ACTIVITY 2
Throwing a baseball overhead
Deltoid
Action: Lateral fibers abduct arm at shoulder joint and anterior fibers flex and medially rotate arm at shoulder joint
Innervation: Axillary nerve
Latissimus dorsi
Action: Extends, adducts, and medially rotates arm at shoulder joint
Innervation: Thoracodorsal nerve
Kicking a ball
Soleus
Action: Plantar flexion of the upper ankle joint, enabling the lifting of the heel against gravity when jumping or walking
Innervation: Tibial Nerve
Iliopsoas
Action: Acts as a hip flexor and assists in external rotation of the hip joint
Innervation: L2-4 nerve roots of the lumbar plexus
Gastrocnemius
Action: Plantar flexion at the ankle joint and flexion of leg at knee joint
Innervation: Tibial Nerve
Doing sit ups
Transversus abdominis
Action: Compresses and compression of the abdomen
Innervation: T8-T12, Thoracic spinal nerve, iliohypogastric nerve, & ilioinguinal nerve
Rectus Abdominis
Action: Flexes the lumbar spine bringing the ribcage closer to the pelvis
Innervation: T7-T12, Thoracic spinal nerve
Breathing
Diaphragm
Action: Its contraction makes itself flat and increases the vertical dimensions which causes inhalation. On the other hand, its relaxation allows itself to move superiorly, as well as decreases the vertical dimension of the thorax, which results in exhalation
Innervation: Phrenic nerve, carrying axons from cervical spinal nerves
External intercostals
Action: Elevates the ribs, which results in inhalation. While, it depresses the rib cage, which causes exhalation
Innervation: Thoracic spinal nerves
REFERENCES:
Tortora, G.J. & Derrickson, B. (2017). Chapter 11: The Muscular System. In Principles of
anatomy and physiology (15th ed.).