Upper Limb Anatomy

Upper Limb Anatomy

• The brachial plexus is formed by the anterior rami of spinal nerves C5 to T1.

• The brachial plexus has roots, trunks, divisions, cords, and branches.

• Roots: C5, C6, C7, C8, T1

• Trunks: Upper (C5-C6), Middle (C7), Lower (C8-T1)

• Divisions: Each trunk divides into anterior and posterior divisions.

• Cords: Lateral, medial, posterior (named relative to the axillary artery)

• Major branches include the musculocutaneous, axillary, radial, median, and ulnar nerves.

• Erb's Palsy: Damage to the upper roots (C5-C6) causing a "waiter's tip" deformity (loss of shoulder abduction, external rotation, and elbow flexion).

• Klumpke's Palsy: Damage to the lower roots (C8-T1) leading to a "claw hand" deformity (paralysis of intrinsic hand muscles).

• The axillary artery is a continuation of the subclavian artery, and is divided into three parts: 1st (superior thoracic), 2nd (thoracoacromial and lateral thoracic), and 3rd (subscapular, anterior, and posterior circumflex humeral).

Carpal Tunnel Syndrome

• Compression of the median nerve within the carpal tunnel causes carpal tunnel syndrome.
• Symptoms include pain, numbness, and tingling in the median nerve distribution.

Rotator Cuff Muscles

• The rotator cuff muscles (supraspinatus, infraspinatus, teres minor, and subscapularis) provide shoulder joint stability and enable movements like abduction and rotation.
• Common injuries in shoulder trauma.

Shoulder Joint

• The shoulder joint is a ball-and-socket synovial joint formed by the humerus head and glenoid cavity of the scapula.
• Dislocations are common due to a shallow glenoid cavity.
• Rotator cuff injuries can impair shoulder function.

Lower Limb Anatomy

Femoral Hernia

• Femoral hernias are more common in females.
• Structures limiting the femoral ring include the inguinal ligament, pectineus, and lacunar ligament.

Popliteal Fossa

• The popliteal fossa contains the popliteal artery and vein, and tibial and common peroneal nerves.
• An important site for popliteal aneurysms and vascular injury.

Femoral Sheath

• A fascial covering around the femoral artery, vein, and canal (excluding the femoral nerve).
• Femoral hernias pass through the femoral canal.

Foot Arches

• The arches of the foot (medial longitudinal, lateral longitudinal, and transverse)
• Flattening of the arches leads to flat feet (pes planus).
• Sciatic nerve, a large nerve formed by L4-S3 and exiting the pelvis through the greater sciatic foramen.
• Injury causes sciatica (radiating pain).

This quiz covers the anatomy of the upper limb, focusing on the brachial plexus, its formation, components, and important clinical considerations like Erb's and Klumpke's Palsy. It also discusses the anatomy of the axillary artery and its branches. Test your knowledge on these fundamental concepts in upper limb anatomy.