ANIMAL REPRO EXAM 1

Whar are the primary function of the ovaries

to produce female gametes and the hormones estrogen and progestrone

What are the primary structures of the ovaries

- ovarian cortex (outer layer)

- oocytes/follicles (except horses)

- corpus luteum

- ovarian medulla (centeral layer)

What are the functions of the oviduct

- transport newly ovulated oocytes and spermatozoa to the site of fertilization

- ova and sperm move in opposite directions

- after fertilization, the zygote remains here for several days

What are the three parts of the oviduct and their functions

1. Infundibulum

- finger-like projections called fimbriae that are used to give it that "catcher's mitt" ability to catch the oocytes

2. Ampulla

- makes up 1/2 or more of the length of the oviduct and is the site of fertilization for most species

3. Isthmus

- It is smaller in diameter compared to the ampulla and connects to the uterine horn. The ampulla-isthmic junction only allows fertilized oocytes to pass into the isthmic

Definition of a uterus

It is the organ of pregnancy and connects the oviducts to the cervix.

What are the functions of the uterus

- transport sperm

- luteolysis and control cyclicity

- an environment for the embryo

- maternal contribution to the placenta

- expulsion of the fetus and placenta

Definition of a cervix

A thick-walled, non-compliant organ that serves as a sperm barrier (in ewes and cows, not in sows and mares). Isolates uterus from external environment during pregnancy with a viscous mucus

Definition of a vagina

Copulatory organ and birth canal

What are the 4 concentric layers (from outer most to inner most)

1. Serosa

2. Muscularis

3. submucosa

4. mucosa

Definition of the serosa layer

outer most coatingmade up of squamous cells

Definition of the muscularis layer

Double layer of smooth muscle (outer longitudinal layer and inner circular layer). This smooth muscle layer is also known as the myometrium

- gives the tract the ability to contract and relax

- transport spermatozoa

- fetal expulsion

Definition of the submucosa layer

Houses blood vessels, nerves, and lymphatics

Definition of the mucosa layer

- secretory layer of epithelium

- each part of the tract is lined with a different type of mucosal epithelium

What makes up the endometrium

The submucosa and mucosa of the uterus

- it's responsible for secreting materials into the lumen of the uterus to enhance embryo development and sperm viability

Definition of the broad ligament

a double-layered sheet of peritoneum that supports and suspends the ovaries, oviduct, uterus, cervix, and anterior vagina; houses vascular supply, lymphatic drainage and nerves for the reproductive organs

What are the three components of the broad ligament

- mesovarium: supports the ovary

- mesosalpinx: supports the oviduct

- mesometrium (largest): supports the uterine horns

What is the differences in the mares ovaries

- Ovaries are "inside-out" compared to other farm species: the ovarian medulla and cortex are reversed in location

- Ovulation occurs only in one place on the ovary

- Corpus luteum are neither visiable nor palpable

definition of folliculogenesis

the process by which immature follicles develop into more mature follicles and eventually become candidates for ovulation

What are the four types of follicles

1. primordial follicles

- smallest with a single layer of squamous cells

2. primary follicles

- has a single layer of cuboidal cells

3. secondary follicles

- has 2+ layers of cuboidal cells, beginning to form a fluid-filled antrum

4. antral follicle (aka tertiary follicle)

- fluid-filled antrum comprises >50% of volume

What are the 3 layers of the antral follicle

1. Theca Externa

- maintains the structure of the follicles

2. Theca Interna

- contains LH receptors

3. Granulosa Cells

- contains FSH receptors

How is Estrodial (E2) produced

1. The hypothalamus releases GnRH that tells the anterior pituitary gland to release LH and FSH

2. LH binds to receptors on theca interna, which triggers the production of converting cholesterol to testosterone

3. Testosterone then diffuses into the granulosa cells

4. Simultaneously, FSH binds to receptors on the granulosa cells, which triggers the synthesis of enzymes that convert testosterone into estradiol

5. Estradiol then enters the systemic circulation, causing an effect on the brain and reproductive organs

What are the different endometrial surfaces in ruminants vs. sow/mares

Ruminants: have small non-glandular areas that protrude from the surface called caruncles. This gives rise to the maternal portion of the placenta

Sows/Mares: they don't have caruncles and instead have endometrial folds, which will provide the uterine surface for placenta attachment

What are the 3 types of classifications of the uterus and what species are associated with each one

1. Duplex (rabbits, marsupials)

- 2 cervical canals that seperate each uterine horn into distinct compartments

2. Bicornuate (cow, mare, sow)

- 2 uterine horns and a small uterine body

3. Simplex (primates)

- large single uterine body with small rudimentary uterine horns

What are the differences in bicornuate uteruses depending on the species

Sows/Ewes: have longer horns due to having liters

Mares: have shorter horns and a larger body

Cows: have shorter horns and a smaller body

What are the external genetalia

the vulva and the clitoris

What are the three things the male reproductive system produces

spermatozoa, hormones (testosterone and estradiol), and proteins/fluids

What are the two primary functions of the male reproductive system

1. formation of sperm

2. deposition of sperm into the female reproductive tract

What are the major components of the male reproductive tract

testis, epididymis, scrotum, spermatic cord, excurrent duct system, accessory glands (vesicular glands, prostate gland, bulbourethral glands), prepuce/sheath, penis and muscles for protusion

What is the definition of the spermatic cord

it suspends the testes in the scrotum, provides a pathway for blood, lymph and nervous tissue and acts as a heat exchanger

What are the 3 components of the spermatic cord and what are their functions if any

1. cremaster muscle

- The primary muscle supporting the testes and its contraction/relaxation facilitates blood flow and heat exchange

2. ductus deferens

3. pampiniform plexus

- a complex vasculature created by the entwinement of the testicular artery and vein, and it is important for temperature control and hormone diffusion

Why is tempreture control so important

Spermatogenesis stops when the temperature of the testes reaches or exceeds normal body temperature

What is cryptorchid

It happens in livestock when the testis doesn't descend properly. This causes limited to no sperm production as well as small levels of testosterone that can affect the animals phenotypically.

Define scrotum

It's a two-lobed sac that encloses the testes, regulates temperature, and consists of four layers

What are the 4 layers of the scrotum and their characteristics

1. Skin:

- has many sebaceous and sweat glands for evaporative cooling and thermosensitive nerves, which control sweating and respiration rate

2. Tunica dartos:

- A smooth muscle layer beneath the skin helps control temperature by adjusting the distance of the testes from the body. As it relaxes, the scrotal surface area increases, allowing for greater heat exchange

3. Scrotal fascia

- loose connective tissue that allows the testis to move freely within the scrotum

4. Parietal vaginal tunic

- innermost layer of the scrotum/lines the scrotum

How do the testes develop

The Y y-chromosome codes for the production of testis-determining factor (TDF), which is what determines male development pathways

What is the process of testicular descent

- Testes form inside the body cavity

- They descend through the inguinal canals into the scrotum during gestation or shortly after

- Ligamentous gubernaculum attaches the testes to the peritoneum, and as the fetus grows, the testes are pulled through the inguinal canals into the scrotum

- chance of bilateral or unilaterial crptorchid during this process

What is the superficial anatomy of the testes

a capsule made of visceral vaginal tunic (a very thin layer on the outside) and tunica albuginea (the inside layer)

What are the 5 funcational anatomy parts of the testes

1. parenchyma

-structure support

2. seminiferous tubules

- takes up the most space in the testes, it is where sperm is developed, and contains nurse and germ cells

3. seminiferous epithelium

- made up of two regions (aluminas compartment and basal compartment)

4. rete testis

- a network of tubules that recieves spermatozoa from the seminiferous tubules and transports them out of the testis

5. efferent duct

- converges into a single duct called the epididymal duct

What seperates the two major compartments of the seminiferous epithelieum

They are separated by tight junctions between Sertoli cells, and these junctions form the blood-testis barrier that protects developing sperm from the immune system.

Where does spermatozoa mature, and where is it stored

They mature as they move through the head, body, and tail of the epididymis, and are stored in the tail of the epididymis

What are the different accessory glands

1. prostate gland

- produces semen and compounds to protect sperm for the acidity of the female repro tract

2. bulbourethral glands

- produce a viscous secretion that forms a coagulate following ejaculation

3. vesicular glands

- contributes large proportion of ejaculate secretion volume

How does the penis vary between species

The penis is composed of three parts: the base, shaft, glans, and sigmoid flexure. The glans and sigmoid flexure are where it differs between species.

What is the embryogenesis

a coordinated series of events involving the merging of several types of tissues that will ultimately form complete reproductive glands and organs

What is differentiation

The process whereby a group of unspecialized cells develops into recognizable groups of cells that have a common function

What and where do the anterior and posterior lobes originate from

They originate from two different tissue types one being neural and the other being epithelial and the anterior lobe originates from the roof of the mouth and the posterior lobe originates from the brain

What determines whether the embryonic gonad develops into testes or ovaries

The chromosomal makeup of the cells of the genital ridge and the development of the male repro tract requires the sex determining gene on the Y chromosome

What do the nerves of the posterior pituitary gland cause

It causes a rapid release of oxytocin that causes milk ejection by mammary glands

What do glandular epithelial cells in the anterior pituitary gland do

They secrete glycoproteins like LH and FSH that are not secreted by nerve cells

What roles do the X or Y chromosomes of the sperm play in sex determination

The Y chromosome contains a gene called the sex determing region that produces SRY, which is a substance that controls the pathway towards either male or female development. SRY initiates male development.

What is freemartinism

When a heifer is born twin to a bull and it causes the heifer to be sterile while the bull remains fertile. This is because they share a common blood supply and are exposed to the same hormonal environment.