Anatomy Essentials: Muscles, Origins, Insertions, and Actions

The gastrocnemius muscle inserts at the calcaneous bone, not the tibia, fibula, or femur.

The subscapularis muscle originates from the scapula, inserts on the humerus, and its actions include medial rotation of the arm and stabilization of the shoulder joint.

The coracobrachialis muscle inserts on the humerus bone.

The infraspinatus muscle inserts on the greater tubercle of the humerus, not on the scapula, clavicle, or radius.

The correct answer describes the specific origin, insertion, and action of the supraspinatus muscle in relation to the scapula and humerus, emphasizing its role in abduction, weak flexion, and stabilization of the shoulder joint.

The sartorius muscle inserts at the tibia, not the ilium, pubic bone, or fibula.

The flexor digitorum profundus muscle inserts at the phalanges, specifically flexing the distal joints of the fingers.

The extensor digitorum communis muscle inserts into the phalanges of the fingers, allowing it to extend the fingers and wrist.

The correct insertion point of pronator quadratus is the distal end of the ulna, not the radius. Additionally, pronator quadratus pronates the forearm and hand, it does not flex or supinate.

The diaphragm is a dome-shaped muscle essential for breathing. It originates from the sternum, lower ribs, and lumbar vertebrae, inserts into the central tendon, and its action involves pulling the central tendon downward to increase the volume of the thoracic cavity for inhalation.

The rectus femoris muscle inserts at the patella (tibia), not at the ilium, ischium, or fibula.

The insertion point of the teres major muscle is the Oscapula, specifically on the humerus. This muscle is responsible for actions such as medial rotation of the arm, adduction of the arm, and extension of the arm.

The teres minor muscle originates from the scapula, inserts into the humerus, and its action includes lateral rotation of the arm, weak adduction of the upper arm, and stabilization of the shoulder.

Orbicularis oculi muscle origin is at the maxilla and frontal bone, it inserts around the orbit and returns to origin, and its action is responsible for blinking or closure of the eyes.

The biceps femoris muscle inserts into the fibula and tibia, not the ischium, patella, ulna, or radius.

The insertion point of the glueteus maximus muscle is on the femur and fascia, allowing for movement of the leg.

The triceps brachii muscle inserts at the ulna bone in the forearm.

The deltoid muscle is inserted into the scapula and clavicle, not the humerus, sternum, ribs, radius, ulna, or vertebrae.

The latissimus dorsi muscle originates from the spinous processes of the thoracic and lumbar vertebrae, as well as the ilium, and inserts on the humerus. Its action includes extending and adducting the arm, as well as rotating the humerus inward.

The trapezius muscle originates from the occipital bone and inserts into the spines of the cervical and thoracic vertebrae. Its actions include elevating, retracting, depressing, and rotating the scapula.

The pectoralis minor muscle inserts on the scapula, not on the sternal ends of upper ribs or the origin of the muscle. Its action is to pull the scapula forward and downward, raising the ribs.

The pectoralis major muscle originates from the clavicle, sternum, and cartilage of ribs, inserts into the humerus, and is responsible for flexing, adducting, and rotating the humerus.

The platysma muscle inserts on the fascia of the chest, not on the forehead bone, upper arm bone, or pelvic bone.

The correct term for the bone that forms the cheek prominence is the zygomatic bone and the upper jawbone is the maxilla. The mandible is the lower jawbone, not the cheek prominence or upper jawbone. The frontal and temporal bones are part of the skull, not the cheek prominence or upper jawbone. The humerus and radius are bones in the arm, unrelated to the cheek prominence or upper jawbone.

The biceps brachii muscle originates from the scapula.

The solus/ muscle is comprised of the origination at the fibula and tibia, insertion at the calcaneous, and action of plantar flexion (adducts foot). The incorrect answers provided do not correspond to the correct components of the solus/ muscle.

The sternocleidomastoid muscle inserts at the temporal and occipital bones, specifically the mastoid process.

The orbicularis oris muscle originates from the maxilla, inserts into the mandible, and its action is to close and protrude the lips.