Male And Female Peritoneum

Question 1

What is the perineum?

What shape is it?

What is the superior boundary?

Inferior boundary?

Answer 1

Most inferior region of the trunk including external genitalia and anal canal

Diamond shaped area between the thighs

Superior boundary: pelvic diaphragm (separates perineum from pelvic cavity)

Inferior boundary: skin associated with external genitalia and anal canal

Question 2

What are the boundaries of the perineum?

Answer 2

Anterior: pubic symphysis

Lateral: ischiopubic ramus, ischial tuberosity, sacrotuberous ligament, obturator internus muscle

Posterior: coccyx

Superior: pelvic diaphragm (levator ani and coccygeus muscle)

Inferior: skin of the buttocks (ischiorectal fascia) and external genitalia

Question 3

What boundary of the perineum aids in defecation?

What are its boundaries?

Answer 3

Ischiorectal fossa: fat filled space inferior to the perineum on either side of the anal canal that allows the anal canal to expand during defecation without compressing vital structures

Lateral wall: obturator internus and ischium

Superomedial wall: levator ani and anal canal

Base: skin of perineum

Question 4

What two triangles form when the perineum is divided by a line joining the ischial tuberosities?

What are the boundaries of these two triangles?

Answer 4

Urogenital triangle (anterior): pubic symphysis, ischiopubic rami, imaginary line

Anal triangle (posterior): coccyx, sacrotuberous L, imaginary line

Question 5

What does the anal canal contain?

Answer 5

Internal anal sphincter: circular smooth muscle; parasympathetics of pelvic splanchnic nerves S2-S4

External anal sphincter: circular skeletal muscle; sympathetics of pudendal N

Question 6

What two anchors does the external anal sphincter attach to?

What is the innervation of the external anal sphincter?

Answer 6

Anteriorly: perineal body

Posteriorly: anococcygeal ligament

Inferior rectal N (branch of pudendal N)

Question 7

What structure travels within the muscle fascia of the medial obturator internus muscle and the lateral walls of the ischiorectal fossae?

What are the contents of this structure?

What are its branches passing from pudendal canal to the anal canal and traveling through the ischiorectal fossae?

Answer 7

Pudendal canal: pudendal N, internal pudendal A, internal pudendal V

Inferior rectal N, inferior rectal A, inferior rectal V

Question 8

What is the anal canal above and below the pectinate line derived from?

What sensory neurons does it contain?

Answer 8

Above the pectinate line: endoderm; visceral afferent sensory neurons

Below the pectinate line: ectoderm; somatic sensory neurons

Question 9

Describe the pathway of the pudendal N and internal pudendal A

What does the pudendal N contain?

What does the internal pudendal A supply?

Answer 9

Come from the pelvis, exit the greater sciatic foramen, wrap around the sacrospinous L, and enter the lesser sciatic foramen to the perineum

S2-S4; Contains motor (somatic and autonomic fibers) plus sensory fibers (somatic and visceral)

Branches supply perineum

Question 10

What is the blood supply of the anal canal and rectum?

Nerve supply?

Answer 10

Internal pudendal A ->inferior rectal A

Superior rectal V, middle rectal V, inferior rectal V

Inferior rectal N (S2-S4)

Question 11

Where do abscesses collect in the male perineum?

Answer 11

Ischiorectal fossa

Question 12

What are parts of the male urethra and what do they pass through?

Answer 12

Prostatic urethra; prostate

Membranous urethra; urogenital diaphragm

Question 13

What is the deep perineal pouch in males?

What are its contents?

Answer 13

Part of the urogenital triangle and includes the urogenital diaphragm

Membranous urethra, external urethral sphincter surrounding the membranous urethra, deep transverse perineous muscle that inserts the perineal body, and bulbourethral glands

Question 14

What is the function of the bulbourethral glands in males?

Answer 14

Produces a clear mucous into the penile urethra just prior to ejaculation that lubricates the urethra

Question 15

What is in the male superficial perineal space?

What three muscles are contained in the male superficial perineal space and where are they located?

Answer 15

Root of penis: L cruz, R crura, bulb of penis (continuous with corpus spongiosum)

Ischiocavernosus muscle: surround free surface of each crus, attaches to ischiopubic rami, and insert into corpus cavernous

Bulbospongiosus muscle: arises from the perineal body and raphe of penis, wraps around the bulb of penis and posterior part of corpus spongiosum (voluntary control; empties spongy urethra of urine or semen)

Superficial transverse perineus muscle: located along the posterior border of the UG diaphragm

Question 16

Bulb of penis is attached to perineal body and is surrounded by a layer of fascia called ____.

This fascia also covers ____.

This is located in the _____ space.

Answer 16

Deep fascia of the penis (Buck’s fascia)

Three sets of erectile tissue including corpus spongiosum and bilateral corpus cavernosum

Superficial perineal space

Question 17

How is an erection maintained?

What muscles are used?

Answer 17

Blood fills the corpus cavernosum and corpus spongiosum in the penis

Ischiocavernosus muscle and bulbospongiosus muscle contract and compress the veins, preventing the blood from draining from the corpus cavernosum; thus maintaining an erection

Question 18

What is the pathway of the internal pudendal A?

What does the internal pudendal A supply in males?

External pudendal A?

Answer 18

Branch off internal iliac, enters perineum by lesser sciatic foramen, enters pudendal canal

Internal pudendal A: supplies anal canal, ischiorectal fossa, deep perineal space; superficial branches to superficial perineal space and posterior scrotum; branches of helicine arteries into penis (dorsal arteries of penis)

External pudendal A (branch off femoral A): sends deep and superficial branches to anterior scrotum and penis

Question 19

What nerve supplies the male perineum?

Answer 19

Pudendal N

Superficial branches supply superficial perineal pouch (muscles and scrotum)

Deep branches supply deep perineal pouch (penis)

Question 20

Inferior hypogastric plexus sends sympathetic and parasympathetic to ___ and ___ in a male.

What can occur during a prostectomy?

Answer 20

Prostate and penis

In removing the prostate, parasympathetic fibers in the prostate that travel to the penis can also be removed; preventing future erections

Question 21

What are possible causes of male impotence/erectile dysfunction?

Answer 21

Prostectomy, neuropathy from diabetes, spinal cord injury, hernia, athrosclerosis

Question 22

What are homologous perineal structures between males and females?

Answer 22

Scrotum -> Labia majora

Raphe of penis -> Labia minora

Gland penis -> clitoris

Question 23

What are the contents of the female deep urogenital pouch?

Answer 23

Urethra, vagina, deep transverse perineus muscle that inserts the perineal body, compressor muscles that close the urethra

Question 24

What openings are on either side of the female urethra orifice?

What openings are on either side of the vagina? Fx?

Answer 24

Openings for paraurethral glands

Openings for greater vestibular glands (Bartholin’s glands): releases a clear mucous during sexual activity between the Labia minora (vestibule of the vagina); lubricates the vulva

Question 25

What is included in the female vulva? What is contained in the vestibule of the vagina?

Answer 25

Glans clitoris, Labia majora, Labia minora External urethral orifice with external urethral sphincter, vaginal orifice, openings of the paraurethral glands, greater vestibular glands

Question 26

What are the contents of the female superficial pouch? What are the contents deep to the skin?

Answer 26

Labia majora (unite anteriorly to form the mons pubis), Labia minora, R and L cruz of clitoris Bulbs of the vestibule, greater vestibular glands, superficial transverse perineus muscles (attach to perineal body)

Question 27

What are the parts of the clitoris? Each crus is continuous with ____ that is composed of _____ tissue. What surrounds the crus and corpus cavernosum and what is its function?

Answer 27

R and L crura, two corpus cavernosum that fuse to form one body, glans clitoris (only visible part) Corpus cavernosum; erectile tissue Ischiocavernosus muscle: contracts during sexual arousal to stop venous blood draining from the corpus cavernosum

Question 28

Blood supply of the female perineum?

Answer 28

Internal pudendal A: supplies anal canal, ischiorectal fossa, deep perineal space; superficial branches to superficial perineal space; branches of helicine arteries into clitoris External pudendal A (branch off femoral A): sends deep and superficial branches to Labia majora and clitoris

Question 29

Nerve supply to the female urogenital triangle What is contained in this nerve? What cutaneous nerve supplies the perineum?

Answer 29

Pudendal nerve: S2-S4; sends branches to all structures supplied by the internal pudendal A Preganglionic parasympathetic fibers: glands and smooth m Somatic motor fibers: skeletal m Somatic sensory fibers: sensory receptors in perineal skin, distal anal canal, distal vaginal canal Postganglionic sympathetic fibers: glands and smooth m Posterior femoral cutaneous N

Question 30

What drains into the superficial inguinal nodes? What a drains into the internal iliac nodes?

Answer 30

Superficial perineal space, distal portion of vagina, distal portion of anal canal below pectinate line Deep perineal space, proximal portion of vagina, proximal portion of anal canal above the pectinate line

Question 31

What is an episiotomy? What are the types?

Answer 31

Surgical incision made in the area between the vagina and anus; during the last stages of labor and delivery; expands the opening of the vagina to prevent tearing of the perineum during delivery Medio-lateral (most common), midline, lateral, J-shaped

Question 32

What is cut during a medio-lateral episiotomy? What are the steps to surgically repairing an episiotomy?

Answer 32

Posterior vaginal wall, bulbospongiosus m, superficial transverse perineus muscles, skin and associated subcutaneous fascia *Does not go through the perineal body* Suture vaginal wall, muscle layer, subcutaneous fascia and skin

Question 33

What are the contents of the anal triangle? What are the contents of the urogenital triangle?

Answer 33

Ischiorectal fossae, anal canal Deep and superficial perineal pouches (spaces)

Question 34

What is the urogenital diaphragm? The muscular diaphragm is split in half by the ____ in females. The superior and inferior (perineal membrane) fascia are fused along the ____ borders ____ is attached to the midpoint of the posterior border

Answer 34

Part of the deep pouch in the urogenital triangle; continuous sheet of muscle that spans the gap between the ischiopubic rami Vagina Anterior and posterior borders Perineal body

Question 35

What is the superficial perineal space? In females, the space is split in half by the ____.

Answer 35

Potential space deep to the perineal skin that covers the external genitalia Vestibule of the vagina

Question 36

Where is the bulb of the vestibule? What are the bulbs composed of? What covers the bulbs and what is its location and fx?

Answer 36

Deep to the skin of the Labia minora Erectile tissue Bulbocavernosus muscle: attached to the perineal body; during sexual arousal they compress the bulbs of the vestibule and stop the draining of venous blood