Activity 2
- Deltoid & pectorialis major
- Rectus femoris & iliopsoas
- Rectus abdominis & sternocleidomastoid
- Diaphragm & external intercostals
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
Pectorialis major
Action - Shoulder joint: Arm adduction, Arm internal rotation, Arm flexion (clavicular head), arm extension (sternocostal head); Scapulothoracic joint: Draws scapula anteroinferiorly
Innervation - Lateral and medial pectoral nerves (C5-T1)
2. Kicking a ball
Rectus femoris
Action - extend leg at knee joint; flexes thigh at hip joint
Innervation - Femoral nerve
Iliopsoas
Action - Psoas major and iliacus muscles acting together flex thigh at hip joint, rotate thigh laterally, and flex trunk on hip as in sitting up from supine position
Innervation - Lumbar spinal nerves L2-L3
3. Doing sit-ups
Rectus abdominis
Action - Flexes vertebral column, especially lumbar portion, and compresses abdomen
Innervation - Thoracic spinal nerves T7-T12
Sternocleidomastoid
Action - Acting together (bilaterally), flex cervical portion of vertebral column, extend head at atlanto-occipital joints; acting singly (unilaterally), laterally flex neck and head to same side and rotate head to side opposite contracting muscle. Laterally rotate and flex head to opposite side of contracting muscle. Posterior fibers of muscle can assist in extension of head.
Innervation - Accessory (XI) nerve, C2, and C3.
4. Breathing
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 (contains axons from cervical spinal nerves (C3-C5))
External intercostals
Action - Contraction elevates ribs and increases anteroposterior and lateral dimensions of thoracic cavity, resulting in inhalation; relaxation depresses ribs and decreases anteroposterior and lateral dimensions of thoracic cavity, resulting in exhalation
Innervation - Thoracic spinal nerves T2-T12
9/8/23 11:50 PM
NOTE: Ma'am I was supposed to edit the original post but I ran out of time. My apologies.
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
Pectorialis major
Action - Shoulder joint: Arm adduction, Arm internal rotation, Arm flexion (clavicular head), arm extension (sternocostal head); Scapulothoracic joint: Draws scapula anteroinferiorly
Innervation - Lateral and medial pectoral nerves (C5-T1)
2. Kicking a ball
Rectus femoris
Action - extend leg at knee joint; flexes thigh at hip joint
Innervation - Femoral nerve
Iliopsoas
Action - Psoas major and iliacus muscles acting together flex thigh at hip joint, rotate thigh laterally, and flex trunk on hip as in sitting up from supine position
Innervation - Lumbar spinal nerves L2-L3
3. Doing sit-ups
Rectus abdominis
Action - Flexes vertebral column, especially lumbar portion, and compresses abdomen
Innervation - Thoracic spinal nerves T7-T12
Sternocleidomastoid
Action - Acting together (bilaterally), flex cervical portion of vertebral column, extend head at atlanto-occipital joints; acting singly (unilaterally), laterally flex neck and head to same side and rotate head to side opposite contracting muscle. Laterally rotate and flex head to opposite side of contracting muscle. Posterior fibers of muscle can assist in extension of head.
Innervation - Accessory (XI) nerve, C2, and C3.
4. Breathing
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 (contains axons from cervical spinal nerves (C3-C5))
External intercostals
Action - Contraction elevates ribs and increases anteroposterior and lateral dimensions of thoracic cavity, resulting in inhalation; relaxation depresses ribs and decreases anteroposterior and lateral dimensions of thoracic cavity, resulting in exhalation
Innervation - Thoracic spinal nerves T2-T12
9/8/23 11:50 PM
NOTE: Ma'am I was supposed to edit the original post but I ran out of time. My apologies.