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Reproductive Physiology > Exam 3 > Flashcards

Exam 3 Flashcards

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

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2
Q

What is the source of progesterone that can cause ovulation in birds when it is above a threshold level?

A

-F1 follicle

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3
Q

What two things does FSH doe in mammals and birds?

A
  1. Stimulate granulosal cells

2. Promote follicular development

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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

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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
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6
Q

True or False: the chicken follicle has no antrum and no follicular fluid.

A

True

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7
Q

What is the chicken follicle filled with?

A

Yolky oocyte

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8
Q

What is ovulation in the bird?

A

The release of the ovum with yolk from the follicle

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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
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10
Q

What occurs to the post-ovulatory follicle of the bird?

A

-It will become inactive and be reabsorbed

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11
Q

Atresia occurs in ___% of primordial and growing follicles of the laying hen.

A

90

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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
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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.

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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
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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

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16
Q

The _____ is where the soft shell membrane is added around the albumen.

A

-Isthmus

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17
Q

What occurs in the shell gland?

A

-The hard shell is added

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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

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19
Q

What occurs in the vagina of the hen?

A

-The mucin coating is added to the egg

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20
Q

The _____ inverts for oviposition.

A

Cloaca

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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
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22
Q

A ____ is consecutive days over which eggs are laid.

A

-Clutch

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23
Q

What three things does optimal spermatogenesis require?

A
  1. Adequate secretion of GnRH from the hypothalamus
  2. FSH and LH secretion from the anterior pituitary
  3. Secretion of gonadal steroids such as testosterone
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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.

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25
Q

Why are patterns of FSH and LH secretion different?

A
  1. Inhibit inhibits only FSH, so FSH amplitude is lower

2. FSH has a longer half-life. so duration is longer

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26
Q

Describe the testosterone secretion patterns and why the patterns are pulsatile.

A
  • 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.
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27
Q

_____ concentrations of androgens withing the _____ _______ are essential for optimal spermatogenesis

A
  • High

- Seminiferous Tubules

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28
Q

Androgens such as testosterone and dihydrogentestosterone are produced by ____ cells. What is their job?

A
  • Leydig

- To maintain spermatogenesis by decreasing germ cell degeneration to increase the number of sperm cells produced

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29
Q

___ from the anterior pituitary stimulates leydig cells to produce _____.

A
  • LH

- Androgen

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30
Q

____ from the anterior pituitary stimulates sertoli cells to increase the production of _____ ______ _____.

A
  • FSH

- Androgen binding protein.

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31
Q

LH stimulates ____ cells, while FSH stimulates _____ cells.

A
  • Leydig

- Sertoli

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32
Q

Sertoli cells make androgen binding protein. What two other things doe they produce?

A
  1. Inhibin for negative feedback

2. Estrogen

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33
Q

What does androgen binding protein do and why?

A

Binds androgen to concentrate it within the seminiferous tubules for optimal spermatogenesis

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34
Q

What does androgen inhibit?

A

The hypothalamus and anterior pituitary for decreased GnRH, FSH, and LH. Decreased LH leads to decreased androgen production.

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35
Q

What does estrogen inhibit?

A

Gonadotropin secretion at the hypothalamus and anterior pituitary

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36
Q

Inhibin is produced by ____ cells and inhibits _____ at the ____ ____.

A
  • Sertoli
  • FSH
  • Anterior Pituitary
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37
Q

____ 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?

A
  • Sertoli
  • Help sperm develop and mature
    1. Fluid for sperm transport
      2. Androgen binding protein
      3. Inhibin
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38
Q

What is the spermatogenic cell lineage?

A

Spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids, spermatozoa

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39
Q

____ are primitive germ cells resting on the basement membrane. They are ___n and replicate by ___.

A
  • Spermatogonia
  • 2
  • Mitosis
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40
Q

____ ______are larger, rounded cells derived form spermatogonia that move away from the basement membrane. They are ___n and will undergo _____.

A
  • Primary spermatocytes
  • 2
  • meiosis
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41
Q

______ _____ result from the first meiotic division of primary spermatocytes. They are ___n.

A
  • Secondary spermatocytes

- 1

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42
Q

_____ result from the second meiotic division. They are _____n and are the smallest cells that are close to the lumen.

A
  • Spermatids

- 1

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43
Q

_____ result from the morphological development of spermatids, in which the head and tail are visible.

A

-Spermatozoa

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44
Q

In males, you get ____ spermatids from ____ primary spermatocyte. In females, you get ___ polar bodies and ____ ovum from one primary ooctye.

A
  • 4
  • 1
  • 2
  • 1
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45
Q

Mitotic divisions result in _____ of spermatogonia. As they divide, ____ changes occur.

A
  • proliferation

- Maturational

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46
Q

During meiosis, a primary spermatocyte becomes ___ spermatids.

A

-4

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47
Q

What occurs during differentiation of sperm?

A
  • Spermatids mature into spermatozoa

- Changes include condensation of nuclear chromatin, formation of flagellum, and development of the acrosome.

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48
Q

The _____ is a balloon of enzymes over top of the sperm head that is acquired during differentiation.

A

Acrosome

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49
Q

True or False: Blood and lymph penetrate the seminiferous tubules

A

False, because of the blood-testis barrier

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50
Q

What are the components of the blood-testis barrier?

A
  • Peritubular cells surrounding seminiferous tubules

- Sertoli cell tight junctions are the principal barrier

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51
Q

What are the three functions of the blood-testis barrier?

A
  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
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52
Q

Primary spermatocytes udergo _____ ____ and are _____. Secondary spermatocytes undergo ____ ____ and are _____.

A
  • Meiosis I
  • Diploid
  • Meiosis II
  • Haploid
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53
Q

______ _____ is one of the strongest drives in animals that often takes precedence over other drives such as eating and sleeping.

A

-Reproductive behavior

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54
Q

When do males and females with estrous cycles show reproductive behaviors?

A
  • Males: Anytime after puberty

- Females: In estrus

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55
Q

What are the three distinct stages of reproductive behavior in the male and describe each.

A
  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
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56
Q

The _____ period is the period of time when a second copulation will not take place.

A

Refractory

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57
Q

In most species, female reproductive behaviors are promoted by high levels of circulating ____.

A

Estrogen

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58
Q

What are the precopulatory and copulatory behaviors of the female and describe them.

A
  • 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
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59
Q

What courtship behaviors are common in several species?

A
  • 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
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60
Q

Name three sustained copulators.

A
  1. Boar
  2. Dog
  3. Camelid
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61
Q

Name an intermediate copulator.

A

-Stallion

62
Q

Name four short copulators.

A
  1. Bull
  2. Ram
  3. Buck
  4. Tom
63
Q

Why are past sexual experiences important for the copulatory behavior of the male?

A

-Negetive experiences, such as kicking from the female, can result in less enthusiasm from the male

64
Q

Describe the programming of reproductive behavior during prenatal development.

A
  • 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
Q

True or False: The sexually dimorphic center of the female hypothalamus is large than that in the male hypothalamus.

A

False, the male sexually dimorphic center is larger

66
Q

In females, estrogen will induce estrous behavior. What can cause stronger estrous behavior?

A

-Progesterone priming followd by estrogen treatment

67
Q

What does castration do to sexual behavior in the male?

A

Decreases sexual behavior

68
Q

Why do males show constant sexual behaviors while females do only during estrus?

A
  • 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
Q

What are the four primary sensory inputs for reproductive behavior?

A
  1. Olfaction
  2. Vision
  3. Audition
  4. Tactility
70
Q

How do female pheromones impact males?

A
  • Estrous females smell different than non-estrous females
  • This difference can be detected by other females
  • Action of pheromones is species specific
71
Q

How do male pheromones impact females? What is an example specific to boars?

A
  • 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
Q

Detection of less volatile pheromones is accomplished by the ____ _____ in the male.

A

-Vomeronasal organ

73
Q

Describe the vomeronasal organ and its function.

A
  • 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
Q

Auditory signaling is valuable for what kind of signaling? Visual signaling is valuable what kind of signaling?

A
  • Auditory: Signaling from a distance

- Visual: Close-Range Signaling

75
Q

_____ is the final stimulus before copulation. Give some examples.

A
  • Tactile
  • Biting the neck of mares and queens
  • Chin resting by the bull on the back of the cow
76
Q

Erection requires that blood be trapped within the _____ sinuses of the penis.

A

Cavernous

77
Q

In response to sexual arousal, an erection results from _____ blood flow to the penis due to ____ of the arteioles supplying it and ____ venous outflow.

A
  • Increased
  • Vasodilation
  • Restrticted
78
Q

An erection is the _____ of erectile tissue and elevated ____ _____ ____.

A
  • Engorgement

- Intra penile pressure

79
Q

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.

A
  • Retractor penis
  • Ischiocavernosus
  • Bulbospongiosus
80
Q

How does viagra work?

A
  • It inhibits phosphodiestrase (PDE2) so that cGMP is not converted to GMP, which causes smooth muscles to relax
  • This sustains an erection
81
Q

Pre-ejaculation is what kind of reflex? Ejaculation is what kind of reflex?

A
  • Neuro-endocrine

- Simple

82
Q

What is a unique reproductive behavior to the dog?

A
  • 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
Q

What is the cervix’s function in sperm transport?

A
  • Filters defective and immotile spermatozoa

- Cervical mucous flushes foreign material introduced during copulation

84
Q

True or False: Dead sperm can be transported in the female reproductive tract.

A

True, but they are not transported as well

85
Q

In the ______, initiation of capacitation occurs. What is this?

A
  • Uterus

- Capacitaiton is the removal of seminal plasma coatings so that they can fertilize

86
Q

What three things occur to sperm in the oviduct?

A
  1. Capacitation Complete
  2. Some sperm attach to the oviductal epithelium to prolong viability
  3. Sperm become hyperactive
87
Q

What are the three parts of fertilization for sperm?

A
  1. Acrosome reaction
  2. Sperm penetrate zona pellucida and vitelline membrane
  3. Male and female pronuclei form
88
Q

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.

A
  • Capacitation

- Decapacitation

89
Q

_____ is the fusion of male and female gametes.

A

Fertilization

90
Q

Sperm become hyperactive in the _____ of the oviduct. Oviductal _____ are involved in hyperactivation. What is hyperactivation?

A
  • Ampulla
  • Secretions
  • A change in the movement of sperm from a straight line to more sporadic
91
Q

Hyperactivation helps sperm do what?

A
  • Break away from the oviductal epithelium
  • Penetrate the zona pellucida more effectively
  • Help sperm find the oocyte
92
Q

Penetration of the zona pellucida involves the binding of sperm to _____ receptors in the zona.

A

-ZP2

93
Q

Binding of sperm to ZP2 in the zona pellucida triggers what?

A

The acrosome reaction

94
Q

What is the purpose of the acrosome reaction?

A
  • 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
Q

In fertilization, a protein in the _____ ____ of sperm fuses with a protein in the ____ _____ of the oocyte. What are the names of these proteins?

A
  • Equatorial segment
  • Vitelline membrane
  • Izumo 1 in the equatorial segment fuses with Juno in the vitelline membrane
96
Q

The fusing of izumo 1 in the equatorial segment of sperm to Juno in the vitelline membrane stimulates what three things?

A
  1. Resumption of the second meiotic division
  2. Zona reaction
  3. Vitelline Block
97
Q

Describe the zona reaction.

A

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
Q

Describe two methods used to make sure only one sperm fertilizes the oocyte.

A
  1. Vitelline Block

2. Zona Reaction

99
Q

What is polyspermy?

A

The deadly fertilization of an oocyte with more than one sperm

100
Q

Describe the vitelline block.

A

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
Q

_____ formation involves swelling an development of male and female nuclear membranes.

A

Pronucleus

102
Q

In _____, male and female pronuclei come into contact. Nuclear membranes disappear and chromosomes unite to form a ______. Lastly, _____ begins and fertilization is complete.

A
  • Syngamy
  • Zygote
  • Mitosis
103
Q

The diploid cell that results from fusion of the male and female pronuclei

A

Zygote

104
Q

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.

A

Embryo

105
Q

The products of conception, which include embryonic and extra-embryonic components

A

Conceptus

106
Q

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.

A

Fetus

107
Q

What are the 8 stages of embryonic development?

A
  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
Q

______ _____ 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

A

Maternal Recognition of Pregnancy

109
Q

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?

A
  • 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
Q

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?

A
  • Identity: Interferon-T
  • Target Tissue: Endometrium
  • Mechanism of Action: Decrease in prostaglandin production from the endometrium
111
Q

In all domestic farm species, there is a substance secreted by the embryo that prevents what in order to maintain the pregnancy?

A

-Luteolytic action of PGF2a

112
Q

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?

A
  • 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
Q

What is the maternal recognition of pregnancy signal in mares?

A

-Unknown, but speculated that the constant movement of the conceptus throughout the uterus is important

114
Q

True or False: The equine conceptus produces interferon-like molecules with anti-PGF2 release properties

A

False

115
Q

Why do dogs not need a maternal recognition of pregnancy factor?

A

-The luteal phase is the same in pregnant and non-pregnant females

116
Q

Why is the maternal recognition of pregnancy factor important for cats?

A

-If they have a non-fertile mating, the result will be a pseudopregnancy with shorter CL function

117
Q

What is the CL function like for sheep throughout pregnancy?

A
  • Present throughout

- Can be removed after day 50 because placenta will make enough progesterone

118
Q

What is the CL function like for cattle throughout pregnancy?

A
  • Present throughout

- Can be removed after day 200, but live calf will be born prematurely

119
Q

What is CL function like for pigs throughout pregnancy?

A

-CL is present and necessary throughout

120
Q

What is CL function like for mares throughout pregnancy?

A
  • 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
Q

What happens to progesterone and estrogen prior to parturition and why?

A
  • Drop in progesterone since it inhibits uterine contraction
  • Rise in estrogen to promote uterine contractions
122
Q

True or False: eCG is responsible for the initial phase of maternal recognition of pregnancy in the mare

A

False, it is secreted after the initial rescue of the CL

123
Q

What is the role of eCG in mares?

A

-Stimulates ovulations and development of accessory CL to increase progesterone

124
Q

_____ are a range of steroids in the placenta in mares that includes progesterone and maintains the pregnancy after ovarian progesterone diminishes.

A

Pregnanes

125
Q

How and why does the fetus signal for parturition?

A
  • Uterine crowing leads to increased fetal adrenal corticotropic hormone (ACTH)
  • ACTH causes increased cortisol production form the fetal adrenal gland, which initiates parturition
126
Q

During parturition, there is ______ PGF2a. What does this do?

A
  • Increased

- Luteat regression and enhanced uterine contractility

127
Q

During parturition, there is _____ progesterone. What does this do?

A
  • Decreased

- Removes the progesterone block

128
Q

During parturition, there is _____ estrogen. What does this do?

A
  • Increased

- Enhances uterine contractility and relaxes the cervix and pelvic ligaments

129
Q

During parturition, there is ____ relaxin. What does this do?

A
  • Increased

- Relaxation of the cervix and pelvic ligaments

130
Q

During parturition, there is _____ oxytocin. What does this do?

A
  • Increased

- Stimulates the final myometrial contractions and generates maximum pressure

131
Q

The ____ is an organ that unites fetal and maternal tissues for physiological exchange.

A

Placenta

132
Q

What are the three functions of the placenta?

A
  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
Q

What is the general structure of placentas?

A
  • 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
Q

Describe the diffuse placenta. What species have this?

A
  • Villi distributed over the entire chorionic surface

- Pig and horse

135
Q

Describe the zonary placenta. What species have this?

A
  • Villi are distributed in a band-like zone that circles the placental unit
  • Dog and Cat
136
Q

Describe the discoid placenta. What species have this?

A
  • Villie are distributed in a single disc-shape pattern

- Primates, rodents

137
Q

In the cotyledonary placenta, fetal _____ are localizes tufts of chorionic villi that fuse with maternal ______, which are rounded projections of the endometrium.

A
  • Cotyledons

- Caruncles

138
Q

The _____ is the name for the fused cotyledon-caruncle.

A

Placentome

139
Q

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.

A
  • Maternal

- Fetal

140
Q

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.

A
  • Epithelial
  • chorionic
  • 6
141
Q

Which placental barrier is the least intimate type?

A

Epitheliochorial

142
Q

In the _____ placental barrier, the endothelial lining of the endometrial blood vessels contacts epithelial cells of the chorionic membrane of the fetus.

A

-Endotheliochorial

143
Q

What species have the epitheliochorial placental barrier?

A

-Cow, horse, pig, sheep

144
Q

What species have the endothelial placental barrier?

A

-Cat and dog

145
Q

In the endothelial placental barrier, there are ____ layers between the maternal and fetal blood

A

4

146
Q

The human, monkey, rat, and mouse have the _____ type placental barrier

A

Hemochorial

147
Q

Describe the hemochorial placental barrier. How many layers are there between the maternal and fetal blood?

A
  • Blood of the mother bathes the epithelial cells of the chorionic membrane of the fetus.
  • Three
148
Q

The _____ placental barrier is the most intimate.

A

Hemochorial

149
Q

Describe the gonadotropins released by the placenta in humans, monkeys, and mares.

A
  • 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
Q

Describe the lactogens released by the placenta in humans, sheep, and rats.

A
  • Humans: Human chorionic somatomammotropin which is a growth hormone
  • Sheep and Rats: Placental lactogen
151
Q

What steroids are produced by the placenta in some species?

A

-Estrogen and progesterone

152
Q

What three hormones can be produced by the placenta?

A
  1. Gonadotropins
  2. Lactogens
  3. Steroids

Reproductive Physiology (3 decks)

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