Physiology and Hygiene for Secondary Schools

by Francis M. Walters

Of the neck: The sterno-mastoids, which pass between the mastoid processes, back of the ears, and the upper end of the sternum. They assist in turning the head and may be felt at the sides of the neck (Fig. 119).

Of the upper arm: The biceps on the front side, the triceps behind, and the deltoid at the upper part of the arm beyond the projection of the shoulder.

Fig. 119—Back and front views of important muscles.

Of the forearm: The flexors of the fingers, on the front[pg 256] side, and the extensors of the fingers, on the back of the forearm (Fig. 119).

Of the hand: The adductor pollicis between the thumb and the palm.

Of the trunk: The pectoralis major, between the upper front part of the thorax and the shoulder; the trapezius, between the back of the shoulders and the spine; the rectus abdominis, passing over the abdomen from above downward; and the erector spinæ, found in the small of the back.

Of the hips: The glutens maximus, fastened between the lower back part of the hips and the upper part of the femur.

Of the upper part of the leg: The rectus femoris, the large muscle on the front of the leg which connects at the lower end with the kneepan.

Of the lower leg: The tibialis anticus on the front side, exterior to the tibia, and the gastrocnemius, the large muscle in the calf of the leg. This is the largest muscle of the body, and is connected with the heel bone by the tendon of Achilles (Fig. 119).