Name at least two muscles that actively contracts during the following activities and name its action and innervation:
1. Throwing a baseball overhead
Deltoid
Action:
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
Innervation:
Axillary nerve
Subscapularis
Action:
Medially rotates arm at shoulder joint
Innervation:
Upper and lower subscapular nerve
2. Kicking A Ball
Gastrocnemius
Action:
Plantar flexes foot at ankle joint and flexes leg at knee joint
Innervation:
Tibial Nerve
Popliteus
Action:
Flexes leg at knee joint and medially rotates tibia to unlock the extended knee
Innervation:
Tibial Nerve
3. Doing sit ups
Rectus abdominis
Action:
Flexes vertebral column and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth
Innervation:
Thoracic spinal nerves T7–T12
Transversus abdominis
Action:
Compresses abdomen
Innervation:
Thoracic spinal nerves T8–T12
Iliohypogastric nerve
Ilioinguinal nerve
4. Breathing
Diaphragm
Action:
Contraction of diaphragm flattens and increases vertical dimension of thoracic cavity = Inhalation
Relaxation of diaphragm moves it superiorly and decreases vertical dimension of thoracic cavity = Exhalation
Innervation:
Phrenic nerve, containing axons from cervical spinal nerves (C3-C5)
External intercostals
Action:
Contraction elevates ribs and increases anteroposterior and lateral dimensions of thoracic cavity = Inhalation
Relaxation depresses ribs and decreases anteroposterior and lateral dimensions of thoracic cavity = Exhalation
Innervation:
Thoracic spinal nerves T2-T12
Tortora, G. J. (2018, May 15). Principles of anatomy and physiology. Google Books.
https://books.google.com/books/about/Principles_of_Anatomy_and_Physiology.html?id=aSaVDwAAQBAJ