Precapillary resistance
Precapillary resistance is a term used in physiology to describe the resistance offered by the arterioles and capillaries in the circulatory system. This resistance is crucial in controlling the distribution of blood flow to different parts of the body.
Overview[edit | edit source]
Precapillary resistance is primarily determined by the diameter of the arterioles and capillaries. These small blood vessels have muscular walls that can contract or relax to change their diameter, thereby increasing or decreasing resistance. This mechanism is known as vasoconstriction and vasodilation, respectively.
Role in Blood Pressure Regulation[edit | edit source]
Precapillary resistance plays a significant role in the regulation of blood pressure. By adjusting the resistance in the arterioles and capillaries, the body can control the distribution of blood flow to meet the metabolic needs of different tissues. For example, during exercise, the arterioles in the muscles dilate to increase blood flow, while those in other parts of the body constrict to maintain blood pressure.
Role in Tissue Perfusion[edit | edit source]
Precapillary resistance also plays a crucial role in tissue perfusion, which is the passage of blood through the blood vessels of an organ. By adjusting the resistance in the arterioles and capillaries, the body can control the amount of blood that reaches different tissues. This is particularly important in organs such as the brain and heart, which require a constant supply of blood.
Factors Affecting Precapillary Resistance[edit | edit source]
Several factors can affect precapillary resistance, including:
- Hormones: Certain hormones, such as adrenaline and noradrenaline, can cause vasoconstriction, thereby increasing precapillary resistance.
- Autonomic nervous system: The autonomic nervous system can influence precapillary resistance through the release of neurotransmitters that cause vasoconstriction or vasodilation.
- pH: Changes in the pH of the blood can affect the diameter of the arterioles and capillaries, thereby influencing precapillary resistance.
See Also[edit | edit source]
References[edit | edit source]
 | This anatomy article is a stub. You can help WikiMD by expanding it. |
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD
|
WikiMD's Wellness Encyclopedia |
| Let Food Be Thy Medicine Medicine Thy Food - Hippocrates |
Translate this page: - East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
தமிழ்,
తెలుగు,
Urdu,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
বাংলা
European
español,
Deutsch,
français,
Greek,
português do Brasil,
polski,
română,
русский,
Nederlands,
norsk,
svenska,
suomi,
Italian
Middle Eastern & African
عربى,
Turkish,
Persian,
Hebrew,
Afrikaans,
isiZulu,
Kiswahili,
Other
Bulgarian,
Hungarian,
Czech,
Swedish,
മലയാളം,
मराठी,
ਪੰਜਾਬੀ,
ગુજરાતી,
Portuguese,
Ukrainian
Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.
Contributors: Prab R. Tumpati, MD
