Heart Physiology Questions (142 #2)

____ allows passive filling of chambers

Diastole

The ____ cycle is how the heart contracts and pumps blood

cardiac

The ____ system is what coordinates and drives cardiac muscle contraction

conducting

In the conduction system, cells generate electrical ____ ____ and carry them throughout the heart

action potentials

What type of cells allows the heart to maintain its rhythm?

Pacemaker

Which conduction system structure holds pacemaker cells?

SA node

Term for the difference in electrical potential between the inside and outside of a cell (2 words)

Membrane potential

The K+ concentration inside of the cell is ____ than the outside of the cell (greater or less)

greater

A cell at rest is overall ____ on the inside (negative or positive)

negative

Cardiac conduction system does NOT contain neurons, but instead contains specialized ____

cardiomyocytes

What ion is very important in cardiac muscle action potentials?

Ca2+

The ____ potential is the membrane potential a cell must reach to initiate an action potential

threshold

Pacemaker cells reach a threshold potential by themselves in a step called ____.

prepotential

What two types of ions slowly enter the cell, making the cell positive enough to reach its threshold to stimulate an action potential?

Na+ and Ca2+

What type of ion quickly leaves the cell, making the cell more negative?

K+

How do pacemaker cells trigger the rest of the conduction system?

Gap junctions

When gap junctions are opened, they connect the ____ of connected cells.

cytoplasms

What structure is a muscle cell’s endoplasmic reticulum (ER)?

Sarcoplasmic reticulum

What type of ions does the sarcoplasmic reticulum store?

Ca2+

____ covers actin during relaxation

Tropomyosin

____ causes tropomyosin to move away from actin, allowing actin to be accessed

Calcium

____ can bind to actin and pull to cause contraction

Myosin

What is the normal adult resting heart rate? (range)

60-100 bpm

Which wave is due to the depolarization of atrial cardiomyocytes during action potentials (atrial systole)?

P wave

Which wave is due to the depolarization of ventricular cardiomyocytes during action potentials (ventricular systole)?

QRS complex

Which wave is due to negative (ventricular) repolarization and does NOT involve contraction?

T wave

If ventricular tachycardia is prolonged, it can result in ventricular ____

fibrillation

An automated external defibrillator (AED) delivers around ____ volts of charge

3000

Term for amount of blood pumped by each ventricle during one minute (2 words)

Cardiac output

What is the term for an above normal heart rate?

Tachycardia

What is the term for a below normal heart rate?

Bradycardia

The sympathetic nervous system is like the “gas pedal” for the heart, whereas the ____ nerve is like the “brakes for the heart

vagus

Sympathetic stimulation ____ heart rate and ____ prepotential time

increases; decreases

Parasympathetic stimulation ____ heart rate and ____ prepotential time

decreases; increases

Term for the difference between maximum CO and resting CO

Cardiac reserve

Term for the amount of blood pumped by each ventricle per contraction (beat)

Stroke volume

Term for amount of blood in the ventricles at the end of atrial systole (volume when fully relaxed)

End-diastolic volume

Term for amount of blood remaining in each ventricle following systole

End-systolic volume

Term for amount of blood that was “squeezed out” from the ventricle

Ejection fraction

Ejection fraction is measured with an ____

echocardiogram

Term for inability of the heart to meet the circulatory needs of the body

Heart failure

Normal ejection fraction?

50-70%

____ peptides are secreted in response to high blood pressure, blood volume, or blood sodium

Natriuretic

Atrial natriuretic peptides (ANP) are produced by ____ ____

atria walls

B-type natriuretic peptides are produced by the ____

ventricles

What abnormality is indicated by this ECG pattern?

Premature atrial contractions (PACs)

What abnormality is indicated by this ECG pattern?

Paroxysmal atrial tachycardia (PAT)

What abnormality is indicated by this ECG pattern?

Atrial fibrillation

What abnormality is indicated by this ECG pattern?

Premature ventricular contractions (PVCs)

What abnormality is indicated by this ECG pattern?

Ventricular tachycardia