Introduction

This comprehensive and structured academic course focuses on the arterial system of the upper limb, specifically known as angiology, angéiology or vascular medicine. The following sections will delve into the anatomy, physiology, functions, and pathophysiology of the arteries of the arm in a clear, detailed, and rigorous manner.

Anatomy of the Arterial System of the Arm

Overview

The arterial system of the upper limb is integral to its proper functioning, supplying oxygenated blood, nutrients, and essentials for tissue repair and growth. This chapter will provide a detailed overview of the anatomical arrangement and distribution of the arm's major arteries.

Brachial Artery

The brachial artery is the primary conduit of systemic blood to the upper limb. It originates from the axillary artery, descending the medial border of the pectoralis major muscle and dividing into its continuations: the radial artery and the ulnar artery.

Radial Artery

The radial artery branches off from the brachial artery at approximately 5 cm below the medial epicondyle of the humerus, continuing down the anterior aspect of the forearm. It eventually divides into the superficial and deep palmar arch, which supplies blood to the dorsal and volar surfaces of the hand and fingers.

Ulnar Artery

The ulnar artery also originates from the brachial artery but travels down the posterior forearm, eventually giving rise to the palmar and common interosseous arteries that supply blood to the volar surfaces of the hand and fingers.

Branches of the Major Arteries

A detailed understanding of the branches of the arm's major arteries is essential for comprehending their functions and potential complications. This section will explore the significant branches of the radial, ulnar, and brachial arteries in depth.

Radial Artery Branches

• Superior and inferior muscular branches: Supplying blood to the muscles of the forearm
• Recurrent branch: Provides blood to the back of the hand and wrist
• Dorsal carpal branch: Supplies the dorsal aspects of the carpus
• Anterior interosseous artery: Branches off to provide blood to the flexor muscles of the forearm and the interosseous membrane
• Principal (posterior) metacarpal branches: Supplies the posterior surfaces of the metacarpals and the dorsal aspects of the hand
• Superficial palmar branch (Snuffbox): Distributes blood to the thumb and first metacarpophalangeal joint, as well as the thenar muscles and the dorsum of the thumb
• Deep palmar branch: Anastomoses with the ulnar artery's palmar branches to form the palmar arch, supplying blood to the volar surfaces of the hand and fingers

Ulnar Artery Branches

• Muscular branches: Supplies blood to the flexor muscles of the forearm
• Common interosseous artery: Provides blood to the ulnar side of the forearm, anastomosing with the anterior interosseous artery
• Palmar carpal branch: Branches off to provide blood to the volar aspect of the wrist and carpus
• Proper palmar digital branches: Distribute blood to the medial three digits (second, third, and fourth fingers) of the hand and their corresponding phalanges
• Superficial palmar arch: Anastomoses with the radial artery's deep palmar branch to supply blood to the volar surfaces of the hand and fingers

Physiology and Functions of the Arterial System of the Arm

The arterial system of the arm plays a crucial role in maintaining proper tissue perfusion, delivering oxygenated blood, nutrients, and essentials for tissue repair and growth. This section will discuss the physiological aspects and functions of the arm's major arteries.

Blood Pressure Regulation

The muscular walls of the arm's arteries contribute to maintaining appropriate blood pressure by allowing for adjustments in vessel diameter in response to changes in intravascular pressure. This ensures an adequate supply of oxygenated blood while preventing excessive pressure that could potentially damage the vessels or organs.

Collateral Circulation

In cases where the main conduit is compromised, collateral circulation becomes essential for maintaining perfusion and limiting tissue damage. Collateral vessels develop over time in response to blockages or occlusions of primary arteries, allowing alternate routes for blood flow.

Pathophysiology and Complications

Understanding the pathophysiological mechanisms responsible for complications within the arm's arterial system is essential for proper diagnosis and treatment. This section will delve into potential issues related to atherosclerosis, embolism, thrombosis, and peripheral artery disease.

Atherosclerosis

Atherosclerosis is the progressive narrowing of an arterial lumen due to the accumulation of cholesterol plaques within the vessel walls. Over time, these plaques may grow and obstruct blood flow, leading to tissue ischemia or infarction. The upper limb's major arteries are susceptible to atherosclerosis, with potential complications in the coronary, cerebral, and peripheral circulatory systems.

Embolism

Emboli are particles that travel through the bloodstream and can obstruct smaller vessels, causing ischemia or infarction. Potential sources of emboli include atherosclerotic plaques, thrombi, air bubbles, or fat globules. The arm's arterial system may be affected by both thromboembolism and arterial embolism.

Thrombosis

Thrombosis refers to the formation of a blood clot within a vessel, which can obstruct blood flow and lead to tissue ischemia or infarction. Risk factors for thrombosis include hypercoagulability, vascular damage, and stasis. The upper limb's arterial system may be affected by both deep vein thrombosis and arterial thrombosis.

Peripheral Artery Disease

Peripheral artery disease (PAD) is a condition characterized by the narrowing or occlusion of the peripheral arteries, often due to atherosclerosis. Symptoms include intermittent claudication, rest pain, tissue loss, and potential gangrene. The upper limb's arterial system may be affected by PAD, with potential complications in the lower extremities as well.