Exam 2 Flashcards
(134 cards)
What is Atherosclerosis?
Plague build-up in the systemic circuit which lowers blood to cells of the tissues in the extremities
Coronary Artery Disease
Plague build-up in the coronary circuit which lowers oxygen to the cardiac muscle cells
Hemodynamics
The physiology of blood flow
Why is blood flow necessary?
Necessary for the cells to receive nutrients like oxygen and glucose
How do you calculate pressure?
Pressure = Cardiac Output X Resistance
What is the relationship between resistance and cardiac output?
Inversely related, so if R goes up, CO will go down
What is the relationship between cardiac output and pressure?
Directly related, so if CO increases, R will increase
Pressure
Force that is exerted on the inner wall of the vessel; it is the push exerted on the tunica
What happens to pressure when the heart contracts?
Pressure increases
What is resistance?
Opposition to blood flow
What is blood viscosity?
How thick the blood is
What does high viscosity lead to?
High resistance which leads to high pressure
What does low viscosity lead to?
Low resistance which leads to low pressure
What changes blood viscosity?
Red cell mass, red cell deformity, plasma levels, amount of water, number of cells in the blood
What happens to blood viscosity when water levels decrease?
Blood viscosity increases
What happens to resistance as blood vessel radius increases?
As a vessel’s radius increases, resistance decreases
How does the sympathetic system affect vessel diameter?
Causes vasoconstriction; resistance goes up, pressure goes up
How does the parasympathetic system affect vessel diameter?
Causes vasodilation; resistance goes down, pressure down
How does blood vessel length affect resistance?
Greater blood vessel length, greater the resistance
What increases blood vessel length?
Increase in adipose tissue
How does obstruction of blood vessel affect resistance?
Increases resistance
Systolic Pressure
Pressure in the artery when the ventricles are contracting: top number
Diastolic Pressure
Pressure in the artery when the ventricles are relaxing: bottom number
What is mean arterial pressure?
Average pressure in the systemic circuit during a complete cardiac cycle