Activity 2:
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Throwing a baseball overhead
Muscle 1: Latissimus dorsi
- Action: Extends, adducts, and rotates arm medially: draws arm downward and backward.
- Innervation: Thoracodorsal nerve.
Muscle 2: Pectoralis major
- Action: flexion, adduction, and internal rotation of the humerus.
- Innervation: lateral and medial pectoral nerves
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Kicking a ball
Muscle 1: Quadriceps
- Action: extend the leg at the knee joint and flex the thigh at the hip joint.
- Innervation: Femoral nerve
Muscle 2: Hamstring
- Action: extend the hip and flex the knee.
- Innervation: nerves that arise from the lumbar and sacral plexuses
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Doing sit-ups
Muscle 1: Rectus abdominis
- Action: flexes the vertebral column in addition to compressing the abdominal wall.
- Innervation: thoracoabdominal nerves
Muscle 2: Obliquus externus abdominis
- Action: ipsilateral lateral flexion of the trunk and contralateral rotation of the trunk when it contracts unilaterally
- Innervation: anterior rami of the thoracic spinal nerves
-
Breathing
Muscle 1: Diaphragm
-
- Action: During inhalation, diaphragm contracts and flattens resulting to the enlargement of cavity. When this happens, this creates a vacuum which pulls up the air into the lungs. Upon exhalation, diaphragm relaxes and returns to its domelike shape and the air is forced out of the lungs.
- Innervation: Phrenic nerve.
Muscle 2: External intercostals
-
- Action: It elevates the ribs during inhalation; increasing the lateral and anteroposterior dimensions of thorax.
- Innervation: Intercostal nerves.
References:
Tortora, G. J., & Derrickson, B. (2017). Tortora’s Principles of Anatomy and Physiology John Wiley & Sons, Inc. eBooks https://ci.nii.ac.jp/ncid/BB23861293
Rectus abdominis muscle. (2016). Kenhub. https://www.kenhub.com/en/library/anatomy/rectus-abdominis-muscle