Circulation Flashcards
Example of a Humoral vasoconstrictor
Endothelin-1
What 5 Factors result in endothelin-1 production
Angiotensin 2
Vasopressin
Cytokines
Thrombin
Oxidative free radicals
How does endothelin 1 result in Vasoconstriction
Attaches to G coupled receptors
Results in calcium release
causing smooth muscle contraction of blood vessels
Examples of Vasodilators
Hypoxia, Adenosine, Bradykinin, NO, K+, CO2, H+ and tissue breakdown products
Where is endothelin-1 and NO produced
Endothelium
How is NO produced
Ach and Insulin stimulate calcium release,
Causes L-Arginine –>NO which causes vasodilation
(NO synthase involved)
Hormonal Vasoconstrictor examples (3)
Angiotensin 2
Vasopressin
Epinephrine (in skin)
What is the principle site of peripheral resistance
Arterioles
(Total Arterial resistance=Total peripheral resistance)
Hormonal Vasodilators (2)
Epinephrine(in muscle) and ANP
What helps maintain blood flow in capillaries
Arteriolar resistance and pre-capillary sphincters
What helps maintain bloodflow in veins
Valves
skeletal muscle
respiratory pump
Vasocostriction
What helps uni-directional flow in the lymphatic system
Smooth muscle
Skeletal muscle pump
Resp pump
Where does the lymphatic system return fluid to in the CV system
Thoracic duct
Left subclavian vein
Two types of Baroreceptors
Arterial and Cardiopulmonary Baroreceptors
