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capillary
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Illustration of a capillary cross section showing red blood cells moving from an artery to a vein. Arrows indicate oxygen and nutrients leaving the blood to enter body cells, while carbon dioxide and wastes enter the blood from body cells. Lung capillary gas exchange in the lung Diagram of the circulatory system showing a red artery carrying blood from the heart, branching into smaller arterioles and capillaries, then merging into blue venules and a vein returning blood to the heart. Diagram showing the anatomy of the small intestine with labeled regions (duodenum, jejunum, ileum), a cross-section highlighting muscle and mucosa layers, an enlargement of mucosal folds (plicae circulares), and a detailed view of a villus structure with epithelial, goblet, endocrine, and Paneth cells, microvilli, blood capillaries, and lacteal.
Watch red blood cells travel through arteries and capillaries to deliver oxygen
Function of red blood cells explained
Understanding the human cardiovascular system
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Illustration of a capillary cross section showing red blood cells moving from an artery to a vein. Arrows indicate oxygen and nutrients leaving the blood to enter body cells, while carbon dioxide and wastes enter the blood from body cells.
Capillary A cross section of a capillary.

capillary

anatomy
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History

capillary, in human physiology, any of the minute blood vessels that form networks throughout the bodily tissues. It is through the capillaries that oxygen, nutrients, and wastes are exchanged between the blood and the tissues. The capillary networks are the ultimate destination of arterial blood from the heart and are the starting point for flow of venous blood back to the heart. Between the smallest arteries, or arterioles, and the capillaries are intermediate vessels called...

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