Anatomy And Physiology Ch 18

Front 1

____= important structure located in the right atrium of the heart, near where venacavae enter; the pacemaker of the heart
-specialized area of cardiac muscle cells that have the quality of automatically generating electrical impulses triggering repeated beating of the heart

Back 1

SA node/sinoatrial node

Front 2

___= important structure at the top of the atrioventricular septum
-specialized grp pf cardiac muscle cells that serve as auxillary pacemakers bc they protect the ventricles from beating too fast
-only route of conduction from the atria to the ventricles

Back 2

AV node/atrioventricular node

Front 3

____= important structure that travels down the interventricular septum
-first part, slow conduction of action potentials
-creates a delay btw atrial and ventricular contractions
-r/l bundle branches ( only route of conduction from atria to ventricles)

Back 3

Bundle of His (AV bundle)

Front 4

___= important structure where av bundle branches break into a dispersed network of fibers
-carry action potentials to into ventricular myocardium from apex upwards
-ventricles actually contract at apex first

Back 4

purkinje fibers

Front 5

___= turbulent flow of blood due to any defect in valves
-indicates the presence of cardiac abnormalities
-systolic murmur/diastolic murmur
-Cause-insufficiency-valve fails to close completely;allows regurgitation
-Cause-stenosis- fails to open completely; narrow valve opening; creates restriction

Back 5

cardiac murmurs

Front 6

The_____ is one complete cycle of cardiac contraction and relaxation (heartbeat)

Back 6

cardiac cycle

Front 7

___ refers to the relaxation of a chamber of the heart just prior to and during the filling of that chamber

_____refers to the contraction of the chamber of the heart that drives blood out of the chamber

Back 7

diastole


systole

Front 8

The period of systole during which all valves are closed in the _______, because during it the volume of each ventricle remains constant

Back 8

isovolumetric contraction period

Front 9

at the beginning of diastole, both the semilunar and AV valves are closed, so the intial phase is termed _____

Back 9

isovolumetric relaxation period

Front 10

____ is the recording of electrical activity on the surface of the body that reflects the electrical activity in the heart.
A ____ is the actual recording

Back 10

electrocardiography


electrocardiogram

Front 11

Discuss the conduction system of the heart

Back 11

SA node initiated action potential by automatically generating electrical impulse
action potential travels quicklt through the internodal pathways
when reaches the AV node, there is a delay/pause which prevents ventricle from beating too fast
Bundle of His/AV bundle- creates delay btw the ventricular contrations as travels down interventricular septum to the R/L bundle branches
then reaches the purkinje fibers where the action potential goes from apex up bc of contraction

Front 12

Cardiac cycle is the ___.

describe

Back 12

heartbeat

-ventricular contraction causes the AV valves to close which signals the beginning of the ventricular systole
-the semilunar valves were closed during the previous diastole and remain closed for this time
-continued ventricular contraction increases the pressure within the ventricles above the pressure in the aorta and pulm trunk causing semilunar valves to open
-when ventricles relax and pressure drops, blood flowing back toward relaxed ventricle causes the semilunar valves to close, which begins the ventricular diastole (av valves closed)
-when pressure in ventricles become lower than the pressure in the atria, the av valves open and blood flows into the relaxed ventricles

Front 13

____= time in cardiac cycle where there is a minimum amt of blood in the ventricles

____= time in cardiac cycle where ther is max amt of blood in the ventricles; occurs at end of ventricular relaxation

Back 13

ESV-end systolic volume

EDV- end diastolic volume

Front 14

The ___ (cardiac cycle) is responsible for the first heart sound
-pressure within each ventricle exceeds pressure within respective atria
-forces the AV valve to shut/close (first heart sound).
ventricular pressue exceeds that in the arteries (aorta and pulm arteries), so semilunar valves open
ejection phase- rapid ejection followd by a reduced ejection which ventricular and arterial pressures fall
-when pressure in aorta and pulm artery increase more than respective ventricle;semilunar valves shut (2nd heart sound)

Back 14

systole

sounds of the heart created during systole

Front 15

in ____, there is a relaxation where both sets of valves are closed
-early- blood flows into both atria
-atrial BP increases more than ventricular; AV valves open and blood flows into ventricles

Back 15

diastole

Front 16

What events occur to hear the first lub and the second dub sounds?

Back 16

pressure within each ventricle exceeds the pressure within respective atria anf forces AV valves to shut making the first/lub sound

when the ventricular pressure exceeds that in the arteries (aorta and pilm arteries, semilunar valves and blood ejected, so pressures fall
when pressure in aorta and pulm artery increase more than respective ventricle, semilunar valves shit (second noise)