The muscles of the upper arms are one of the most powerful and important muscles groups in the body. Because of these muscles, we are able to rotate, swing, fold, and raise our upper extremities. If there would be any abnormality on the structure and function of the upper arm muscles, the overall quality of life of an individual will surely be affected. This is the main reason that we should take care of our muscles and maintain its vitality.
Overview of the Muscles of the Upper Arm
The muscles of the arm are basically the same with other muscles in the body. The main difference is in their structure, location and function. There are four main muscles of the arm and these are the following.
- Credit: http://christopherdhoward.wordpress.com/2009/06/15/coracobrachialis/Coracobrachialis – this is the smallest muscle among the four major muscles of the upper arm. The proximal end of this muscle is attached to the apex of coracoid process and runs along the short heads of the biceps. A tendon allows the coracobrachialis to be attached between the triceps brachii and brachialis. It is controlled by the brain through the musculocutaneous nerve.
- Credit: http://www.sciencelearn.org.nz/Contexts/Sporting-Edge/Sci-Media/Images/Biceps-brachii-muscleBiceps brachii – located at the anterior aspect of the upper arm. This muscle of the upper arm is also supplied by the musculocutaneous nerve. The brachialis is the primary flexor of the upper arm and to a certain extent, of the shoulder. It is also a powerful supinator.
- Credit: http://www.polykarbonbbs.com/showthread.php?t=3990Brachialis – this muscle cover the anterior part of the elbow joint and it originated from the lower half of the humerus. It is separated by the brachioradialis and the extensor carpi.
- Credit: http://muscle-a-day.blogspot.com/2011/09/triceps-brachii.htmlTriceps brachii – this is the main extensor of the muscles of the upper arm. It is located at the posterior aspect of the upper arm. It has three heads; long, lateral, and medial. All of the heads of the triceps is attached to the humerus through the help of tendons. The triceps are innervated by the seventh and eight cervical nerves through the radial nerve. It is also a direct antagonist muscle of the biceps.
Microscopic Anatomy of Upper Arm Muscles
A skeletal muscle such as the muscles of the upper arm consists of fascicles enclosed by an epimysium. These bundles are separated from each other through the perimysium and are surrounded by the endomysium. Each muscle fiber has its own nuclei, mitochondria, and other organelles.
Upper Arm Muscle Injuries
The muscles of the upper arm are always utilized by an individual in accomplishing different tasks. This increases the chance for the upper arm muscle to get injured and strained. Mechanical trauma and strong external force can injure the muscles. Sprains are also common when the tendons that hold the muscles are stretched or torn. In most cases, upper arm injury can heal by itself but others need medical attention.
Summary of the Muscles of the Upper Arm
Just like any muscles, the upper arm is very important for our daily activities. The muscles of upper arm are composed of various muscle groups and are organized in a brilliant way.
This article has given you brief information about a part of the musculoskeletal system. The muscles of the upper arm should be studied further to create an understanding about its nature.