BIOL 2420 Lecture Notes - Lecture 7: Vascular Smooth Muscle, Posterior Pituitary, Perfusion

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 2420
• Professor: W.G.Anderson

Document Summary

Chapters 14, 15, and 16: non-metabolic chemical mediators. Most potent vasoconstrictor released by endothelium in response to increased mechanical pressure. Binds to receptors with extremely high af nity - exerts response for extended period of time. Opens non-stretch sensitive ca2+ channels and enhances ca2+ release by sr. Preventing blood loss - constricts to stop blood ow - emergency response. Potent vasodilator that plays a role in in ammation. Localized release occurs during allergic reactions (quick onset) or in response to injury or infection (2-8 hour onset) Practically all blood serotonin is found within platelets. Neurotransmitter -> serotonergic -neurons (sleep and wake cycle) Binds to 5ht1 receptors and causes constriction (especially in the brain - causing migraines -sumatriptan drug to stop it - antagonist to 5ht1 receptors: systemic regulation of blood vessel caliber. Extrinsic control of arteriolar radius alters total peripheral resistance (tpr) and is a very important regulator of map. Main governing site of caliber - cardiovascular control centre.