Male Reproductive Systems and Reproductive Systems

ANSC 410

list the structures of the male reproductive system

• penis

• prepuce

• sheath

• inguinal canal

• peritoneum

• testicles

• scrotum

• spermatic cord

• epidiymis

• vas deferens

• accessory sex glands

what is the organ of copulation?

penis

what type of structure makes up the penis?

fibrous structure

describe the different shapes of the penis

bull- S-shaped (sigmoid flexure)

boar - corkscrew

dog - os penis (bone)

what is the main structure of penis tissue?

corpus cavernosum

(true/false) the corpus cavernosum is highly vascular and capable of trapping blood

true

erection

engorgement of blood in corpus cavernosum

what are the structures of the penis?

• glans penis

  • sensitive area

  • tip of penis

• urethra

  • runs through the middle

• prepuce

  • double folded lining that covers the penis

• sheath

  • external opening

what are three functions of the penis?

• transport of semen

• urination

• organ of copulation

what are two important muscles of the penis?

• retractor penis muscle

• ischiocavernosus muscle

function of testicles

produces sperm

where are the testicles located

descends from the kidney area to scrotum

what are the 2 types of cells of the testicles?

• cells of leydig

• sertoli cells

retractor penis muscle aids in…

retraction of the penis

ischiocavernosus muscle

• aids in erection process

• contracts penis against ischium of the pelvis causing blood to be trapped in the penis

cells of leydig produces…

hormone testosterone

sertoli cells provide…

nutrition for maturing sperm

list the structures of the testicles

• tunica albuginea

• tunica vaginalis

• gubernaculum testis

• seminiferous tubules

• rete testis

• epididymis

• vas deferens

• spermatic cord

• cremaster muscle

tunica albuginea

outside covering of the testicles and penis thinner capsule

white and shiny

tightly adhered to the testicle

tunica albuginea was originally part of the ___________

peritoneum

the testicle becomes the tunica albuginea as it descends into the _________

scrotum

tunica vaginalis

also white and shiny thick capsule

also formed from the vaginal tunic and peritoneum

outside layer of the tunica albuginea

what is the first structure you will see after excising the scrotum?

tunica vaginalis

gubernaculum testis

ligament hooks the testicle to the scrotum and guides the testicle to scrotum

seminiferous tubules

• tubes where spermatogenesis takes place

• massive numbers of tubules in the testicle

rete testis

collection duct where maturing spermatozoa go to the epididymis

the epididymis has three parts. what are they?

• head

• body

• tail

function of epididymis head

• receives spermatozoa from the rete testis

• storage and maturation of sperm

what does the epididymis tail turn into?

vas deferens

function of vas deferens

transports sperm from the tail of the epididymis to the urethra (ampulla)

where is the ampulla located?

where the epididymis joins the urethra (reservoir for sperm)

ampulla is present in all domestic animals except for ______

pigs

what is the spermatic cord made up of?

pampiniform plexus + vas deferens

function of spermatic cord

suspends the testicle

the spermatic cord contains:

• arteries, nerves, veins (pampiniform plexus)

• gubernaculum

• common vaginal tunic

• vas deferens

• cremaster muscle

• lymph structures

what is a muscle that lies near the spermatic cord?

cremaster muscle

function of cremaster muscle

allows the testicles to move closer or further away from the body for temperature regulation

where does spermatogenesis occur?

in the seminiferous tubules

how long does it take sperm to complete maturation?

13-17 days

what cells line the seminiferous tubules?

sertoli cells

what are the parts of sperm?

• head

• midpiece

• tail

what does the head of sperm contain?

• genetic material

• acrosome contains enzymes to penetrate the ova

function of midpiece of sperm

powerhouse of sperm (contains mitochondria)

function of tail of sperm

responsible for locomotion

scrotum

outer sac that holds and encloses the testicles; has fibrous division

describe the appearance of the scrotum in stallions, bulls/rams, and boars

stallions - more attached to abdominal wall (more horizontal)

bulls/rams - more pendulous (more vertical)

boars - close to anus

the scrotum has one muscle called the _______

dartos

function of dartos

causes the scrotum to contract or relax; important for thermoregulation of the testicles*

inguinal canal

slit-like structure in groin area where the abdominal muscles join

what structure do testicles pass through when descending from the abdomen into the scrotum?

inguinal canal

peritoneum

lines the abdominal cavity; forms the vaginal tunic of the testicle as the testicle descends through the inguinal canal

list the accessory sex glands

• bulbourethral

• prostate

• seminal vesicles

• ampulla

bulbourethral

• paired gland

• in all domestic animals except dog

prostate

thick glandular structure that surrounds the urethra; located just over the pelvic arch

single gland - can have 2 lobes in some animals

found in all domestic animals

seminal vesicles

• paired gland

• all domestic animals except dog and cat

ampulla

• not present in boar

• sits at base of vas deferens

what are the functions of accessory sex glands?

• add fluid to ejaculate (semen = sperm + fluid)

• provide nutrients to the sperm by releasing sucrose

what animals have all 4 accessory sex glands?

horses, cows, sheep and goats

what animal has all accessory sex organs except for the ampulla?

pig

what are the 2 types of castration methods?

• banding

• cutting castration

banding

involves placing a rubber ring around the pampiniform plexus to restrict blood supply to the testicles

must make sure BOTH testicles are in the band

when is it best to band calves?

within 1st week of life

cutting castration

involves excising the scrotum with a blade and pull the testicles out of the body

• open - excising the tunica vaginalis

• closed - excising scrotum only

when is it best to perform a cutting castration on a calf?

done as a newborn or around 6 months of age at weaning

the entire penis must be examined on the ….

breeding soundness exam

paraphimosis

inability to retract the penis

what can paraphimosis cause?

preputial trauma and tumors

phimosis

inability to extend the penis

what can phimosis lead to?

adhesions, stenosis of the preputial opening, congenital abnormalities

cryptorchidism is an ___________ defect

inherited

what are the 2 types of cryptorchidism?

unilateral and bilateral

unilateral cryptorchidism

• 1 testicle is retained in the abdomen

• may still be fertile

• the descended testicle is usually larger

bilateral cryptorchidism

• both testicles are retained in the abdomen

• usually sterile

• will still behave like an intact male and try to breed

• increased chance for the testicles to develop tumors

what temperature do the testicles need to be to adequately produce viable sperm?

need to be 4 degrees cooler than the body temperature

hernias

condition when abdominal organs or tissues protrude through weak areas in the abdominal wall

where are hernias most commonly seen?

in the groin, scrotum, testicle, umbilicus

clinical signs of hernias depend on what?

what tissue is trapped in the hernia

what are clinical signs of a hernia?

• swelling

• pain

• lethargy

• depression

• vomiting/diarrhea

what are the 2 types of hernias?

• congenital

• acquired

examples of how hernias can be acquired

• bull fights

• trauma

• increased abdominal pressure

treatment for hernias

surgical correction

orchitis

inflammation of the testicles

what is orchitis a potential complication of?

giving the Brucellosis vaccine to bulls

causes of orchitis include:

• Brucella abortis

• Mycobacterium tuberculosis

• Herpesvirus

• trauma

clinical signs of orchitis

• reluctance to move

• swollen, painful, hot scrotum

• reduced fertility

penile hematomas are most common in what cattle breed?

Bos Indicus

when do penile hematomas most commonly occur?

during the act of breeding

how does a penile hematoma occur during breeding?

• cow moves

• penis misses the cow

• bull steps on the penis and or prepuce when trying to stand up

clinical signs of penile hematomas

• decreased libido

• infertile breedings

• reluctance to breed

complications of penile hematomas

• cellulitis

• abcesses

• fibrosis

what do penile hematomas often lead to?

preputial prolapse

when do lacerations most commonly occur?

occur due to violent ejaculatory lunge

where is the most common location of a laceration found on bulls?

the ventral aspect of the prepuce

lacerations often lead to…

preputial prolapse because fluid easily accumulates in the damaged portion

preputial prolapse is most common in what cattle species?

Bos Indicus

what is a preputial prolapse most commonly caused by?

a laceration that eventually allows so much fluid to accumulate in the penis/prepuce that the penis cannot be retracted back into the sheath

the longer the injured prepuce tissue remains prolapsed, what can it lead to?

secondary injuries such as necrosis, frostbite, extensive lacerations

how many classes of preputial injuries are there?

4

treatment options for a prolapsed prepuce?

• surgical correction

• hydrotherapy

• pain control

• antibiotics

• urethral catheter

what often leads to bull fighting?

having multiple bulls in pastures with the same groups of cows