Perineum Flashcards Preview

Genitourinary System > Perineum > Flashcards

Flashcards in Perineum Deck (23)
1

Urogenital and Anal triangles

Made from muscles of the perineum

Anal: more posterior
Urogenital: more anterior 

2

What makes up the Pelvic Outlet?

  • Pubic Symphysis
  • Ischiopubic Ramus
  • Ischial Tuberosity
  • ST lig.
  • Coccyx

*Roughly diamond shape

3

What is the Perineal Body?

Made of fibrous CT, an attachment point!

Attaching is?

  • Levator ani
  • Bulbospongiosus
  • External anal sphincter
  • Perineal Muscles

4

What two main muscles make up the pelvic floor?

  1. Levator ani 
  2. Coccygeus

5

Levator Ani divisions and supply

  1. Iliococcygeus
  2. Pubococcygeus

Forms a V shaped structure

Pudendal nerve (S2-4) and nerve to levator ani (S3-4)

6

Levator Ani: Pubococcygeus

  1. Levator Prostatae/pubovaginalis
  2. Pubococcygeus
  3. Puborectalis; helps maintain fecal continence, forms sling around the rectum (creates angulation)

7

Levator divisions: Iliococcygeus

Attaches to fascia of Obturator internus, prevents prolapse of pelvic viscera

8

Label Levator Ani muscles

9

What is the External Anal sphincter? Function and innervation?

Made of skeletal muscle, it closes the anus (accompanied by puborectalis) and is also under partial voluntary control!

From perineal body to anococcygeal ligament

supplied by Pudendal Nerve (S2-4) - inferior rectal branch

10

Internal Anal sphincter

Smooth Muscle (involuntary control (ANS)) 

Deep to External Anal Sphincter (seperated by CT)

11

Label

12

Landmarks of the urogenital and anal Sphincters

Laterally: ischial Tuberosity

Posteriorally: Coccyx

Midline: Perineal Body

 

**avoid the lateral apex (where the nerves are) → impotence or incontinence

13

The Anal Canal

Where the rectum pierces the pelvic floor it becomes the Anal canal (once passed the puborectalis)

14

Arterial and Lymphatics of the rectum

Superior rectal artery (inf mesenteric)
Pre-aortic nodes @ L3


Middle rectal artery (int iliac)
Internal iliac nodes


Inferior rectal artery (int pudendal)
Internal Iliac nodes

** anal canal inferior to pectinate line (SF inguinal nodes)

15

Rectal/anal venous drainage

Superior and inferior recal vein meet at portal-systemic anastomosis

These drain the internal and external venous plexuses

16

The perineal membrane

Has an anterior deficiency (where the deep dorsal vein of penis/clitoris moves through)

  • Attachment site for nearly all perineal muscles eg; deep transverse perineal muscles and compressor urethra
  • Forms inferior layer of urogenital diaphragm/ Deep perineal pouch

17

Urogenital Diaphragm

18

What's the male/female variation of the Deep Perineal Pouch

Female: 

  • Compressor urethrae
  • DOrsal n. of the clitoris
  • **Bartholins glands in SF pouch

Male:

  • 'membranous' urethra
  • Bulbospongiosus
  • DOrsal n. of the penis

19

Superficial Perineal Pouch

Structures between the perineal membrane and skin

  • Nerves + vessels
  • Erectile tissues
  • Perineal muscles
  • Bartholins gands (females)

 

20

Internal Pudendal artery important branches. Draw.

21

Pudendal Nerve 

Mirrors the artery. (S2-4) motor and sensory

Perineal muscles, ext. urethral sphincter, skin of genitalia, erectile muscles

22

Sec- the nervous system

23

Saddle anasthesia

Compression of cauda equina (S5 to anus) → numb butt thighs and perineum