VA: Male Reproductive System

If the tube that makes up the human epididymis was stretched out, how long would it be?

6m or 20feet

What do the blood vessels in the spermatic cord form?

A heat exchange mechanism that helps keep the temperature of the testes slightly lower than that of the rest of the body.

The epididymis functions as...?

A storage elite for spermatozoa and a place for them to mature before they are expelled by ejaculation

Spermatozoa are immature she. They leave the seminiferous tubules. They must mature in the epididymis for how long before they can fertilize an ova?

A week or more

A cap like structure that covers the head of spermatozoa. Contains digestive enzymes that are released once the spermatozoon is inside the female reproductive tract. It helps the spermatozoon penetrate through the layers of surrounding the ovum to accomplish fertilization.

Acrosome

In many species, the vas deferens enlarges just before joining the urethra. This enlargement, if present, is called the _____________, which may contain glands that contribute material to semen.

Ampulla

Testosterone has a general ____________ effect on the body, which results in the enhanced muscle and bone development that gives male animals their size and bulk

Anabolic (protein building)

What is the name of male sex hormones?

Androgens

As the tiny embryo grows, the gubernaculum remains fairly constant in length. This results in the testes gradually being pulled causally and ventrally. What is actually happening is that the fetus is growing larger and longer while the testes are ?

Being held in place

The penis has a very large ________ and many __________

Blood supply; nerve endings

Region of the epididymis: the main portion that lies along the surface of the testis

Body

Part of Penis: the largest part that is mainly made up of two bundles of erectile tissue

Body of the penis

A unique structure in the penis of a dog that is an enlargement toward the red of the glans that is made up of erectile tissue that is derived from the corpus cavernosum urethrae.

Bulb of the glans

The two ______________ glands, are located further caudally than the other accessory reproductive glands. Their ducts enter the urethra back near the caudal border of the pelvis. They secrete a mucinous fluid just before ejaculation that clears and lubricates the urethra for the passage of semen. All common domestic animal species have this gland except for dogs

Bulbourethral glands; Cowper's glands

The testes have to be kept slightly ______ that the body temperature to produce spermatozoa

Cooler

The penis of the horse contains a large component of erectile tissue, and the glans at the distal end flairs into a distinctive mushroom shape, the widest part of which is called the ___________

Corona glandis

A band like muscle that passes down through the inguinal ring and attaches to the scrotum. It can adjust the the position of the testes relative to the body.

Cremaster muscle

The process of the testes descending (the testes being pulled down through the inguinal rings into the scrotum)

Descent of the testes

When spermatozoa complete their physical development in the seminiferous tubules, they are transported to a storage site where they will be prepared for ejaculation. After they detach from their protective serotoli cells, the spermatozoa enter the complex of ducts that make up the rete testis. From there, they flow through the ________________ to their storage site- the epididymis

Efferent ducts of the testes

What is the urethra reproductive function?

Ejaculation

The accessory reproductive glands produce alkaline fluid containing substances such as ...?

Electrolytes, fructose, and prostaglandins

Grossly, this structure of the testis is a flat, ribbonlike structure that lies along the surface of the testis. It is actually a single, long, very convoluted tube that connects the efferent ducts of the testis with the vas deferens

Epididymis

Tissue composed of a spongy network of fibrous connective tissue and many tiny, blood filled spaces called sinuses.

Erectile tissue

When the penis becomes a little larger and a lot stiffer

Erection

The Sertoli cells are also known to produce small amounts of _____________ under the stimulation of Follicle stimulating hormone from the anterior pituitary.

Estrogens

The tail of sperm contains muscle like contractile _______ that produce a ship like movement of the tail and propel the forward once it's activated.

Fibrils

What is testosterone responsible for?

For the development of male secondary sex characteristics (such as male body shape) and the male libido (sex drive)

Horse penis: the distal end of the urethra (urethral process) extends from a central depression, the _____________, at the tip of the penis

Fossa glandis

A simple sugar that acts as an energy source for the very active spermatozoa

Fructose

The tip, or the distal free end of the penis. It's structure and appearance vary considerably among species

Glans of the penis

Part of Spermatozoa: contains the payload of the cell, the nucleus, and is covered by a cap like structure called the acrosome

Head

Region of epididymis: is where the spermatozoa enter from the efferent ducts

Head

What does the alkalinity of the fluid help with?

Helps to counteract the acidity of the female reproductive tract to help more spermatozoa survive to reach the oviducts, where they hope to meet up with an ovum.

At or soon after birth, the testes are normally pulled down through the ________________ into the scrotum

Inguinal rings

Two slit like openings in the abdominal muscles located in the groin region

Inguinal rings

Between the seminiferous tubules, cells called ____________ cells produce male sex hormones

Interstitial

Between the seminiferous tubules are the endocrine cells of the testis known as the ____________. They produce androgens under the influence of luetinizing hormone.

Interstitial cells

During breeding in canines, what happens with the bulb of the glans?

It becomes engorged with blood more slowly than the other erectile structures and usually doesn't reach full size until after ejaculation has taken place. Once it enlarges, the swollen bulb is tightly clamped in place by contractions of the muscles surrounding the vagi and Vulva of the female, making it impossible for the male to retract his penis.

The penis of the dog and other canine species is unusual because?

It includes a bone and an erectile structure that causes the male and female to remain stuck together after breeding is completed

The prostrate gland in dogs is particularly large because?

It is the only accessory reproductive gland they have

Before birth, the testes begin development in the abdominal cavity near the __________. They are attached to their eventual permanent home in the scrotum by a band of connective tissue called the ___________.

Kidneys ; gubernaculum

The spermatids undergo many physical changes to become spermatozoa. While they are undergoing these changes, what are they attached to?

Large "nurse" cells called Sertoli cells

Because of the large amount of erectile tissue it contains, the penis of the horse enlarges considerable in both ______________________ when erect

Length and circumference

How many arteries carry blood down to the testes?

One

The bone in the penis of dogs is called the

Os penis

What is the name of the intricate mesh work of tiny veins derived from the testicular veins that surround the single artery in the testes

Pampinform plexus

As body temperature blood passes down to the testis through the testicular artery, it is cooled by the blood returning from the testis in the ?

Pampinoform plexus

The thick, outer layer of the vaginal tunic that is derived from the parietal layer of peritoneum that lines the abdominal cavity. It forms a visible fibrous sac around each testis and spermatic cord

Parietal vaginal tunic; common vaginal tunic

Portion of Urethra: within the pelvic cavity. Where the vas deferens and accessory reproductive glands enter

Pelvic portion

Portion of Urethra: runs down the length of the penis

Penile portion

The male breeding organ. Made of mainly of muscle, erectile tissue, and connective tissue, with the urethra running down its center.

Penis

The sheath of skin that encloses the penis when it is not erect.

Prepuce

The produce of the boar also contains a small ________ pouch in which urine and cellular debris accumulate. Decomposition of this material gives boars their typical ripe odor (makes cows attracted to them)

Preputial

Division process of spermatocytes

Primary spermatocytes——secondary spermatocytes——spermatids

Some of the ______________ are thought to stimulate the contraction of the female reproductive tract which help move the spermatozoa up to the oviducts

Prostaglandins

Single structure that more or less completely surrounds the urethra. Multiple ducts carry its secretions into the urethra. . It is present in all common animal species.

Prostate gland

Besides providing a home for the testes, the scrotum also helps ?

Regulate their temperature

In warm conditions, the cremaster muscle ______ and the testes hang down away from the warm body to help reduce their temperature

Relaxes

Each tubule is shaped like a long, convoluted "u" that is attached at both ends to a complex system of ducts called the _____________

Rete testis

Regardless of the species, the surface of the glans has a...?

Rich supply of sensory nerve endings that make it very sensitive to physical stimulation

Part of Penis: attach it to the brim of the pelvis

Roots of the penis

The testes are located outside the abdomen in the inguinal (groin) region, housed in s sac of skin called the __________.

Scrotum

Spermatozoa make up only a small portion of the total volume of semen. The majority is made up of...?

Secretions from the various accessory reproductive glands

Once the sperm are in the urethra, they are mixed with secretions from accessory reproductive glands to form _________, which is pumped out into the female reproductive tract

Semen

Ducts from the 2 _______________ e Ted the pelvic urethra in the same area as the vas deferens. They are present in all common domestic animal species except for cats and dogs.

Seminal vesicles (vesicular glands)

The area where Spermatogenesis takes place

Seminiferous tubules

Many small partitions called ___________ , extend into the testis from the capsule. They divide each testis into tiny lobules that contain the seminiferous tubules, as well as other cells and structures

Septa

In addition to providing mechanical and nutritional support, the Sertoli cells also help...?

Shield the developing spermatozoa from the bodies immune system

The non erect penis of the bull, ram, and boar is normally bent into an s shape. This is called the ?

Sigmoid flexure

What are the two erectile tissue structures that make up the body of the penis?

Small corpus cavernosum urethrae (corpus spongiosum) Larger corpus cavernosum penis

The outer part of the prepuce is normal skin, but the inner portion that is in contact with the penis is a ?

Smooth, moist, mucous membrane

The vas deferens passes up through the inguinal ring as part of the ____________________.

Spermatic cord

Tubelike, connective tissue structure that contains blood vessels, nerves, lymphatic vessels, and the vas deferens

Spermatic cord

What is the name of the structure that links the testes with the rest of the body?

Spermatic cord

Long, thin cells with 3 main parts

Spermatozoa

Part of Spermatozoa: long, thin. Resembles the flagellum that many single-celled organisms use for propulsion.

Tail

Region of the epididymis: continues on as the vas deferens

Tail

Generally oval, and their size vary considerably amongst species.

Testes

The ________ are the male gonads - the organs where the male reproductive cells are formed.

Testes

At the same time, the blood in the pampinoform plexus is warmed by the blood in the _______________

Testicular artery

What is the principle androgen produced by the interstitial cells in the testes produce?

Testosterone

Part of Spermatozoa: the "power plant" of the cell. Contains a large concentration of energy producing mitochondria arranged in a spiral pattern.

The midpiece

What gives the vas deferens a very solid, cordlike texture?

The thick layers of smooth muscle in its wall

What happens to spermatozoa if they are never ejaculated?

They live out their lives in the epididymis, die, and are broken down and absorbed by the tubular lining cells

In cold conditions, the cremaster muscle pulls the testes up _______ against the body wall, which helps warm them.

Tight

What is the job of the vas deferens?

To move spermatozoa from the epididymis (located way down in the scrotum) up to the urethra (within the pelvic cavity) when ejaculation occurs. To propel spermatozoa and the fluid they are suspended in quickly form the epididymis to the urethra when ejaculation occurs.

Beneath the tunics, the testis is enclosed by a heavy, fibrous connective tissue capsule called the _______________ that protects and supports the soft contents of the testis

Tunics albuginea

What do the roots of the penis primarily consist of?

Two bands of connective tissue called the crura, covered by the ischiocavernous muscles

Once in the abdome, each vas deferens separates from the rest of the spermatic cord, loops back caudally, and connects with the urethra just caudal to the neck of the ____________________.

Urinary bladder

What is the name of the two layers of connective tissue that surrounds the testes in the scrotum and the spermatic cord?

Vaginal tunics

The thin, inner layer of the vaginal Tunis is derived from the visceral of peritoneum that coated the testes as they developed in the abdomen. It is tightly adherent to the surface of the testes and the structures of the spermatic cord. It is also so thin and transparent that is invisible to the naked eye

Visceral vaginal tunic; proper vaginal tunic

What is known as the "tie" in dog breeding

When the male dismounts the female, still stuck together, and turns so that he faces the opposite direction

Erectile tissue dorsal to the urethra

corpus cavernosum penis

The erectile tissue that forms a sleeve around the urethra is as it passes through the body of the penis

corpus cavernosum urethrae (corpus spongiosum)

What are the three regions of the epididymis?

head, body, tail

What are the 3 main parts of a spermatozoa?

head, midpiece, tail

What are the 2 portions of the urethra?

pelvic portion and penile portion

What are the three main parts of the penis?

roots, body, glans

What are the two main functions of the testes?

spermatogenesis and hormone production

A muscular tube that connects the tail of the epididymis with the pelvic portion of the urethra

vas deferens