Thoracic wall/ ab

Question 0

Transverse thoracic

Answer 0

SA: Posterior surface of lower sternum
IA: Internal surface of costal cartilages 2-6
N: intercostal N
MA: weakly depresses ribs

Question 1

Intercostals : external, internal, innermost

Answer 1

SA: Inferior border of ribs
IA: Superior border of ribs below
N: intercostal nerve
MA: External intercostal: during forced inspiration elevates ribs
Internal/ innermost intercostals: during forced respiration; interosseus part depresses ribs; interchondral part elevates ribs

Question 2

External oblique

Answer 2

O: External surfaces of 5th-12th ribs
I: linea alba, pubic tubercle, and anterior half of illiac crest
N: thoraco-abdominal nerves (anterior rami of T7-T11) and subcostal nerve
MA: Compress and support abdominal viscera; flex and rotate trunk

Question 3

Internal oblique

Answer 3

O: Thoracolumbar fascia, anterior 2/3 of illiac crest, and connective tissue deep to ingunial ligament
I:inferior borders of 10th-12th ribs, linea alba, and pubis via conjoint tendon
N:Thoraco-abdominal nerves (anterior rami of T7-T11), subcostal and first lumbar nerve
MA: Compress and support abdominal viscera; flex and rotate trunk

Question 4

Transverse abdominis

Answer 4

O: internal surfaces of 7th-12th costal cartilages, thoraco-lumbar fascia, illiac crest, and connective tissue deep to inguinal ligament
I: linea alba with aponeurosis of internal oblique, pubic crest, and pubis via conjoint tendon
N:Thoraco-abdominal nerves (anterior rami of T7-T11) subcostal and first lumbar nerve
MA: compresses and supports abdominal viscera

Question 5

Rectus abdominis

Answer 5

O: pubic symphysis and pubic crest
I: Xiphoid process and 5th-7th costal cartilages
N: Thoraco-abdominal and subcostal nerves (anterior rami of T7-T12 spinal nerves)
MA: Flexes trunk (lumbar vertebrae) and compresses abdominal viscera; stablizes and controls tilt of pelvis (antilordosis)

Question 6

psoas major

Answer 6

SA: transverse process of lumbar; sides of bodies of T12-S1 vertebrae and intervening IV discs
IA: by a strong tendon to a lesser trochanter of femur
N: lumbar plexus via anterior branches of nerves L2-L4
MA: acting inferiorly: flexes thigh
acting superiorly: flexes vertebral column
acting inferiorly: flex trunk

Question 7

Iliacus

Answer 7

SA: superior 2/3 of illiac fossa, ala of sacrum, and anterior sacro-iliac ligaments
IA: less trochanter of femur and shaft inferior to it and to psoas major tendon
N: femoral N (L2-L4)
MA: flexes thigh and stabilizes hip joint; acts with psoas major

Question 8

Quadratus lumborum

Answer 8

SA: medial half of inferior border of 12th rib and tips of lumbar transverse processes
IA: iliolumbar ligament and internal lip of iliac crest
N: anterior branches of T12 and L1-L4 erves
MA: extends and laterally flexes vertebral column; fixes 12th rib during inspiration

Question 9

Levator ani

Answer 9

PA: body of pubis, tendinous arch of levator ani, ischial spine
IA: pernieal body, coccyx, anococcygeal ligament, walls of prostate or vagina, rectum, and anal canal
N: N of levator ani (S4), inferior anal (rectal) nerve, coccygeal plexus
MA: helps support pelvic viscera; resists increases in intra-abdominal pressure

Question 10

coccygeus

Answer 10

PA: ischial spine
IA: inferior end of sacrum and coccyx
N: branches of S4 and S5 nerves
MA: forms small part of pelvic diaphragm that supports pelvic viscera, flexes coccyx

Question 11

Obturator internus

Answer 11

PA: pelvic surface of illium and ishcium, obturator membrane
IA: greater trochanter of femur
N: nerve to obturator internus (L5-S2)
MA: laterally rotates hip joint, assists in holding head of femur in acetabulum

Question 12

Piriformis

Answer 12

PA: pelvic surface of 2nd-4th sacral segments; superior margin of greater sciatic notch and sacrotuberous ligament
IA: greater trochanter of femur
N: anterior rami of S1 and S2
MA: laterally rotates hip joint; abducts hip joint; assists in holding head of femur in acetabulum