Exam 3: pelvis & perineum

Question 0

contents of pelvis major

Answer 0

lumbar nerve plexus
sympathetic trunk
lower ilium
cecum
appendix
sigmoid colon
upper rectum
common iliac vessels
ureter
psoas major/minor mm
iliacus mm

Question 1

pelvic diaphragm

Answer 1

• located in pelvis minor
• closes floor of inferior bony pelvis
• supports pelvic viscera
• consists of:
  
  • levator ani
    
    • iliococcygeus
    • pubococcygeus (medial fibers attach to rectum, vagina, prostate)
      
      • puborectalis
      • pubovaginalis
      • levator prostate
• coccygeus (ischiococcygeus)

Question 2

contents of pelvis minor

Answer 2

urinary bladder
reproductive organs
rectum, anus
lumbar plexus
sacral plexus
sacral sympathetic trunk
external, internal iliac vessels
obturator internus
piriformis
pelvic diaphragm

Question 3

5 functions of pelvic diaphragm

Answer 3

1. support viscera
2. sphincteric control
3. sexual function
4. stabilize
5. helps pump lymphatic system

Question 4

pelvic diaphragm innervation

Answer 4

coccygeus: S4,5
iliococcygeus: nerve to pelvic diaphragm S3,4
pubococcygeus: nerve to pelvic diaphragm S3,4

Question 5

sacral plexus

Answer 5

lumbosacral trunk: ventral rami L4,5 of lumbar plexus

ventral rami S1-4

Question 6

6 nerves from lumbar plexus that enter pelvic region

Answer 6

*iliohypogastric N not in pelvis

1. ilioinguinal: L1
2. genitofemoral N: L1,3
3. lateral femoral cutaneous N: L2,3
4. femoral N: L2,3,4
5. obturator N: L2,3,4
6. lumbosacral trunk: L4,5

Question 7

8 nerves from sacral plexus that enter pelvic region

Answer 7

1. sciatic N: L4,5 S1,2,3
2. superior gluteal N: L4,5 S1
3. inferior gluteal N: L5,S1,2
4. Nerve to quadratus femoris: L4,5 S1
5. Nerve to obturator internus: L5 S1,2
6. pudendal N: S2,3,4
   
   • S = ext genitalia
   • M = muscles of perineum, ext anal sphincter
7. N to piriformis:S1,2
8. N to pelvic diaphragm: S3,4 (levator ani, coccygeus)

Question 8

autonomic nerves to pelvic viscera

Answer 8

sympathetic: via lumbar & sacral splanchnic nerves
parasympathetic: via pelvic splanchnic nerves

Question 9

pelvic urinary structures

Answer 9

• distal part of ureter
• urinary bladder:
  
  • females: inf & ant to uterus, ant to vagina
  • males: superior to prostate, ant to seminal vesicles, ampulla of vas deferens and rectum
• urethra
  
  • females: passes through UG diaphragm to vestibule of vagina
  • males: passes through prostate (prostatic urethra) then UG diaphragm (membranous urethra) before entering penis (spongy urethra)

Question 10

structures of male reproductive system that lie in pelvic cavity

Answer 10

vas deferens
seminal vesicles
prostate gland

Question 11

testis and epididymis

Answer 11

Develop in abdomen, descend into scrotum

• scrotum: outer skin, inner fascia and dartos mm (smooth mm) –> contracts skin
• cremaster mm: elevates testis toward pelvis to maintain testicular temp
• seminiferous tubules: sperm development
• epididymis: outer surface of testis
  
  • head,body, tail –> vas deferens

Question 12

continual of abdominal layers to scrotum

Answer 12

1. external oblique aponeurosis: external spermatic fascia
2. internal oblique aponeurosis: cremaster mm
3. transverse abdom: nothing
4. transversalis fascia: internal spermatic fascia

Question 13

3 cylinders of erectile tissue

Answer 13

ventral (1): corpus spongiosum
  *bulb of penis (prox part of corpus spongiosum)
  *glans (distal part)
dorsal (2): corpus cavernosum
 *crus of penis (@ pubic ramus)
 *deep A

Question 14

female reproductive system

Answer 14

1.clitoris

within pelvic cavity: post to urinary bladder, ant to rectum

2. vagina
3. uterus
4. uterine tubes
5. ovaries

Question 15

ovaries

Answer 15

• lateral to uterus, inferior to fibriae of uterine tubes
• ovarian lig: connects each ovary to uterus
• suspensory lig:
• connects each ovary to pelvic brim
• ovarian vessels, lymphatics, nerves

referred pain: LB, inguinal region and thigh
*ovarian cysts, uterine fibroid, pelvic inflammatory disease, endometriosis, uterovaginal prolapse

Question 16

perineum boundaries

Answer 16

ant: pubic symphysis
post: tip of coccyx
lateral: pubic arch, ischial tuberosities, sacrotuberous lig
sup: pelvic diaphragm

• line connecting ischial tuberosity
  
  • urogenital triangle (anteriorly)
  • anal triangle (posteriorly)

Question 17

median part of anal triangle (perineum)

Answer 17

1. anal canal/opening
   * terminal part of large intestine: extends from rectum–>anus
   * internal anal sphincter: smooth mm, pelvic parasympath N
   * external anal sphincter: skeletal mm, inf rectal N from pudendal N
2. perineal body: small fibrous mass
   * females: between anus, vagina
   * males: between anus, bulb of penis
   * muscle attachments:
   • superficial/deep transversus perinei
   • bulbospongiosus
   • external anal sphincter

3.anococcygeal lig

Question 18

ischioanal fossa of anal triangle

Answer 18

borders:

• medial: anal canal, sphincters, anus
• laterally by: obturator internus mm & fascia
  
  • pudendal canal: pudendal N, internal pudendal A & V
  • pudendal N –> inf rectal N –>ext anal sphincter, skin around anus
• anterior: urogenital triangle
• posterior: sacrotuberous triangle

Question 19

urogenital triangle spaces

Answer 19

superficial & deep perineal space divided by perineal membrane

Question 20

superficial perineal space of UG triangle

Answer 20

ischiocavernosus mm
bulbospongiosus mm
superficial transversus perineal mm

Question 21

deep perineal space of UG diaphragm

Answer 21

sphincter & compressor urethrae mm
deep transversus perineal mm (ischial rami to perineal body)
urethra passes through UG diaphragm

Question 22

urogenital nerves

Answer 22

1. perineal N:
   * branches to superficial and deep mms of UG triangle
   * post scrotal or labial N in superficial space
   
   • cutaneous to post scrotum or labia majora
2. dorsal N of penis or clitoris
   * enters deep perineal space
   * innervates dorsum and glans of penis or clitoris

**perineal N and dorsal N are divisions of pudendal N

Question 23

male anal triangle and superficial space of UG triangle

Answer 23

1. ischiocavernosus mm
2. bulbospongiosus mm
3. superficial transversus perineal mm
4. anococcygeal lig
5. perineal body

Question 24

female anal triangle and superficial space of UG triangle

Answer 24

1. ischiocavernosus mm 2. bulbospongiosus mm 3. superficial transversus perineal mm 4. anococcygeal lig 5. external anal sphincter 6. anus

Question 25

male anal triangle and deep space of UG triangle

Answer 25

1. perineal body 2. external anal sphincter 3. deep transverse perineal mm 4. sphincter urethrae mm