| - Sertoli cell tight junctions are the principal barrier
51
What are the three functions of the blood-testis barrier?
1. Exclude substances that may be harmful to spermatogenesis such as toxins
2. Retain high levels of substances such as androgen binding protein
3. Immunological isolation of developing spermatids, since haploid cells are recognized as foreign
52
Primary spermatocytes udergo _____ ____ and are _____. Secondary spermatocytes undergo ____ ____ and are _____.
- Meiosis I
- Diploid
- Meiosis II
- Haploid
53
______ _____ is one of the strongest drives in animals that often takes precedence over other drives such as eating and sleeping.
-Reproductive behavior
54
When do males and females with estrous cycles show reproductive behaviors?
- Males: Anytime after puberty
| - Females: In estrus
55
What are the three distinct stages of reproductive behavior in the male and describe each.
1. Precopulatory stage: Male is searching for a sexual partner, courtship, arousal, erection, penile protrusion out of the sheath
2. Copulatory stage: Mounting, intromission of penis into vagina, ejaculation
3. Postcopulatory stage: Dismount, refractory period, memory
56
The _____ period is the period of time when a second copulation will not take place.
Refractory
57
In most species, female reproductive behaviors are promoted by high levels of circulating ____.
Estrogen
58
What are the precopulatory and copulatory behaviors of the female and describe them.
- Precopulatory: 1. Attractivity: signals that attract the male such as posture, vocalizations, and pheromones 2. Proceptivity: Behaviors stimulate the male to copulate such as maintaining proximity, presentation of genetalia, increase in activity, and mounting other females
- Copulatory: Receptivity behaviors may include accepting the male, standing to be mounted, lordosis, and deviation of the tail
59
What courtship behaviors are common in several species?
- sniffing of the vulva by the male
- urination by the female in the presence of the male
- flehmen behavior of the male
- Male's chin resting on the hind end of the female
- Increased phonation
60
Name three sustained copulators.
1. Boar
2. Dog
3. Camelid
61
Name an intermediate copulator.
-Stallion
62
Name four short copulators.
1. Bull
2. Ram
3. Buck
4. Tom
63
Why are past sexual experiences important for the copulatory behavior of the male?
-Negetive experiences, such as kicking from the female, can result in less enthusiasm from the male
64
Describe the programming of reproductive behavior during prenatal development.
- In the male, testosterone can enter the brain and be converted to estorgen to result in masculinization of the behavioral centers
- Alpha-fetoprotein binds estrogen in the female so that it cannot enter the brain, resulting in feminization of the behavioral centers of the brain
65
True or False: The sexually dimorphic center of the female hypothalamus is large than that in the male hypothalamus.
False, the male sexually dimorphic center is larger
66
In females, estrogen will induce estrous behavior. What can cause stronger estrous behavior?
-Progesterone priming followd by estrogen treatment
67
What does castration do to sexual behavior in the male?
Decreases sexual behavior
68
Why do males show constant sexual behaviors while females do only during estrus?
- In males, there is a tonic, consistent provision of testosterone, which is then converted to estradiol in the behavior centers of the brain. Estradiol causes reproductive behavior.
- In females, high estradiol promotes reproductive behavior only once per cycle
69
What are the four primary sensory inputs for reproductive behavior?
1. Olfaction
2. Vision
3. Audition
4. Tactility
70
How do female pheromones impact males?
- Estrous females smell different than non-estrous females
- This difference can be detected by other females
- Action of pheromones is species specific
71
How do male pheromones impact females? What is an example specific to boars?
- They can attract and stimulate females
- Preputial pouch and salivary gland secretions in the boar cause females to become sexually aroused if they are in estrus
72
Detection of less volatile pheromones is accomplished by the ____ _____ in the male.
-Vomeronasal organ
73
Describe the vomeronasal organ and its function.
- Males will nuzzle the genital regions or the ground to pick up urine or vaginal secretions
- Two small openings in the anterior roof of the mouth lead to the nasopalatine ducts
- Curling the upper lip closes the nostrils and allows a negative pressure to form in the nasopalatine duct
- This causes fluids to aspirate to the vomeronasal organ
- Sensory neurones in the vomeronasal organ examine materials to detect a female in estrus
74
Auditory signaling is valuable for what kind of signaling? Visual signaling is valuable what kind of signaling?
- Auditory: Signaling from a distance
| - Visual: Close-Range Signaling
75
_____ is the final stimulus before copulation. Give some examples.
- Tactile
- Biting the neck of mares and queens
- Chin resting by the bull on the back of the cow
76
Erection requires that blood be trapped within the _____ sinuses of the penis.
Cavernous
77
In response to sexual arousal, an erection results from _____ blood flow to the penis due to ____ of the arteioles supplying it and ____ venous outflow.
- Increased
- Vasodilation
- Restrticted
78
An erection is the _____ of erectile tissue and elevated ____ _____ ____.
- Engorgement
| - Intra penile pressure
79
In order for an erection to occur, ___ ___ muscles must relax, ___ muscles must contract to compress penile veins and restrict venous outflow, and the alternate contractions of this muscle and the ____ muscle help pump blood into erectile tissues.
- Retractor penis
- Ischiocavernosus
- Bulbospongiosus
80
How does viagra work?
- It inhibits phosphodiestrase (PDE2) so that cGMP is not converted to GMP, which causes smooth muscles to relax
- This sustains an erection
81
Pre-ejaculation is what kind of reflex? Ejaculation is what kind of reflex?
- Neuro-endocrine
| - Simple
82
What is a unique reproductive behavior to the dog?
- Turn around in the second stage of coitus to encourage uterine insemination instead of vaginal
- The turn helps maintain high blood pressure in the penis by decreasing venous outflow
83
What is the cervix's function in sperm transport?
- Filters defective and immotile spermatozoa
| - Cervical mucous flushes foreign material introduced during copulation
84
True or False: Dead sperm can be transported in the female reproductive tract.
True, but they are not transported as well
85
In the ______, initiation of capacitation occurs. What is this?
- Uterus
| - Capacitaiton is the removal of seminal plasma coatings so that they can fertilize
86
What three things occur to sperm in the oviduct?
1. Capacitation Complete
2. Some sperm attach to the oviductal epithelium to prolong viability
3. Sperm become hyperactive
87
What are the three parts of fertilization for sperm?
1. Acrosome reaction
2. Sperm penetrate zona pellucida and vitelline membrane
3. Male and female pronuclei form
88
Sperm must reside in the female repro tract for a period of time before they acquire maximum fertility. To acquire maximum fertility, _____ takes place. If returned to seminal plasma, _____ can also take place.
- Capacitation
| - Decapacitation
89
_____ is the fusion of male and female gametes.
Fertilization
90
Sperm become hyperactive in the _____ of the oviduct. Oviductal _____ are involved in hyperactivation. What is hyperactivation?
- Ampulla
- Secretions
- A change in the movement of sperm from a straight line to more sporadic
91
Hyperactivation helps sperm do what?
- Break away from the oviductal epithelium
- Penetrate the zona pellucida more effectively
- Help sperm find the oocyte
92
Penetration of the zona pellucida involves the binding of sperm to _____ receptors in the zona.
-ZP2
93
Binding of sperm to ZP2 in the zona pellucida triggers what?
The acrosome reaction
94
What is the purpose of the acrosome reaction?
- Enables sperm to penetrate the zona pellucida because enzymes in the acrosome are released to chemically break down the zona
- Exposes the equatorial segment of sperm so that it can later fuse with the vitelline membrane
95
In fertilization, a protein in the _____ ____ of sperm fuses with a protein in the ____ _____ of the oocyte. What are the names of these proteins?
- Equatorial segment
- Vitelline membrane
- Izumo 1 in the equatorial segment fuses with Juno in the vitelline membrane
96
The fusing of izumo 1 in the equatorial segment of sperm to Juno in the vitelline membrane stimulates what three things?
1. Resumption of the second meiotic division
2. Zona reaction
3. Vitelline Block
97
Describe the zona reaction.
Cortical granules release their contents, including ovastacin, which hydrolyzes ZP2 sperm receptors in the zona to stop new sperm from binding, and creates zonal hardening through cross-linking
98
Describe two methods used to make sure only one sperm fertilizes the oocyte.
1. Vitelline Block
| 2. Zona Reaction
99
What is polyspermy?
The deadly fertilization of an oocyte with more than one sperm
100
Describe the vitelline block.
After the cortical granules are released, the ability of the vitelline membrane to fuse with additional spermatozoa is reduced. This is partially due to the shedding of Juno in extracellular vesicles. Shed Juno also serve as a decoy to increase the potency of the sperm block by not allowing sperm to bind to the oocyte.
101
_____ formation involves swelling an development of male and female nuclear membranes.
Pronucleus
102
In _____, male and female pronuclei come into contact. Nuclear membranes disappear and chromosomes unite to form a ______. Lastly, _____ begins and fertilization is complete.
- Syngamy
- Zygote
- Mitosis
103
The diploid cell that results from fusion of the male and female pronuclei
Zygote
104
Organism in an early stage of prenatal development. This stage begins with a zygote and ends when the individual takes on a form that makes it recognizable as a member of its species.
Embryo
105
The products of conception, which include embryonic and extra-embryonic components
Conceptus
106
Organism in a later stage of prenatal development. This stage begins when the individual takes on a form that makes it recognizable as a member of its species.
Fetus
107
What are the 8 stages of embryonic development?
1. Fertilized ovum
2. Zygote
3. 2-celled embryo
4. 4-celled embryo
5. 8-celled embryo
6. Morula
7. Blastocyst
8. Hatched blastocyst
108
______ _____ of _______ is a signal from the embryo to the mother that is necessary for luteal cell maintenance, continued production of progesterone, and continued endometrial developement
Maternal Recognition of Pregnancy
109
For primates, what is the identity of the signal for maternal recognition of pregnancy, the target tissue of the signal, and the mechanism of action of the signal?
- Identity: Chorionic gonadotropin secreted by trophoblastic cells at the time of implantation
- Target Tissue: Luteal cells of the CL
- Mechanism of Action: Increases the lifespan of the CL
110
For Sheep and cows, what is the identity of the signal for maternal recognition of pregnancy, the target tissue of the signal, and the mechanism of action of the signal?
- Identity: Interferon-T
- Target Tissue: Endometrium
- Mechanism of Action: Decrease in prostaglandin production from the endometrium
111
In all domestic farm species, there is a substance secreted by the embryo that prevents what in order to maintain the pregnancy?
-Luteolytic action of PGF2a
112
For pigs, what is the identity of the signal for maternal recognition of pregnancy, the target tissue of the signal, and the mechanism of action of the signal?
- Identity: Estradiol is secreted from the embryo
- Target Tissue: Endometrium
- Mechanism of Action: Converts uterine prostaglandin secretion from an endocrine event to an exocrine event so that it can't reach the ovaries and cause luteal regression
113
What is the maternal recognition of pregnancy signal in mares?
-Unknown, but speculated that the constant movement of the conceptus throughout the uterus is important
114
True or False: The equine conceptus produces interferon-like molecules with anti-PGF2 release properties
False
115
Why do dogs not need a maternal recognition of pregnancy factor?
-The luteal phase is the same in pregnant and non-pregnant females
116
Why is the maternal recognition of pregnancy factor important for cats?
-If they have a non-fertile mating, the result will be a pseudopregnancy with shorter CL function
117
What is the CL function like for sheep throughout pregnancy?
- Present throughout
| - Can be removed after day 50 because placenta will make enough progesterone
118
What is the CL function like for cattle throughout pregnancy?
- Present throughout
| - Can be removed after day 200, but live calf will be born prematurely
119
What is CL function like for pigs throughout pregnancy?
-CL is present and necessary throughout
120
What is CL function like for mares throughout pregnancy?
- Equine chorionic gonadotropin causes the development of accessory CL
- These regress between the 5th and 7th month of gestation because progesterone from the placenta will maintain the pregnancy
121
What happens to progesterone and estrogen prior to parturition and why?
- Drop in progesterone since it inhibits uterine contraction
- Rise in estrogen to promote uterine contractions
122
True or False: eCG is responsible for the initial phase of maternal recognition of pregnancy in the mare
False, it is secreted after the initial rescue of the CL
123
What is the role of eCG in mares?
-Stimulates ovulations and development of accessory CL to increase progesterone
124
_____ are a range of steroids in the placenta in mares that includes progesterone and maintains the pregnancy after ovarian progesterone diminishes.
Pregnanes
125
How and why does the fetus signal for parturition?
- Uterine crowing leads to increased fetal adrenal corticotropic hormone (ACTH)
- ACTH causes increased cortisol production form the fetal adrenal gland, which initiates parturition
126
During parturition, there is ______ PGF2a. What does this do?
- Increased
| - Luteat regression and enhanced uterine contractility
127
During parturition, there is _____ progesterone. What does this do?
- Decreased
| - Removes the progesterone block
128
During parturition, there is _____ estrogen. What does this do?
- Increased
| - Enhances uterine contractility and relaxes the cervix and pelvic ligaments
129
During parturition, there is ____ relaxin. What does this do?
- Increased
| - Relaxation of the cervix and pelvic ligaments
130
During parturition, there is _____ oxytocin. What does this do?
- Increased
| - Stimulates the final myometrial contractions and generates maximum pressure
131
The ____ is an organ that unites fetal and maternal tissues for physiological exchange.
Placenta
132
What are the three functions of the placenta?
1. Transfer of nutrients and oxygen from the mother to fetus
2. Transfer of excretory products from the fetus to the mother
3. Synthesis of certain hormones
133
What is the general structure of placentas?
- Outer fetal membrane, called the chorion, intimately joins the endometrium, and the villi of the chorionic membrane protrude into the endometrium
- Connected to the embryo by the cord of blood vessels called the umbilical cord
134
Describe the diffuse placenta. What species have this?
- Villi distributed over the entire chorionic surface
| - Pig and horse
135
Describe the zonary placenta. What species have this?
- Villi are distributed in a band-like zone that circles the placental unit
- Dog and Cat
136
Describe the discoid placenta. What species have this?
- Villie are distributed in a single disc-shape pattern
| - Primates, rodents
137
In the cotyledonary placenta, fetal _____ are localizes tufts of chorionic villi that fuse with maternal ______, which are rounded projections of the endometrium.
- Cotyledons
| - Caruncles
138
The _____ is the name for the fused cotyledon-caruncle.
Placentome
139
The types of placental barriers are based on the number of layers that separate fetal blood from the maternal blood. The prefix represents the _____ side, while the suffix represents the _____ side.
- Maternal
| - Fetal
140
In the epitheliochorial type of placental barrier, the _____ lining of the uterine endometrium contacts epithelial cells of the _____ membrane of the fetus. There are _____ layers between the maternal and fetal blood.
- Epithelial
- chorionic
- 6
141
Which placental barrier is the least intimate type?
Epitheliochorial
142
In the _____ placental barrier, the endothelial lining of the endometrial blood vessels contacts epithelial cells of the chorionic membrane of the fetus.
-Endotheliochorial
143
What species have the epitheliochorial placental barrier?
-Cow, horse, pig, sheep
144
What species have the endothelial placental barrier?
-Cat and dog
145
In the endothelial placental barrier, there are ____ layers between the maternal and fetal blood
4
146
The human, monkey, rat, and mouse have the _____ type placental barrier
Hemochorial
147
Describe the hemochorial placental barrier. How many layers are there between the maternal and fetal blood?
- Blood of the mother bathes the epithelial cells of the chorionic membrane of the fetus.
- Three
148
The _____ placental barrier is the most intimate.
Hemochorial
149
Describe the gonadotropins released by the placenta in humans, monkeys, and mares.
- Humans & Monkeys: hCG and mCG are released by the early embryo to rescue the CL
- Mare: eCG not secreted until around day 40 because it is not a maternal recognition of pregnancy factor
150
Describe the lactogens released by the placenta in humans, sheep, and rats.
- Humans: Human chorionic somatomammotropin which is a growth hormone
- Sheep and Rats: Placental lactogen
151
What steroids are produced by the placenta in some species?
-Estrogen and progesterone
152
What three hormones can be produced by the placenta?
1. Gonadotropins
2. Lactogens
3. Steroids
