Cardiac Physiology Flashcards
What is cardiac output at rest?
5 L/min
CO=SV x HR
What are the two divisions of circulation?
- systemic
- pulmonary
What is the normal stroke volume of the heart?
60mL per beat
What controls regional flow of blood?
Arteriole resistance, local regulation
What is the equation for blood flow?
Flow = Change in pressure/Resistance Flow = (P1-P2)/R
What is laminar flow pattern?
- Blood flow against wall of vessel has very low velocity
- Blood in middle of vessel has maximum velocity
Where in the arterioles and veins are cellular constituents of blood carried ?
-The middle of the vessel
How is turbulent flow different from laminar flow?
- not physiological
- Makes noise
- Happens when you have obstruction in vessel or a narrowing of the vessel
- damages endothelium
What is a murmer?
-Turbulent flow in the heart
What is bruit?
-turbulent flow in the arteries
What determines resistance to fluid flow in a tube (blood vessel or airway)?
- Length
- Fluid Viscosity
- Radius of tube (only one that really changes)
What is systole?
-The stage in the cardiac cycle in which the ventricles are ejecting blood into the aorta/pulmonary artery
What is diastole?
- Stage in cardiac cycle when R and L ventricles are filling with blood for the next contraction
- Pressure in arterial system is lowest
What is the pulse pressure?
-The difference between systolic and diastolic pressure
What is the equation for mean arterial pressure?
MAP = diastolic pressure + 1/3 Systolic pressure
What is contractility?
The intrinsic property of the cardiac muscle that accounts for varying force of contraction, it is the net effect of many variables
What keeps the majority of the capillary beds closed?
Sympathetic Tone
What are fenestrae?
-Holes in capillaries that allow water, ions, glucose, and amino acids through
What is head pressure?
pressure in the arterioles going into the capillary bed
What is back pressure?
Pressure in the venule leaving capillary beds
What are the three types of control in the vascular system?
- Nervous control - SYMPATHETIC ONLY
- Hormone control
- Local control
What are the factors that determine fluid movement through across capillary walls? (starling forces)
- Water permeability (hydraulic conductance)
- Capillary hydraulic pressure
- Capillary osmotic pressure (Albumin)
- Interstitial fluid pressure
- Interstitial osmotic pressure
What generates capillary osmotic pressure?
-albumin (negatively charged)
What are the three divisions of local control of blood flow?
- autoregulation
- active hyperemia
- reactive hyperemia
