Upper Limb Anatomy Overview

Study Notes

General Overview

The upper limb is comprised of the shoulder, arm, forearm, and hand.
It's responsible for various functions, including reaching, grasping, and manipulating objects.
It's structured for both strength and mobility.

Shoulder Girdle

The shoulder girdle connects the upper limb to the axial skeleton.
It consists of the scapula (shoulder blade) and clavicle (collarbone).
The scapula is a flat, triangular bone that articulates with the humerus and clavicle.
The clavicle acts as a strut, providing stability and support to the shoulder.
Glenoid cavity: A shallow socket on the scapula that articulates with the head of the humerus. This shallow socket allows for a large range of movement but also increases susceptibility to dislocation.

Arm

The arm is the region between the shoulder and elbow.
It's primarily composed of the humerus, a long bone extending from the shoulder to the elbow.
The humerus head articulates with the glenoid cavity of the scapula.
Important bony landmarks include the greater and lesser tubercles, the deltoid tuberosity, and the anatomical neck.
Medially located is the anatomical coronoid process of the humerus.

Elbow Joint

The elbow joint connects the arm to the forearm.
It's a hinge joint formed by the articulation of the humerus, radius, and ulna.
The trochlea and capitulum of the humerus articulate with the corresponding parts of the radius and ulna.

Forearm

The forearm comprises the radius and ulna.
The radius and ulna are parallel bones that articulate at both ends.
The radius runs laterally and the ulna runs medially.
The radius and ulna allow for rotation and flexion of the forearm.

Wrist and Hand

The wrist is formed by eight carpal bones arranged in two rows.
These bones articulate with the radius and ulna.
The wrist allows for flexion, extension, and side-to-side movement.
The hand contains five metacarpal bones that articulate with the carpal bones.
The fingers (digits) and thumb are made up of phalanges (finger bones.)
The thumb (pollex) is a unique digit.

Muscles of the Upper Limb

Numerous muscles are involved in the movement and support of the upper limb. The muscles work together to allow flexion, extension, abduction, and adduction.
Muscles of the shoulder girdle are responsible for stabilizing the shoulder complex.
Muscles of the arm, forearm, wrist, and hand control movements of the joint and individual digits.

Nerves and Vessels

Nerves supply sensory and motor information to the upper limb.
Major nerves include the axillary, musculocutaneous, radial, median, and ulnar nerves.
Blood vessels supply oxygen and nutrients to tissues throughout the upper limb.
Arteries such as the subclavian, axillary and brachial arteries are important components of the vascular system of the upper limb.

Articulations of the Upper Limb

Articulations are the joints where bones meet.
The shoulder joint (glenohumeral joint) connects the humerus to the scapula.
The elbow joint connects the humerus to the radius and ulna.
The wrist joint connects the radius and ulna to the carpal bones.
The hand has complex articulations for finger movement and prehension.

Clinical Considerations

Injuries to the upper limb are common, affecting various tissues.
Fractures, dislocations, sprains, tendinitis, and nerve damage are potential issues.
Medical imaging (X-rays, MRI, etc.) is critical in evaluating injuries.
Physical therapy is often needed for recovery from upper limb injuries.

Description

This quiz covers the anatomy of the upper limb, including the shoulder girdle, arm, forearm, and hand. You'll learn about their structures, functions, and the biomechanics involved in movements like reaching and grasping.