In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint and the elbow joint. The distal part of the upper limb between the elbow and the radiocarpal joint is known as the forearm or "lower" arm, and the extremity beyond the wrist is the hand.
The brachioradialis is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by way of the brachioradialis tendon, and to the lateral supracondylar ridge of the humerus.
The median nerve is a nerve in humans and other animals in the upper limb. It is one of the five main nerves originating from the brachial plexus.
The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is used to describe the entire appendage of the upper limb, but which in anatomy, technically, means only the region of the upper arm, whereas the lower "arm" is called the forearm. It is homologous to the region of the leg that lies between the knee and the ankle joints, the crus.
The axillary nerve or the circumflex nerve is a nerve of the human body, that originates from the brachial plexus at the level of the axilla (armpit) and carries nerve fibers from C5 and C6. The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery and vein to innervate the deltoid and teres minor.
In human anatomy, the ulnar nerve is a nerve that runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest in the human body unprotected by muscle or bone, so injury is common. This nerve is directly connected to the little finger, and the adjacent half of the ring finger, innervating the palmar aspect of these fingers, including both front and back of the tips, perhaps as far back as the fingernail beds.
Wrist drop is a medical condition in which the wrist and the fingers cannot extend at the metacarpophalangeal joints. The wrist remains partially flexed due to an opposing action of flexor muscles of the forearm. As a result, the extensor muscles in the posterior compartment remain paralyzed.
The upper limbs or upper extremities are the forelimbs of an upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digits, including all the musculatures and ligaments involved with the shoulder, elbow, wrist and knuckle joints. In humans, each upper limb is divided into the arm, forearm and hand, and is primarily used for climbing, lifting and manipulating objects.
The cubital fossa, chelidon or inside of elbow is the area on the anterior side of the upper part between the arm and forearm of a human or other hormid animals. It lies anteriorly to the elbow when in standard anatomical position.
In human anatomy, the extensor pollicis longus muscle (EPL) is a skeletal muscle located dorsally on the forearm. It is much larger than the extensor pollicis brevis, the origin of which it partly covers and acts to stretch the thumb together with this muscle.
In human anatomy, the supinator is a broad muscle in the posterior compartment of the forearm, curved around the upper third of the radius. Its function is to supinate the forearm.
The posterior interosseous nerve is a nerve in the forearm. It is the continuation of the deep branch of the radial nerve, after this has crossed the supinator muscle. It is considerably diminished in size compared to the deep branch of the radial nerve. The nerve fibers originate from cervical segments C7 and C8 in the spinal column.
The lateral cutaneous nerve of forearm is a sensory nerve representing the continuation of the musculocutaneous nerve beyond the lateral edge of the tendon of the biceps brachii muscle. The lateral cutaneous nerve provides sensory innervation to the skin of the lateral forearm. It pierces the deep fascia of forearm to enter the subcutaneous compartment before splitting into a volar branch and a dorsal branch.
The deep artery of arm is a large artery of the arm which arises from the brachial artery. It descends in the arm before ending by anastomosing with the radial recurrent artery.
The radial nerve divides into a superficial (sensory) and deep (motor) branch at the cubital fossa. The deep branch of the radial nerve winds to the back of the forearm around the lateral side of the radius between the two planes of fibers of the supinator, and is prolonged downward between the superficial and deep layers of muscles, to the middle of the forearm. The deep branch provides motor function to the muscles in the posterior compartment of the forearm, which is mostly the extensor muscles of the hand.
The muscular branches of the radial nerve supply the Triceps brachii, Anconæus, Brachioradialis, and Extensor carpi radialis longus, and are grouped as medial, posterior, and lateral.
The fascial compartments of arm refers to the specific anatomical term of the compartments within the upper segment of the upper limb of the body. The upper limb is divided into two segments, the arm and the forearm. Each of these segments is further divided into two compartments which are formed by deep fascia – tough connective tissue septa (walls). Each compartment encloses specific muscles and nerves.
The posterior compartment of the forearm contains twelve muscles which primarily extend the wrist and digits. It is separated from the anterior compartment by the interosseous membrane between the radius and ulna.
The following outline is provided as an overview of and topical guide to human anatomy:
The cervical spinal nerve 8 (C8) is a spinal nerve of the cervical segment.
