Anatomy
Fact-checked

At TheHealthBoard, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is the Brachium?

Debra Durkee
Debra Durkee

The brachium refers to the upper arm, or the portion of the human arm between the shoulder and the elbow. This term is distinguished from the antebrachium, or forearm, which includes the parts of the arm between the elbow and the wrist. Also a zoological term, it can also reference the portion of an animal's limb that corresponds to the same region on the human skeleton.

Made up of a single long bone called the humerus, the upper arm contains one of the longest bones in the body. The top end of the humerus consists of a single ball joint, which sits inside the scapula, or shoulder joint. When seen from the front, the humerus appears to have the joint at an angle at the back of the bone; this is because the ball joint fits into the shoulder in an oblique manner called retroversion. At the other end of the humerus are two joints facing in nearly the opposite direction as the top joint. These two bottom joints mark the attachment of the antebrachium at the elbow.

The upper arm, between the elbows and the shoulder, is considered the brachium.
The upper arm, between the elbows and the shoulder, is considered the brachium.

Two major muscles are found in the brachium. The bicep houses a tendon that is attached through a furrow in the upper humerus, and the muscle itself sits on the front of the brachium. On the back side is the triceps, which attaches opposite the biceps. Tension in these muscles and their connective tissues flexes the arm, and the bumps at the top of the humerus not only provide a place for the tendon but increase leverage for the brachium.

An X-ray of the brachium can determine the age of a child judging by the bone-to-cartilage content.
An X-ray of the brachium can determine the age of a child judging by the bone-to-cartilage content.

A strong bone in adults, the brachium is partially made of cartilage in childhood. Bone replaces cartilage slowly and at a regular rate, so regular that examination of the cartilage-to-bone content can help determine the age of a child. A simple x-ray is needed to determine what state of development the arm is in. 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 12.

Because of the number of muscles required for shoulder movement, an injury to brachium may affect the range of motion in the joint.
Because of the number of muscles required for shoulder movement, an injury to brachium may affect the range of motion in the joint.

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.

Discuss this Article

Post your comments
Login:
Forgot password?
Register:
    • The upper arm, between the elbows and the shoulder, is considered the brachium.
      By: pixelcaos
      The upper arm, between the elbows and the shoulder, is considered the brachium.
    • An X-ray of the brachium can determine the age of a child judging by the bone-to-cartilage content.
      By: Gennadiy Poznyakov
      An X-ray of the brachium can determine the age of a child judging by the bone-to-cartilage content.
    • Because of the number of muscles required for shoulder movement, an injury to brachium may affect the range of motion in the joint.
      By: olly
      Because of the number of muscles required for shoulder movement, an injury to brachium may affect the range of motion in the joint.
    • The humerus is the only bone in the brachium.
      By: Balint Radu
      The humerus is the only bone in the brachium.
    • A brachial plexus injury is sustained when there is damage to the nerves that run to the arm.
      By: stockshoppe
      A brachial plexus injury is sustained when there is damage to the nerves that run to the arm.
    • Some types of elbow and arm fractures require physical therapy during recovery.
      By: praisaeng
      Some types of elbow and arm fractures require physical therapy during recovery.
    • Two major muscles -- the biceps and triceps -- are found in the brachium.
      By: high_resolution
      Two major muscles -- the biceps and triceps -- are found in the brachium.
    • A brachial plexus injury may be characterized by loss of movement in parts of the arm or hand.
      By: Photographee.eu
      A brachial plexus injury may be characterized by loss of movement in parts of the arm or hand.