Pelvis - Perineum

Question 0

Perineum boundaries

Answer 0

Anterior:
- pubic symphysis
Posterior:
- coccyx
Lateral:
- ischial tuberosity
Lateral margins:
- ischiopubic ramus (A)
- sacrotuberous ligament (P)
Roof:
- levator ani

Question 1

Subdivisions of perineum:

Answer 1

Anal triangle (posterior) + urogenital triangle (anterior)

Question 2

Characteristics of perineum:

Answer 2

• thick fibrous sheet
• free posterior border (att medially to perineal body + laterally to pubic arch)
• deep perineal pouch=superior; contains skel muscles, nerves, vessels
• supports external genitalia
• pierced by urethra (+vagina)

Question 3

Anal triangle boundaries

Answer 3

Anterior:
- ischial tuberosity
Posterior:
- coccyx
Lateral:
- sacrotuberous ligament
Roof:
- levator ani

External anal sphincter surrounds anal canal

Question 4

Ischio-anal fossa:

Answer 4

• in anal triangle
• b/t ischiopubic rami + rectum/anal canal
• contains: fat, pudendal n., internal pudendal a.+v.
• medial wall = levator ani
• lateral wall = ischium+obituator internus+sacrotuberous ligament
• pyramid-shaped anterior recess projects into urogenital triangle

Question 5

Urogenital triangle boundaries

Answer 5

Anterior:
- pubic symphysis 
Lateral:
- ischiopubic rami 
Posterior:
- ischial tuberosity
Roof:
- levator ani

Question 6

Urogenital triangle: contents

Answer 6

Deep perineal pouch:

• bulbourethral glands of Cowper (M)
• sphincter urethrae (F/M)
• sphincter urethrovaginalis (F)

—PERENIAL MEMBRANE+BODY—-

Superficial perineal pouch:

• sup. transverse perineus m.
• greater vestibular gland Bartholin (F)
• external genitalia+ asso. muscles
• branches of pudendal n. + internal pudendal a./ v.

Question 7

Urogenital triangle: contents

Answer 7

External genitalia (erectile tissues+muscles):

• corpus cavernosum
• corpus spongiosum

Question 8

corpus cavernosum

Answer 8

• R/L crus surrounded by ischiocavernosus m.
• body of penis
• body & glans of clitoris

Question 9

corpus spongiosum

Answer 9

• bulb of penis
• bulbs of clitoris surrounded by bulbospongiosus m.
• body & glans of penis

Question 10

Superficial perineal pouch: 3 paired muscles

Answer 10

• ischiocavernosus
• bulbospongiosus
• superficial transverse perineus m.

Question 11

All branches of internal iliac a. + internal pudendal a. have corresponding veins EXCEPT…?

Answer 11

Umbilical a.

Iliolumbar a.

Question 12

Deep dorsal vein corresponds with what arteries?

Answer 12

Deep artery + dorsal artery (of clitoris/penis)

Question 13

Perineal lymphatic drainage …?

Answer 13

Follows internal pudendal a. branches

- mainly drains to INTERNAL ILiAC NODES

Question 14

Lymph from superficial penis/clitoris, scrotum, labia majora drain into…

Answer 14

mainly SUPERFICIAL INGUINAL NODES

Question 15

Lymph from glans penis, glans clitoris, labia minora, terminal inferior end of vag drain into…

Answer 15

DEEP INGUINAL NODES + EXTERNAL ILIAC NODES

Question 16

Lymph from testers (& ovaries) drain directly into …

Answer 16

LATERAL AORTIC (lumbar) + PRE-AORTIC NODES (scattered on/around ab. aorta)

Question 17

Abscess in ischio-anal fossa:

Answer 17

• soft anal mucosa can be torn by hard poops
• infection/inflammation of anal canal can spread b/t sphincters = intersphincteric fistulas
• infection may spread superiorly into pelvic cavity; laterally into ischio-anal fossa

Question 18

Ano-rectal hemorrhoids:

Answer 18

• enlarged submucosal veins
• common = blood in stool
• may indicate portal hypertension
• treatments: self-medication; surgery