Where is the brachium

Intrinsic muscles of the thoracic limb have both attachments on the limb and thus they move one part of the limb relative to another part in contrast to extrinsic muscle which move the limb relative to the trunk. The proximal less mobile attachment of an intrinsic limb muscle is called its origin.

The distal more mobile attachment is called the insertion of the muscle. Multi-head muscles are named biceps, triceps, quadriceps for their number of heads in the human.

The muscles that originate on the scapula and insert on the proximal end of the humerus close to the shoulder-joint fulcrum are "high gear" muscles with respect to shoulder joint motion large limb-movement; weak power. Such muscles are effective when the limb is not bearing weight.

The first piece to change is the capitellum joint at the elbow, which turns to bone at about age two. The last is the lateral condyle on the outside of the base of the brachium, which turns to bone at about age Injuries to the brachium can affect other parts of the body and, in turn, the arm can be affected by injuries to other areas.

A brachial plexus injury is sustained when there is damage to the nerves that run to the arm, and most commonly characterized by numbness and weakness in the brachium or loss of movement in any part of the arm or hand. The grooves at the bottom of the humerus also house nerve endings, including the spot known as the funny bone.

Sudden pressure can create an electric pain, and chronic pressure on the base of the brachium can weaken the muscles of the hands. Debra Durkee. Please enter the following code:. The triceps brachii has three origins, called the long head, the lateral head, and the medial head.

Figure shows the three origins of the triceps brachii in different colors. It is easiest to view the triceps brachii from the posterior, but the medial head and its origin are deep to the lateral head and the long head, and so is the medial head of the triceps brachii is partially obscured from the posterior.

Figure The three heads of the triceps brachii color-coded to distinguish them. Keep in mind, despite the different colors all three are parts of the same one muscle. Skip to main content. Module 9: Muscles of the Limbs. Search for:. Muscles of the upper arm Information Anatomists refer to the upper arm as just the arm or the brachium.