Male Genetalia Flashcards
What are the 7 structures of the male genital tract?
Scrotum
Testes
Epididymis
Spermatic Cord
Accessory Glands
Penis
Prepuce
Scrotum
Sac-containing testes
Function: Thermoregulation and protects the testes
What are the layers of the scrotum?
- Skin
- Tunica dartos
- Scrotal fascia
- Tunica vaginalis
- Tunica albuginea
Skin of the scrotum
Outermost
Smooth with large number of sebaceous glands and sweat glands
Tunica dartos
Composed of muscular and fibroelastic tissue
Lines the scrotum
Contracts and relaxes in response to the environment and testicular temp
Scrotal fascia
Loose CT
Allows testicles to move freely within the scrotal sac
Tunica vaginalis
Continuous with peritoneal lining
Two layers: inner/visceral and outer/ parietal
Tunica albuginea
Divides testes into lobes
Clin sig of the Tunica vaginalis
Closed castration: remain closed
Open castration: exposed, open
What are the risks of both closed and open castration?
Closed: takes longer but reduces the chance of peritoneal infection
Open: quicker, risk of peritonitis
Which structures of the scrotum are responsible for thermoregulation?
Tunica dartos and cremaster muscle
Castration
Standing or lateral recumbency
1 to 2 cm incision adjacent to the median raphe
Testicles palpated before surgery and stays in hand of surgeon
What is illegal when performing castrations?
Leaving one testicle in the horse
What are the most common complications for castration?
Edema
Infection
Heavy bleeding from testicular artery
Omental prolapse
Intestinal herniation/ evisceration
Scrotal hernia
Intestines in scrotum
Due to severe inguinal ring opening during breeding
NOT a castration complication
Testes
Produces sperm cells and hormones
Size correlates with amount of sperm produced (breeding potential)
Thermoregulation
Temp is 3-5° less than body temp
Scrotal muscles work with cremaster to help change testicle position
Pampiniform plexus (veins of cord)
Arteries carry warm blood and vein brings cool blood
Sertoli cells
Nourishment and alert development
Secreting luminal fluids and proteins
Forming the blood-testis barrier
Having phagocytic functions
Leydig cells
Secret hormones that develop secondary sex characteristics and help with spermicide production
Cryptocordism
If one or both testes failed to descend within the first several months of age
Genetic/ heritable
Bilateral or unilateral
Abdominal cryptorchidism
High flanker
Horse with testicles in abdominal cavity
Inguinal cryptorchidism
Low flanker
Testicle remained in the inguinal canal
Which breeds does cryptorchidism occur in mostly?
Quarter horses
Saddlebreds
Percheron
Standardbreds
produce sperm but shouldn’t be bred
How do you treat cryptorchidism?
Through linea alba or laparoscopy (flank region through abdominal tunic)
Where do sperm cells travel after production?
Epididymis
Tail of the epididymus
Site of sperm storage prior to ejaculation
Epididymus
Help transport sperm cells from the testicles to the ductus deferens
Helps sperm mature, concentrate the testicular fluid and protects the sperm
What structures are within the spermatic cord?
- Ductus deferens
- Testicular artery, vein and nerves
- Lymphatic vessels
- Cremaster muscle
What is the function of the spermatic cord?
Transports blood and semen
Thermoregulation
What are the accessory sec glands?
Ampulla
Vesicular glands (seminal vesicles)
Prostate
Bulbourethral glands
What is the main function of the bulbourethral glands?
To produce a portion of the seminal fluid
What are the functions of the fluid that the gland produces?
Help move sperm through urethra
Provide nutrients to sperm cells
Stimulate sperm metabolism
Motility
Buffers environment
Ampulla
Where sperm cells are stored until they are ejaculated
Seminal vesicles
Add gel volume to the ejaculate
Prostate
Produce pre-sperm fraction or pre-ejaculate (alkaline secretions)
What are the 3 parts of the penis?
Root
Body
Glans
Penis
When flaccid, penis lies in prepuce
2.5 to 6 cm in diameter, 50 cm in length
When erected penis can double in length and thickness
Ischiocavernosus muscle
Attaches the penis to the floor of the pelvic bone
Urethra clin sig
At the level of the prostate and ischiocavernosus, it’s reduced in diameter from 6cm to 1 or 2
Important point when catheterizing urethra of stallions
What are the inguinal structures of the male?
Spermatic cord
Genitofemoral nerve
External pudendal artery
Lymphatic
What are the different structures of the penis?
Ischiocavernosus muscle
T. Albuginea
Corpus cavernosum
Corpus spongiosum
Urethra
Bulbospongiosus
Retractor penis
Body of the penis
Made of corpus cavernous (erectile tissue)
Filled with blood and expands during erection
Retractor penis muscle
Retracts the penis into the prepuce
What structure does the glans create?
Fossa glandis that creates a sinus that harbors smegma
Smegma (Beans of the Penis)
Dried secretions of the sebaceous and sweat glands
Harbors bacterial growth (must be cleaned before service)
Glans
Terminal part of the penis
Expands during erection
Vascular supply of the penis
Pudendal artery
Middle artery of the penis
Obturator artery
External pudendal venous plexus
Rapidly drains blood from the recited penis following ejaculation
What are the clinical conditions of the penis?
Preputial Edema (enlarged)
Paraphimosis
Tumors
Frost bites (amputation)
Lacerations
Paraphimosis
Inability of penis to retract back into the sheath
How to you fix penile injuries
Urethrostomy and penile amputation
Prepuce
Sheath, double invagination of the skin that covers the distal portion of the non-erect penis
Preputial fold
Second fold of skin
Reserve of skin during erection
Catheter incision
- Insert the urinary catheter into the urethra
- 10 cm ventral to the pelvic floor so urine won’t go into the bladder
- Incise skin tend retractor penile muscle
- Suture the bulbospongiosus and corpus spongiosum muscles
- Remove the penis and suture skin
