Lab 1 - electrocardiography analysis Flashcards
t/f the heart is the simplest organ
true
What is assessed by the electrocardiogram (ECG or EKG)
efficiency of the heart
area of the brain where sensory stimuli are monitored, information is relayed an adjustments are made according to the physical requirements of the body
medulla of the brain
the heart is a hollow organ made of muscular tissue called _____
myocardium
what is the first leg of the journey of blood in the heart in 6 steps
- CO2 saturated blood enters the right atrium from vena cave
- blood is pumped into right ventricle
- right ventricle pumps blood in pulmonary artery
- pulmonary artery carries blood to the lungs
- exchange of CO2 and O2
- carbon dioxide is exhaled
what is the second leg of the journey of blood in the body in 5 steps
- newly oxygenated blood goes back to left atrium via the pulmonary veins
- blood enters the left ventricle
- blood is forced out through the aorta
- blood goes to the tissues to deliver oxygen and nutrients (collects carbon dioxide)
- return to the heart - cycle begins again
serves as a reservoir from the ventricles, assuring a constant flow of blood through the heart
the atria
ventricular primer
atria
where are the specialized cells in the SA node located?
in the right atrium near the superior vena cava
what joins the myocardial cells tightly together
intercalated discs
what are intercalated dics?
lower resistance to electrical conductivity than the outside of the myocardium = quick propagation of the cardiac action potential
where is the AV node located?
roughly at the border between the atria and ventricles along the midline of the heart
From the AV node, the action potential travel downwards toward the apex of the heart via ____, and ____ and _____
Bundle of His, Right and left Bundle branches and Purkinje fibers
this electrical pathway is composed of ___ (explain)
specialized non-contractile, highly conductive cardiac tissue that ensures the heart depolarizes and contracts in a sequential manner and as a coordinated unit
The voltage changes caused by the action potentials can be measured on the body’s surface and are known the ____
electrocardiogram (ECG)
The usual amplitude of the voltage changes is only about __ mV but they can easily be recorded
1-2mV
Offers a reliable, non-invasive way of studying the integrity of the heart’s electrical conductive system and allows for an overall evaluation of cardiac health
Electrocardiogram (ECG)
three words to describe the heart’s electrical activity
polarisation, depolarisation, repolarisation
polarisation
refers to the heart at rest, awaiting a depolarising signal, normally from the SA node
depolarisation
discharge of electrical energy that triggers the contraction
repolarisation
electrical recovery of the heart as the cells recharge themselves and return to polarised state
which 2 phases from the heart’s electrical activity can be measured by the ECG
depolarisation and repolarisation
t/f the ECG trace is a measurement of the strength of the contractions of the heart
false
what is the ecg
recording of the electrical impulses prior to the contraction and relaxation of the myocardium
what are the letters of the ECG recording
P, Q, R, S, T and U
first waveform to appear
P wave