Male Reproductive Gross Anatomy Flashcards
list the layers you will cut through or expose between the skin and the vaginal cavity to reach the visceral layer of the vaginal tunic of the testis (7)
- skin of scrotum
- dartos muscle (cutaneous, smooth muscle)
- spermatic fascia
- cremaster muscle (skeletal, last branch from internal abdominal oblique)
- parietal layer of vaginal tunic (thick, leathery white membrane)
- vaginal cavity (space between tunic layers)
- visceral layer of vaginal tunic (adherent to surface of testes)
describe the scrotum (3)
- a cutaneous pouch: lightly haired and pigmented in the dog and densely covered n hair in the cat
- divided into 2 cavities by a scrotal septum, demarcated by the median groove and raphe scrotum
- houses one testis in each cavity
describe the vaginal tunic (5)
- evaginated peritoneal pouch
- passes through the vaginal ring, deep inguinal ring, inguinal canal, and superficial inguinal ring
- attached to scrotum via spermatic fascia
- cremaster muscle runs alongside the surface of the vaginal tunic and attaches to it but is anatomically separate
- two layers:
a. parietal vaginal tunic: attached to inner surface of scrotum via spermatic fascia; incised during open castrations, NOT closed castrations
b. visceral vaginal tunic: inseperably attached to tunica albuginea of testis, epididymis, ductus deferens, and testicular vasculature
which layer of the vaginal tunic is incised in an open castration that is not incised during a closed castration?
parietal vaginal tunic
describe the inguinal canal (3)
- short, flattened, oblique intermuscular space
- a potential space; is only a canal if something is residing there or passing through, otherwise is flattened and empty
- connects two orifices: deep inguinal ring (triangular) and superficial inguinal ring (an oval slit)
define cryptorchidism
when one or both testes fail to completely descend from the abdomen into the scrotum; may either stop at the inguinal canal or simply remain in the abdominal cavity
define the boundaries of the deep inguinal ring (3)
more like a muscular triangle with 3 boundaries:
1. cranial boundary: caudal edge of the internal abdominal oblique muscle
2. medial: lateral border of rectus abdominis muscle
3. caudolateral: inguinal ligament (rounded edge of the aponeurosis of the external abdominal oblique muscle)
describe the superficial inguinal ring
a slit like opening in the aponeurosis of the external abdominal oblique muscle that is normally sealed off with connective tissue
what structure pulls the testis from its developmental position in the abdomen down into the scrotum? list the two ligaments that are remnants of this structure
the gubernaculum:
1. proper ligament of the testis
2. ligament of the tail of the epididymis
differentiate between the superficial inguinal ring, the vaginal ring, the deep inguinal ring, and the inguinal canal
deep inguinal ring: muscular borders, inner triangle exit from abdominal cavity
superficial inguinal canal: actual hole punched through aponeurosis of external obdominal oblique to exit peritoneal cavity and allow spermatic cord to enter testes
inguinal canal: connects deep and superficial inguinal rings
vaginal ring: inside peritoneal cavity, inside deep inguinal ring
list the contents of the inguinal canal in the male; differentiate between the contents of the neurovascular bundle (3) that passes through the canal and describe the purpose of these structures (4)
- connective tisse
- spermatic cord
- cremaster muscle
- neurovascular bundle:
4a. external pudendal artery and vein (artery terminates in a preputial and scrotal branch)
4b. genitofemoral nerve (motor to cremaster muscle)
4c. lymphatics from superficial inguinal lymph node
describe the boundaries of the structure referred to by clinicians as the spermatic cord (5)
definition: the parietal vaginal tunic and its contents that extend between the superficial inguinal ring and the testes
- parietal vaginal tunic
- visceral vaginal tunic
- testicular veins: form pampiniform plexus
- ductus deferens
- supporting mesentery:
5a. mesoductus deferens: connects to ductus deferens
5b. mesorchium: connects to testicular vasculature
5c. mesofuniculus: connects to parietal vaginal tunic
list the structures passing through the vaginal ring and include whether they are entering or exiting the peritoneal cavity (2)
- testicular artery, vein, nerve: EXITing the peritoneal cavity
- ductus deferens: ENTERing the peritoneal cavity (leaving the testis, coming back into abdominal cavity)
differentiate between the mesoductus deferens (and the ductus deferens), and the mesorchium (and the testicular vasculature) both within the peritoneal cavity (adjacent to the vaginal ring) and within the spermatic cord
just gonna have to look at pics for this one
what is a pampiniform plexus? what is its function?
the tendril formed by testicular veins wrapping around the testicular arteries
function is countercurrent heat exchange and countercurrent testosterone reclamation
right vein empties into caudal vena cava
left vein enters into left renal vein
describe the testes (3)
- endocrine organs via interstitial cells that secrete testosterone
- exocrine organs via spermatozoa production and secretion via ducts
- blood supply from testicular arteries that arise from the aorta
describe the capsule/tunica albuginea of the testes (4)
- very thick and collagenous
- fused with visceral vaginal tunic
- penetrated by branches of testicular artery and vein
- non-elastic, so orchitis or injury with swelling is extremely painful
differentiate between the head, body, and tail of the epididymis and list the structures present within each region
head:
1. most cranial
2. contains efferent ductules
3. beginning of epididymal duct
body:
1. long axis of testes
2. continuation of epididymal duct
tail:
1. most caudal
2. termination of epididymal duct
describe the pathway of the ductus deferens between the tail of the epididymis and the prostate gland, including the structures these ducts pass through
function: convey sperm from tail of epididymis to pelvic urethra
blood supply: artery of the ductus deferens
path:
1. enter peritoneal cavity at vaginal ring
2. loop around ventral surface of ureters
3. prior to entering prostate, are connected by a fold of peritoneum known as the genital fold
4. are ducted to the prostatic urethra on either side of the seminal colliculus
differentiate between the proper ligament of the testis and the ligament of the tail of the epididymis and list the structures these ligaments contact
proper ligament of testis: connects the testis to the tail of the epididymis
ligament of tail of epididymis: connects tail of epididymis to parietal vaginal tunic
both are remnants of gubernaculum
list the 3 means of thermoregulation of the testes
- tunica dartos/dartos muscle of scrotum: causes scrotum to wrinkle when smooth muscle contracts (cutaneous, in the CT of dermis)
- cremaster muscle: caudal slip off IAO, contraction draws testicles closer to body wall, innervated by genitofemoral nerve
- pampiniform plexus: counter-current heat exchange
list the 3 divisions of the penis, and include the erectile tissue and skeletal muscle that is present in each division (carnivores, describe the whole penis)
root:
2 crura:
outer muscle: ischiocavernosus muscle
inner erectile tissue: corpus cavernosum; supplied by the deep artery of the penis
1 bulb:
outer muscle: bulbospongiosus muscle
inner erectile tissue: corpus spongiosum; supplied by the artery of the bulb
body: covered by tunica albuginea
contains retractor penis muscle: smooth muscle that returns penis to prepuce
3 erectile bodies, each enclosed within tunica albuginea:
1. corpora cavernosum: 2 erectile bodies dorsally positioned, continuation of erectile bodies of the 2 crura
2. corpus spongiosum: single erectile body ventrally positioned, surrounds urethra, continuation of erectile tissue of bulb
glans: 2 parts, separated by CT
1. pars longa glandis: has its own erectile tissue, supplied by dorsal artery of penis, drains to bulbus glandis
2. bulbus glandis: distal enlarged part of corpus spongiosum, drains to dorsal veins of penis
list the 2 parts of the glans penis; the erectile tissue of which of these 2 parts is a continuation of the corpus spongiosum?
- pars longa glandis: has its own erectile tissue, supplied by dorsal artery of penis, drains to bulbus glandis
- bulbus glandis: distal enlarged part of corpus spongiosum, drains to dorsal veins of penis
what is a baculum? can it be fractured?
penis bone! can be fractured!
has a ventral groove for passage of urethra, this urethral groove is narrow at its base so urinary stones tend to get lodged here
base is attached to tunica albuginea of corpora cavernosa, apex extends in a fibrocartilaginous tip
list the 3 terminal branches of the artery of the penis and include which erectile tissue these branches supply
- dorsal artery of the penis: supplies prepuce and pars longa glandis
- deep artery of penis: supplies corpus cavernosum
- artery of the bulb: supplies corpus spongios
list the blood supply to the prostate gland and the ductus deferens
prostate: left and right prostatic arteries, which are branches internal pudendal
ductus deferens: artery of the ductus deferens
differentiate between the outer and inner laminae of the prepuce, the preputial orifice, and the preputial fornix
the prepuce is a fold of integument
outer haired layer: external lamina
inner layer: mucosa, internal lamina
layers meet at preputial orifice
preputial cavity: between internal lamina and the glans
inner layer reflects onto skin of glans at preputial fornix
describe the condition that leads to presence or absence of cornified spines on the glans penis of the male feline
sexually mature intact male glans penis is covered in cornified spines that disappear after castration
list the accessory sex glands of the male feline (2)
- prostate gland
- bulbourethral glands
