Vascular tone
Vascular tone refers to the degree of constriction experienced by a blood vessel relative to its maximally dilated state (which occurs when the vessel is relaxed and dilated). The regulation of vascular tone is an essential aspect of homeostasis, contributing to the maintenance of blood pressure and the distribution of blood flow.
Mechanism of Vascular Tone Regulation[edit | edit source]
Vascular tone is regulated by a complex interplay of various factors, including neural control mechanisms, hormones, and local metabolites. The endothelium (inner lining of blood vessels) plays a crucial role in this process, producing various substances that can cause either vasodilation (relaxation of the blood vessel, leading to increased diameter and blood flow) or vasoconstriction (contraction of the blood vessel, leading to decreased diameter and blood flow).
Neural Control Mechanisms[edit | edit source]
The autonomic nervous system (ANS) plays a significant role in the regulation of vascular tone. The sympathetic nervous system (SNS) primarily mediates vasoconstriction through the release of norepinephrine, which binds to alpha-adrenergic receptors on the smooth muscle cells of the blood vessel wall, causing them to contract.
Hormonal Control[edit | edit source]
Various hormones also influence vascular tone. For example, angiotensin II and vasopressin are potent vasoconstrictors, while atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) have vasodilatory effects.
Local Metabolites[edit | edit source]
Local conditions within the tissues can also influence vascular tone. For instance, a decrease in oxygen levels (hypoxia) or an increase in carbon dioxide levels (hypercapnia) can lead to vasodilation, improving blood flow to the area.
Clinical Significance[edit | edit source]
Abnormalities in vascular tone regulation can lead to various pathological conditions. For example, excessive vasoconstriction can contribute to hypertension (high blood pressure), while inadequate vasoconstriction (leading to excessive vasodilation) can contribute to hypotension (low blood pressure).
This physiology-related 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
