Male Genetalia Flashcards
Secondary sex organs of the male reproductive tract
Paired duct system
Accessory sex glands
Penis
Skin adaptations (scrotum and prepuce)
Testis
Primary reporductive organ
Primary site of sperm production
What structures are within the paired duct system?
Epididymis
Deferent ducts
Urethra (pelvic, penile)
Scrotum position
Dog: horizontal with cr. pole cranially
Tom: vertical with cr. pole ventrally
Scrotum
Skin: thin and hairless for heat dissipation
Tunica dartos: smooth muscle with elastic tissue and collagenous fibers
Epididymus
During cold & _______, _______ wrinkles
- Sexual arousal
- Tunica dartos
Scrotum temperature
At about 4-5 degrees Fahrenheit below core body temperature
Hormonal function is NOT affected by temperature
Spermatogenesis
All cellular stages involved in the production of sperm (mitosis and meiosis)
Spermatogonia to sperm
What is the clinical significance of gubernaculum regression?
Cryptorchidism, if not removed could turn into a tumor
What are the borders of the deep inguinal ring?
Medial: Rectus abdominus
Caudolateral: Inguinal ligament
Craniolateral: Internal abdominal oblique
Pampiniform plexus
Cooling of blood by absorption of heat from vein
Absorption of pulsation (systolic-diastolic) pressure in artery
Coverings of the testis
- Tunica albuginea testis: covers the immediate surface of the testicle (DRCT)
- Visceral Vaginal Tunic (mesothelium)
How is the tail of the epididymus attached to the cd. pole of the testicle?
By the proper ligament of the testicle
How is the epididymus attached to the parietal vaginal tunic?
Via the ligament of the tail of the epididymus
What are the proper ligament of the testicle and ligament of the tail of the epididymus?
Remnants of the fetal gubernaculum testis
How is the vaginal tunic attached to the skin?
Scrotal ligament
Seminiferous tubule
Rete testis
Efferent ducts
Epididymus
Head, body and tail
Long coiled tube, interconnecting testicle with ductus deferens
Site of final maturation and storage of sperm
Spermatic Cord
Testicular vessels, nerves and lymphatics
Ductus deferens
Vaginal tunic (serous membrane wrapped around)
Where does the r. testicular vein drain?
Directly into the cd. vena cava
Left testicular vein
Drains into the l. renal vein
Ruptured by pulling too hard during neuter, causes internal bleeding and hemoabdomen
Testicular lympahtic drainage
Testicle drains directly into the medial iliac lymph node
Testicular thermoregulation
Structures involved are the cremaster muscle (skeletal), tunica dartos m. (smooth) and the pampiniform plexus
Penis
Primary copulatory organ
Urethra for ejection of urine and semen
Prepuce
What is the structure of the penis?
Root, body and glans penis (bulbus glandis, pars longa glandis)
Corpus cavernosum penis (erectile tissue)
Tunica albuginea penis
Tunica Albuginea penis
Tough CT allowing for increased length and diameter of the penis during erection
Copus Cavernosum Penis (CCP)
Cd. end splits into 2 crura
Anchored to an ischial tuberosity
What is the CCP surrounded by?
A pair of ischiocavernosis muscles (contraction compresses “stiffen” the penis)
CCP ossification
The distal 3-4 inches of the CCP is ossified in the dog to form the baculum (os penis)
Tom has a poorly developed baculum (~1/4 inch)
Other than the CCP what erectile tissue doe the penis have?
Corpus spongiosum penis
Corpus spongiosum glandis (bulbus glandis, pars longa glandis)
Corpus spongiosum penis (CSP)
Begins as a pair of bulbous enlargements to either side of the urethra just below the anus
Penile urethra
Covered with bulbospongiosus m.
How does the CSP extend?
Distally as a single tube of erectile tissue completely surrounding the penile urethra
Bulbus glandis
Proximal ring-like
Expansion of CSP(venous sinuses and elastic tissue)
Surround os penis
How is the bulbus glandis separated from the pars longa glandis?
By CT septum
Pars longa glandis
Distal elongated part of the penis
Forms the apex of the penis
Coital Tie
Male dog dismounts, turns around, lifting one hind-limb over the female and the animals stand facing opposite directions
What is the function of spasmodic contractions?
Send pulses down the CSP and forces semen down and out of the urethra
Tom cat’s penis
Caudally directed penis (flaccid state)
Cranially directing during copulation
Penile spines (on glans penis) to assist with maintaining intromission (not neutered)
Urine Spraying in cats
Behavioral problem
Territorial marking
Becomes a problem when tom chooses household objects for marking (smell)
Posture of the tom during urine spraying
Standing position with tail erect
Hindquarters directed toward object
Ears caudally directed
Clinical consideration of the urethra for dogs
Canine Urethral obstruction
Urethral Calculi
Clinical consideration of the urethra for cats
Tom Feline Urologic Syndrome
Urethral Plug
What is derived from the internal pudendal?
Artery of the penis
Dorsal artery of the penis
Nutritional supply
What does the deep artery of the penis supply?
Supplies CCP for erections
What does the artery of the bulb supply?
Supplies CSP for ejaculation
Pelvic nerves
Parasympathetic- S2 and 3 (vasocontrol to engorge penis)
Assists in relaxing helicine vessels and increasing CCP blood flow (erection)
Hypogastric nerves
Sympathetic- L1-L4
(ejaculation)
Pudendal nerves
Somatic- S2 and 3
Innervates the striated muscles (ejaculation)
Dorsal nerves of the penis
Sensation to the glans penis
Prepuce
Sheath of skin surrounding and protecting the penis
Outer lamina haired, inner lamina with delicate skin
Fornix
Preputial ostium and cavity
What are the accessory sex glands in the dog?
Prostate and ampullary glands
Prostate
Around proximal urethra
R. and l. lobes
What are the accessory sex glands in the cat?
Prostate and the bulbourethral gland
Clinical consideration of the prostate?
Benign prostate Hyperplasia
Prostate Hyperplasia
Press on large intestine (rectum)
Producing constipation and difficulty in defecation
Treatment: castration (surgical removal)
What are the extrinsic muscles of the penis?
Ischiocavernosus m.
Bulbospongiosus m.
Rectractor penis m.
Ischiourethralis m.
Retractor penis m.
Pair of smooth m
Arise from the sacrocaudal spines, pass around the anus, and attach half way down the penis
