ANSC 333 Test 1

Major functions of male reproductive tract?

produce sperm, produce hormones, and deliver sperm

Testes

Site of Sperm production

Pampiniform Plexus

Help testes stay cool. It is a network of small blood vessels and arteries. Acts as a heat exchanger and blood from the vein cools the blood in the artery that goes towards the testes

Ductus/Vas deferens

Delivers sperm from from epididimus to ejaculatory position

Testicular artery

provides blood and nutrients to testes from heart.

Cremaster Muscle

Striated muscle that move the testes up and down. Used for short term contraction to prevent injury to testes during copulation and regulate scrotal temperature. Located in spermatic cord. Fight or flight

Dartos Muscle

Smooth muscle that moves testes up and down. Used for long term contraction usually relating to weather. Located in sctrotum

Vaginal Tunic

Allows for movement of the testes inside the scrotum. Developed in the fetus when the testes descend from the abdomen

What are the male accessory sex glands

ampulla, vesicular glands, bulbourethral gland, and prostate

Ampulla

Acts as a storage chamber for sperm and contains secretions that help to nourish the sperm. Located within the vas deferens

Vesicular Glands

These secrete fluids that form the bulk of ejaculatory fluid

Bulbourethral Gland

Secretes a fluid that neutralizes the acidity of the vaginal canal

Prostate

Prostate secretions help to promote motility of the sperm

Rete testis

network of small tubes in the testicle that helps move sperm cells (male reproductive cells) from the testicle to the epididymis.

Epididymus

Tube that connects testes to the vas deferens. Tail, body, and head

Where is mature sperm stored

Tail of the epididymis

What are the two types of penises

vascular and fibro-elastic

What makes a ram penis unique

It has a filiform appendage. This is necessary because the ram has low semen volume and so the appendage 'sprays' semen at the cervix

Sigmoid flexure

Straightens to cause erection

Vascular penis

A penis type that extends in length and grows in volume (Stallion & male)

Fibro-elastic penis

A penis type that only extends in length (ram, boar, bull)

Inguinal ring

In fetal testicular development, the testes begin in the abdomen, but pass through the inguinal ring to get to their proper position. The ring then closes

What happens if the ring fail to close correctly?

Scrotal hernia

What is it called when one or both of the testes fail to descend?

Cryptorchid

Testicular Perinchyma

Sperm producing tissue found in the testes.

Mediastinum

White connective tissue in testes that surrounds the rete testis

What structures are found in the spermatic cord?

Cremaster muscle, Pampiniform plexus, vas deferens, spermatic fascia, and vaginal cavity

Thermoregulation of pampiniform plexus

Single testicular artery wrapped in extensively branched veins. PP is a system that trasnports heat. Essentially cools blood from artery before it reaches testes
Exchange of heat between artery and veins.

Thermoregulation of Dartos muscle

Smooth muscle that contracts long term in response to weather

Thermoregulation of respiration

Controlled by thermosensitive neurons that are located in scrotal skin. Neurons send signals to repsiratory center in brain which causes panting.
The harder we breathe, the more heat we expel

Thermoregulation of sweating

Evaporative cooling helps to cool testes.

Blood-testis barrier

Filters some things from blood into testes. Keeps immune cells from killing sperm. Made of peritubular myoid cells. Basically "offensive lineman"

Tight junctions

Protein barriers in between spermatocyte cells. Illnesses can disrupt this barrier and cause infertility

Why are spermatagonium on the opposite side of the blood testes barrier?

Spermatagonium are on the opposite side of this barrier because they have not undergone meisosis yet and aren't targeted by immune cells

Sertoli Cells

Support spermatogenesis by producing protein

Leydig Cells

Produce testosterone

What does castration remove?

Leydig cells

Structures that make up the basis of all female reproductive structures besides the ovary?

All structures have a central lumen surrounded by mucosal cells. Outside of mucosal cells is a sub-mucosal layer which contains stromal cells and vascular structures. These structures are surrounded by a layer of circular smooth muscle and longitudinal smooth muscle. These muscles have a primary role in contraction. Not only expelling fetus, but also work to bring sperm deeper into repro tract and referred to as the muscularis

Broad Ligament

Suspends the major organs of the repro tract. There are 3 components

Mesovarium

Part of broad ligament that supports the ovary

Mesometrium

Part of broad ligament that supports the uterus

Mesosalphynx

Part of broad ligament that supports the oviduct

Ovary

Female gonad. Made of medulla and cortex

Medulla

Center of ovary and contains blood and lymphatic vessels and nerves

Cortex

Surrounds medulla (Except mare. In mare: Medulla is outside, cortex is inside). Site of follicle growth

Follicle

Grows and supports the oocyte and its maturation and prepares it for fertilization

What produces estrogen?

Follicles produce estrogen and bigger follicles produce more estrogen

Primordial Follicle

Made of oocyte and single layer of cells surround it.
These cells are not organized.

Primary follicles

Single layer of cells surrounding the oocyte becomes polarized

Secondary follicles

Additional layers of cells surrounding oocyte

Zona Pallucida

Shell that develops on the secondary follicle

Developing antral (tertiary) follicle

Oocyte devlops an antrum (fluid filled cavity)

Dominant follicle

Large antrum filled with follicular fluid. When the animal is "in heat"

Parts of dominant follicle

Basement membrane
Granulosa
Theca Interna
Theca externa

Ovulating follicle

Release of oocyte from dominant follicle.
Will occur as female goes out of estrous.

Corpus Hemmorhagicum

Blood vessels that support follicle break during ovulation
Follicle looks like a large blood clot and cells are in transition

Corpus luteum

Produces progesterone (required for maintenance of pregnancy)

What happens in the CL if pregnancy does not occur?

If female is not pregnant this cycle,
luteolisys occurs. This kills the CL,
lowering progesterone levels and the
cycle repeats.

Corpus Albicans

White clump of dead scar tissue.
Does nothing, but acts as an indicator that
female has cycled recently.

Where does fertilization occur?

Ampulla/isthmus junction

What happens to the oocyte after ovulation?

It is released into the abdominal cavity

What are the three segments of the oviduct

Infindibulum, Ambulla, and Isthmus

Infindibulum

catches oocyte after it is released into abdomen. Has cillia that helps this process. Surrounds the ovary.

Ambulla

Has extensive mucosal branching and secretes of factors that are important to survival of early embryo.

Isthmus

Less mucosal branching and developed muscularis level. Contracts to move sperm up into the oviduct.
Helps to bring sperm closer to the oocyte.

How is the mare's ovidcut different from other species?

The mare has an underdeveloped ampulla because the medulla and cortex are switched. Gametes exit the ovary through the ovulation fossa

Early embryonic development

Early embryo develops in the oviduct for 4-5 days and then move to uterus.

Duplex Uterus

two cervices (rabbit & marsupials)

Simplex Uterus

No uterine horns, common uterine body (primates)

Bicornuate uterus

Most common. Two uterine horns, but one cervix and common uterine body.

Endometrium

Segment of uterus that encompasses the mucosal and submucosal regions

Myometrium

Segment of uterus that houses the circular and longitudinal muscles

Uterine Glands

Specialized mucosal cells that secrete factors that are required for early embryonic development. Spiral shaped

Caruncles

Only in ruminants, but form mother's portion of the placenta. Retained placenta is a risk in cows because of these caruncles

Breed differences in uterus

Sows have lots of uterine folds to increase surface area to allow for litters. mares have longitudinal folds to allow for large fetuses.

Where is prostoglandin F2alpha produced?

Endometrium

What does prostoglandin F2alpha do?

Cause destruction of corpus luteum

Functions of the cervix

Produce secretions for lubrication and serve as barrier to things getting into or out of uterus (preterm birth/abortion, bacteria)

Cow cervix

Anular ringed cervix

Ewe cervix

Cervix is wonky and they must be AI through laproscopy

Sow cervix

Spiral shaped cervix. Allows for long copulation time and large amounts of semen

Mare cervix

Cervix has longitudinal folds. Easy to AI, but allows for uterine infections

Where in vagina is site of semen definition and why?

The cranial vagina. Better environment for semen because there is no residual urine

Vulva

External female genitalia

Genetic sex

Genetic makeup that determines male vs female. Determined at fertilization. XX vs XY

Phenotypic sex

Visual characteristics. Determined later in gestation.

What does TDF cause?

It causes testes to develop

What happens if there is no TDF?

Ovaries develop

Anti-mullerian hormone (AMH)

Hormone in fetal development that causes leydig cells to form and the degeneration of the paramesonephric duct

Peramesonephric duct in females

This duct becomes the oviducts, uterus, cervix, and vagina in the fetus after no AMH is detected

Freemartin

Twin cattle share a blood supply. In cases of male/female twins, AMH is secreted by male calf and enters into shared blood supply. Female calf partially develops a teste rather than an ovary. The female will be sterile

Simple neural reflex

Stimulus activates a nerve ending that send signal to brain and brain activates another nerve to release neurotransmitters
on a target tissue that induce a response. Ex: Scrotal sweating

Neuroendocrine mode of action

Situation where nerve cell produces a hormone and the hormone travels through blood supply to act on a distant target. ex: calf nurses on teat and signals to hypothalamus and anterior pituitary to release oxytocin, which travels through blood, down to mammary gland, binds to receptor to cause muscles to contract which causes milk letdown.

Endocrine mode of action

Non nerve cell produces a hormone that travels through the blood and acts on a distant target. ex: Uterus makes prostoglandin f2alpha, leaves uterus through uterine vein, gets transported to ovarian artery through utero-ovarian plexus to act on corpus luteum.

Parocrine mode of action

Cell produces hormone and hormone leaves cell and then acts on a neighboring cell. No blood supply required ex: When the submucosa produces a hormone that acts on the mucosal layer.

Autocrine

Cell produces a hormone that acts on the cell itself.

Lactocrine

Stimulates mammary gland. Mother produces the hormone which travels through the milk and acts on the offspring which consumes the milk. ex: Relaxin is produced during parturition and helps to stimulate uterine gland growth in female neonates

What are the primary regions involved in regulation of reproduction

Hypothalamus and pituitary gland

What does the hypothalamus produce?

GNRH

Parts of the hypothalamus

Tonic and surge (females only)