week 5 cardiac Flashcards
what do these three tissues compose- epicardium - outer
myocardium- middle muscle - endo cardium - inner
the heart wall
damage to the heart muscle caused by loss of blood means a block in what
arteries
blockages result in what
damaged cells
exercise training protects the heart against what
MI - heart attack - myocardial infarction
blood comes from where
superior vena cava
myocardium helps with muscle contraction of
the heart
which is the first valve before on right side
tricuspid
myocardium has what type of tissue
connective
what does the myocardium do
provides muscular contractions that eject blood from the chamber
what does the epicardium do
serves as lubricates outer covering
what does the endocardium do
serves as a protective inner lining of chambers and valves
disks in the heart allows what
cardiac muscle together
heart muscle has what kind of nuclei
single
heart muscle fibres are shorter and branched why
smoother movement for heart beat
what type of energy does the heart use
aerobic
where does the calcium come from
sarcoplasmic reticulum and extracellular
electrical contraction depend on what
stimulation of the myocardium
Sa node initiates what
depolarization
AV node does what
passes depolarization to ventricles - allowing V filling
what do bundle branches do
connect atria left and right too bundle of his
what do purkinje fibres do
spread a wave of depolarization throughout the ventricles
what is the T wave in ecg
ventricular repolarization
what is the p wave in the ecg
atrial depolarization
what is the QRS
ventricular depolarization and atrial repolarization
ventricular pressure rises as what contracts
ventricles
what is the intrinsic pacemaker base
100 bpm
maximal cardiac output will increase - what will increase
oxygen consumption for muscles
cardiac output and oxygen consumption is higher in athletes compared to
sedentary people
2 ways blood flow changes for exercise -
cardiac output increases
redistribution of blood from inactive organs
cardiac output is ….. proportional to the metabolic rate required to perform the exercise
directionally
equation for cardiac output
SV X HR
What is edv
end-diastolic volume
what is edv ( preload)
volume of blood after preload and venous return
what is average blood pressure
pressure the heart must pump against to eject blood - map
starlings law is
elastic band theory
what factors regulate Cardiac output
nerves - para and sympathetic
contraction strength
stretch
map
how does cv system help aerobic performance
c output increases, o2 consumption will also increase to support the body and muscles demand for o2
during exercise increase in metabolic pathway need for what
oxygen and blood flow delivery to muscles
c output is directly proportional to the
metabolic rate required to perofm exercise
when will hr platue
40% vo2 max stroke volume
rest phase is the what
filling of the ventricles
volume of blood in the ventricles at the end of the diastole is the
pre load
hr is influcned by the what
diet, symp nerves and contractility
double product is what
HR X systolic Bp
what is myocardial workload
how hard the heart works
does stroke volume paltue in runners
in elite there is no plateau
