Cardio Flashcards
What is plasma composed of?
Mostly water, dissolved proteins, hormones, and ions
What is hematocrit?
% of blood volume that is red blood cells
What is hematocrit usually?
45%
What proteins are in plasma?
Albumin, globulin, and fibrinogen
What are the 4 great arteries?
Vena cava, pulmonary trunk, pulmonary veins, and aorta
Which valves are semilunars?
aortic and pulmonary
Which valves are AVs?
tricuspid and bicuspid
What valves are associated with the right side of the heart?
Tricuspid valve and pulmonary valve
What are the 4 valves?
Bicuspid, tricuspid, pulmonary and aortic
Which valves are associated with the left side of the heart?
Bicuspid valve and aortic valve
Which side of the heart is the pulmonary side?
Right side
Which side of the heart is the systemic side?
The left side
What is the vena cava connected to?
Right side of the heart
What causes the valves to open and close?
Pressure
What makes the AV valves open?
When atrial pessure>ventricular pressure
What makes the semilunars open?
Ventricular pressure>pressure in aorta or pulmonary trunk
What is stenosis?
Abnormally narrowed valve
What causes stenosis?
Can be congenital or due to calcium buildup
When is turbulent flow seen?
During stenosis
What happens in a leaky valve?
Flow goes backwards
What happens when the AVs are leaky?
Blood backs up into the atria or the great vessels
What happens when the semilunars are leaky?
Blood flow returns to the ventricles
What factors play into resistance?
Viscosity, length and radius
What is poiseuilles law?
Associated with resistance, equation is R=1/r^4
What is the flow rate law?
Difference in pressure/Resistance
What are the two types of heart cells?
Electrically conducting and cardiomyocytes
The SA node and AV nodes are what type of cell?
Electrically conducting cell
What is the function of cardiomyocytes?
Contractile, produce force
What is released during sympathetic drive?
Epinephrine and norephrine
Which receptors do epi and norepi bind to?
Beta-adrenergic receptors
Are beta-adrenergic receptors metabotropic or ionotropic?
Metabotropic
What is vasodilation?
Occurs in sympathetic drive, smooth muscle in arteries relax
How does sympathetic drive affect cardiomyocytes?
Increased contractility
When does the vagus nerve release acetylcholine?
Parasympathetic drive
Where is acetylcholine released into?
The nodal cells in the atria
Is parasympathetic drive associated with hyperpolarization or depolarization?
Hyperpolarization, K+ channels open
What does the SA node do?
Depolarizes the atria
What happens when the atria depolarize?
They contract
What does the AV node do?
Allows for delay while the atria depolarize
How does the signal spread to the ventricles?
Through the AV bundle
What do the bundle branches do?
Finish conduction through the ventricles
How do signals spread so quickly through the heart?
Gap junctions
The cardiac action potential is also known as
The ventricular action potential
Why is the cardiac stable resting potential slightly more negative than the nerve RMP?
Leak K+ current
What happens during the upstroke of the cardiac action potential?
Rapid depolarization from voltage gated Na+ channels opening
What happens during the notch phase of the cardiac action potential?
VG Na+ channels close, K+ channels open
What is the Kto or Ito?
Current due to K+ channel
What happens during the plateau of the cardiac action potential?
L type Ca2+ channels open, begins to open K+ channels. Keeps the potential steady
What happens during the repolarization phase of the cardiac action potential?
Efflux through rectifying K+ channels
What are the Kr/Ks channels?
Delayed rectifiers, responsible for final repolarization of the cardiac action potential
What makes the AVs close?
Atrial pressure is less than ventricular pressure
What makes the semilunars close?
Ventricular pressure less than the aortic/pulmonary trunk pressure
Why is the resting potential of the nodal action potential unsteady?
If - funny Na+ current
Whats different about the funny Na+ current?
Peak opening during the hyperpolarized current, and it has slower kinetics
What happens during the depolarization phase of the nodal cell action potential?
Ca2+ channels are open, both T-type and L-type
What happens during the repolarization phase of the nodal cell action potential?
K+ efflux from rectifying K+ channels
What is associated with the P wave?
Atrial depolarization
What is associated with the QRS wave?
Vetricular depolarization
What is associated with the T wave?
Ventricular repolarization
Why does the heart have such a long refractory period?
It has to completely relax to fill with blood
