what is this?
Results from movement of the ______________ wave from the __________ through the ____
P-wave
depolarization
SA node
atria
what is this?
Results from _____________ _____________ and precedes ___________ ___________
QRS complex
ventricular depolarizations
ventricular contractions
what is this?
Caused by _________________
Precedes ________________
T-wave
ventricular repolarization
ventricular relaxation
Cardiac _____________ _____ are found at __________ and _________________ ________
pacemaker cells
sinoatrial
atrioventricular nodes
Pacemaker cells have an ___________ ________ __________ that continuously ____________towards the ________
unstable resting potential
depolarizes
threshold
what is this?
what is it considered?
what does it do?
sinoatrial node
pacemaker
generates impulses
what is this?
atrioventricular node
what is this?
connects impulses through the ________________ ________
bundle branches
interventricular septum
what is this?
________ the contractile cells of both __________
subendocardial conducting network
depolarizes
ventricles
_____________ activation of the nervous system triggers the __________ _________ to release neurotransmitters ___________ and _____________ at _________ _________
Sympathetic
adrenal medulla
epinephrine
norepinephrine
cardiac synapses
β1 receptors ________ heart rate and force of contraction when ___________ binds
increase
norepinephrine
________ atrium receives blood from 3 veins
list them:
right
superior vena cava
inferior vena cava
coronary sinus
name and function
superior vena cava
returns blood from body regions superior to diaphragm
name and function
inferior vena cava
returns blood from body regions inferior to diaphragm
name and function
coronary sinus
collects blood draining from myocardium
name
___________into the _______________ which routes blood to the ______ for _____________
right ventricle
pumps blood
pulmonary trunk
lungs
gas exchange
name
__________ into the ______, the _______ artery in the body
pumps blood
aorta
largest
The the blood that circulates the heart provides little nourishment to the heart because the ____________ is too thick to diffuse nutrients
Requires a functional blood supply of the heart and the shortest circulation in the body known as ________________________
myocardium
coronary circulation
___________________ originate from the aorta with blood coming from the _____________
Coronary arteries
left ventricle
Valves open and close in response to differences in ________________ on their two sides
blood pressure
______________________ prevent backflow into the ______when each __________ contracts
atrioventricular valves
atria
ventricle
Semilunar (SL) Valves _______ and _________ valves prevent backflow into the associated ventricles
Aortic
Pulmonary
The heart contracts as a _____
unit
The heart relies almost exclusively on __________ respiration
aerobic
___________ contractions cannot occur in cardiac muscles
Tetanic
Period of contraction when blood is forced out of chambers
Systole
Period of relaxation when the chambers refill with blood
Diastole
Amount of blood pumped out by each ventricle in 1 minute
The product of heart rate and stroke volume
cardiac output
Volume of blood pumped out by one ventricle with each beat
Represents the difference between EDV and ESV
Stroke Volume
The amount of blood that collects in a ventricle during diastole
End Diastolic Volume
The volume of blood remaining in a ventricle after it has contracted
End Systolic Volume
what is this?
Time beginning _____ excitation to the beginning of __________ excitation
P-R interval
atrial
ventricular
what is this?
Period where the entire ________ system is depolarized
S-T segment
ventricular
What is this?
Period from the beginning of ventricular __________ through ventricular ___________
Q-T Interval
depolarization
repolarization
the first heart sound is the result of the ____ ________ _________
AV valves closing
the second heart sound is the result of the ___ _________ __________
SL valves closing
Blood flow is normally ______, but if blood strikes obstructions then flow generates abnormal _________ ______ called ______ _________
silent
heart sounds
heart murmurs
the ____________ __________ is a pulse taken at the apex of the heart
Apical Pulse
the __________ __________ is the difference between the heart rate and pulse rate
Pulse Deficit
__________ ___________ refers to the pressure the blood exerts against the inner walls of the blood vessels
blood pressure
a _________ is the pressure wave created by the alternating expansion and recoil of an _______ that occurs with each beat of the left ventricle
Pulse
artery
________ is the period of contraction when blood is forced out of chambers
Systole
_____________ is the period of relaxation when the chambers refill with blood
Diastole
the ___________ ___ _________ are when a blood pressure cuff is used to prevent blood flow past the brachial artery
First sounds heard with a stethoscope are soft tapping sounds which is blood spurting through the constricted artery due to ________ pressure
As cuff pressure is reduced these sounds become _________
sounds of korotoff
systolic
louder
__________ pressures are pressure in arteries at the peak of ___________ contraction
Systolic
ventricular
________ pressures are the pressures when the __________ are relaxing
Diastolic
ventricles
Standing suddenly will cause gravity to make blood to pool to legs and feet causing blood pressure to _____
drop
Physical stress, exercise or fear triggers __________ ANS for ______________ except in _________ __________
Vessels of the skeletal muscles ______ to _______ blood flow to working muscles
sympathetic
vasoconstriction
skeletal muscles
dilate
increase
Nicotine causes _____________ leading to increased ____________ _____________ of arteries and increased __________ _________
vasoconstriction
peripheral resistance
blood pressure