cardiovasular lab 2 Flashcards
what does the cardiovascular system consist of?
the heart and all blood vessels
what are the two receiving chambers of the heart?
atria
what are the two pumping chambers of the heart?
ventricles
What kind of blood does the left side of the heart pump?
oxygenated
what kind of blood does the right side of the heart pump?
deoxygenated
what is the pulmonary circuit?
Blood vessels that take deoxygenated blood from the right ventricle to the lungs and then return oxygenated blood to the left atrium, then to the left ventricle where it is pumped out to the rest of the body
where do all gas exchanges occur?
the capillaries
what are capillaries?
microscopic blood vessels only one layer thick
what is the capillary wall made of?
simple squamous epithelium
What do the capillary cells permit?
the diffusion of of carbon dioxide and oxygen
What is a normal by product of cellular respiration?
carbon dioxide
What are the two populations of cardiac myocytes?
nonpacemaker cells and pacemaker cells
What percentage of cardiac myocytes are nonpacemaker cells?
99%
What percentage of cardiac myocytes are pacemaker cells?
1%
what do pacemaker cells do?
spontaneously depolarize and generate action potentials
What does the action potentials from pacemaker cells trigger?
trigger action potentials of non pacemaker cells, causing them to contract
what is the cardiac conduction system made of?
clusters of pacemaker cells
where is the sinoatrial node located?
upper right atrium
what is the main pacemaker of the heart?
sinoatrial node
How often does the Sinoatrial node depolarize?
60 times per minute
where is the atrioventricular node located?
lower right atrium just medial to the tricuspid valve
What is considered the backup pace maker?
atrioventricular node
How often does the atrioventricular node have the heart beat?
40 beats per minute
what is the AV node delay?
the conduction through the AV node is slow, which allows the atria to depolarize and contract before the ventricles, which allows the ventricles to fill with blood
What is the purkinje system?
group of pacemaker cells that transmit impulses from AV node to ventricles
what are the 3 components of the purkinje system?
Atrioventricular bundle, right and left bundle branchess, purkinje fibers
Where is the atrioventricular bundle located?
lower interarterial septum and upper interventricular septum
what does the atrioventricular bundle do?
transmit impulses from the atrioventricular node to the ventricles
What do the right and left bundle branches do?
Bring impulses from the AV bundle down either side of the interventricular septum
What are purkinje fibers?
left and right branches that fan out through the myocardium (extend 1/3 of the way into the heart muscle)