Male Anatomy
Where does the spermatic cord begin?
At the abdominal ring where its constituents come together
Where is the tail of the epididymis located?
At the opposite end of the testicle from head
What happens during an erection of the penis?
It becomes engorged with blood (more blood enters penis via arteries than leaves via veins)
Where is the deep fascia located?
Just superficial to the common vaginal tunic of the testicle (the outer layer of peritoneum covering the testicle)
What are examples of secondary sex characteristics associated with masculinity?
-Massive head and shoulders in bull -Well developed jaws and crest in stallions -Horns in some breeds of rams -Tusks in boars -Less subcutaneous fat -Poorer marbling of muscle
What does the spermatic cord consists of?
-Testicular artery -Testicular veins -Lymphatics -Nerves (sympathetic) -Ductus deferens (vas deferens) -Internal cremaster muscle (smooth muscle) -Visceral layer of tunica vaginalis (proper vaginal tunic)
What is the purpose of castration?
-To prevent the reproduction of inferior animals -To improve the quality of animals used for food -To produce a more docile animal
What is the deep fascia derived from?
3 abdominal muscle
What is the epididymis?
A long convoluted tube
What type of tissue is the tunica dartos?
A mixture of connective tissue and smooth muscle
What is a cryptorchid testicle?
A testicle that fails to descend into the scrotum
What does the visceral layer of the proper vaginal tunic do?
Acts as an envelope and covers the testicle and cord that is an extension of the peritoneum cavity
What does the prostate gland produce?
An alkaline secretion
What is a high flanker animal?
An animal in which testicle descends into the inguinal canal/ring but not into the scrotum
What is a cryptorchid animal?
An animal with a cryptorchid testicle
What is a monorchid animal?
An animal with only one retained testicle
Why are cryptorchids usually sterile?
Because body temperature is too high for normal spermatogenesis
Where is the tunica albuginea located?
Beneath proper vaginal tunic
Where is connective tissue in the testicle?
Between seminiferous tubules
Where is the superficial fascia?
Between tunica dartos and underlying deep fascia
When is the descent of the testicles complete?
By birth or soon after
What does the connective tissue in the testicles contain?
Cells of Leydig
What does the tunica dartos do?
Contracts and relaxes according to climatic conditions
What is the scrotum?
Cutaneous sac which contains the testicles
What part of the testicle produces sperm?
Cytogenic
What happens to the tunics of the testicle when it passes into the scrotum?
It becomes enfolded in parietal peritoneum
What does the tail of epididymis connect with?
Directly to the vas deferens
What is free end of the penis shaped like in a boar?
Distal portion of boar's penis is corkscrew shaped
What is the scrotal septum?
Divide scrotum into two compartments (one for each testicle)
When is an inguinal hernia prone to happen?
During an act of breeding
What is the internal inguinal ring formed by?
Edges of muscles and tendons
What dos the head of the epididymis connect with?
Efferent ducts
What does the epididymis connect?
Efferent ducts with the vas deferens (ductus deferens)
Where are the bulbourethral glands located?
Either side of pelvic urethra just caudal to other accessory glands
What part of the testicle produces hormones?
Endocrine
What is free end of the penis shaped like in a horse/ram?
Free portion of urethra (urethral process) projects beyond the glans
What is free end of the penis shaped like in a bull?
Helmet-shaped gans - galea glandis
Where are the testicles located?
In scrotum outside abdominal cavity
Where do testicles originate?
In the sublumbar region immediately caudal to the kidneys
How are the testicles positioned in stallions?
Long axis nearly longitundinal
How are the testicles positioned in bulls and rams?
Long axis perpendicular to ground (vertical)
How are the testicles positioned in boars?
Long axis upward and backward
What type of tissue is the superficial fascia?
Loose connective tissue
What is the interior of the testicle?
Masses of seminiferous tubules
How is the testicle shaped in the bull?
More elongated
Where does the crura originate?
On caudal surface of ischial arch, one on each side of symphysis of pelvis
How is the testicle shaped in most species?
Ovoid (egg shaped)
Where is the body of the epididymis?
Parallel to the long axis of the testicle
What is the inguinal canal?
Passageway from the abdominal cavity to the exterior
What is the corpus cavernosum?
Primary erectile tissue
What does the testicle do?
Produce and transport sperm
What is the function of the ductus deferens?
Propels sperm from epididymis to ejaculatory duct in the prostatic urethra at the time of ejaculation
What is the relative testicle size according to body weight and size?
Ram > Bull > Stallion >/= Boar
What is the testicle size in rams?
Relatively larger than a bull
What is the testicle size in bulls?
Relatively larger than a horse
What is castration?
Removal of the testes of the male
What is a risk of cryptorchidism?
Retained testicle may become tumorous
What does the tunica albuginea give rise to?
Septa
What type of membrane in the proper vaginal tunic?
Serous membrane
What is the function of the epididymis?
Serves as a place for spermatozoa to mature prior to the time they are expelled by ejaculation Serves as tubule of transport of sperm from area of formation (seminiferous tubules)
What is the external inguinal ring formed by?
Slit in aponeurosis of one of the abdominal muscles
Retained testicles are often what?
Smaller and softer than normal
What is the danger with an inguinal hernia?
Strangulation of a loop of gut
Where is the corpus spongiosum?
Surrounds urethra- erectile tissue
What does the body of the epididymis connect with?
Tail of epididymis
What is the structure of the tail of the epididymis like?
Takes a 180 degree turn and runs back along the body of the epididymis
Why can't normal spermatogenesis occur in the abdomen?
Temperature is too high
What are the primary orangs of reproduction in the male?
Testes
What does the reproductive system for males consist of?
Testicles, epididymis, scrotum, ductus deferens, accessory sex glands, penis, and prepuce
What do the cells of Leydig secrete?
Testoterone
What is the gubernaculum testis?
The fibrous cord
What does the ductus deferens pass through after leaving the tail of the epididymis?
The inguinal canal as part of the spermatic cord
Where does the inguinal canal extend from?
The internal inguinal ring to the external inguinal ring
What does the prostate gland surround?
The pelvic urethra
What does the tunica dartos form in the scrotum?
The scrotal septum as it passes on the median plane
What does the efferent ducts pierce?
The tunica albuginea
What does the crura converge for?
To form body of penis (corpus penis)
Where does the head of the epididymis attach?
To the same end of the testicle that blood vessels and nerves enter
What divides the parenchyma (the testicle) into lobules?
Trabeculae
What is the ductus deferens?
Tubule for transport of sperm. It is a muscular tube of smooth muscle that extends from tail of epididymis to the pelvis part of the urethra
What are efferent ducts in the testicle?
Tubules from seminiferous tubule to epididymis
Where does the Trabeculae extend from?
Tunica albuginea
How many roots (crura) does the penis have?
Two
What is Mediastinum testis formed by?
Uniting of trabeculae in the center of the testicle
What is an inguinal hernia?
Usually a loop of bowel
Where is the urethra located in respect to the corpus penis?
Ventral to the body
The right and lest testicle are. . .
paired glands