What is the scrotum?
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A cutaneous fibromuscular sac that contains the testis and associated structures.
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What is the scrotum?
A cutaneous fibromuscular sac that contains the testis and associated structures.
What type of veins are involved in internal hemorrhoids?
Dilated tributaries of the superior rectal vein.
What does the posterior labial artery supply?
Skin of the posterior part of labia majora and minora.
What is the origin of the artery of the bulb of vestibule?
Terminal branch of the perineal artery.
What arteries supply the anterior scrotum?
Anterior scrotal artery (from deep external pudendal artery) and posterior scrotal artery (from perineal artery).
What marks the commencement of the anal canal?
The anorectal junction, marked externally by the puborectalis sling.
What is the drainage pathway for the scrotum?
External pudendal veins drain into the great saphenous vein.
What approaches can be employed for males during a pudendal nerve block?
Transperineal or perirectal approaches.
Which nerves innervate the anterior aspect of the scrotum?
Anterior scrotal nerves (from ilioinguinal nerve) and genital branch of genitofemoral nerve.
What type of muscle is primarily associated with the anal canal?
Smooth muscle of the muscularis externa, under involuntary control.
What is the homologous structure of the glans penis in females?
Glans clitoris (formed by corpus cavernosum).
Which muscle is associated with the ischioanal fossa?
Levator ani.
Which vein drains the superior half of the anal canal?
Superior rectal vein, which drains into the portal system.
What is the intrabulbar fossa?
An expansion of the spongy urethra at the bulb of the penis.
What are the components of the external anal sphincter (EAS)?
It consists of three parts: deep, superficial, and subcutaneous.
What is the glans penis?
Distal enlargement of the corpus spongiosum.
What does the dorsal artery of the penis supply?
Superficial tissue of the penis, corpus spongiosum, and spongy urethra.
What is the course of the deep artery of the penis?
Runs within the corpora cavernosa.
What is the primary nerve that innervates the spongy urethra?
Dorsal nerve of the penis.
What are the contents of the anal triangle?
Ischioanal fossa, anal canal and anus, external anal sphincter, anococcygeal ligament, pudendal canal and its enclosed structures, inferior rectal nerves and vessels.
What is the purpose of a pudendal nerve block?
To diagnose and manage chronic pelvic pain caused by pudendal neuralgia.
What is the pectinate line (dentate line)?
A serrated line along the anal valves that divides the anal canal into upper and lower halves.
Why are internal hemorrhoids usually less painful?
They receive autonomic innervation.
When might internal hemorrhoids become painful?
If they are clotted and prolapsed outside.
What is the suspensory ligament of the penis?
A condensation of deep fascia that arises from the pubic symphysis.
What does the artery of the bulb of vestibule supply?
Bulbs of vestibule and greater vestibular glands.
What is the function of anal cushions?
They aid in maintaining fecal continence.
Where does the anal canal terminate?
At the anal verge (anocutaneous line).
What are anal columns?
Longitudinal folds of mucosa containing the terminal branches of superior rectal vessels.
What does the deep artery of the clitoris supply?
Erectile tissue of the clitoris.
What nerves innervate the posterior aspect of the scrotum?
Posterior scrotal nerves (from perineal nerve) and perineal branch of posterior femoral cutaneous nerve.
What does the fundiform ligament blend with inferiorly?
Darto’s fascia that forms the scrotal septum.
Which ligament is associated with the Pudendal nerve in the Pudendal canal?
Sacrotuberous ligament (cut).
What is the origin of the dorsal artery of the penis?
Internal pudendal artery.
In which section was the internal pudendal artery discussed in detail?
In the section 'arteries of the pelvis' (Pelvis I).
What is the scrotal raphe?
A visible ridge of tissue on the surface of the scrotum that divides it into two lateral portions.
What characterizes the lower half of the anal canal?
It features the anal pecten, which is a smooth area lined by non-keratinized squamous epithelium with no hair or sweat glands.
What are portocaval anastomoses?
Connections present around the anal pecten line.
What forms the inferior boundary of the anal region?
Skin of the anal region.
What is the typical location of hemorrhoids associated with?
The location of anal cushions.
What is the origin of the external pudendal arteries?
Femoral artery.
What is the origin of the deep artery of the clitoris?
Terminal branch of the internal pudendal artery.
What areas do the external pudendal arteries distribute blood to?
Mons pubis and anterior aspect of labia.
What is a prolapsed internal hemorrhoid?
An internal hemorrhoid that has protruded outside the anal canal.
How do most structures drain venously in relation to their arteries?
By veins with the same names as the corresponding arteries.
What is the function of the inner circular muscle in the anal canal?
It thickens to form the internal anal sphincter and surrounds the superior 2/3 of the anal canal.
What are the two main parts of the root of the penis?
Crura and bulb.
What is the transverse fibrous septum associated with?
Ischioanal fossa.
What is the lymphatic drainage for the superior half of the anal canal?
Internal iliac lymph nodes.
What does the genital branch of the genitofemoral nerve innervate?
Skin of anterior labium majus and mons pubis.
What ligament is associated with the anal region?
Anococcygeal ligament.
What is the characteristic of the internal anal sphincter?
It is tonically contracted.
What is the distribution of the deep artery of the penis?
Corpora cavernosa (for erection).
What are the corpora cavernosa?
Paired erectile tissues containing the deep arteries of the penis.
What is the general description of the ischioanal fossa?
Large, bilateral wedge-shaped spaces filled with fat and fibrous septa.
At which positions are hemorrhoids usually found when viewed inferiorly?
At the 3, 7, and 11 o’clock positions.
What is a common cause of pudendal neuralgia?
Pudendal nerve entrapment.
How is the scrotal raphe connected to the penile raphe?
It is continuous with the penile raphe on the ventral surface of the penis.
What does the corpus spongiosum enlarge to form?
The glans penis.
What can happen to pus/abscesses in the ischioanal fossa?
They can spread to the other side through a communication pathway behind the anus.
What is the general description of the Pudendal (Alcock’s) canal?
A horizontal passageway within the condensation of the obturator fascia, quite short (mean length of ~1.6 cm in adults).
Which bone is located laterally in the anal region?
Ischium.
What are the two divisions of the spongy urethra?
Bulbous portion and penile portion.
What muscle is found medially in the anal region?
External anal sphincter.
What is the primary function of the penis?
Male organ of copulation and outlet for urine and semen.
What structure separates the deep pouch from the ischioanal fossa?
The perineal membrane.
What is the arterial supply for the superior half of the anal canal?
Superior rectal artery.
What is the anterior recess of the ischioanal fossa?
An extension of the ischioanal fossa forwards, beyond the posterior border of the perineal membrane and into the UG triangle.
What are anal valves?
Crescent mucosal folds joining the inferior ends of anal columns.
What is the origin of the posterior labial artery?
Terminal branch of the perineal artery.
Where is the local anesthetic injected for a pudendal nerve block?
Near the ischial spine.
What is the anal canal?
The terminal part of the large intestine.
What components make up the anal cushions?
Arterial and venous plexuses, arteriovenous connections, smooth muscles, and fibrous strands.
What approach is usually used for females during a pudendal nerve block?
Transvaginal approach.
How are tumors distal to the anal verge managed?
They are managed as skin cancer.
What is the fundiform ligament of the penis?
A band of subcutaneous tissue descending from the midline from the linea alba, surrounding the penis.
What structures are associated with the anal canal?
Anal columns, anal sinuses, anal valves, anal cushions, and anal pecten.
What vessels are found in the pudendal canal?
Internal pudendal vessels.
What anatomical position is the penis in when erect?
In the correct anatomical position.
What forms the posterior boundary of the anal region?
Sacrotuberous ligament and gluteus maximus.
What does the dorsal artery of the clitoris supply?
Connective tissue of the clitoris.
What is the origin of the anterior labial nerve?
Ilioinguinal nerve (L1).
What is Gallaudet’s fascia associated with?
It is associated with the structures in the ischioanal fossa.
What is the arterial supply for the inferior half of the anal canal?
Inferior rectal artery.
What is the origin of the posterior labial nerve?
Perineal nerve (S2 – S4).
What is the function of the dorsal nerve of the clitoris?
Sensory innervation to the clitoris.
Where does the anterior recess of the ischioanal fossa lie?
Above the deep perineal pouch (or UG diaphragm).
Where are internal hemorrhoids located in relation to the pectinate line?
Above the pectinate line.
What type of anesthesia technique is a pudendal nerve block?
A regional anesthesia technique.
What does the scrotal raphe connect to posteriorly?
It connects posteriorly along the midline with the perineal raphe.
What does the pudendal nerve block aim to block?
Sensory signal transmission in the pudendal nerve.
What is the anal verge?
The distal end of the anal canal where pigmented skin is present, along with hair and sweat glands.
What ligament is involved in the spread of pus/abscesses from the ischioanal fossa?
The anococcygeal ligament.
Where does the Pudendal canal begin and end?
It begins just below the ischial spine and ends near the posterior margin of the perineal membrane.
How can pus/abscesses spread to the UG triangle?
Via the anterior recesses of the ischioanal fossa.
What is the location of the Pudendal canal?
It runs on the lateral wall of the ischioanal fossa.
With which fascia is the fundiform ligament continuous superiorly?
Scarpa’s fascia.
What are the main contents of the Pudendal canal?
Pudendal nerve and internal pudendal vessels.
Where does the deep dorsal vein of the clitoris drain?
Into the vesical venous plexus.
What are anal sinuses?
Recesses between anal columns, proximal to anal valves, containing openings of ducts of anal glands.
What is the role of the internal pudendal artery in scrotal anatomy?
It supplies blood to the perineal vessels, including the posterior scrotal arteries.
What is the main arterial supply of the perineum?
The internal pudendal artery.
What is the corpus spongiosum?
A single erectile tissue containing the spongy urethra.
Where is the corpus spongiosum located in relation to the corpora cavernosa?
Ventral to the corpora cavernosa.
What are anal cushions?
Three swellings in the interior wall of the anal canal.
What is the scrotal septum?
A prolongation of the Darto’s fascia that divides the internal space of the scrotum into two compartments.
What is the spongy urethra?
It begins at the distal end of the membranous urethra and ends at the external urethral orifice.
What does the suspensory ligament of the penis fuse with?
The deep (Buck’s) fascia of the penis at the junction between the root and body.
What is a thrombosed external hemorrhoid?
An external hemorrhoid that has formed a clot.
What are the associated ligaments mentioned?
Suspensory ligament and Buck’s fascia.
Where is the bulbous portion of the spongy urethra located?
In the bulb of the penis.
What structures are located anteriorly in the anal region?
Bodies of the pubic bones inferior to puborectalis.
What is the origin of the dorsal artery of the clitoris?
Terminal branch of the internal pudendal artery.
What is the homologous structure of the bulb of the penis in females?
Bulb of vestibule (formed by corpus spongiosum).
What fascia is found in the male coronal section related to the ischioanal fossa?
Buck’s fascia.
Where is the root of the penis located?
In the superficial perineal pouch.
What is the navicular fossa?
An expansion of the spongy urethra at the glans penis.
What is Colles’ fascia?
A fascia related to the perineal region and ischioanal fossa.
Which vein drains the inferior half of the anal canal?
Inferior rectal vein, which drains into the caval system.
What is the lymphatic drainage for the inferior half of the anal canal?
Superficial inguinal lymph nodes.
What is the origin of the artery of the bulb of the penis?
Perineal artery.
What is the mons pubis?
A cushion of fatty tissue anterior to the pubis, covered by coarse pubic hair.
Where does the deep dorsal vein of the penis run?
Deep to Buck’s fascia, medial to the deep arteries of the penis.
What is unique about the labia minora?
They are hairless and contain erectile tissue and small blood vessels.
Where do the ducts of Skene glands open?
On each side of the external urethral orifice.
What does the root of the clitoris consist of?
Two crura that attach to the ischiopubic rami.
What is the origin of the anterior scrotal artery?
It is a branch of the deep external pudendal artery, which comes from the femoral artery.
What is the role of the puborectalis muscle?
It forms a sling around the anorectal junction and helps maintain fecal continence.
What is the homologous gland to the bulbourethral gland in females?
Greater vestibular gland (in superficial perineal pouch).
Where does the dorsal artery of the penis run?
Deep to Buck’s fascia in the penis, medial to the dorsal nerves of the penis.
How does the outer longitudinal muscle layer behave in the anal canal?
It is relatively thin compared to the circular layer and extends outwards as the fibrous septa of the ischioanal fossa.
What covers the glans in an uncircumcised penis?
The prepuce (foreskin).
What is the frenulum?
A median fold of skin that attaches the prepuce to the glans.
What innervates the superior half of the anal canal?
Inferior hypogastric plexus.
How are the crura of the penis attached?
To the inferior parts of the internal surfaces of the ischial rami.
What is the function of fat in the ischioanal fossa?
Helps with fecal continence and allows distension of the anal canal.
What does the deep dorsal vein of the penis drain blood from?
Cavernous spaces of corpora cavernosa and other deep structures.
Why are external hemorrhoids more painful?
They involve dilated tributaries of the inferior rectal vein and receive somatic innervation.
What is the origin of the dorsal nerve of the penis?
Terminal branch of the pudendal nerve, S2 – S4.
What effect do cavernous nerves have?
Vasodilation of helicine arteries (branches of deep artery of penis).
What clinical issue can arise from infection of anal glands?
It can produce abscesses and form fistulae in the wall of the anal canal.
What is the homologous structure of the skin over the penis in females?
Labia minora.
What supplies blood to the spongy urethra?
Urethral artery and dorsal artery of the penis.
How does the spongy urethra drain blood?
Through urethral veins and dorsal veins of the penis.
What is the effect of the cavernous nerves?
Vasodilation of helicine arteries to produce erection/engorgement of erectile tissue.
What type of sensory information does the superior half of the anal canal respond to?
Sensitive to stretch only.
What innervates the inferior half of the anal canal?
Inferior rectal nerve.
What do the labia minora surround?
The vestibule.
What does the superficial dorsal vein of the penis drain into?
Superficial external pudendal vein, which then joins the great saphenous vein.
What does the superficial dorsal vein of the penis drain?
Superficial tissues of the penis.
What is the vaginal orifice?
The opening of the vagina.
Which muscle is part of the posterior border of the perineal membrane?
Levator ani.
What are the names of the three anal cushions?
Left anal cushion, right anterior anal cushion, right posterior anal cushion.
What is the homologous structure of the scrotum in females?
Labia majora.
What forms the anterior boundary of the anal triangle?
Posterior border of perineal membrane.
What surrounds all erectile tissues in the penis?
A fibrous capsule called tunica albuginea.
What is the bulb of vestibule?
Paired elongated erectile tissue that stretches along the sides of the vaginal orifice.
What are the labia majora?
Broad folds of skin on each side that pass from the mons pubis towards the anus, covered with crisp pubic hair.
What causes hemorrhoids?
Weakened anal cushions due to frequent straining.
What forms the frenulum of the clitoris?
The medial folds of the labia minora unite to form it, anchoring the clitoris in place.
What are the three parts of the clitoris?
Root, body, and glans.
What is the origin of the cavernous nerves?
Prostatic nerve plexus (fibers from S2 – S4).
What forms the posterior boundary of the anal triangle?
Coccyx.
What does the artery of the bulb of the penis supply?
Bulb of penis, corpus spongiosum, glans penis, urethra.
What forms the bulb of vestibule?
The corpus spongiosum.
What forms the superior boundary (roof) of the ischioanal fossa?
Pelvic diaphragm.
What are Skene glands?
Paraurethral mucous glands homologous to prostatic glands in males.
What is the labium majus?
The lateral fold of the labium minus.
What is the glans of the clitoris?
The exposed part at the distal end of the body, covered by prepuce.
What does the deep dorsal vein of the penis drain into?
Prostatic/vesical venous plexus.
What is the vestibule?
The space surrounded by the labia minora that contains the vaginal and urethral orifice.
Where do external hemorrhoids occur?
Below the pectinate line.
Where is the clitoris located?
Where the labia minora meet anteriorly.
Where does the dorsal nerve of the penis run?
Deep to Buck’s fascia, lateral to the dorsal arteries of the penis.
What types of sensory information does the inferior half of the anal canal respond to?
Sensitive to pain, temperature, and touch.
What are the greater vestibular glands?
Glands located in the superficial perineal pouch that secrete mucus.
Where does the superficial dorsal vein of the penis run?
Between superficial and deep fascia of the penis.
What is the function of the frenulum in the vulva anatomy?
It connects the glans clitoris to the labia minora.
