UB PAS 407 EXAM 3 QUESTIONS AND ANSWERS
External intercostals - CORRECT ANSWER✅✅Function: Elevation of ribs during inhalation
Innervation: Intercostal nerves
Internal intercostals - CORRECT ANSWER✅✅Function: Depression of ribs during forced exhalation
Innervation: intercostal nerves
Transversus thoracis - CORRECT ANSWER✅✅Function: Weak depression of ribs
Innervation: Intercostal nerves
External oblique - CORRECT ANSWER✅✅Function: Unilateral: rotation of trunk
Bilateral: flexion of trunk (sit-ups)
Compression of anterior abdominal wall and viscera (increases intra-abdominal pressure)
Innervation: thoracoabdominal nerves
internal oblique - CORRECT ANSWER✅✅Function: Unilateral: rotation of trunk
Bilateral: flexion of trunk (sit-ups)
Compression of anterior abdominal wall and viscera (increases intra-abdominal pressure)
Innervation: thoracoabdominal nerves
Transversus abdominis - CORRECT ANSWER✅✅Function: Compression of anterior abdominal wall and
viscera (increases intra-abdominal pressure)
Innervation: thoracoabdominal nerves
Rectus abdominis - CORRECT ANSWER✅✅Function: Flexion of trunk (sit-ups)
Compression of anterior abdominal wall
Innervation: thoracoabdominal nerves
, Dartos muscle - CORRECT ANSWER✅✅Function: regulate the temperature of the testicles,
Innervation: genitofemoral nerve
Psoas major - CORRECT ANSWER✅✅Function: Flexion of thigh, Lateral rotation of thigh, Lateral flexion
of trunk
Innervation: Ventral rami of L2-3 spinal nerves
Psoas minor - CORRECT ANSWER✅✅Function: Flexion of trunk (weak)
Innervation: Ventral rami of L1 spinal nerves
iliacus - CORRECT ANSWER✅✅Function: Flexion of thigh
Innervation: Femoral nerve
Quadratus lumborum - CORRECT ANSWER✅✅Function: Unilateral: lateral flexion of trunk
Bilateral: extension of trunk
Fix/depress rib 12
Innervation: subcostal nerve
Diaphram - CORRECT ANSWER✅✅Function: Dome of diaphragm flattens during inspiration
,Contraction increases vertical dimension of thoracic cavity
Innervation: phrenic nerve
Platysma - CORRECT ANSWER✅✅Function: Elevates and creases skin of neck (e.g., expression of
"horror"), Depression of lower lip and angle of mouth
Innervation: facial nerve (CN 7)
Digastric - CORRECT ANSWER✅✅Function: Depression of mandible (opens mouth), Elevation of hyoid
bone
Innervation: Anterior belly: Trigeminal nerve (CN 5 (3)), Posterior belly: Facial nerve (CN 7)
External intercostals - CORRECT ANSWER✅✅Function: Elevation of ribs during inhalation
Innervation: Intercostal nerves
Internal intercostals - CORRECT ANSWER✅✅Function: Depression of ribs during forced exhalation
Innervation: intercostal nerves
Transversus thoracis - CORRECT ANSWER✅✅Function: Weak depression of ribs
Innervation: Intercostal nerves
External oblique - CORRECT ANSWER✅✅Function: Unilateral: rotation of trunk
Bilateral: flexion of trunk (sit-ups)
Compression of anterior abdominal wall and viscera (increases intra-abdominal pressure)
Innervation: thoracoabdominal nerves
internal oblique - CORRECT ANSWER✅✅Function: Unilateral: rotation of trunk
Bilateral: flexion of trunk (sit-ups)
Compression of anterior abdominal wall and viscera (increases intra-abdominal pressure)
Innervation: thoracoabdominal nerves
Transversus abdominis - CORRECT ANSWER✅✅Function: Compression of anterior abdominal wall and
viscera (increases intra-abdominal pressure)
Innervation: thoracoabdominal nerves
Rectus abdominis - CORRECT ANSWER✅✅Function: Flexion of trunk (sit-ups)
Compression of anterior abdominal wall
Innervation: thoracoabdominal nerves
, Dartos muscle - CORRECT ANSWER✅✅Function: regulate the temperature of the testicles,
Innervation: genitofemoral nerve
Psoas major - CORRECT ANSWER✅✅Function: Flexion of thigh, Lateral rotation of thigh, Lateral flexion
of trunk
Innervation: Ventral rami of L2-3 spinal nerves
Psoas minor - CORRECT ANSWER✅✅Function: Flexion of trunk (weak)
Innervation: Ventral rami of L1 spinal nerves
iliacus - CORRECT ANSWER✅✅Function: Flexion of thigh
Innervation: Femoral nerve
Quadratus lumborum - CORRECT ANSWER✅✅Function: Unilateral: lateral flexion of trunk
Bilateral: extension of trunk
Fix/depress rib 12
Innervation: subcostal nerve
Diaphram - CORRECT ANSWER✅✅Function: Dome of diaphragm flattens during inspiration
,Contraction increases vertical dimension of thoracic cavity
Innervation: phrenic nerve
Platysma - CORRECT ANSWER✅✅Function: Elevates and creases skin of neck (e.g., expression of
"horror"), Depression of lower lip and angle of mouth
Innervation: facial nerve (CN 7)
Digastric - CORRECT ANSWER✅✅Function: Depression of mandible (opens mouth), Elevation of hyoid
bone
Innervation: Anterior belly: Trigeminal nerve (CN 5 (3)), Posterior belly: Facial nerve (CN 7)
