Repro Phys. Exam one

What is the start of reproduction

development of the reproductive system in the embryo

Sequence of Reproduction

Development of system, growth to puberty (producing fertile gametes with reproductive behavior), Copulation, Fertilization, Development of pre attachment embryo, Conceptus attaches to uterus via placenta, Birth of fetus, first lactation

Copulation

process of introducing sperm into the female body

Conceptus

the total product of conception from fertilization until birth, including the embryo or fetus along with all associated extra embryonic structures like placenta and membranes

Placenta

a specialized organ that allows conceptus to grow and develop to term

At what point does the fetus turn into neonate

Once born

what must happen before another pregnancy

Reestablishing cyclicity

Cyclicity

Predictable and repeatable process of physical or behavioral changes like estrus, menstruation, etc. that allows for reproduction

Form & Function

the shape of something can give us insight on what it does

Types of Epithelial Tissue

Simple, Stratified, Columnar, Pseudostratified, Cuboidal

major structures of the reproductive tract (female)

ovaries, oviducts, uterus, cervix, vagina, external genitalia

What animals can/cannot be palpated and why?

Horses, cows, and camels can be palpated due to the form of their anatomy being larger while the rectum of an ewe, bitch, and queen is too small for human hand to be inserted

Palpation

Physical exam where Dr. uses. hands to feel. You can palpate the outer body but also in some species can palpate via rectum if anatomy allows

What is an ultrasonic examination of the reproductive tract used for

detect pregnancy, AI, detect abnormalities, monitor follicles to the time of ovulation, embryo transfer

Function of epithelial tissue

covers the outside of the body and lines the organs and cavities within the body

Form of epithelial tissue

cells are closely joined together to create a sheet like covering

Internal reproductive system

Ovaries, oviduct, uterus, cervix, vagina

What are the two primary reproductive functions of the ovaries in animals?

Producing and maturing female gametes (oocytes/ova) and synthesizing and secreting reproductive hormones (estrogen and progesterone).

Describe the basic internal structural zones (zonation) of most mammalian ovaries.

Cortex (Outer zone) contains the developing follicles and oocytes and the Medulla (Inner zone) contains the blood vessels, nerves, and lymphatics.

Compare and Contrast: Difference in zonation of ovaries in mares vs other species

in mares, the cortex is the inner zone containing the developing follicles and oocytes while the Medulla is the outer zone containing the blood vessels, nerves, and lymphatics. In other species the zones are switched

What are the primary hormones produced by the ovaries and their main functions?

Estrogen: Secreted by follicles; controls estrus (heat) behavior and secondary sex characteristics.

Progesterone: Secreted by the corpus luteum; responsible for maintaining pregnancy.

What type of epithelium is in the vagina, and why

Glycogen-rich stratified squamous epithelium provides friction protection and mechanical defense against wear and tear during copulation and parturition. It is glycogen-rich to provide nutrients and maintain the acidic environment to fight off illness.

What type of epithelium is in the uterus, and why

Simple columnar epithelium acts like a microscopic factory to secrete nutrients, while the heavy lifting (contractions) is done by the smooth muscle layer surrounding it.

What type of epithelium is in the oviduct, and why

simple columnar and pseudostratified for fertilization and transport of oocyte and fluid while also sometimes providing nutirents.

Compare and Contrast Ovaries

Bitch: oval and surface is rough and nodular

Sow: many follicles projected over entire surface, looks very lobule

Cow: ovaries small, but firm and irregular overall body

Mare: kidney bean shaped

What makes up the oviducts

ovary, uterine tubes, infundibulum, Fimbrae, and the uterine opening. Only difference between mammals is uterine tube size

What are the defining anatomical features and species examples of a Duplex uterus?

Horns: Two completely separate, prominent uterine horns.

Body: Entirely absent.

Cervix: Two distinct cervical canals (one dedicated to each horn).

Examples: Rabbits, rodents, and marsupials (e.g., opossums).

What are the defining anatomical features and species examples of a Bicornuate uterus?

Horns: Two well-developed horns that open into a shared chamber.

Body: Small to moderate in size.

Cervix: A single, shared cervical canal.

Examples: Sows (pigs), cows (cattle), ewes (sheep), mares (horses), and dogs.

How does the degree of embryonic fusion affect the uterine horns in different bicornuate species (Sow vs. Cow vs. Mare)?

• Sow (Pig): Very little fusion → Very long, winding horns to accommodate large litters.

• Cow (Cattle): Moderate fusion → Intermediate-length horns.

• Mare (Horse): High fusion → Short horns and a relatively large uterine body.

What are the defining anatomical features and species examples of a Simplex uterus?

Horns: Completely absent or reduced to tiny remnants where oviducts attach.

Body: A single, large, highly developed cavity.

Cervix: A single cervical canal.

Examples: Humans and other primates.

Where is the internal reproductive system located?

underneath the rectum

What is the internal reproductive system held by?

the broad ligament

What is the piece that separates the rectum from the internal reproductive system of a female?

rectogenital pouch

What is the chronological order of ovarian follicle maturation, from least mature to most mature?

1. Primordial follicle

2. Primary follicle

3. Secondary follicle

4. Antral (Tertiary) follicle

Compare the microscopic structure of a primordial follicle and a primary follicle.

Primordial Follicle: Oocyte surrounded by a single layer of squamous (flat) epithelial cells.

Primary Follicle: Oocyte surrounded by a single layer of cuboidal epithelial cells.

What are the defining structural features of a secondary follicle?

• Oocyte is now surrounded by multiple layers of cuboidal cells (granulosa cells).

• The zona pellucida (a protective glycoprotein shell around the oocyte) becomes clearly visible.

What are the key anatomical components of an Antral (Tertiary) follicle, and what is its reproductive significance?

It is the only follicle stage capable of ovulating

Oocyte & Zona Pellucida

Antrum: A fluid-filled cavity (follicular fluid).

Granulosa Cells: Inner cellular layers.

Basement Membrane: Separates granulosa from theca.

Theca Interna & Theca Externa: Outer cellular layers (theca interna produces androgens under LH stimulation).

Lordosis

instinctive reflex posture assumed by female mammals when they are sexually receptive

Define the myometrium of the uterus, including its tissue type and primary function.

The thick, middle muscular layer of the uterine wall. It contains smooth muscle, and its primary function is to contract powerfully to expel the fetus during parturition (birth) and to assist with sperm transport during mating.

Define the endometrium of the uterus, including its tissue type and primary function.

The highly vascular, innermost mucosal lining of the uterine wall. It contains Simple columnar epithelium (containing deep uterine glands), and its primary Function is to house and nourish the embryo

Give two primary examples of interdigitating structures in the female reproductive tract.

The Cervix (especially in Sows/Pigs): The cervix features interdigitating pads (prominences) that lock together tightly to seal the uterus from bacteria and lock the boar's corkscrew penis in place.

The Placenta: The maternal side (endometrium) and fetal side (chorion) interdigitate via villi to maximize surface area for nutrient and oxygen exchange.

Where does fertilization occur?

in the oviduct

What is a fibroelastic penis?

A penis type composed primarily of stiff fibroelastic connective tissue with minimal blood spaces (erectile tissue). It stays relatively rigid even when flaccid.

which major animal species have a fibroelastic penis?

Bulls (cattle), rams (sheep), and boars (pigs).

How does a fibroelastic penis differ from a vascular penis (like a stallion's or human's) during an erection?

A vascular Penis relies on a massive influx of blood to drastically increase both length and diameter, while a fibroelastic penis has very little blood engorgement; it hardly changes in diameter or length during erection.

How does an animal with a fibroelastic penis achieve an erection if the penis doesn't engorge with blood?

Via the sigmoid Flexure. In the flaccid state, the penis is held inside the body in an S-shaped curve called the sigmoid flexure.

Retractor Penis Muscle (RPM): This muscle stays contracted to hold the "S" shape.

Erection Mechanism: During arousal, the RPM relaxes, allowing the rigid penis to straighten out and extend (protrude) from the sheath.

List the five primary physiological functions of the uterus in animal reproduction.

1. Sperm transport (via contractions)

2. Embryo development (nutritional support via endometrium)

3. Implantation and Placentation

4. Signaling luteolysis (triggers the death of the corpus luteum)

5. Parturition (expulsion of the fetus via myometrium)

How does the uterus support sperm transport and early embryo development?

Sperm Transport: Myometrial smooth muscle contractions pump sperm upward toward the oviducts after mating.

Embryo Development: The endometrial lining and its uterine glands provide vital nutritional support ("uterine milk" or histotroph) to the early embryo before attachment.

Which specific uterine layer drives parturition, and what is its mechanism?

The myometrium (middle smooth muscle layer).

Mechanism: Under the influence of hormones like oxytocin, it generates powerful, coordinated muscular contractions to physically expel the fetus and fetal membranes during birth.

What type of cervical structure does a sow (pig) have, and how does it relate to the male anatomy?

Interdigitating prominences (cervical pads arranged in a zigzag/spiral pattern).

Mating Function: They tightly lock around the boar's corkscrew-shaped penis. This structural lock ensures high-pressure, high-volume ejaculation directly into the uterus without backflow.

What type of cervical structure do cows (cattle) and ewes (sheep) possess, and what is its clinical significance?

Multiple rigid, interlocking annular rings (cervical rings) that form a tight, winding pathway.

Significance: They form an exceptionally tight physical and mucous barrier to protect the uterus from bacteria. This winding path requires a specific "manipulation technique" when threading a rod during Artificial Insemination (AI).

What type of cervical structure does a mare (horse) have, and how does it change during estrus (heat)?

Continuous, highly vascular longitudinal folds running parallel down the canal.

During Estrus: Under estrogen, these folds become incredibly soft, relaxed, and engorged. They flatten out completely so the stallion's penis can press flush against the external cervix to ejaculate into the uterine body.

How does the cervix of a bitch (dog) or queen (cat) compare to that of livestock species?

A relatively short, smooth canal that typically features a single, simple circular ring projecting into the vagina.

Difference: Lacks the complex structural folds, rings, or prominent pads seen in pigs, cattle, or horses.

How does the caudal vaginal epithelium change from low estrogen to high estrogen?

Low Estrogen: The lining is thin and delicate (often low cuboidal or simple squamous cells).

High Estrogen (Estrus): The lining transforms into a thick, multi-layered stratified squamous epithelium. The top layers become packed with glycogen, preparing the tract physically and biochemically for copulation.

What is the fornix vagina, and what is its role in natural breeding for species like the cow and ewe?

The blind pouch or pocket formed where the cervix bulges into the cranial (anterior) vagina.

Role: It serves as the exact anatomical site where sperm is naturally deposited by the male during copulation in species like cattle and sheep.

Why does the fornix vagina have simple columnar epithelium, while the caudal vagina has stratified squamous?

The fornix is located deep inside the tract; the penis presses against or near it, but the heavy mechanical friction happens further back in the caudal vagina.

Mucus Production (The Main Job): Columnar cells are built like factories. They secrete large amounts of mucus during estrus to lubricate the tract, flush out bacteria, and create a favorable pathway for sperm to swim into the cervix.

How does the epithelium change as you move from the outside of the female tract inward toward the cervix?

Caudal Vagina: Stratified squamous epithelium (built for protection against friction).

Cranial Vagina / Fornix: Gradually transitions to simple columnar epithelium (built for secretion and lubrication).

Clitoris is developed from what type of tissue

the same tissue as glans penis because it also has nerve ending and erectile tissues

What are the four primary functional components of the male reproductive tract?

1. The testes

2. Duct system

3. Accessory Sex Glands

4. The penis

Function of testes

produce sperm and testosterone

what is the male duct system made of and what is its function

Epididymis, vas deferens, and urethra. Used to mature and transport sperm

What are the accessory sex glands in male repro and their functions?

Seminal vesicles, prostate, and bulbourethral glands. They produce seminal fluid

What is the glans penis function

it is a sensory organ that signals ejaculation

Differences in erection of fibroelastic vs musculovascular penis?

Fibroelastic has the relaxation of the retractor penis muscle, which allows for lengthening of the sigmoid flexure to extend penis out of the sheath while in a vascular penis arousal triggers arterial dialation forcing a rush of blood into the corpus cavernosum and spongiosum causing the penis to fgrow in length and diameter

Why are mares the easiest to inseminate?

The Mare has straight, soft longitudinal folds with NO obstructions. During estrus, these folds relax and flatten completely, acting like an open hallway straight into the uterus. Versus a cow who has rigid, interlocking annular rings that form a tight, winding maze that is difficult to thread

where does sperm travel from the testis

Sperm exits the testis and enters the head of the epididymis, travels down the body, and moves toward the tail.

Where is sperm stored?

The tail of the epididymis acts as the primary warehouse where mature sperm are stored prior to ejaculation.

What is the name of the S-shaped curve in a bull's penis?

The sigmoid flexure.

What muscle controls the sigmoid flexure?

The Retractor Penis Muscle. It keeps the penis retracted inside the sheath when contracted, and relaxes to let the sigmoid flexure straighten out during an erection.

List the three main accessory sex glands of a male

Seminal Vesicles (Vesicular glands)

Prostate

Bulbourethral gland

What are the three primary functions of the spermatic cord?

1. Suspension: Physically suspends the testis inside the scrotum.

2. Pathway: Houses and protects the blood vessels, nerves, lymphatics, and vas deferens.

3. Thermoregulation: Controls temperature regulation to keep testes cooler than core body temperature.

What major anatomical structures travel inside the spermatic cord?

• Testicular Artery: Brings warm blood from the abdomen.

• Pampiniform Plexus: A dense network of veins wrapped around the artery.

• Vas Deferens: The duct transporting sperm out toward the urethra.

• Cremaster Muscle: The muscular lining running along the cord.

• Nerves and Lymphatics: For sensation and fluid drainage.

What is the pampiniform plexus and why is it vital for sperm production?

It acts as a countercurrent heat exchanger. The cool blood leaving the testis via the veins absorbs heat from the warm blood entering via the artery. This cools the incoming arterial blood by several degrees before it hits the testis, protecting heat-sensitive sperm production.

What is the function of the cremaster muscle

inside the spermatic cord?

Provides short-term lifting of the testes. It contracts to pull the testes closer to the body during danger (flight-or-fight) or sudden cold shocks. It also creates a "pumping action" to help venous blood return back up to the abdomen.

What temp is the counter heat exchange at in the pampiniform plexus

39-34 degrees Celsius

What is the structural analogy, daily output, and primary environmental requirement for the testis?

• Analogy: The Factory.

• Daily Output: 1–25 \(\times 10^{9}\) sperm per day.

• Requirement: The "plant" must be air conditioned (requires thermoregulation to stay cool).

What is the analogy for the epididymis, its capacity, and its key biochemical functions?

• Analogy: The Finishing School.

• Capacity: 8–25 \(\times 10^{9}\) sperm.

• Key Functions:

  1. Fluid absorption

  2. Membrane changes

  3. Nuclear & flagellar stabilization

  4. Gaining motility and fertility

  5. Cytoplasmic droplet translocation (moving the droplet down the tail)

What is the analogy for the tail of the epididymis, its storage capacity, and its contraction trigger?

• Analogy: Warehouse and Delivery.

• Storage Capacity: 10–50 \(\times 10^{9}\) sperm (holds enough sperm for 5–10 ejaculates).

• Contraction Trigger: Undergoes smooth muscle contractions upon sexual stimulation to move sperm out.

where does sperm go immediately after leaving the tail of the epididymis warehouse?

It travels through the ductus deferens (vas deferens) toward the accessory sex glands and pelvic urethra.

What is the analogy for the accessory sex glands, and what three components do they contribute to semen?

• Analogy: Alterations & Packaging.

• Contributions:

  1. Metabolic substrates (energy/nutrients like fructose)

  2. Surface coatings

  3. Transport medium for the sperm fluid

What is the analogy for the penis, and what are its three sequential mechanical steps during mating?

• Analogy: The Delivery System.

• Mechanical Steps:

  1. Erection

  2. Protrusion

  3. Ejaculation

Which procedure is more invasive: castration or a vasectomy? Why?

Castration involves removing the entire testicle, cutting large blood vessels, and causing significant tissue trauma. A vasectomy only requires severing or blocking the tiny vas deferens tubes, leaving the rest of the anatomy intact.

What are the specific temperatures of the body core versus the testes?

Body/Core Temp is 39, while the testes target temperature is 34. They must be kept cooler for proper sperm production.

What happens when the thermal sensors in the scrotum detect heat stress?

Triggers panting and activates sweat glands to act like a "swamp cooler."

Role: Acts as a thermosensor and protective sac.

Compare the cooling/heat-dissipating functions of the tunica dartos and the cremaster muscle.

Tunica Dartos: Smooth muscle that drops the testes away from the warm body to dissipate heat, or pulls them back up when cold.

Cremaster Muscle: Holds the testes and physically massages the pampiniform plexus to assist vascular countercurrent heat exchange.

How does the pampiniform plexus function inside the spermatic cord?

Countercurrent heat exchange. Cool venous blood leaving the testis weaves around warm arterial blood coming from the body, pre-cooling it before it reaches the testicles.

How does sperm maturity change as it travels through the epididymis, and how long does it take?

The head (caput) has less mature sperm; sperm matures as it travels down to the tail. Takes approximately 9–14 days (species-specific).

Trace the step-by-step pathway of sperm movement out of the male tract.

• Testes (where sperm is made)

• Ductus Deferens (Vas Deferens)

• Urethral process of bladder

• Urethra

• Gland penis

What is the fundamental formula for semen, and where does the non-sperm portion come from?

Semen = Sperm + Fluid

Fluid Sources: Contributed by the epididymis and accessory sex glands (including the ampullae). Contains fructose for sperm energy.

What is the primary function and composition of the fluid from the vesicular glands?

Produces the most fluid in semen.

Fluid Type: Thick and highly rich in fructose (to give sperm energy).

What are the unique species-specific features of the bulbourethral and prostate glands noted in the lectures?

Bulbourethral Gland: Highly pronounced in the boar.

Prostate Gland: The only accessory sex gland that a dog has.