Mia Joy Q. Formalejo
1. Throwing a baseball overhead
Muscle 1: Deltoid (anterior fibers)
Action: Flexes and medially rotates the arm.
Innervation: Axillary nerve.
Muscle 2: Triceps brachii (long head)
Action: Extends the elbow and aids in shoulder extension.
Innervation: Radial nerve.
2. Kicking a ball
Muscle 1: Quadriceps (Rectus femoris)
Action: Extends the knee and flexes the hip.
Innervation: Femoral nerve.
Muscle 2: Gluteus maximus
Action: Extends and laterally rotates the hip.
Innervation: Inferior gluteal nerve.
3. Doing sit-ups
Muscle 1: Rectus abdominis
Action: Flexes the vertebral column.
Innervation: Lower six thoracic nerves (T7-T12).
Muscle 2: External oblique
Action: Flexes and rotates the trunk.
Innervation: Lower six thoracic nerves (T7-T12).
4. Breathing
Muscle 1: Diaphragm
Action: Contracts to increase thoracic volume during inhalation.
Innervation: Phrenic nerve (C3, C4, C5).
Muscle 2: External intercostals
Action: Elevates ribs to expand the thoracic cavity during inhalation.
Innervation: Intercostal nerves (T1-T11).