How many humerus

Quiz questions. Susan Standring, Henry Gray. Gray's Anatomy. Anatomy for Diagnostic Imaging. Related articles: Anatomy: Upper limb. Promoted articles advertising. Figure 1 Figure 1. Case 1: humerus radiographs Case 1: humerus radiographs. Figure 2: anterior muscle attachments Gray's illustration Figure 2: anterior muscle attachments Gray's illustration.

Figure 3: posterior muscle attachments Gray's illustration Figure 3: posterior muscle attachments Gray's illustration. Figure 4: ossification centers Gray's illustrations Figure 4: ossification centers Gray's illustrations.

Loading more images Close Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. Loading Stack - 0 images remaining. By System:. Patient Cases. Contact Us. The shape of the joint between the capitulum and radius allows the forearm and hand to rotate and bend at the elbow while the ulna forms a tight hinge with the trochlea. On the posterior side of the humerus, a small cavity known as the olecranon fossa allows the tip of the ulna, known as the olecranon, to lock into the humerus and prevent the extension of the elbow beyond degrees.

The humerus is classified structurally as a long bone because it is considerably longer than it is wide. Like all long bones, the humerus is hollow in the middle of its shaft and is reinforced at the ends by small columns of spongy bone known as trabeculae.

Red bone marrow, the tissue that produces new blood cells, is found in the ends of the humerus and supported by the trabeculae. The hollow medullary cavity in the middle of the shaft of the humerus is filled with fatty yellow bone marrow for energy storage. Compact bone forms the largest and strongest structure in the humerus, surrounding the trabeculae in the ends and the medullary cavity in the shaft.

Surrounding the entire bone is the fibrous periosteum layer that provides a thin, yet strong connecting material for the tendons and ligaments that bind the humerus to muscles and other bones. Finally, the ends of the humerus are capped by a thin layer of hyaline known as articular cartilage that acts as a shock absorber in the joints.

A humerus fracture most often occurs due to a direct blow. This type of injury often happens in contact sports or car accidents.

You can also break your humerus if you fall with your arm outstretched. Sometimes a humerus fracture can happen due to an underlying health condition. This is called a pathologic fracture and can be caused by conditions such as osteoporosis or cancer.

The type of treatment will depend on the severity of the fracture. Some treatment options may include one or a combination of the following:. Generally, it could take between 8 to 12 weeks to recover from a humerus fracture. Keep in mind that you may need to do physical therapy for several months afterward. Your humerus is the long bone in your upper arm.

The connections it makes at the shoulder and elbow enable you to make many different arm movements. The humerus is also a connection point for arm and shoulder muscles. Humerus fractures are a common injury that are often caused by falls, car accidents, or contact sports. These fractures are typically treated with medications, immobilization, and physical therapy. Surgery may be needed in more severe cases. Make an appointment to see your doctor if you have upper arm pain that is severe, unexplained by another health condition, or affects your range of motion.

Your doctor can help diagnose what may be causing your pain and develop a treatment plan. Arm pain is defined as discomfort or pain experienced anywhere throughout your arm.