Vascularity and Capillary Physiology

A series of flashcards covering key concepts related to vascularity and capillary physiology.

Capillaries

Small blood vessels known as microcirculation or exchange vessels, facilitating the exchange of water and solutes between blood and interstitial fluid.

Elastic Vessels

Arteries that contain a large amount of elastic material along with smooth muscle, allowing them to distend and return to original shape.

Muscular Vessels

Small arteries and arterioles that have relatively thick walls and less elastic tissue, predominantly smooth muscle to adjust resistance to blood flow.

Diffusion Rate Factors

The rate of diffusion through a capillary depends on concentration difference, available area for diffusion, distance, and temperature.

Blood-Brain Barrier

A protective barrier formed by tighter junctions between endothelial cells in brain capillaries, allowing only water and small ions to pass.

Continuous Capillaries

Capillaries characterized by a continuous tube structure with tiny, water-filled pores, allowing the passage of water and small solutes.

Discontinuous Capillaries

Also called sinusoids, these capillaries have larger clefts and allow larger proteins to pass, found in the liver, spleen, and bone marrow.

Fenestrated Capillaries

Capillaries with windows that allow large amounts of fluid and solutes to pass, located in regions like the gastrointestinal tract and kidneys.

Transcytosis

A three-step process in which plasma proteins cross capillary walls through vesicles, involving pinocytosis, vesicle transport, and exocytosis.

Pre-capillary Sphincters

Muscle structures in arterioles that control blood flow to capillaries by alternating between constriction and dilation.