Perineum Flashcards
What is the perineum? (2)
- External surface area & shallow compartment
- Contains: external genitalia, lower segments of genitourinary & gastrointestinal systems & perineal body
How is the perineum bounded?
- Bounded
- Pelvic outlet
What is the perineum separated from?
- Separated from pelvic cavity (roof)
- Pelvic diaphragm
What is the perineum between? (3)
- Narrow region btw proximal parts of thigh
- Diamond shaped (x2 triangles)
- Anal triangle (post) & urogenital triangle (ant)
Perineum: Surface Landmarks
* Borders
* Anterior:
Pubic symphysis,
ischiopubic rami
Perineum: Surface Landmarks
* Borders
* Lateral:
Ischial tuberosity,
sacrotuberous ligament
Perineum: Surface Landmarks
* Borders
* Posterior:
Coccyx
Perineum: Surface Landmarks
* Perineal body
* Convergence of fibres:
- Bulbospongiosus, external
anal sphincter, superficial
& deep transverse perineal, external urethral sphincter, levator ani
What is the superficial perineal pouch? (3)
- Potential space
- Subcutaneous tissue & perineal membrane
- Laterally: ischiopubic rami
Superficial perineal pouch
Male contents: (4)
- Root of penis & ischiocav. &
bulbosp. muscles - Proximal part of spongy
urethra - Superficial transverse
perineal muscles - Deep perineal branches of
internal pudendal vessels &
pudendal nerves
Superficial perineal pouch
Female contents: (5)
- Clitoris & ischiocv. muscles
- Bulbs of vestibule &
bulbosp. muscles - Superficial transverse
perineal muscles - Greater vestibular glands
- Deep perineal branches of
internal pudendal vessels &
pudendal nerves
Deep perineal space
* Bounded:
* Inferiorly =
- Perineal membrane
Deep perineal space
* Bounded:
* Superiorly =
- Inferior fascia of pelvic diaphragm
Deep perineal space
* Bounded:
* Laterally =
- Inferior portion of obturator fascia
Deep perineal space
* Contents
* Both sexes: (3)
- Part of urethra
- Inferior part of external urethral sphincter
- Anterior extensions of ischioanal fat pads
Deep perineal pouch
Male contents: (4)
- Membranous urethra
- Deep transverse
perineal muscles - Bulbourethral glands
- Dorsal neurovascular
structures of penis
Deep perineal pouch
Female contents: (3)
- Proximal part of urethra
- Mass of smooth muscle
in place of deep transverse perineal muscles - Dorsal neurovascular
structures of clitoris
What is the Scrotum?
- Pouch-like structure – continuation of lower part of abdominal wall
Scrotum
* Contains: (3)
- Testes, epididymus & spermatic cord
Scrotum
* Skin: (2)
- Thin, wrinkled (dartos fascia and muscle)
- Pigmented, few hairs; Many sweat glands
Scrotum
* Fascial layers (_____ muscle)
cremaster
- Raphe of scrotum
- Lateral labioscrotal folds:
- Septum:
- Lateral labioscrotal folds: fuse
- Septum: two compartments
Neurovascular supply: Scrotum
* Arterial = (3)
- External pudendal artery
- Anterior scrotal arteries - Internal pudendal artery
- Posterior scrotal arteries - Cremasteric arteries (IEA)
Neurovascular supply: Scrotum
* Venous drainage
=
- Follow arteries
Neurovascular supply: Scrotum
- Innervation
- Ant:
- Post:
*
- Ant: ilio-inguinal & genitofemoral
- Anterior scrotal nerves
- Post: perineal branch of pudendal nerve
- Posterior scrotal nerves
Testes
* Suspended
= ______ cord
spermatic
Testes
* F: produce ________ & testosterone
* Secondary sexual characteristics
spermatozoa
Testes
* Tunica Vaginalis
- Outer….
- Inner ….
* Serous fluid between 2 layers
- Outer parietal layer
- Inner visceral layer
- Tunica Albuginea
- Firm, white fibrous covering around _____
- Forms septa → runs into testis → ______ _____ _______
testis
divides into lobules
What is the Epididymis?
- Elongated structure
posterior to testis
Epididymis
* Head:
- Superior part of testis
Epididymis
* Tail:
- Tapering and continues
as ductus deferens
Neurovascular supply: T & E
* Arterial: (5)
- Testicular artery
- Cremasteric artery
- Artery to ductus deferens
- Anterior scrotal artery
= External pudendal (Fem a.)
Posterior scrotal artery
= Internal pudendal artery
Neurovascular supply: T & E
* Venous drainage:
- Pampiniform plexus
Neurovascular supply: T & E
* Innervation
- Autonomic:
- Autonomic: testicular plexus (testicular artery)
- Sympathetic & parasympathetic (vagal)
What is the spermatic cord? (4)
- Suspends testis within scrotum
- Contains structures coursing to and from the testis (12)
- Begins at the deep inguinal ring
- Ends at the posterior border of testis
Spermatic Cord
* 3 fascial layers:
- Outer spermatic
- Cremasteric (and muscle)
- Inner spermatic
Spermatic Cord
* 3 arteries:
- Testicular artery
- Cremasteric artery
- Ductus deferens artery
Spermatic Cord
* 3 nerves:
- Genital branch of genitofemoral
- Ilioinguinal
- Sympathetic nerve fibers
Spermatic Cord
* 3 other structures:
- Ductus deferens
- Pampiniform venous plexus
- Lymphatics
What is the penis?
- Erectile tissue
- Corpus cavernosa and corpus spongiosum
What is the root of the penis? (2)
- Found in superficial perineal pouch
- Suspensory ligament
Penis
What is the Bulb of penis?
- Central portion – attach inf. layer of urogenital diaphragm
Penis
- Bulb of penis
* Contains:
penile/spongy urethra
Penis
- Bulb of penis
* Covered by:
bulbospongiosus
Penis
- Bulb of penis
* Continued as corpus _______ of penis
spongiosum
Penis
* Crura
- Attach laterally –
ischial rami
Penis
* Crura
* Covered by:
ischiocavernosus muscles
Penis
* Crura
* Continued as corpus _______ of penis
cavernosa
Penis
* Body
* Covered by skin and ______ tissue (deep fascia of penis)
connective
Penis
* Body
- Paired corpora cavernosa:
- Corpus spongiosum:
- Neck of glans:
- Paired corpora cavernosa – continuous of the crura
- Corpus spongiosum – ends distally in glans
- Neck of glans – separates glans from body
Penis
* Glans
- Glans covered by extra skin
* Prepuce with ______ (inf)
frenulum
Penis
- Glans =
* Navicular fossa –
dilation of urethra in glans
Neurovascular Supply
What is the arterial supply of the penis? (4)
- Dorsal artery of penis
- Deep artery to penis
- Artery of bulb of penis
- Additional branches from ext. pudendal aa.
- Arterial
- Dorsal artery of penis:
- Skin and erectile tissue of penis
- Arterial
- Artery of bulb of penis:
- Bulb of corpus spongiosum, urethra, bulbo-urethral gland
- Venous drainage
- Deep dorsal vein of penis:
- Superficial dorsal vein of penis:
– prostatic venous plexus
– external pudendal vein
Neurovascular Supply
Penis: (5)
- Dorsal nerve of penis
- Perineal nerve
- Ilio-inguinal nerve
- Sympathetic fibres
- Parasympathetic fibres
Neurovascular Supply
* Perineal nerve
Structures:
- Bulb & urethra
Neurovascular Supply
* Dorsal nerve of penis
Structures:
- Skin & glans (sensory afferent)
Neurovascular Supply
* Ilio-inguinal nerve
Structures:
- Skin near root
Neurovascular Supply
* Sympathetic fibres
Structures:
- Inferior hypogastric plexus
Neurovascular Supply
* Parasympathetic fibres
Structures:
- Pelvic splanchnic
