ACTIVITY 2
Name at least three muscles that actively contract during the following activities and name its action and innervation:
- Turning a door knob
- Biceps brachii
ACTION: flexion and supination (outward rotation) of the forearm
INNERVATION: Musculocutaneous nerve
- Triceps brachii
ACTION: extension of the forearm
INNERVATION: Radial nerve
- Pronator teres
ACTION: pronation of forearm at the proximal radioulnar joint, flexion of the forearm at the elbow joint
INNERVATION: median nerve
- Throwing a baseball overhead
- Deltoid
ACTION: arm abduction; flexion and internal rotation of the arm
INNERVATION: axillary nerve
- Latissimus dorsi
ACTION: arm internal rotation, arm extension
INNERVATION: thoracodorsal nerve
- Subscapularis
ACTION: arm internal rotation
INNERVATION: upper and lower subscapular nerves
- Kicking a ball
- Gastrocnemius
ACTION: leg flexion
INNERVATION: tibial nerve
- Tibialis anterior
ACTION: foot dorsiflexion
INNERVATION: deep fibular nerve
- Rectus femoris
ACTION: leg extension
INNERVATION: femoral nerve
- Doing sit-ups
- Rectus abdominis
ACTION: compresses the abdominal wall; flexes the vertebral column
INNERVATION: thoracoabdominal nerves
- Transversus abdominis
ACTION: supports the abdominal wall; trunk rotation
INNERVATION: lower intercostal nerves
- Iliopsoas
ACTION: flexion of the trunk
INNERVATION: anterior rami of spinal nerves
- Walking
- Soleus
ACTION: foot plantar flexion
INNERVATION: tibial nerve
- Vastus lateralis
ACTION: extend lower leg
INNERVATION: femoral nerve
- Sartorius
ACTION: leg flexion and abduction
INNERVATION: femoral nerve
- Breathing
- Diaphragm
ACTION: inspiration and expiration (primary muscle of respiration)
INNERVATION: phrenic nerves
- External intercostals
ACTION: elevates ribs during forced inspiration
INNERVATION: intercostal nerves
- Internal intercostals
ACTION: depress ribs during forced expiration
INNERVATION: intercostal nerves