Human limbs have a rather complicated structure, which displays their high functionality. Those wishing to get acquainted with the device of the limbs will experience the knowledge of a large number of muscles in the arms and legs, tendons, and various types of bones. Of particular interest is the topic among athletes, as well as people who care about the beauty and health of their bodies. Consider the muscles of the arm.
Anatomy: what are muscles
Muscles are organs of the body that consist of muscle tissue, which is characterized by firmness and elasticity and is able to contract under the influence of nerve impulses. Thanks to the muscles, a person can perform various actions: move parts of the body, breathe, speak, cry, smile, etc. Not only the mobility of the body, but also the course of all physiological processes depends on the proper functioning of the muscles, based on their ability to contract. The nervous system regulates the work of muscle tissues and energy processes of the body . She connects them with the spinal cord and brain.
The size and shape of the muscles are very diverse. The smallest are located in the ear and are attached to the smallest bones. The largest are the gluteal muscles, which move the legs.
Spindle-shaped muscles, which are most characteristic of the limbs, as well as the wide muscles that form the walls of the trunk, are the most common muscle in shape. Muscles having a common tendon and two or more heads are called biceps, triceps or quadriceps.
Depending on the method of counting various muscle groups, their total number ranges from 639 to 850. Such many different muscles are usually divided into groups.
What muscles are your arms made of?
The muscles of the human arm span two groups.
The first is the muscles of the shoulder girdle, which include the deltoid, infraspinatus, supraspinatus, subscapularis, small round and large round muscles. The second is the muscles of the free upper limb. This group includes, respectively, the muscles of the hands, forearms (front, back and radial) and shoulder.
The main muscles of the arm include:
- deltoid shoulder muscle;
- biceps;
- anterior muscle of the upper arm;
- triceps;
- back muscle of the upper arm;
- muscles of the forearm.
Deltoid - these are the muscles of the hands involved in their raising and lowering, as well as their rotation in different directions, that is, responsible for the movements occurring in the elbow joint. The delta consists of 3 beams: rear, front and middle. It forms the roundness of the shoulder, covering the surface of the shoulder joint from the outside. This broad muscle has a feathery structure.
Biceps are the biceps of the arms. They are relatively small and, nevertheless, the most popular among beginner bodybuilders. Biceps are responsible for flexion of the arm that occurs in the elbow joint. Biceps are the two main muscle ligaments - a long and short head. In the lower part, they are attached to the radius of the forearm.
Triceps (triceps muscles of the shoulder) - the largest and most developed muscles of the hands. The action of these muscles is the opposite of the action of biceps and consists in the extension of the arm in the elbow joint. The triceps is located above the elbow on the back of the upper arm. This muscle consists of three ligaments. These are lateral, long and medial heads.
The arm muscles belonging to the forearm comprise four layers of the anterior group and two layers of the posterior group. They allow you to move your fingers, squeeze your hand into a fist, rotate your wrist.
The muscles of the hands also include:
- brachial muscle - flexor muscle, located under the biceps;
- brachioradialis muscle is a flexor muscle located on the forearm.
The muscles of the hand include the muscles of the surface of the palm, the elevation of the thumb, as well as a separate short muscle that takes the thumb away.