ANS 220 Exam 2

Fetus

What does the inner cell mass in an embryo become?

placenta

What does the trophoblast in a embryo become?

glycoprotein

What type of hormone is Human Chorionic Gonadotropin (hCG)?

primates

What species is human Chorionic Gonadotropin found in?

the placenta

Majority of the embryonic hormones are produced by…

the gonads

What does hCG and eCG stimulate?

in the trophoblastic cells of the blastocyst (placenta)

Where is the human chorionic gonadotropin hormone produced?

Human chorionic gonadotropin

What hormone does pregnancy tests test for in urine?

Stimulates P4 production from CL

Indirectly blocks luteolysis

Causes ovulation in non-primate females

Increases fetal growth

What are the roles of human chorionic gonadotropin?

as early as 8 days of gestation

How early can human chorionic gonadotropin be detected?

Pregnant Mare’s Serum Gonadotropin (PMSG)

What is another name for Equine Chorionic Gonadotropin (eCG)?

glycoprotein

What type of hormone is equine chorionic gonadotropin?

endometrial cups of the placenta

What produces eCG?

chorionic girdle

What specific cell produces eCG?

formation of CLs which increase P4 production

indirectly blocks luteolysis

==acts like FSH in other species==

What are the function of eCG?

no (maternal recognition in mares is shown on day 14-16, which is before the peak of eCG)

Is eCG the signal of maternal pregnancy?

35 days

What day does eCG peak at?

Glycoprotein

What type of hormone is Interferon Tau (IFNT)?

Only ruminants

What type of animals is INFT found in?

trophoblastic cells of the blastocyte

What produces IFNT?

inhibits oxytocin receptors in the endometrium (blocks smooth muscle contractions)

prevents PGF2a synthesis (allows for the survival of CL and decreases P4)

==Promotes protein production to nourish concepts (embryo)==

\

What is the functions of IFNT?

LH and FSH would increase

==ovulation/rupture of the follicle would occur==

What would happen if you increase GnRH levels?

No changes to GnRH levels since GnRH is released from the anterior pituitary and not the posterior pituitary like oxytocin

What would happen if you give a single injection of oxytocin?

GnRH levels would increase, which would cause LH levels to increase

The follicle on the ovary could also rupture

What would happen if you gave a single injection of estrogen?

LH, FSH, and testosterone levels would decrease, and GnRH levels would increase

What would happen if you disconnect the hypothalamic portal system?

There would be an increase in LH because of the decrease in testosterone

What would happen to hormones if you castrate bulls at birth?

there would be an increase in LH levels because of a decrease in estrogen

What would happen to hormones in a postmenopausal female?

GnRH, LH, and FSH would decrease, and testes would shrink because of feedback to the hypothalamus

What would happen to hormones if there was continuous testosterone injections?

GnRH and LH levels would decrease and ==ovulation would be blocked==

What would happen to hormones if progestin supplement is given?

GnRH and LH would increase and P4 would decrease, which would lead to the loss of pregnancy

What would happen to hormones if PGF2a is given?

Would cause masculinity in females and a reduction in sperm production

What would happen to hormones if an aromatase inhibitor was given?

No progesterone would be produced and there would be a reduction in pregnancies

What would happen to hormones if a 3-b HSD inhibitor was given?

ectoderm, mesoderm , and endoderm

What are the three layers of the reproductive tract?

ectoderm

What is the outermost layer of the repro tract?

mesoderm

What is the muscular layer of the repro tract?

endoderm

What is the innermost layer of the repro tract?

hypothalamus, nervous system, skin, hair

What does the ectoderm consists of?

muscle, skeletal, cardiovascular, and reproductive system

What does the mesoderm consists of?

digestive system, lungs, endocrine system

What does the endoderm consists of?

1. The oral portion of the mouth starts to reach for the infundibulum

2. Infundibulum and Rathke’s pouch touch

3. Stalk of Rathke’s pouch regresses

4. Rathke’s pouch wraps around the posterior pituitary

5. Bone encloses the anterior pituitary

How is the anterior and posterior sections of the pituitary developed?

infundibulum

What turns into the posterior pituitary?

Rathke’s pouch

What turns into the anterior pituitary?

there would be no growth hormones or gonadotropins

What would happen if you cut out Rathke’s pouch?

somatic cells and germ cells

What are the two cell types?

all cells in the body except germ cells

autosomes

sex chromosomes

What are somatic cells?

mitosis

Do somatic cells undergo mitosis or meiosis?

diploid

Are somatic cells diploid or halploid?

60

How many chromosomes do cattle have?

64

How many chromosomes do horses have?

38

How many chromosomes do swine have?

46

How many chromosomes do humans have?

56

How many chromosomes do sheep have?

==oogonia and spermatogonia== formed from primordial germ cells

What are germ cells?

haploid

Are germ cells diploid or halploid?

both

Do germ cells undergo mitosis or meiosis?

produces two identical daughter cells

only 1 phase

Overview of mitosis…

2 phases

only in germ cells

Meiosis 1: exchange or alteration of genetic material between homologous chromosomes

Meiosis 2: just like mitosis

Overview of meiosis…

epithelial lining of the gut

What cells have a high rate of mitosis?

brain cells

What cells have a low rate of mitosis?

Germ Cell Migration (Know the labels)

nutrient source of fetus

origin of the primordial germ cells

What is the purpose of the yolk sac?

waste holder

What is the purpose of the allantois?

where the primary sex cords are formed

What is the purpose of the gonadal ridge?

Duct that will become kindey

What is the nephros?

1. germ cells start at the yolk sac

2. They migrate through or pass the hindgut

3. they enter the gonadal ridge and start to undergo mitosis

4. primordial germ cells are sealed off by the tunica albuginea forming an indifferent gonad

What is the germ cell migration?

neither a female or a male (sex determination has not been determined)

What is an indifferent gonad?

mesonephros or wolfian duct

What are the names for the male duct?

Paramesonephros or Mullerian duct

What are the names for the female duct?

You get a female adult

What happens if you remove the ovaries from a female fetus?

You get a female adult

What happens if you remove the testes from a male fetus?

SRY (sex determining region)

What is the determining factor of a Y chromosome?

==synthesized by developing sex cords==

causes differentiation of sertoli cells

What is testis determining factor?

==anti-mullerian hormone== and testosterone

What do male Sertoli cells produce?

rete testes

==efferent ducts==

epididymis

==vas deferens==

What does the mesonephros duct form?

Yes

Does the mesonephros contain AMH and androgens?

No

Does the paramesonephros contain AMH and androgens?

male tract

Which tract develops first?

a hormone that causes regression of the mullerian tract

What is anti-mullerian hormone (AMH)?

==oviducts==

==uterus==

==anterior vagina==

What does the paramesonephros tract form?

rete testis (ADD FUNCTIONS)

efferent duct

epididymis

vas deferens

seminiferous tubules

tunica albuginea

Wolfian tract development (know the labels)

infundibulum (ADD FUNCTIONS)

primordial follicles

ovarian medulla

future oviduct and uterus

Mullerian tract development (Know the labels)

it regresses

What happens to the mullerian duct in the wolfian duct formation?

it regresses

What happens to the wolfian duct in the mullerian duct formation?

==primary proliferation in the medullary region==

==Primordial germ cells in the medulla is lost==

What happens in ovary development?

Secondary proliferation only occurs in the inner hollow of the cortex

Why is there a fixed number of cells in the ovary?

1. Female egg cells contain an X chromosome

2. Half of the male’s sperm cells have an X chromosome and half of them have a Y chromosome

3. An egg cell fertilized by a sperm cell containing a Y chromosome develops into a boy

4. An egg cell fertilized by a sperm cell containing an X chromosome develops into a girl

How is sex determined?

ectoderm

What does external genitalia developed from?

sex hormones

What is external genitalia regulated by?

External Genitalia (picture)

==growth rates==

==body size==

==muscle vs adipose (fat storage)==

==hair growth==

What are some sexual dimorphisms?

Can cause behavioral changes (masculine vs. feminine)

Steroids can impact (high stress can increase cortisol which can increase masculinity)

intrauterine environment (male fetus in between two females will see more estrogen and vise versa)

How does sex influence the brain?

estrogen

What does alpha-fetoprotein bind to?

estrogen would be able to enter the hypothalamus and knock out the surge center

What would happen if there was a lack of alpha-fetoprotein in a female brain?

1. the gonads release testosterone and it travels to the hypothalamus

2. testosterone is lipophilic and can transport through the cell membrane

3. testosterone is converted to estrogen due to an increase in aromatase

4. Estrogen regresses surge center

What is the process to knock out the surge center in males?

1. the gonads release estrogen and it travels to the hypothalamus

2. estrogen binds to alpha-fetoprotein which causes them to be rejected from passing through the blood brain barrier

   1. Both the surge center and the tonic center can develop

What is the process for the tonic and surge center in the female?

in both males and females

Where is alpha-fetoprotein present?

since males do not have a surge center, there is more room for development of the pre-optic area

Why is there an increase of the pre-optic area in males only?

freemartins

true hermaphrodite

pseudo-hermaphrodite

What are the three types of intersexuality?

only cattle

What animal can be a freemartin?

some fish

What animals can be a true hermaphrodite?