Cardiac Flashcards
Inflow/Outflow of blood from the heart
Inflow
- > sup/infer. vena cava
Outflow
- > aortic arch
What are auricles
Their purpose is to increase the capacity of the atrium, and so also increase the volume of blood that it is able to contain

myocardium
muscle/tissue of tje heart
cardiac myocytes
cytes=mature cells
they’re individual cardiac muscle cells
List the layers of the heart
endocardium = inner tissue layer of the heart
epicardium = outer tissue layers of the heart
pericardium = fibrous sac that surrounds the heart
list all the heart chambers
right atrium; right ventricle; left atrium; left ventricle
systole vs diastole
systole
- > contraction of the heart = ejection phase
diastole
- > relaxation of the heart = filling phase
systolic pressure
pressure within the aorta during systole when blood volumes within the vessel are at their highest
- > usually determined using brachial artery
diastolic pressure
pressure within the aorta during distole when blood volumes are at their lowest
cardiac cycle
1 heartbeat = 1 systolic + 1 diastolic event (bump-bump)
atria vs ventricle
Atria
- > resevoir for blood; low pressure chambers
ventricle
- > high pressure pumps for the ejection of blood from the heart
list all major corornary arteries involved in the myocardial blood supply

Which two major arteries branch from the root of the aorta and what do they supply?
- right coronary artery
- > supplies right atrium, right ventricle, part of left ventricle - left coronary artery
- > supplies left atrium and ventricle

how does blood return from the myocardium to the right atrium
- > the great cardiac vein drains into the coronary sinus and then into the right atrium
- > the middle cardiac vein

explain coronary blood to the left side heart/ how it can be affected
during ventricular systole(contraction) extravascular compression(closure of the coronary artery) of the coronary circulation occurs
- > this causes BF to be left coronary artery to be briefly reverse

Where is the left ventricular myocardial pressure the greatest and lowest
Greatest
- > near the endocardium
Lowest
- > near the epicardium
When does maximal left and right coronal inflow occur
Max left inflow occurs in early diastole, when the ventricle relaxes
max right coronary inflow still occurs during diastole
explain the cornary blood supply to the right side of the heart
- > lower pressures here during systole because it requires less force for contraction to move the blood a shorter distance
- > blood flow reversa does not occur, therefore more coronary inflow during systole than for the left side of the heart
S1 and S2 are caused by what?
Sound 1
- > closure of AV valves
Sound 2
- > closure of semilunar valves
both S1 and S2 cna be heard sometimes as “split” sound as the AV and semilunar valves don’t close at the same time
Which two structures transport blood to the lungs and which two structures transport blood to the rest of the body
Blood - > lungs
right atria + right ventricle
Blood - > rest of body
left atria + left ventricle
What is action potential
AP = a brief reversal of membrane potential
AP = a brief reversal in the overall charge inside vs the overall charge ouside the cell
how are action potentials transported
through gap junctions
SA nodes vs AV nodes
SA Nodes
- > primary pacemaker that sets the rate for tansmission of the action potentials
AV Nodes
- > the pacemaker (rate setters) for heart activity
Explain how AV and SA nodes work together to set heart rate
- > electrical signal travels from SA node, through the atrial tissue to the AV node down the AV/His bundle and is split between the right and left bundle branches to the Purkinje fibres
- > the small Purkinje bibres will then send the electrical signals to all the cells of the ventricular myocardium






