Week 2 Flashcards
(95 cards)
In order for there to be a change in energy, there must be an ______________ ______________.
Energy Gradient
Total Energy = ________ + __________
Potential energy (PE) + Kinetic energy (KE)
What is KE in blood flow?
Velocity of Blood
What is PE in blood flow?
Pressure
The main form of energy in the circulatory system is __________________
pressure energy (PE)
Two forms of circulatory PE are what?
- Blood pressure
- Gravitational pressure
What is the stroke volume?
The amount of blood squeezed into the aorta from the heart
What happens when the stroke volume is pumped into the aorta?
the pressure is increased in the blood vessels and causes the artery to stretch (distend)
Define Systolic pressure
the pressure Immediately following a heart beat when the artery is at its fullest distention
Define Diastolic pressure
the pressure exerted on the artery due to recoil and inertia continuing to pump the blood
What is the typical amount of stroke volume?
70 mL
What is the initial pressure at the heat?
120 mmHg
Why does blood continue to flow to arterial regions where the pressure is higher than that at the heart?
the overall mean pressure decreases in distal arteries
Why does blood flow?
Because of the PRESSURE GRADIENT from the heart through the circulatory system back to the heart
The amount of blood squeezed into the aorta from the heart is called what?
Stroke Volume
Define “Flow”
the volume of a fluid that moves past a certain point in a certain amount time
What is the gradient set up in the vascular system allowing blood to flow?
the change from high pressure to low pressure
Describe how the gradient and flow are related
Directly. As the gradient increases, flow increases. As the gradient decreases, flow decreases.
What must flow overcome in order to work?
Resistance
What is Gravitational energy in the vascular system called?
Hydrostatic pressure
How much does standing increase the pressure at your ankles?
by 100 mmHG
What causes hydrostatic pressure?
Gravity
What causes friction in the vascular system?
Vessel walls, turbulence at curves & branches
Poiseuille’s law tells us what factors are related how?
FLOW (Q) = Is directly proportional the the CHANGE IN PRESSURE from point a to point b (delta P) AND inversely proportional to RESISTANCE (R).