Artären

Artären, in Swedish anatomy, refers to the artery—the blood vessel that carries blood away from the heart. In humans, systemic arteries typically transport oxygenated blood to tissues, while the pulmonary arteries carry deoxygenated blood from the heart to the lungs.

Structure and function: Arteries have three layers: tunica intima (an endothelium-lined inner surface), tunica media (smooth muscle and elastic fibers), and tunica adventitia (connective tissue). The walls are thick and more elastic than those of veins, enabling them to withstand and transmit the pressure generated by each heartbeat. The muscular middle layer regulates diameter and blood flow, while arteries maintain flow under high pressure.

Classification and distribution: Elastic arteries near the heart, such as the aorta and pulmonary trunk, contain many elastic fibers to absorb pressure waves. Muscular arteries, including branches like the brachial or femoral arteries, distribute blood to specific organs. Arterioles are small branches that deliver blood to capillary beds and are key regulators of microcirculation and resistance.

Physiology: Arteries respond to the autonomic nervous system, hormones, and local metabolic cues. Vascular tone controls systemic vascular resistance and arterial pressure. Local factors, such as nitric oxide or endothelin, can induce vasodilation or vasoconstriction to match tissue needs.

Clinical relevance: Atherosclerosis involves plaque buildup within arteries, narrowing lumens and increasing ischemia risk. Aneurysms are focal dilations that can rupture. Arterial disease can affect any region, including coronary, carotid, and cerebral arteries, with implications for heart attack or stroke risk.

Development and microanatomy: Large arteries receive nutrients via the vasa vasorum in their outer layers, and the arterial wall features a thick tunica media that supports pulsatile flow.