00:00 / 00:00
Microcirculation and Starling forces
0 / 16 complete
0 / 2 complete
The capillaries have a single layer of endothelial cells lining their walls with clefts between these cells.
Normally, blood flows into smaller and smaller arteries, eventually reaching the arterioles, the metarterioles, and then the capillaries. In the capillary bed, due to the capillary’s thin walls and clefts, substances like nutrients or waste products can move from the blood into surrounding tissues and vice-versa.
After the capillaries, blood moves into venules, and then finally into veins. Intertwined with these capillaries are the lymphatic capillaries, which return interstitial fluid and proteins to the vascular system.
The microcirculation refers to the network of small blood vessels that deliver oxygen and nutrients to individual cells and remove waste products. Starling forces are the physical forces that determine the movement of fluid between capillaries and tissue fluid.
The two major starling forces are hydrostatic pressure and oncotic pressure. Hydrostatic pressure is the force exerted by blood inside the capillary or in the interstitial space. It is generated by the contraction of the heart muscle, which squeezes blood through the arteries and pushes it into the capillaries. On the other hand, the oncotic pressure is created by proteins (mainly albumin) in the blood, which pulls water out of tissue fluid into capillaries.
Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Cookies are used by this site.
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.