The human humerous is an important bone in the arm. In fact, it is the primary bone in the upper arm, between the shoulder joint and the elbow. The humerous is a long bone with numerous muscles attached at various points. This article will take a look at some of the more relevant anatomy of the human humerus.
The humerus is the bone that connects the scapula to the bones of the forearm (the radius and the ulna). The proximal (shoulder) end of the humerus articulates in with the scapula in the glenoid fossa. The humeral head is the round, smooth part of the bone that fits in to the shoulder joint, allowing for a wide range of motion in the upper arm.
The lower part of the humerus forms part of the elbow joint. There are two connections in the lower humerus to the radius and ulna. The capitulum attaches to the radius while the trochlea attaches to the ulna. These names may sound confusing, and they can be. They are just specific parts of the humerus. Yes, even parts of bones have their own names - much to the worry of anatomy students worldwide.
There are many muscles that attach to various parts of the humerus. These muscles can be used to move the shoulder or the elbow joints. Some of the more important muscles that attach to the humerus include the triceps (but not the biceps, even though it sits next to the humerus).
Pectoralis major, teres major, and latissimus dorsi attach to the humerus. These are chest muscles and muscles located on the side of your trunk (latissimus).
Infraspinatus, subscapularis, and teres minor also attach at different points of the humerus. And don't forget the deltoid. The deltoid is an important muscle that covers the side aspect of your shoulder and upper arm. It helps raise your arm above your head.
The joint that makes up the shoulder has a wide range of motion, but it can be unstable. It can dislocate easily. A shoulder dislocation occurs when the humeral head pops out of the glenohumeral joint, usually to the front of the joint (but it can go the other way). Dislocation of this joint can cause damage to the axillary nerve, which helps control the deltoid muscle.
There are two other nerves that run along the humerus. The radial nerve curves around the midshaft of the humerus and is often damaged in fractures of the middle of the bone. The ulnar nerve gets very close to the surface just above the elbow joint. When you bump your elbow in just the right place, you can hit the "funny bone", which is actually the ulnar nerve near the end of the humerus.
The anatomy of the human humerus is important not only to students, but also in clinical practice. There are many important structures and functions related to the humerus and it is often involved in damage to the upper limb.