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Perineum Part II Morse Anatomy Block II Unit II


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What facets with the name "pudendal" run together?
The nerve, artery and vein (artery + vein = internal pudendal) run together
What are internal hemorrhoids? What causes them?
Vericose veins of the anal canal due to impediment of venous drainage. This can result from chronic increase in abdominal pressure, pregnancy, tumors and sometimes sclerosis of the liver.
What portion of the anal canal is affected by internal hemorrhoids?
The upper portion.
What artery supplies blood to the upper portion of the anal canal?
Superior rectal.
While internal hemorrhoids are a pathology in themselves, what other condition can they lead to? Describe how this happens.
Anal columns become engorged with blood and protrude into the lumen of the anal canal. This increases the chance that the anal columns will tear.
Describe the appearance of internal hemorrhoids.
They can look like raisins projecting from the anus and can actually prolapse out of the anus. These are still INTERNAL hemorrhoids.
What artery supplies blood to the lower portion of the anal canal?
The inferior rectal artery.
Where is the plexus located that external hemorrhoids effect?
It is subcutaneous (covered by skin) and may be found in the anal canal.
Are external hemorrhoids painful? How about internal?
External hemorrhoids are very painful. Internal hemorrhoids may get dry and itch but are not very painful.
Where is the plexus that internal hemorrhoids effect located?
In the submucosal layer (mucosal layer covers them) of the upper portion of the anal canal.
What 2 superficial fascias extend from the abdomen into the urogenital triangle?
Camper's and Scarpa's fascia.
Describe the extension that camper's fascia has into the urogenital triangle. What kind of tissue is it? What is its new name?
Now called Dartos layer and it consists of very little fat and mostly loose CT and smooth muscle in the scrotum.
What is the action of the Dartos muscle? What does the dartos muscle contract in response to?
Regulates the size of the scrotal sac. It contracts with response to cold giving dimples or an "orange peel" appearance to the scrotum.
Where is there no fat in the urogenital triangle?
No fat on the shaft of the penis and clitoris.
Does the female camper's faschia lose fat like in the male?
No, the labia majora is made prominent by fat.
Can you distinguish the scarpa's fascia from the dartos fascia on the scrotum? Where would this point be?
Describe the colles fascia. What does it line?
The colles fascia lines the crotal sac and is a thick/opaque membrane.
What does colles fascia separate?
The urogenital triangle from the anal triangle.
Can fluid move between the urogenital triangle and the anal triangle?
NO!, Colles fascia separates them.
What very important function does dartos fascia assist with?
Erection of the penis.
What makes up the floor of the superficial perineal pouch?
The dartos and colles fascia.
What makes up the roof of the superficial perineal pouch?
The perineal membrane.
What structure does the perineal membrane close?
The pubic arch (fills it in)
What forms the deep pouch?
The perineal membrane and fascia that faces the pelvis (superior fascia of urogenital diaphragm.
Where are most of the structures of the perineum found? In the superficial or deep pouch?
Superficial pouch.
What paired muscle lies laterally in the superficial pouch?
The ischiocavenosus muucle
What paired muscle lies medially in the superficial pouch? How does it differ in males and females?
The bulbospongiosus muscle is a fused muscle in males and 2 muscles in females.
What muscle is lateral from the ischial tuberosity and runs to the perineal body?
The superficial transverse perineal body. (Not large/important)
What type of muscle are the ischiocavernosus and the bulbospongiosus? Do they extend into the shaft of the penis?
These muscles are striated and they do not extend into the shaft of the penis.
What sort of tissue does extend into the shaft of the penis? Describe the tissue.
Erectile tissue extends into the shaft and is rich invenous sinusoids.
What is the lateral attachment of the crus of the penis?
Along the inferior pubic ramus toward the pubic symphysis.
What does the crus extend as into the penis?
The corpus cavernosa.
Describe the 3 parts of the root of the penis.
2 crura and 1 bulb
What does the bulb of the penis become once it loses its muscular covering as it heads into the shaft of the penis?
The corpus spongiousum.
In what tissue is the urethra found?
The corpus spongiosum
What is the glans? What forms it?
The glans is the head of the penis, it is formed from corpus spongiosum.
What is the orifice at the tip of the penis called?
The external urethral orifice.
What does the glans form a cap over?
The corpus cavernosa.
What is the white/gray membrane that connects the ischial pubic rami?
The perineal membrane.
What is the proximal attachement of the bulb and crura?
The perineal membrane.
What separates the deep transverse perineal muslce from the the superficial one?
The perineal membrane
What is the external urethral sphincter and what type of muscle is it?
It is a muscle that can close off the urethra voluntarily. It is voluntary/striated.
Which has more erectile tissue the corpus spongiosum or the corpus cavernosa?
The corpus cavernosa has more erectile tissue (provides most of the rigidity of the penis).
What is the fibrous septum that separtaes teh corpus spongiosum and the corpus cavernosa?
Buck's fascia.
What does the ischiocavernosus muscle do?
Acts like asleeve to restrict increase in diameter. This increases engorgement of blood into the crus.
Which is more lateral the ischiocavernosus or the bulbospongiosus muscle?
The ischiocavernosus is more lateral.
What is the function of the bulbospongiosus muscle?
IT contracts to expel urine or semen.
Where is a gland found in the male urogenital triangle? What is it called?
In the deep pouch, it is called the bulbourethral or cowper's gland.
What does the duct of the bulbourethral or cowper's gland pierce?
The perineal membrane.
Where does the bulbourethral or cowper's gland deliver its secretions?
To the bulb of the penis. (Superficial pouch)
What sort of secretion does the bulbourethral or cowper's gland secrete and what is the purpose of it?
It is a watery secretion or preejaculate that neutralizes the acidity along the male urethra and in the female vagina.
What artery supplies the perineum?
The internal pudendal.
What is the first branch of the internal pudendal that cuts through fat to supply the anal triangle?
The inferior rectal artery.
What supplies most of the structures of the superficial pouch?
The perineal artery.
What does the perineal artery supply (3)?
Erectile bodies, skin of urogenital, posterior aspect of scrotum.
What supplies most of the structures in the deep pouch?
The internal pudendal artery.
At what edge does the internal pudendal artery enter the deep pouch?
At the posterior edge.
What structures does the deep pouch supply? (3)
Urethra, bulbourethral gland, muscles in the deep pouch.
What are the 2 branches the internal pudendal artery provides as it approaches the pubic symphysis?
The Deep artery of the penis and the dorsal artery.
What does the deep artery of the penis supply?
The crus and the penis.
What does the dorsal artery supply?
The dorsal aspect of the penis
When the penis is flaccid which way does the dorsal surface face?
What are the 2 terminal branches of the pudendal nerve in the perineum?
The perineal and dorsal nerve.
What does the perineal nerve supply?
The superficial pouch.
What does the dorsal nerve supply?
The skin of the penis.
What sort of nerve is the perineal nerve? What is it sensory to? What is it motor to?
It is a mixed nerve that is sensory to the skin, labia and scrotom and motor to all muscles of the superficial and deep pouch.
What sort of nerve is the dorsal nerve? What is it sensory to? What is it motor to?
IT is a pure sensory nerve that only supplies the skin of the penis. NO MOTOR!
How many corpus spongiosum are there? How about corpus cavernosus?
1 corpus spongiosum
Paired corpus cavernosa
What is the deep thick sleeve of fascia that envelopes the penis?
Buck's fascia or deep fascia of the penis.
What lies between Buck's fascia and the skin?
The dartos muscle.
What is the 1 vein in the dartos and what does it drain?
The superficial dorsal vein. IT drains the skin of the penis.
Describe the path of the superficial dorsal vein.
Torturous in its path.
What separates the superficial and deep doral veins?
Buck's fascia.
What drains the erectile tissue?
The deep dorsal vein.
What are the 5 structures under Buck's fascia that maintain an erect penis together? (Give them in proper orientation to each other)
The deep dorsal vein flanked by the paired dorsal artery (from internal pudendal) which is flanked by the paired dorsal nerves.
What has the highest amount of sensory nerves in the penis?
The corona or edge of the glans.
What are helicine arteries? What is/controls their function?
Helicine arteries are tightly coiled vessels in the penis that are coiled by sympathetic nerves. Parasympathetic nerves mediate their action or cause the smooth muscle to relax and blood to drain into the helicine arteries. Thus erectile tissue becomes engorged (sinusoids) and an erection is produced.
What fascia envelopes the penis?
Buck's fascia
How is the deep dorsal vein involved in the maintainance of an erection?
The deep dorsal vein is compressed which keeps an erection erect.
Is the whole process of blood becoming engorged in the penis have a similar process in females?
What is the name of the skin that covers the head of the penis?
The foreskin or prepuce.
What is smegma and where does it form?
A secretion which helps to lubricate the genitals. It can be found under the foreskin or prepuce in the male.
WHat is balonitis and what causes it?
Balonitis is inflammation of the glans of the penis. It is due to improper hygene and most often occurs in boys in diapers.
What is priapism? What pathology can it generate?
An erect penis in a pathological sense (erection longer than 4 hrs is NOT a sexual response). Priapism can compromise blood to other areas of the penis due to a maintained erection.
What is phimosis? What pathology can it generate?
IT is where the foreskin is a tight collar around the glans and cannot be retracted. This causes discomfort in males during an erection.
What is paraphimosis? What pathology can it generate?
It is where the foreskin stays retracted and forms a collar at the junction of the glans and shaft. This can compromise blood flow.
What type of muscle is the bulbus spongiosus? Where does it end proximally?
IT is skeletal muscle and it ends at the pubic symphysis?
How big is the deep pouch approximately?
A very thin layer (soda cracker)
Where does colles fascia end?
At the perineal body.
What is the perineal body?
The central tendon of the perineum.
If a male falls directly onto a bar between his legs what pathology will develop? To what areas can this pathology extend? Can this occur in a female?
Trauma can tear the urethra causing urine to leeak and accumulate over days into fascial reflections (scrotum, penis). Eventually urine will show up deep to scarpa's fascia (abdominal). But it CANNOT enter the anal triangle due to colles fascia. Cannot occur in a female due to different path of the urethra.
What flanks the deep dorsal vein? What is its origin?
The paired dorsal arteries flanks the deep dorsal vein. It comes from the internal pudendal.
What flanks the dorsal arteries?
The dorsal nerves.
What are the 5 structures under Buck's fascia that together maintain an erect penis?
2 nerves (dorsal nerves), 2 arteries (dorsal arteies), 1 vein (deep dorsal vein)

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