Lisa Emeri C. Tena
- Throwing a baseball overhead
A. Teres minor
Action: Laterally rotates and extends arm at shoulder joint
Innervation: Axillary nerve
B. Infraspinatus
Action: Laterally rotates and extends arm at shoulder joint
Innervation: Suprascapular nerve
2. Kicking a ball
A. Biceps femoris
Action: Flexes leg at knee joint and extends thigh at hip point
Innervation: Tibial and fibular nerves from sciatic nerve
B. Gluteus maximus
Action: Extends thigh at hip joint and laterally rotates thigh: help lock knee in extension
Innervation: Inferior gluteal nerve
3. Doing sit-ups
A. Rectus abdominis
Action: Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth
Innervation: Thoracic spinal nerves T7-T12
B. External oblique
Action: Acting together, compress abdomen and flex vertebral column
Innervation: Thoracic spinal nerves T7-T12 and the iliohypogastric nerve
4. Breathing
A. Diaphragm
Action: Contraction of diaphragm causes it to flatten and increases vertical dimension of thoracic cavity, resulting in inhalation; relaxation of diaphragm causes it to move superiorly and decreases vertical dimension of thoracic cavity, resulting in exhalation
Innervation: Phrenic nerve, containing axons from cervical spinal nerves C3-C5
B. Internal intercostals
Action: Contraction draws adjacent ribs together to further decrease anteroposterior and lateral dimensions of thoracic cavity during forced exhalation
Innervation: Thoracic spinal nerves T2-T12