Perineum I

Question 1

What is the general position/shape of the perineum?

Answer 1

Between the thighs

Below the pelvic diaphragm (wedge shaped)

Question 2

Describe the boundary of the perineum from anterior to posterior

Answer 2

• From anterior to posterior
  
  • pubic synphysis
  • inferior pubic ramus
  • ischial ramus
  • ishcial tuberosity
  • sacrotuberous ligament
  • coccyx
• Roof
  
  • Pelvic diaphragm (levator ani)

Question 3

What two triangles are shown in the provided image?

What landmark separates the two triangles?

Answer 3

Red: urogenital triangle

Blue: anal triangle

Ischial tuberosity = most inferior portion

Question 4

What is the perineal body?

Where is it located?

What are the boundaries of the perineal membrane?

Why is this an important landmark

Answer 4

• Perineal body
  
  • confluence of tendinous tissue, connective tissue & where we see a lot of muscles anchoring
  • location
    
    • anterior to the anus (closer to anus than pubic symphysis)
    • posterior to vagina in female
• Progression anteriorly from perineal body is the perineal membrane
  
  • traversed by
    
    • urethra & vagina in females
    • urethra in males
    • vasculature, nerves & glandular ducts
  • anchored to ischial pubic rami back towards ischial tuberosities
  • anterior aspect is transverse perineal ligament (thickened edge)
  • posterior aspect is the perineal body
  • Important to separate superficial & deep perineal spaces

Question 5

What structure exists between the pubic symphysis and the transverse perineal ligament?

Answer 5

deep dorsal vein

of penis or clitoris

Question 6

Identify the muscle indicated by the photos & the highlighted components

Answer 6

• External anal sphincter
  
  • Deep: continuation of the puborectalis
  • Superficial: anchored to perineal body & coccyx via analcoccygeal ligament
  • Subcutaneous: most superficial aspect
• Function: voluntary defecation

Question 7

What is the name of the space adjacent the anus & surrounding the anal triangle?

Boundaries?

Answer 7

Ischioanal fossae - Right & Left

some continuity that exists between the two sides - intermitent anterior to the anus but more continuos posterior

(between ischial tuberosity & anus)

• Lateral wall
  
  • obturator internus (the portion below the pelvic floor levator ani)
  • obturator internus fascia
    
    • Pudendal canal containing internal pudendal nerve & artery
• Ceiling
  
  • fascial covering levator ani
• Floor
  
  • inferior superficial skin

Question 8

What neurovasculature is shown in the provided image?

It supplies what areas?

Answer 8

Inferior Rectal Nerve & Artery

from internal pudental nerve & artery

• external anal sphincter
• skin of the anus
• inferior surface of the fascia covering levator ani
• some of the levator ani

Question 9

What is the name of the most anterior portion of the ischioanal fossa?

What is important about this anterior-most boundary?

Answer 9

Deep perineal pouch

anterior recess of the ischioanal fossa

continuous anteriorly (important for infection spread)

Question 10

An anastamosis of what arteries feeds the rectum down to the anal canal?

Answer 10

• Terminal portion of inferior mesenteric is the superior rectal
• Terminal portion of anterior division of internal iliac is the internal pudendal
  
  • Internal pudendal will give off inferior rectal
• Anterior division of internal iliac gives off middle rectal
• Inferior rectal, middle rectal and superior rectal will anastamose

Question 11

Describe the pathway of the internal pudental artery and

Answer 11

The terminal portion of the anterior division of the internal iliac artery is the internal pudendal artery. The internal pudendal artery & nerve go out of the pelvic cavity into the gluteal region through the greater sciatic foramen and come back into the perineum region throuh the lesser sciatic foramen to course their way forward into the urogenital triangle

Question 12

Identify the indicated features of the provided image

Answer 12

Question 13

What branches are shown in the provided image

Answer 13

Question 14

What is the positioning of the pudendal canal along obturater internus?

Answer 14

anteromedially toward the pubic symphysis

with internal pudendal artery & pudendal nerve within the canal

Question 15

The deep perineal space is continuous with what structure?

What structure creates the roof of the deep perineal space?

What structure demarcates the boudary between the deep and superficial space?

Answer 15

the deepest portion of the deep space is continuous with the ischioanal fossae

Roof of deep space is the inferior fascia of the pelvic diaphragm

Deep & superficial space are separated by the perineal membrane

Question 16

What contents are located within the deep perineal space?

What contents are located within the superficial perineal space?

Answer 16

• Deep
  
  • external urethral sphincter (female)
  • bulbourethral gland (male)
• Superficial
  
  • external genetalia

Question 17

What are the components of the root & body of penis

Answer 17

• Root of Penis
  
  • Bulb of penis is anchored to perineal membrane
  • Crura of penis are anchored to ischopubic rami & perineal membrane
• Body of the penis
  
  • from pubic symphysis out toward glans penis/head
    
    • 3 erectile tissues w/ spongy urethra running through one of them

Question 18

What is anatomical position of the penis?

Identify the dorsal & ventral surfaces of the penis

Answer 18

Erect

Dorsum of the penis is anterior when flacid

Ventral/Urethral surface is opposing the scrotum when flacid

Question 19

What features of the penis are indicated in the provided image?

Answer 19

• Yellow: Glans penis/Head
• Blue line: Corona/Crown
• Orange line: Neck (constriction where body & glans meet)

Question 20

What is the name for the erectile tissue of the penis?

Describe where each is located

Answer 20

• Corpus Cavernosum
  
  • bunch of vascular caverns running through
  • so, if you pump blood into it, you will have an erection that occurs due to the increased pressure
• Erectile Tissue
  
  • 2 crura (corpus cavernosum) that converge at the pubic symphysis to form one general body of cavernous tissue
  • 1 corpus spongiosum – forms the bulb at the root & has spongy urethra running through it
    
    • does not become as rigid as corpus cavernosum

Question 21

Identify the indicated aspect of the provided image

Answer 21

Question 22

Identify the indicated aspects of the provided image

Answer 22

Corpus Spongiosum

• Blue
  
  • perineal membrane
• Brown
  
  • bulb
  • fuses to the perineal membrane
• Green
  
  • body of corpus spongiosum
  • Ventral portion that contains the spongy urethra
• Yellow
  
  • glans penis
  • notice that it is distal end of corpus cavernosum inserts up into the hollow end of the gans penis

Question 23

What is the most narrow portion of the spongy urethra?

What is the most narrow portion of the system?

Answer 23

exeternal urethral orfice

membranus urethra (& least pliable)

Question 24

What two types of glands are located within the spongy urethra?

Answer 24

• Throughtout spongy urethra
  
  • Ducts of paraurethral glands
    
    • mucous that conditions the inside of the urethra
• Openings in the bulb of the penis
  
  • openings for bulbar urethal (preejaculation)
  • glands sitting in the deep perineal pouch within the external urethral sphincter
  • when external urethral sphincter contracts it will release some preejaculate

Question 25

Ignore the black boxes, but identify the indicated features of the provided image

Answer 25

* Red arrow: Skin * loose skin on the penis & scrotum * tight skin on the glans penis * Yellow line: Penile raphe -- where two sides grew together * some defects, the spongy urethra can open along this line rather than at the glans penis * continuous with the scroal raphe * Blue line: scrotal raphe * Pink: foreskin * skin on the body that extends forward along the glans penis * Green circles * anchored to the neck of the glans * proximal to external urethral orifice: _frenulum_

Question 26

What is phimosis? Treatment?

Answer 26

constriction of the foreskin distal to the head of the penis caused by inappropriately pulling the foreskin back to clean it at a young age not pliable, does not stretch out and retract Steroid creams to loosen the tissue or partial circumcision

Question 27

What is the issue shown in the provided image & what was the cause?

Answer 27

Skin bridges cause by some of the foreskin not being removed during a circumcision remaining adhered to the glans penis

Question 28

Identify the differnet fascial layers of the penis What is the significance of the fascial layers?

Answer 28

* Skin - **subcutaneous infectious will stay out of the superficial fascial system** * Dartos fascia (superficial penile fascia) * fascia with some smooth muscle within it * Buck's fascia (deep penile fascia) * investing fascial that surrounds the erectile tissue * \*\* FYI, deep perineal fascial is different from deep penile fascia * covering the muscles of the perineum

Question 29

What is the name of the superficial fascial tha tis continuous form the abdomen to the perineum?

Answer 29

Scarpas (abdomen) Dardos (penis & scrotum) Colles (perineum)

Question 30

What is happens in a penile fracture?

Answer 30

* During an erection, a penis gets bent * this can cause disruption of the deep penile fascia and blood can spill out of the confined erectile tissue into the area deep to the dartos fascia

Question 31

Identify the ligaments indicated on the provided image and name their attachment points

Answer 31

* Suspensory ligament * from pubic symphysis into deep fascia of the penis * Fudiform ligament * From linea alba * Sweeps down & around the proximal body of the penis attaching to the raphe portion on the ventral side of body of the penis

Question 32

Identify the muscles indicated by the provided image Describe attachment sites & function of each muscle

Answer 32

* **Bulbospongiosus** * Attachments * covers the bulb of the corpus spongiosum * 2 muscles that fuse at midline along a raphe * anchored to perineal body & perineal membrane * Function * when it contracts it will press down on the bulb of the penis pushing blood form that area out into the body of the penis to create rigidity * also involved in expulsion of urine & semin through spongy urethra * **Ischiocavernousus** * attachment * covers the cura of the corpus cavernosum * anchored to ischiopubic ramus & perineal membrane all the way back toward the ischiotuberosities * **Superficial Transverse Perineal** * Attachment * anchoring to perineal body to ischial tuberosity * Function * create rigidity and helping to reinforce the positon of the perineal body