cardiovascular system anatomy and phys Flashcards
dimensions of the heart
10-12cm long
9cm wide
6cm wide
what surrounds the heart?
a fibrous sac called the pericardium
what are the layers of sac around the heart
- parietal layer of serous pericardium
- visceral layer of serous pericardium
what is the point of pericardial fluid
reduce friction as two layers rub against each other
what are the three layers that the heart wall is composed of?
- EPIcardium
- MYOcardium
- ENDOcardium
what are the three layers that the heart wall is composed of?
- EPIcardium
- MYOcardium
- ENDOcardium
large blood vessel systemic circulation
macrocirculation
tiny blood vessels systemic circulation
microcirculation
what regulates the heartbeat
natural pacemaker called the sinoatrial
where is the sinoatrial found
muscle of right atrium
what is important to remember about the pacemaker cells
they do not contract
- they generate electrical activity spontaneously
- regular intervals
- spreads through heart
function of the atrioventricular node
electrical gatekeeper between atria and ventricles
- introduces a delay for efficient ventricular filling
- controls heart rate
where does electrical activity pass to and from
from SA node to AV
SA node vs AV node
SA node generates power and causes contraction
AV node distributes it and sends electrical signal
bundle of HIS
purpose is electrical conduction
carries electrical impulses in the heart
connects AV node to other branch bundles
