N3 Anatomy and Physiology AY 2023-2024

Answers:

1. Throwing a baseball overhead:

   • Muscle: Deltoid

   1. 1. Action - The deltoid muscle abducts and flexes the arm at the shoulder joint.

      2. Innervation - Axillary nerve

• Muscle: Rotator cuff muscles (e.g., Supraspinatus)

  1. Action - It stabilizes the shoulder joint during the throw.

  2. Innervation - Suprascapular nerve

2. Kicking a ball:

   • Muscle: Quadriceps femoris (specifically the rectus femoris)

   1. 1. Action - It extends the knee and flexes the hip

      2. Innervation - Femoral nerve

• Muscle: Hamstrings (e.g., Biceps femoris)

  1. Action - The hamstrings flexes the knee and extends the hip.

  2. Innervation - Sciatic nerve (tibial division for the biceps femoris)

3. Doing sit-ups:

   • Muscle: Rectus abdominis

   1. 1. Action - The trunk flexes (brings the chest toward the pelvis).

      2. Innervation - Lower six intercostal nerves and subcostal nerve (T7-T11)

• Muscle: External oblique

  1. Action - This muscle assists in trunk flexion and rotation.

  2. Innervation - Lower six intercostal nerves and subcostal nerve (T7-T11)

4. Breathing:

   • Muscle: Diaphragm

   1. 1. Action - The diaphragm contracts to increase thoracic volume during inhalation (or inspiration).

      2. Innervation - Phrenic nerve (C3-C5)

• Muscle: External intercostal muscles

1. Action - It elevates the ribs during inhalation (inspiration).

2. Innervation - Intercostal nerves (T1-T11)

REFERENCE:

Tortora, G. J., & Derrickson, B. (2017). Principles of anatomy & physiology. Fifteenth edition; Wiley Loose-Leaf Print Companion. Hoboken, New Jersey, John Wiley & Sons, Inc.