Comparative Reproductive Anatomy: Gross Anatomy - Male (Cram)

Which gland is common to every mammal species of veterinary interest?

Prostate gland

The prostate gland is typically round, in which species is it flattened?

Bull

In this diagram, the tail of the epididymis and origin of the ductus deferens is located ventrally. In which three species is this the case?

1. Bull
2. Ram
3. Goat

In this diagram, the ductus deferens is leaving the epididymis on the cranial ventral aspect of the testicle. In which three species is this the case?

1. Stallion
2. Dog
3. Boar

Which four species have a sigmoid flexure in the penis?

Note: Indicated by #9 in the diagram

1. Bull 2. Ram
2. Boar
3. Cat

Note: The sigmoid flexure prevents urethral scoping in these species

Fill in the blank: The bull, ram, and boar all have a ______ -______ penis, while the stallion has a penis.

The bull, ram, and boar all have a fibro-elastic penis, while the stallion has a vascular penis

Note: The dog and cat have a combination of fibro-elastic and vascular penis

Incomplete descent of the testes

Cryptorchidism

Note: Can be unilateral or bilateral

Condition where the testicles pass through the abdominal wall through the inguinal canal

Inguinal hernia

Usually the epididymis head is located dorsally to the epididymis tail. In which two species is the opposite true?

1. Boar
2. Stallion

What structure is responsible for the production, maturation, transportation and storage of spermatozoa?

Testicles

What is the advantage to testicles being outside of the abdominal cavity?

For proper sperm production, the testicles need to be kept at 1-2C colder than the body temperature

Fill in the blank: Testicles develop in the ________ ______, and they must descend into the ______ to become functional.

abdominal cavity, scrotum

True or false: The testicles are responsible for most of the production of male sex hormones

True

Most external of the coverings around the testes

Scrotum

Fill in the blank: The scrotum is divided into two compartments by the ______ ______.

median septum

This is the layer of peritoneum surrounding the testicle and cord inside the scrotum. This layer was pushed ahead of the testicle during its descent

Tunica vaginalis

The outer shell of the testicle proper. This is a smooth layer of tough connective tissue that holds the testicle together

Tunica albuginea

Note: "Albus" means white in latin, this layer is often white-ish in colour

Fill in the blank: The difference between a closed and open castration is whether the ______ _______ is breached or not.

tunica vaginalis

Castration leaving the tunica vaginalis intact

Closed castration

Note: This creates MORE chance of infection than if the tunica vaginalis is removed, but it can be better for animals with a large inguinal ring

Remember: This is the method Dr. B uses

Castration breaching the tunica vaginalis

Open castration

Term for the scrotal ligament

Gubernaculum

The tunica albuginea radiates into the substance of the testicle from dividing the testicle togetherinto lobules. What are these lobules called?

Septa

The bulk of the testes consists of what?

Seminiferous tubules

Fill in the blank: Seminiferous tubules are lined by _______ ________ which produces _______.

germinal epithelium, spermatozoa

What kind of division leads to the production of immature spermatids in the seminiferous tubules?

Meiotic division

Where the seminiferous tubules empty into

Rete teste

The small tubules connecting the seminiferous tubules to the rete teste

Canaliculi recti

Label A, B, and C on this diagram of a testis

A – Rete teste
B – Canaliculi recti
C – Seminiferous tubules

What type of cells are located between the seminiferous tubules?

Interstitial cells

A single tube with many convolutions in which sperm matures and is transported, nourished and stored

Epididymis

In which species is the epididymis tail separate from the body of the testicle?

Horse

Note: In all other species the epididymis lies along the outer surface of the tunica albuginea

Which is longer, the length of all the seminiferous tubules or the epididymis?

Seminiferous tubules (5000m in a bull, while the epididymis is 30m)

A continuation of the tubule of the epididymis, it transports sperm to the urethra

Ductus deferens

Note: Is commonly called the vas deferens in humans, we are supposed to use the term ductus derferns instead

The enlarged area in the ductus deferens in the bull and the horse. It is located where the ductus deferens enters the urethra near the neck of the bladder

Ampulla

Note: Some storage of sperm can take place here too

In a sexually rested intact male, where will the excess sperm go if there is no more space for it to be stored?

It will be excreted in urine

Procedure in which a section of the epididymis is removed. This is a way of sterilizing a male animal

Epididymectomy

Note: Because of the loosely attached epididymus of horses, this is easier than a vasectomy in that species

Procedure in which a section of the ductus deferens is removed. This is a way of sterilizing a male animal.

Vasectomy

What is the advantage of a epididymectomy/vasectomy over an orchiectomy?

It leaves the male hormone production intact. This way you can still identify if females are in estrus. Or in zoo situations, if genetic material from that animal may be needed in the future

What are the four componants of the spermatic cord?

1. Ductus deferens
2. Cremaster muscle
3. Pampiniform plexus
4. Blood vessels, nerves, and lymph vessles

Muscle in the spermatic cord which raises and lowers the testicle in the scrotum

Cremaster muscle

Part of temperature regulating mechanism of the testicle whereby the blood entering the testicle is cooled by the blood leaving

Pampiniform plexus

What are the three accessory sex glands?

1. Prostate
2. Vesicular gland
3. Bulbourethral gland

Which accessory sex gland is also known as the Cowper's gland?

Bulbourethral gland

Which accessory sex gland is also known as the seminal vesicles?

Vesicular gland

Fill in the blank: Semen is comprised of ______ from the accessory sex glands and spermatozoa from the _____ (think of where the semen is mixed).

secretions, ampulla

What are the four functions of accessory sex gland secretions?

1. To cleanse the urethra

2. To activate the sperm

3. To nourish the sperm

4. To protect sperm in the environment of the vagina

Which accessory sex gland secretes a slippery lubricating fluid which prepares the urethra for ejaculation?

Prostate gland

During rectal massage, what might you see from a bull that lets you know you're stimulating the prostate?

Prostatic fluid may be seen as a clear fluid dripping from the glans just prior to coitus

What are the two areas of the prostate?

1. Body
2. Disseminate portion

Note: Dogs are said to have a well developed prostate because it has a large body portion

In which species are the bulbourethral glands most developed in?

Boar. The bulbourethral gland produces the bulk of boar ejaculate and creates a plug in the sow

Note: Stallions also have well a developed bulbourethral gland

Which accessory sex glands are located on floor of pelvis where it empties secretions into the urethra near the entrance of the ductus deferens?

Vesicular glands

Which accessory sex gland is located just caudal to the vesicular gland?

Prostate gland

Which accessory sex gland empties into the urethra in the area where the penis goes ventral below the anus

Bulbourethral gland

The terminal portion of the penis

Glans

Does the glans have more or less erectile tissue than the rest of the penis?

Less. The softness provides some protection to the female

Is this cat intact or neutered?

The barbs indicate the tom is intact

Is this a fibro-elastic or vascular penis: Engorgement of blood in corpus cavernosum causes the erection with an increase in size of 2-3 times

Vascular penis

Is this a fibro-elastic or vascular penis: Increased turgidity and relaxation of the retractor penismuscle allows protrusion to occur

Fibro-elastic penis

Label 1–7 on this diagram of a crosssection of a fibro–elastic (left) and vascular penis (right)

1. Dorsal blood vessels of the penis
2. Tunica albuginea of penis
3. Outer epithelium
4. Corpus cavernosum penis
5. Corpus cavernosum urethrae
6. Urethra
7. Retractor penis muscle

Outer covering of skin covering the penis and opening into the preputial orifice

Sheath

Fold of mucous membrane covering the inside of sheath and reflecting back over part of the glans penis

Prepuce

Note: The prepuce produces preputial fluid to lubricate the penis

Which species has a preputial diverticulum, which gives him his typical odour. It accumulates cellular debris, urine, and preputial fluid

Boar

Is the retractor penis muscle smooth or striated?

Smooth, hence why it cannot be consciously controlled

Fill in the blank: Dogs and cats have a ______ or os penis, which is a bone in the penis.

baculum

What is an uncommon cause of blood in the urine of male dogs that only involves the lower urinary tract?

Penile fracture

Bulls don't have a baculum, why can they have a "broken penis"?

Damage to the tunica albuginea causing a hematoma and impairing erectile capacity