Lab 8 Flashcards
The technique used for measuring the Electrical Activity of the Heart, is called what?
Electrocardiography or Electrocardiogram
(ECG)
What are contractile cells of the heart and their function?
Contractile cells:
are striated
They have actin and myosin proteins
their job is to contract the heart
What are conducting cells of the heart and their function?
Conducting cells:
Fluid filled
Spread electrical signal
Wiring system of the heart
Sinoatrial node is located where and does what?
Located: right atrium
Action potential generated
the pacemaker of the heart
Generating an action potential all on its own is called what?
Autorhythmicity
Where does the electrical signal slow in the electrical conduction pathway?
At the AV node (waits for Atria to complete contraction)
What is the first step of the electrical conduction pathway that is completely in the ventricles?
Bundle of his
(Aka AV bundle)
What is the end result of the electrical conduction pathway?
A contraction
What allows electrical signals to spread from cell to cell in the heart?
Gap junctions
These create direct connection from one adjacent cell to another?
Connexin
How are action potential spread through cells of the heart?
Through Gap junctions
What is an electrocardiography
Allows us to view conduction of electrical signals through the heart
In an ECG deflections above or below the baseline are called:
Waves
Atrial depolarization is represented by what in the ECG
(First point at which the P-wave deflects upward)
P wave
This indicates the signal is not moving very quickly (delay in the AV node) in an ECG reading
P-R segment
Movement of the depolarization wave through the large mass of ventricles.
is represented by this in a nice EGG
QRS complex
The ventricles repolarizing is represented by this in an ECG
T wave
Ventricle contraction is represented by what in an ECG (Joi is this right?) 😂
S-T segment
Sections of baselines between waves is defined as ______
Segments
This part of an ECG includes some waves and segments
Intervals
Decreased blood flow to regions of the heart is known as what?
And would be found in what segment of the ECG?
Coronary ischemia
S-T segment
Damage or death to heart tissue (AKA heart attack) is called a ____ _____
What segment of an ECG
Myocardial infarction
S-T segment
This abnormality of the heart can indicate ION channel defects
(low calcium or potassium levels May indicate risk of sudden death and can be drug-related)
Elongation
Q-T interval
Normal heart rhythm that originates at the sinoatrial node is called _____ and sets the heart rate
Sinus rhythm
The average heart rate at rest is
60-100 BPM
An abnormally fast heart rate is called
Tachycardia
An abnormally slow heart rate is called
Bradycardia
This heart irregularity originates at the sinoatrial node but the length of one cardiac cycle to the next can vary
Sinus arrhythmia
This heart irregularity has an absence of sinus rhythm. Other cells of the heart generate an action potential
Ventricular tachycardia
When the electrical signal originates somewhere other than the sinoatrial node THE CELLS that generate that signal are called?
Ectopic pacemaker
This is a fairly common condition that patients report feeling a jump or palpitation in their heart
Premature ventricular contraction
(PVC)
In this condition of the heart there is no rhythm all cells depolarize at their own rate
(Requires a defibrillator)
Ventricular fibrillation
This machine delivers a jolt of electricity to the heart. Allows the cells of the sinoatrial node to take over as pacemaker and reset the
Defibrillator
Heart beats on its own because the cells of the heart are:
Autorhythmic
When someone is at rest what branch of the autonomic nervous system is being used?
Parasympathetic
What neurotransmitter is used in the parasympathetic system (rest)
Acetylcholine
What specific receptors on the cells of the sinoatrial node bind acetylcholine
Muscarinic
What is the name of the general type of receptor used in the parasympathetic system?
G protein-coupled receptor
What effect does parasympathetic have on the heart (excitatory or inhibitory)
Inhibitory
Parasympathetic effects on heart rate and blood pressure
(increase or decrease)
HR: decrease
BP: decrease
During exercise what branch of the autonomic nervous system is used
Sympathetic
The sympathetic branch of the autonomic nervous system uses what neurotransmitter
Norepinephrine
For the sympathetic branch what is the specific receptor on the Cell of the sinoatrial node
B1 adrenergic
For the sympathetic system what is the general receptor type
G protein-coupled receptor
The sympathetic nervous system effector is _____ (excitatory or inhibitory)
Excitatory
What effects on heart rate and blood pressure does the sympathetic nervous system have
(Increase or decrease)
HR: increase
BP: increase
What is the hearts physiological pacemaker
Sinoatrial node
How do you set up an ECG on a
Einthovens triangle
Einthovens triangle means you place the readers where? (3 total)
Left wrist
Right wrist
left ankle
What are the waves on an ECG
Deflections above or below the baseline
What is a segment on an ECG
The flat area between two waves
What is an interval on an ECG
A straight line and one or more waves
What is a complex in an ECG
More than one wave appearing in succession of one another
(Ex QRS complex)
What happens to heart rate as R-R intervals decrease
Heart rate increases
Which waveform changes the most when heart rate increases
T-P segment
What happens at p wave
Depolarization of Atria fibers at the sinoatrial node
What happens at the P-R interval
The time from beginning depolarization of atrial fibers to beginning of depolarization of the ventricles
What is p-q segment
Cardiac impulse passes through AV node
What is QRS complex
Depolarization of ventricular fibers
What is ST segment
Time for ventricles to contract
How do you calculate heart rate
Measure from r to r interval
Divide 60 by r r interval to get beats per minute
What is caused by the movement of Ions?
Electrical Activity
______ generate action potentials?
Myocardial Cells
_______ myocardial cells are specialized fluid-filled cells that are able to spread an electrical signal rapidly?
Conducting Cells
These cells make up 1% of the myocardial cells and serve as the wiring system for the heart?
Conducting Cells
_________ Cells in the Right Atrium serve as a main pacemaker in the heart?
Autorhythmic
_____ rhythm sets the Heart Rate?
Sinus
Endurance Athletes have ( higher or Lower) resting heart rate? What would the range of BPM be_____?
Lower
40-60BPM
The name that represents the number of Cardiac Cycles per minute?
Heart Rate
What is it called when the signal originated somewhere in the ventricles and the SA Node is not able to regain its role as a pacemaker?
Ventricular Tachycardia
Located where in the Heart, does the Autonomic Nervous System and the Cardiovascular System Function at?
Sinoatrial Node
The SA Node cells depolarize and generate action potentials all on their own without any _______ influence?
External
Ions can move freely from one cell to the next, why?
Gap Junctions
When cations like Calcium and Sodium enter one myocardial cell to the next what is happening?
It is depolarizing
When Ca+ and Na+ enter one myocardial cell and starts to depolarize it, what does this stimuli do?
Stimulates Voltage Gated Channels
to Open
When Blood is squeezed out of the Atria into the Ventricles;
& then blood squeezes out of the Ventricles into what Circuit?
- Right Ventricle Goes Where?
- Left Ventricle Goes where?
- Right Ventrilce = Pulmonary Circuit
- Left Ventrilce = Systemic Circuit
What kind of ECG Reading is this?
Sinus Arrhythmia
The valve between the left atrium and ventricle is called what?
Bicupsid Valve
The valve between the right atrium and ventricle is called what?
Tricupsid Valve
The valves between the ventricles and blood vessels are
called _______ valves?
Semilunar
The graphical representation of the electrical activity in the heart is called?
Electrocardiogram
