External Genitalia and Perineum

Perineum

This is the diamond shaped region positioned between the thighs

Pelvic Floor

The perineum is positioned inferior to what structure?

Symphysis pubis

Anterior boundary of the perineum

Tip of coccyx

Posterior boundary of the perineum

Ischial tuberosity, Ischiopubic rami, sacrotuberous ligaments, Pubic Arch

Lateral boundary of the perineum

Pelvic diaphragm

What separates the pelvic cavity from the perineum

Ischial tuberosities

A line connecting what 2 structures divides the perineum into 2 perineal triangles

Urogenital

What triangle is the anterior perineal triangle

Anal

What triangle is the posterior perineal triangle

Openings of urinary and reproductive tracts

Content of the urogenital triangle

Anus and lower opening of the anal canal

Content of the anal triangle

Ischiorectal fossa

This structure lies on each side of the lower opening of the anal canal

Pubic symphysis

Anterior boundary of the MALE perineum

Pubic Arch

Anterior boundary of the FEMALE perineum

Diamond shaped

Describe the pattern of pubic hair distribution in males

Inverted triangle

Describe the pattern of pubic hair distribution in females

Ischocavernosus

This muscle covers the crus of the penis and clitoris

Bulbospongiosus

This muscle covers the bulb of the penis and vestibule wall

F; Absent

T/F: The deep transverse perineal muscle is prominent in females (According to snell’s)

Perineal Body

This is a small mass of fibrous tissue that keeps the integrity of the pelvic floor

Center of posterior margin of the urogenital diaphragm

Where is the perineal body located?

T

T/F: The superficial fascia in males is made up of the camper’s fascia while the membranous layer is made up of the colles’ fascia

Dartos muscle

The camper’s fascia will become what structure in the scrotum

F; Superficial (Potential) while Deep (Anatomic)

T/F: The superficial pouch is an anatomic space while the deep pouch is a potential space in males

Colles’ fascia

What structure is found inferior to the superficial pouch in both females and males

Perineal Membrane

What structure is found superior to the superficial pouch in both females and males

Superior fascia of the urogenital diaphragm and the inferior fascia of the pelvic diaphragm

What structure is found superior to the deep pouch in both females and males

Perineal membrane

What structure is found inferior to the deep pouch in both females and males

Membranous urethra, sphincter urethra, Cowper’s glands, Deep transverse perineal m., Internal pudendal a., dorsal nerve of the penis

Structures found in the deep pouch of males

Ischiocavernosus, Bulbospongiosus, superficial transverse perineal muscle, penis, and scrotum

Structures found in the superficial pouch in males

Ischiocavernosus and Bulbospongiosus

These 2 muscles assists in erection

Deep dorsal vein

What structure does the bulbospongiosus compress to assist in erection

Superficial transverse perineal muscle

This muscle fixes the perineal body in the center

Perineal branch of the pudendal nerve

Innvervation of the superficial pouch muscles

Deep transverse perineal m. and Urethral Sphincter

What forms the triangular musculofascial diaphragm

Sphincter urethrae

What muscle surrounds the membranous urethra

Pubic Arch

Origin of the sphincter urethrae muscle

Urethra

Insertion of the sphincter urethrae muscle

Perineal branch of the pudendal nerve

Innervation of the sphincter urethrae muscle

Voluntary sphincter of the urethra

Action of the sphincter urethrae muscle

Cowper’s gland/Bulbourethral Gland

This gland is located in the deep perineal pouch and functions to release fluids the lubricates the distal urethra and neutralize the acidic urine in the urethra

Ischial Ramus

Origin of the deep transverse perineal m.

Perineal Body

Insertion of the deep transverse perineal m.

T

T/F: The deep transverse perineal m. is insignificant in males

Perineal Branch of the pudendal nerve

Innervation of the deep transverse perineal m.

Anterior trunk of the internal iliac artery

Origin of the internal pudendal artery

Greater sciatic foramen

The internal pudendal artery exits the pelvic cavity via?

Lesser sciatic foramen

The internal pudendal artery enters the perineum via?

Dorsal nerve of the penis

This is the deepest division of the pudendal nerve the gives a branch to the corpus cavernosum and ends in the glans penis

Mons pubis

This is the rounded hair-bearing elevation of skin above the pubis

Clitoris

This structure is located at the apex of the vestibule and is partially covered by the prepuce

Labia majora

This is the fat filled skin folds extending from the mons pubis

Labia minora

This is smaller, hairless skin folds between the labia majora

Vestibule

This is the triangular area formed by the labia minora that contains the vaginal and urethral orifice

Bartholin Glands

These are the openings in the female external genitalia that secrete lubrication during intercourse and acts as homologues to the cowper’s gland

Between hymen and labia majora at 5 and 7 o’ clock

Where are the bartholin glands located?

Internal pudendal a. & v.

Blood supply (and venous drainage) of the female external genitalia

Pudendal nerve and Pelvic Plexus

Innervation of the female external genitalia

Urogenital hiatus

This structure pierces the deep transverse perineal muscle in females

Perineal Body

Origin of bulbospongiosus

Corpus spongiosum / Fascia of vestibular bulb

Insertion of bulbospongiosus

Bulbospongiosus

This muscle serves as a sphincter for the vagina and for clitoral erection

Ischial tuberosity

Origin of the ischiocavernosus

Corpus cavernosum

Insertion of the ischiocavernosus

Ischial tuberosity

Origin of the superficial transverse perineal m.

Perineal body

Insertion of the superficial transverse perineal m.

T

T/F: The perineal body of females is larger than males

F; Shorter

T/F: The urethra of females is much longer compared to males

Paraurethral glands (Skene’s Glands)

This structure is located at the sides of the external urethral meatus in females and functions similarly to the prostate gland in males

Dorsal nerve of the clitoris

This nerve provides sensation to the skin and surroundings of the clitoris

Transverse perineal, Posterior labial, Deep and Dorsal artery of the clitoris, Inferior rectal artery

Give the 5 branches of the internal pudendal artery the supplies the female perineum

Posterior scrotal, Perineal, and Pudendal

Nerves of the male perineum (3)

Ilioinguinal and Genitofemoral (Genital Branch) n.

Nerve supply of the anterior vulva

Perineal and Posterior cutaneous n.

Nerve supply of the posterior vulva

Inferior hypogastic plexus

Nerve supply of the vagina

Perineal branch of the pudendal n.

Nerve supply of the muscles and skin of the perineum

Bulb

This part of the penial root is located in the midline with the urethra running through it

Corpus spongiosium

The bulb extends into the penis as what structure?

Crus

This part of the penile root is attached to the pubic arch

Corpus cavernosum

The 2 crus will converge anteriorly to form what structure?

Buck’s fascia

This is the tubular sheath of deep fascia the encloses the 3 cylinders of erectile tissue

Glans penis

This is the helmet shaped part on the anterior end of the corpus spongiosum

External urethral meatus

This structure perforates the glans penis anteriorly

Colles’ fascia

Superficial fascia of the penis

External pudendal

Blood supply of the skin and superficial fascia of the penis

Femoral a.

Origin of external pudendal a.

Internal pudendal a.

Blood supply of the deeper structures of the penis

Deep artery of the penis

This artery supplies the crus and corpus cavernosum of the penis

Helicine arteries

What artery does the deep artery of the penis give rise to?

Dorsal artery of the penis

This artery supplies the dorsum of the penis, skin, and fascia

Artery of the bulb

This artery supplies the spongiosum, bulb, and glans penis

Large deep dorsal vein → Prostatic venous plexus

Where does the veins of the penis drain into?

Medial group of superficial LN → Internal Iliac LN

Lymph drainage of the penis

Pudendal n.

This nerve supplies the somatic nerve to penile skeletal muscles and skin

Inferior hypogastric plexus

This supplies the smooth muscle and vascular smooth muscle of the helicine arteries

Prepuce

This structure covers the glans penis

Frenulum

Structure that attaches the prepuce to the galns

Clitoris

This is the female phallic organ

F; Clitoral only 2

T/F: Both the penile root and clitoral root are made up of 3 columns of erectile tissue

Glans of the clitoris

This is the most sensitive part of the clitoris