Urogenital Triangle Flashcards
Contents of the superficial perineal pouch
- bulb of the penis plus the bulbospongiosus muscle (male); bulb of the vestibule (female)
- crura of the penis and the ischiocavernosus muscle (male); clitoris (female)
- superficial transverse perineal muscles
- perineal nerves and vessels
- greater vestibular glands (female)
Musculofascial structure situated in the anterior part of the perineum and fills in the urogenital hiatus (the gap under the pubic arch where the levator ani is incomplete)
Urogenital diaphragm
Muscle in the scrotum - from the camper’s fascia
Dartos muscle
(1) Muscle that covers the crus of the penis
(2) the proximal segment
(1) ischiocavernosus - skeletal muscle
(2) corpus cavernosum
(1) muscle that covers the bulb of the penis
(2) distal continuation of bulb of the penis
(1) bulbospongiosus - skeletal muscle
(2) corpus spongiosum
Boundaries of the urogenital triangle (ant. half of the perineum)
- anteriorly: pubic arch
- laterally. : ishiopubic rami & ischial tuberosities
*at midline: urogenital opening
Layers of the urogenital triangle
- skin
- superficial perineal fascia
- deep perineal fascia
- superficial perineal space (inferior)
- deep perineal space (superior)
Two layers of the superficial perineal fascia
- Camper’s fascia - superficial fatty
- Colle’s fascia - deep membranous
In the scrotum, the superficial fat is replaced by a smooth muscle called
Dartos muscle
(contracts in response to cold and reduces the surface area of the scrotal skin)
Colle’s fascia is continuous anteriorly- superior with (1) and inferiorly with (2)
(1) Scarpa’s fascia of the abdominal wall
(2) tubular sheath (penis or clitoris)
The deep membranous layer is attached at the
- posterior border of the perineal membrane
- perineal body
- margins of the pubic arch
Contents of the superficial perineal pouch
1) Bulb of the (M: penis; F: vestibule) & Bulbospongiosus muscle
2) Crura of the (M: penis; F: clitoris) & ischiocavernosus mucsle
3) Superficial transverse perineal muscles
4) Perineal nerves and vessels
5) Greater vestibular glands (F)
Deep to the superficial perineal pouch at the anterior part of the perineum (urogenital triangle)
three-layered, flat, triangular, musculofascial structures - fills in the urogenital hiatus
Urogenital diaphragm
Urogenital diaphragm layers:
(superficial)
1. Perineal membrane or Inferior fascia of the urogenital diaphragm
- Deep perineal space formed by the sphincter urethrae and deep transverse perineal pouch
- Superior fascia of the urogenital diaphragm
A strong, thin, fibrous sheet that attaches along the ischiopubic rami
perineal membrane
Contents of the deep perineal space
- part of the urethra
- inferior part of the external urethral sphincter
- neurovascular brancher to the external genitalia
- anterior recess of the ischioanal fossae
The 3 masses of erectile tissue and their:
* attachment
* covering muscle
* anterior structure
(1) bulb of the penis
* attachment: perineal membrane
* muscle : bulbospongiosus
* anteriorly : corpus spongiosum
(2) Crura of the penis (right & left)
* attachment: side of the pubic arch
* muscle : ischiocavernosus
* anteriorly : corpus cavernosa
Name the tubular sheath of the deep fascia that encloses the 3 cylinders of erectile tissue
Buck’s fascia
(1) dorsal erectile tissue
(2) ventral erectile tissue
(1) corpus cavernosum (#2)
(2) corpus sopongiosum
What expands at its distal extremity to form the glans penis
corpus spongiosum
The pronounced posterior edge of the glans is the (1) and the hoodlike fold of skin that covers the glans is the (2)
(1) corona
(2) prepuce
The () is a tissue fold connecting the prepuce to the glans just below the urethral orifice or the slit-like external urethral meatus
frenulum
The 2 suspensory ligaments of the penis that assist in supporting the body of the penis are condensations of the ()
deep fascia
Blood supply to the penis
(1) to the skin and superficial fascia: external pudendal artery - branch of the femoral artery
(2) to the deeper parts of the penis: internal pudendal artery - branch of the anterior division of the internal iliac artery
(3) to the crus and corpus cavernosum: deep artery of the penis
(4) to the corpus cavernosum (spongy mass): helicine arteries
(5) to the bulb, corpus spongiosum, & glans: artery of the bulb
(6) to the skin and deep fascia: dorsal artery of the penis
Venous drainage of the penis
….> deep dorsal vein > prostatic venous plexus
Lymph drainage of the penis
- skin: medial group of the superficial inguinal nodes
- erectile bodies: internal iliac nodes
Nerve Supply to the penis
(1) somatic
(2) autonomic
(1) pudendal nerve
(2) inferior hypogastric plexus
Scrotum contents:
(1) testes
(2) epididymides
(3) lower ends of the spermatic cord
(True/False)
subcutaneous plexuses and arteriovenous anastomoses promote heat loss and thus assist in the environmental control of the temperature of the testes
True
Blood supply to the scrotum
(1) external pudendal artery - from the femoral artery
(2) scrotal branches - from the internal pudendal artery
Lymph drainage of the scrotum
- scrotum: medial group of the superficial inguinal nodes
- Testes and epididymides: paraortic lymph nodes
Nerve Supply of the scrotum
(1) anterior portion: ilioinguinal nerve & genital branch of the genitofemoral nerve
(2) posterior portion: pudendal & posterior femoral cutaneous nerve
Muscles in the male perineum:
(1) function to compress the penile part of the urethra emptying residual urine and semen; also assisting during erection by compressing blood vessels
(2) compress the crus penis to assist in the process of an erection
(3) in the posterior part of the superficial perineal pouch; function to fix the perineal body in the center of the perineum
(1) bulbospongiosus muscle
(2) ischiocavernosus muscle
(3) superficial transverse perineal muscle
Nerve supply of superficial perineal pouch
perineal branch of the pudendal nerve
Nerve supply of the muscles and skin of the ant. perineum
perineal branch of the pudendal nerve
Point of attachment for the external anal sphincter, bulbospongiosus muscle, and superficial transverse perineal muscle
Perineal body
small mass of fibrous tissue that attaches to the center of the posterior margin of the perineal membrane
Contents of Deep perineal pouch - Male
- part of the urethra - intermediate/membranous part
- part of the urethra
- inferior part of the external urethral sphincter - sphincter urethrae
- neurovascular branches to the external genitalia - dorsal nerves to the penis
- internal pudendal vessels
- bulbourethral glands
- deep transverse perineal muscles
Three urethral segments of the male urethra
1) prostatic urethra
2) intermediate/membranous urethra
3) penile urethra
Urethra surrounded by the external urethral sphincter - shortest (1.3 cm) and least dilatable
Intermediate (Membranous) Urethra
(True/False)
The inferior portion of the external urethral sphincter/ sphincter urethrae muscle compresses the intermediate part of the urethra during
Micturation
False
The sphincter urethrae muscle compresses the intermediate part of the urethra and relaxes during micturition. This is the voluntary urethral sphincter.
Nerve supply to the sphincter urethrae
Perineal branch of the pudendal nerve
Bulbourethral glands:
(1) gland location
(2) duct opening
(3) secretion
(1) sphincter urethrae muscle
(2) into the penile urethra
(3) alkaline mucus like fluid - lubrication
(True/False)
Penile erection is a sympathetic stimulation causing vasodilation of the helicine arteries
False
…..parasympathetic stimulation
(True/False)
During ejaculation - a parasympathetic response; the internal urethral sphincter of the bladder contracts and the detrusor muscle relaxes, preventing reflux of the spermatozoa into the bladder (retrograde ejaculation)
False
(Parasympathetic) > sympathetic
Length of the male urethra
20 cm
3cm long part of the male urethra that is the widest and most dilatable
Prostatic urethra
The longest part of the male urethra (15.75 cm). Runs through the corpus spongiosum where just before the external meatus, the urethra will dilate to form the fossa terminalis (navicular fossa)
Penile urethra
The collective name for the area of the female external genitalia
Vulva
The vestibule is a space posterior to the glans clitoris, between the labia minora. It contains:
1) openings of the urethra
2) vagina
3) ducts of the greater and lesser vestibular glands
Blood supply to the vulva
- external pudendal artery
- internal pudendal artery
Lymph drainage of the vulva
Medial group of the superficial inguinal nodes
Nerve Supply of the vulva
- anterior : ilioinguinal nerves & genital branch of the genitofemoral nerves
- posterior: perineal nerves & posterior femoral cutaneous nerves
Female counterpart of the penis
Clitoris
- made up of 2 erectile tissue right and left corpora cavernosa and its surrounding muscle, ischiocavernosus
What is the most sensitive part of the clitoris
Glans clitoris - covered by the prepuce
(1) Blood supply of the clitoris
(2) lymph drainage of the clitoris
(3) nerve supply of the clitoris
(1) internal pudendal artery
(2) internal iliac nodes or deep inguinal nodes
(3) pudendal nerve
Paired erectile bodies on each side of the vestibule, deep to the labia minora
Vestibular bulbs (erectile body) - Covered by the bulbospongiosus muscle
Female counterpart of the bulbourethral glands in males
Greater vestibular glands
- drains its secretion into the vestibule by a small duct, which opens into the groove between the hymen and the posterior part of the labium minus. These glands secrete lubricating mucus
(True/False)
A notable sex difference is the presence of the greater vestibular glands in the female superficial space, whereas the male counterpart bulbourethral glands are located in the deep perineal space.
True
It is a wedge-shaped mass of fibrous tissue situated between the lower end of the vagina and the anal canal
It is the point of attachment of many perineal muscles including the levatores ani muscles.
Perineal body
Muscles in the female perineum:
(1) reduces the size of the vaginal orifice and compresses the deep dorsal vein of the clitoris for clitoral erection
(2) contraction assists in causing the erection of the clitoris - on each side of the crus of the clitoris
(1) bulbospongiosus muscle
(2) ischiocavernosus muscle
(True/False)
The deep transverse perineal muscles support the vaginal canal of the females
False
Deep transverse perineal muscles are only present in males
Female counterpart of the prostate gland for males
paraurethral or lesser vestibular glands
*note the difference in position of the 2 vestibular glands
Thin mucosal fold in the vaginal orifice
hymen
Vaginal supports:
(1) upper 1/3
(2) middle 1/3
(3) lower 1/3
(1) upper 1/3: levatores ani muscles, with transverse cervical, pubocervical, & sacrocervical ligaments
(2) middle 1/3: perineal membrane or urogenital diaphragm
(3) lower 1/3: perineal body
Blood supply to the vagina
(1) vaginal artery - from ant. division of the internal iliac artery
(2) vaginal branches of the uterine artery
Lymph drainage of the vagina
(1) upper 1/3: internal and external iliac nodes
(2) middle 1/3: internal iliac nodes
(3) lower 1/3: superficial inguinal nodes
Nerve Supply of the vagina
Inferior hypogastric plexus
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