N3 Anatomy and Physiology (1st Sem AY 2022-2023)

ACTIVITY 2

Name at least three muscles that contracts during the following activities and name its action and innervation:

Turning a door knob

1. Supinator - supinates forearm at radioulnar joints; deep radial nerve

2. Pronator quadratus - Pronates forearm at radioulnar joints; median nerve

3. Pronator teres - Pronates forearm at radioulnar joints and weakly flexes forearm at elbow joint; median nerve

Throwing a baseball overhead

1. Teres Major - extends arm at shoulder joint and assist in adduction and medial rotation of the arm at shoulder joint; lower subscapular nerve

2. Deltoid - lateral fibers abduct arm at shoulder joint, anterior fibers flex and medially rotate arm at shoulder joint, posterior fibers extend and laterally rotate arm at shoulder joint; axillary nerve

3. Latissimus dorsi - extends, adducts, and medially rotates arm at shoulder joint, draws arm inferiorly and posteriorly; axillary nerve

 Kicking a ball

1. Rectus femoris - extend leg at knee joint, weakly flexes, abducts, and laterally rotates thigh at hip joint; femoral nerve

2. Psoas major - flex thigh at hip joint, rotate thigh laterally; lumbar spinal nerves

3. Gluteus maximus - extends thighs at hip joint and laterally rotates thigh; superior gluteal nerve

Doing sit-ups

1. Rectus abdominis - flexes vertebral column; thoracic spinal nerve T7-T12

2. External obliques - compress abdomen and flex vertebral column; Thoracic spinal nerves T7-T12

3. Transversus abdominis - compresses abdomen; Thoracic spinal nerve T8-T12

Walking

1. Soleus - plantar flexes foot at ankle joint; Tibial nerve

2. Popliteus - flexes leg at knee joint and medially rotates tibia to unlock the extended knee; Tibial nerve

3. Tibialis posterior - plantar flexes foot at ankle joint and inverts foot at intertarsal joints; Tibial nerve

Breathing

1. Diaphragm - its contraction causes it to flatten and increases vertical dimensions of thoracic activity, resulting in inhalation; Phrenic nerve

2. External intercostals - contraction elevates ribs and increases anteroposterior and lateral dimensions of thoracic cavity; Thoracic spinal nerves T2-T12

3. Internal intercostals - contraction draws adjacent ribs together to further decrease anteroposterior and lateral dimensions of thoracic cavity during forced exhalation; Thoracic spinal nerves T2-T12