Blood pressure and Blood flow Flashcards
What factors cause an increase in resistance
Increase in length of the vessels
Increase in blood viscosity
Decrease in vessel diameter
What are the two consequences of transition of laminar to turbulent flow
Higher resistance
Audible
What % of blood are made up of blood cells in both men and women
Men - 40% to 54%
Women - 37% to 47%
What is stroke volume
The volume of blood pumped out of ventricles with every contraction
What is systolic and diastolic
Systolic is maximum pressure during contraction whereas diastolic is minimum pressure during relaxation
What factors could influence blood pressure when measuring for it
Blood pressure cuff too small - 10 to 40 mmHg
Blood pressure cuff over clothing - 10 to 50 mmHg
Not resting 3-5 minutes - 10 to 20 mmHg
Arm position - 2mmHg for every inch above/below your heart level
Back unsupported -6mmHg
Legs crossed - 2 to 8 mmHg
Talking - 10 to 15 mmHg
Full bladder - 10 to 15mmHg
Emotional state
Temperature- increased when cold
Smoking, alcohol and caffeine - refrain for 30 minutes before test
What is pulse pressure
systolic blood pressure - diastolic blood pressure
What is mean arterial blood pressure
diastolic BP + 1/3 pulse pressure
physical factors affecting blood pressure
Cardiac output Peripheral vascular resistance Volume of circulating blood Viscosity of blood Elasticity of vessel walls
What is normal blood pressure in arteries, arterioles, capillaries, and veins
arteries - 120/80 mmHg
arterioles - 80-90/70 mmHg
capillaries - 35/16 mmHg
veins - <16 mmHg , no diastolic pressure
What helps blood return to the heart
Valves in veins Skeletal muscle contraction Breathing Blood volume The activity of sympathetic nerve
What does the CV center regulate
Heart rate
Stroke volume
Blood vessel diameter
What does the CV center regulate
Heart rate
Stroke volume
Blood vessel diameter
Where does the CV center receive inputs from
Higher brain centers
Baroreceptors
Chemoreceptors
What are baroreceptors
Stretch receptors sensitive to arterial pressure fluctuations