Cardiovascular Physiology Flashcards
A 1
Smooth muscle contracion
Control conduits for blood flow
Arterioles
B2
Smooth muscle relaxation
Veins contain what receptors
A1
What is Ohm’s law
Q(flow)= ^P/R
Associated with high reynold’s number
Turbulent flow
Turbulent flow is seen in
Anemia
Stroke volume/ arterial compliance
Pulse pressure
Pressure in the capillaries
17mmHg
Pressure in the vena cava
0mmHg
Pressure in the pulmonary arteries
25mmHg
Pressure in the capillaries
7mmHg
Atrial depolarizatiob
P wave
Av node conduction
PR sement
Conduction time/ velocity through the av node
PR interval
Ventricular depolarization
QRS
Ventricular repolarization
T wave
Period of depolarization+ repolarization of ventricles
QT interval
Plateau of ventricular action potential
ST segment
Ventricular action potential: Na influx
0
Ventricular action potential: K efflux
1
Ventricular action potential: Ca influx
2
Ventricular action potential: K efflux
3
Ventricular action potential: RMP
4
SA node action potential: slow Na influx towards threshold
4
SA node action potential: Ca influx
0
SA node action potential: K efflux
3
Basis for v fib
Circus movements
Changes in the rate of relaxation
Lusitrophic
Changes in conduction velocity
Dromotrophic
Stressed volume
Arteries
Low P waves, tall T waves
Hyperkalemia
Flat inverted t waves, with u waves
Hypokalemia
Prolonged qt interval
Hypocalcemia
Shortened QT interval
Hypercalcemia
AV block that causes fainting in patients due to initially supressed state of Purkinje fibers
Stokes Adam syndrome
Produces changes jn rate of relaxation
Lusitrophic
Produces changes in conduction velocity
Dromotrophic
Affected by inotropes
Stroke volume
Chronotropes affect
SA node
Dromotropes affect
AV node
Phase of cardiac cycle: distal third of diastole
Atrial contraction
A wave is seen
Atrial contraction
4th heart sound
Atrial contraction
Preceeded by p wave
Atrialn contraction
Phase of cardiac cycle: preceeded by QRS complex
Isovolumic contraction
Phase of cardiac cycle: c wave
Isovolumic contractiont
First heart sounds
Isovolumic contraction
Phase of cardiac cycle: atrial filling begins
Rapid ventricular ejection
Phase of cardiac cycle: t wave
Reduced ventricular ejection
Phase of cardiac cycle: incisura
Isovolumic relaxation
Phase of cardiac cycle: v wave
Isovolumic relaxatiob
Phase of cardiac cycle: second heart sound is heard
Isovolumic relaxation
3rd heart sound is heard
Rapid ventricular filling
Longest phase of cardiac cycle
Reduced ventricular filling
Slight increase in aortic pressure during isovolumic relaxation
Incisura
Center responsible for regulation of HR and BP
Vasomotor area of medulla; lateral - excitatory; medial-inhibitory
Parasympathetic stimulation of the heart causes
Dec contractility in the atria ONLY; dec HR and conduction velocity
Where are baroreceptors found
Carotid sinus and aortic arch
Respond to increase/ derease in pressures from 50-180 mmHg
Carotid baroreceptors
Respond to increase in pressures >80 mmHg
Aortic baroreceptors
Caratois sinus baroreceptors are mediated by what CN?
IX
Aortic arch baroreceptors are mediated by what CN?
x
BP control mechanisms that respond to low O2, high CO2 concentration whenever BP is <80mmHg
Chemorecptord
Increased HR; helps match VR with CO
Bainbridge reflex
CNS ischemic response stars at BP of
<60mmHg
All systemic arterioles vasoconstrict severely except for coronary vessels, cerebral vessels
CNS ischemic response
Triad of HPN, bradycardia, irregular respirations
Cushing rxn or cushing reflex
Describes fluid movement into or out of the capillary
Starling forced
Normal net filtration (starling forces)
2mL/min
Mehanisms for local blood flow control
Myogenic theory, metabolic theory
Most potent vasoconstrictor
Vasopressin
Implicated in migraine
Serotonin
Released by damaged endothelium
Endothelin
Counteracts TXA2
Prostaglandin
Vasodilators in muscles
Lactate, adenosine