Chapter 20 Part 2 heart Flashcards
What forms a plate of fibrous CT between atria and ventricles?
Heart Skeleton
What forms fibrous rings around the AV and SL valves
Heart skeleton
The heart skeleton supports AV and SL valves by reinforcing valve ______
Openings
The heart skeleton acts as _________ ________ between atria and ventricles
electrical insulation
What is the rigid site to which cardiac muscle attaches?
Heart skeleton
What is the relay system for APs in the heart?
Conducting system
1% of cardiac fibers are specialized cardiac muscle cells that are ________
autorhythmic
Autorhythmic cells are also known as __________
Cardiac Pacemaker cells
Cardiac pacemaker cells are able to ________ spontaneously and pace the heart
depolarize
Cardiac pacemaker cells initiate APs that spread throughout the heart and trigger __________________
rhythmic contractions
Rhythmic contractions allow for synchronous heart activity that increases pump _________
effectiveness
what are the 5 places that are stimulated for the sequence of excitation?
SA node
AV node
AV bundle
L/R Bundle Branches
Purkinje Fibers
What heart node is located in the right atrial wall, inferior to SVC
SA node
What node is the pacemaker of the heart?
Sinoatrial (SA) node
The “pacemaker” is the fastest depolarization rate in the heart at _________ impulses/min
75
Sinus rhythm determines _________
HR
In the sequence of excitement, the wave of depolarization spreads via gap junctions in atria to the AV node via the _________
internodal pathway
What heart node is located in the inferior interatrial septum, superior to tricuspid valve ?
AV node
the AV node impulse is delayed by _______
0.1 s
(allows full atrial contraction before vents)
What node is located in the superior interventricular septum?
AV bundle
AV bundle is also called ______
bundle of His
What is the only electrical connection between atria and ventricles?
AV bundle
What structure is nonconducting and insulates the rest of AV junction?
Cardiac Skeleton
What part of the heart extends beneath the endocardium of the interventricular septum to the apex and the L/R ventricles?
L/R bundle branches
What heart part is located at the inferior terminal branches of the bundles?
Purkinje Fibers
Purkinje fibers have fewer ________
myofibrils
APs travel well along the Purkinje fibers much faster than other cardiac muscles because _______ and _________
intercalated discs &
gap junctions
What is when any part of the heart other than the SA node generates a heartbeat? (Abnormal pacemaker)
Ectopic Focus
what can cause ectopic focus (4)?
abnormal SA node
Hyperexcitable state (xs caffeine/nicotine)
inflammation
ischemia
Heart muscle inflammation or ischemia can cause ___________
cardiac tissue injury
IF the AV node becomes the pacemaker that is known as a ___________
Junctional rhythm
if the AV node is the pacemaker the heart rate is usually _______
40-60 bpm
If the stimulation doesn’t go through the AV node that is called ___________
conduction pathway blockage
What is the heart rate if there is a conduction pathway blockage?
30 bpm
What is a record of the electrical activity of the heart?
EKG
EKGs are measurements of small _______ changes that occur with summation of APs in the heart at any given time
voltage
Electrodes are places on body surface areas like … (3)
Chest wall
upper arms
legs
Ekgs are used to diagnose abnormalities in the _______ (non-invasively)
cardiac cycle
Ekgs Dx … (3)
Abnormal conduction pathways
hypertrophy/atrophy
location of cardiac tissue damage
The P wave indicates _____
atrial depolarization (contraction)
The QRS wave indicates ______
ventricular Depolarization (contraction)
T wave and Ventricular Repolarization precedes_______
ventricular relaxation
What is the blood flow through the heart during 1 complete heart beat called?
cardiac cycle
What are the two pumps that work together in the cardiac cycle?
Atrial pump
Ventricle pump
What heart pump is the primer pump that fills ventricles with blood?
Atrial pump
What heart pump is the power pump that sends blood to the body and lungs?
Ventricle pump
What is a predictable pattern of contraction and relaxation of the heart chambers?
Cardiac Cycle
What are the two phases of the cardiac cycle?
Systole and diastole
Systole is …
contraction
Diastole is …
relaxation
What part of the heart cycle is mid to late diastole and involves relaxed chambers with low heart pressure?
Ventricular filling
In ventricular filling, blood passes through the atria and AV valves passively into the ______
Ventricles
How full do the ventricles get during ventricular filling? (%)
70%
What are the three parts of the cardiac cycle?
Ventricular filling
Ventricular systole
Isovolumetric Relaxation
In ventricular filling, when the atria contract what occurs?
Active ventricular filling (Top off)
What part of the cardiac cycle is where the ventricles contract and pressure closes the AV valve?
Ventricular Systole
What are the two parts of ventricular systole?
isovolumetric contraction
Ventricular ejection
When briefly all valves are closed it is called ___________
isovolumetric contraction
When ventricle pressure increases, and the SL valves are forced open to let the blood out that is called _________
Ventricular ejection
What occurs in early diastole when the ventricles relax, pressure drops, and the aortic and pulmonary trunk back flow
Isovolumetric Relaxation
What is the brief closing of SL valves?
Isovolumetric Relaxation
What sounds are produced by the pumping heart?
heart sounds
Heart sounds are heard with a _______
stethoscope
Heart sounds are produced as valves ______
close
What are the 4 kinds of heart sounds?
S1-4
What is the 1st heart sound caused from the closing of AV valves? (Lub)
S1
s1 indicates the beginning of ____________
ventricular systole
What is the 2nd heart sound caused by the closing of the SL valves? (DUB)
S2
S2 indicates the beginning of _________
Ventricular diastole
What heart sound is a ventricular gallop in early diastole (turbulence)
S3
S3 heart sound is normal in _________ (2)
kids
Athletes
For S3, is vs >35 that means _________
CHF
What heart sound is an atrial gallop in late diastole?
S4
S4 is always ______
abnormal
And S4 heart sound can indicate what two conditions?
HTN
Aortic Stenosis
Abnormal heart sounds are also called _______
murmurs
Murmurs indicate cardiac __________
abnormalities
What abnormal heart sound is caused from blood leaking backward as valve flaps do not close properly
Incompetent/Insufficient valves
Regurgitation of blood in the valves can cause _______ (sound)
turbulence
What abnormal heart sound is indicated by a turbulent rushing sound prior to valve opening?
Stenosis
(narrow/stiff)
both murmurs increase the amount of work done by the cardiac muscle and can lead to _______
heart failure
Inflammation of the valves is also known as ______________ and can cause murmurs
Rheumatic fever
Murmurs can be caused by ______ and _______
MI
Congenital Abnormalities
What are two congenital abnormalities that can cause murmurs?
Septal Defect
PDA
