Skeletal Muscle AOIs for Mini Exam 1

Flashcards reviewing the Action, Origin, and Insertion (AOI) of 15 key skeletal muscles categorized by anatomical region for Mini Exam 1.

Temporalis

A muscle of the head and neck. Action: elevates mandible. Origin: parietal bone (temporal lines). Insertion: coronoid process of mandible.

Masseter

A muscle of the head and neck. Action: elevates mandible. Origin: zygomatic arch (temporal and zygomatic bones). Insertion: ramus of mandible.

Diaphragm

A muscle of the trunk. Action: inspiration (increases volume of thorax). Origin: xiphoid process, lower 6 ribs, lumbar vertebrae. Insertion: central tendon of diaphragm.

Rectus abdominis

A muscle of the trunk. Action: compresses abdomen, flexes spine. Origin: pubis near symphysis. Insertion: costal cartilages and xiphoid process.

Deltoid

A muscle of the upper limb. Action: abducts arm, medially or laterally rotates arm. Origin: clavicle and scapula. Insertion: humerus (deltoid tuberosity).

Trapezius

A muscle of the upper limb. Action: adducts; elevates, depresses, retracts scapula. Origin: occipital bone, thoracic vertebra. Insertion: clavicle and scapula (spine and acromion).

Pectoralis major

A muscle of the upper limb. Action: flexes, adducts, medially rotates arm. Origin: costal cartilages, sternum (body) and clavicle. Insertion: proximal anterior surface of humerus (near intertubercular groove).

Latissimus dorsi

A muscle of the upper limb. Action: extends, adducts, medially rotates arm. Origin: lower ribs; lower thoracic and all lumbar vertebrae. Insertion: proximal anterior surface of humerus (near intertubercular groove).

Biceps brachii

A muscle of the upper limb. Action: flexes, supinates forearm; flexes arm. Origin: scapula (coracoid process and above glenoid fossa). Insertion: radial tuberosity.

Triceps brachii

A muscle of the upper limb. Action: extends forearm; extends arm. Origin: posterior surface of humerus and scapula (long head). Insertion: olecranon process of ulna.

Gluteus maximus

A muscle of the lower limb. Action: Extends, laterally rotates thigh. Origin: iliac crest, sacrum, coccyx. Insertion: gluteal tuberosity of femur and iliotibial tract.

Adductor magnus

A muscle of the lower limb. Action: adducts thigh. Origin: pubis. Insertion: linea aspera of femur.

Rectus femoris

A muscle of the lower limb. Action: extends leg and flexes hip. Origin: ilium (anterior inferior iliac spine). Insertion: tibial tuberosity.

Biceps femoris

A muscle of the lower limb. Action: flexes leg, extends hip. Origin: ischial tuberosity and linea aspera of femur. Insertion: fibula (head) and tibia (lateral condyle).

Gastrocnemius

A muscle of the lower limb. Action: flexes leg, plantar flexion foot. Origin: medial and lateral condyles of femur. Insertion: calcaneus.