Question | Answer |
Muscle Overview | Muscles support and maintain body posture through a low level of a contraction, Skeletal muscles produce a substantial amount of heat when they contract, More than 600 muscles in the body |
Skeletal | Attaches to the bones of the skeleton, Voluntary, Striated in appearance, Operates under conscious control, Many work in pairs |
Smooth(Visceral Muscle) | Involuntary, Not striated, Not under conscious control, In walls of hollow organs and tubes, Contraction controlled by hormones and autonomic nervous system |
Cardiac | Specialized muscle forming the wall of the heart, involuntary, Controlled by the autonomic nervous system, Striated in appearance |
Tendon | Attaches muscles to bones |
Fascia | Sheets of fibrous connective tissue around muscle |
Point of Origin | Muscle attachment to less movable part of skeleton |
Point of insertion | Muscle attachment to movable part of skeleton |
Buccinator | Located in fleshy part of cheek; assists in actions such as whistling and smiling |
Temporal | Located above and near the ear; assisting in chewing |
Masseter | Located at the angle of the jaw; Raises the mandible and closes the jaw |
Sternomastoid (Sternocleidomastoid) | Extends from the sternum upward along the side of the neck to the mastoid process; Assists with actions such as bending your neck and turning your head side to side |
Trapezius | Triangular-shaped muscle, extends across the back of the shoulder, Covers back of neck, Inserts on clavicle and scapula, assists with "shrugging" of shoulders |
Latissimus Dorsi | Originates from vertebrae of the Lower back, Crosses lower half of the thoracic region, Passes through the humerus and scapula, Inserts on anterior surface of humerus, Forms the posterior border of the axillae, Allows moving of arms (swinging motion) |
Deltoid | Covers the shoulder joint, Originates form the clavicle and scapula, Inserts on the lateral side of the humerus, Allows abduction of the arm, may be site of IM injections |
Triceps Brachii | Muscle has three heads, originates from scapula and humerus, Inserts onto olecranon process of the ulna at the elbow |
Pectoralis Major | Large, fan shaped muscle, Crosses the upper part of the front crest, Originates from the sternum, Crosses over the humerus, allows adduction of the arm |
Biceps Brachii | Muscle has two heads, originates from the scapula, inserts on the radius, allows flexing of the lower arm |
Quadriceps Femoris | Forms anterior part of the thigh, Helps in extension of the thigh, Group of four muscles |
Hamstring Muscles | Located in the posterior part of the thigh, can be felt behind the knee, Assists in the flexion of the leg on the thigh and extension of the thigh, Group of three muscles |
Gluteus Maximus | Forms most of the fleshy part of the buttock, originates from the ilium and inserts in the femur, Extends the thigh |
Gluteus Medius | Located above the upper outer quadrant of the gluteus maximus muscle; site of IM injection, Originates from the posterior part of ilium, Inserts in the greater trochanter of the femur |
Gastrocnemius | Main muscle of the calf, attaches to the heel bone by way of the achilles tendon, used to plantar flex foot and flex toes |
Tibialis anterior | Positioned on the front of the leg, used to dorsiflex foot and turn foot inward |