2015-2016
The forearm is the structure and distal region of the upper limb, between the elbow and the wrist. The forearm is covered by skin, the anterior surface usually being less hairy than the posterior surface.The forearm contains two long bones, the radius and the ulna, forming the radio-ulnar joint.
The interosseous membrane connects these bones.
FROM the anterior and posterior branches of the lateral cut.n.of the forearm,A continuation of the musculocutaneous n. FR0M the anterior and posterior branches of the medial cut.branches of the forearm. ANARROW strip of the skin down the middle of the posterior surface is supplied by the posterior cut.n. of the fore arm.The superficial veins lies in the superficial fascia . THE CEPHALIC VEIN arises from the lateral side of the dorsal venous arch on the back of the hand and winds around the lateral border of the forearm . It ascend into the cubital fossa and up the front of the arm on the lateral side of the biceps . It terminate in the axillary vein. As it ascend up ,it receives a variable numbers of tributaries from the lateral and posterior surfaces of the limb.
THE MEDIAN CUBITAL VEIN a branch of the cephalic vein in the cubital fossa, run ward and medially and joins the basilic vein.
The basilic vein arise from the medial side of the dorsal venous arch on the back of the hand and winds around the medial border of the forearm. It ascend into the cubital fossa and up the front of the arm on the medial side of the biceps . It terminate by joining the venae comitantes of the brachial artery to form the axillary vein. As it ascend up ,it receives a variable numbers of tributaries from the lateral and posterior surfaces of the limb.
From the thumb and lateral fingers and lateral areas of the hand and forearm follow the cephalic vein to the infra-clavicular group of nodes. Those from the medial fingers and medial areas of the hand and forearm follow the basilic vein to the cubital fossa . Here ,some drain into the supratrochlear L.N. other to the lateral group of the axillary nodes .The efferant vessels from the supratrochlear node also drain into the lateral group of the axillary nodes
The forearm is enclosed in a sheath of deep fascia which is attached to the periosteum of the posterior subcutaneous border of the ulna. This fascial sheath together with the interosseous membrane and fibrous intermuscular septa divides up the forearm into a number of compartments each having its own muscles,nerves and blood supply.
The posterior compartment contains the extensors of the hands, which are supplied by the radial nerve. The anterior compartment contains the flexors, and is mainly supplied by the median nerve. The ulnar nerve also runs the length of the forearm
Radius head neck radial tuberosity styloid process Ulna coronoid process olecranon process ulnar tuberosity slyloid process Interosseous Membrane
Muscles in the Anterior Compartment of the Forearm are split into three categories: Superficial Intermediate Deep
The superficial muscles in the anterior compartment are the flexor carpi ulnaris, palmaris longus, flexor carpi radialis and pronator teres.
They all originate from a common tendon, which arises from the medial epicondyle of the humerus
Attachments: Originates from the medial epicondyle with the other superficial flexors. It also has a long origin from the ulna which springs from the medial aspect of the olecranon process of the ulna and the posterior border of the ulna . It passes into the wrist, and attaches to the pisiform carpal bone. Actions: Flexion and adduction at the wrist. Innervation: Ulnar nerve.
This muscle is absent is about 15% of the population. Attachments: Originates from the medial epicondyle, attaches to the flexor retinaculum of the wrist. Actions: Flexion at the wrist. Innervation: Median nerve.
Attachments: Originates from the medial epicondyle. Insertion: attaches to the base of metacarpals II and III. Actions: Flexion and abduction at the wrist. Innervation: Median nerve.
The lateral border of the pronator teres forms the medial border of the cubital fossa, an anatomical triangle located over the elbow. Attachments: It has two origins, one from the medial epicondyle, and the other from medial border of the coronoid process of the ulna. It attaches laterally to the mid-shaft of the radius. Actions: Pronation of the forearm. Innervation: Median nerve.
It can sometimes be classed as a superficial muscle, but in most cadavers it lies between the deep and superficial muscle layers.The muscle is a good anatomical landmark in the forearm – the median nerve and ulnar artery pass between its two heads, and then travel posteriorly.Attachments: It has two heads – one originates from the medial epicondyle of the humerus, the other from the radius from oblique lineon the anterior surface of the radial shaft.