Which of these mediate the precapillary sphincter relaxation:
Correct Answer: Local hormones
Description: A i.e. Local hormonesPrecapillary sphincters are layer of smooth muscle fibres present just at the point where a metaeriole.There is no innervation on precapillary sphincter.Q- Their dilatation or constriction (to control the blood flow) depends on local hormones.Q , product of metabolism, hydrogen ions etc.Catecholamines causes sphincter constriction.Factors affecting the caliber of aeriole- Decreased local temperature - Autoregulation- Endothelin-1- Platelet serotonin- Thromboxane A2Epinephrin (except in skeletal muscle & liver)- Norepinephrin- AVP- Angiotensin II- Neuropeptide YDilatationIncreased K+, adenosine.- Increased CO2- Decreased 02- Decreased local pH- Decreased local temperature- NO- Prostacyclin- Kinins- Epinephrin in skeletal muscle & liver Q- Substance P Q- Histamine Q- ANP- VIP
Category:
Physiology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now