A&P first exam

The heart is actually (one, two, or three) pumps?

two pumps

Which chamber receives blood from superior and inferior vena cava?

right atrium

Which heart chamber receives blood form the pulmonary veins?

left atrium

Which heart chamber pumps unoxygenated blood out the pulmonary trunk?

right ventricle

Which chamber pumps oxygenated blood out of aorta to the systemic circuit?

left ventricle

Intercalated discs have desmosomes for

strong connection, to transmit force, and to gap junctions for electrical communication btwn cells

Blood returning to the heart from the pulmonary circuit first enters the

left atrium

The papillary muscles function to

prevent AV valves from reversing into the atria

What is not found in the mediastinum

lung

Tetanic musc contractions dont occur in a normal cardiac muscle because

the refractory period lasts until the muscle relaxes

Excess fluid causes cardiac tamponade in the...

pericardial cavity

Blood leaves the right ventricle by passing through the

pulmonary valve

The AV valves permit blood flow

in one direction

The right ventricle pumps blood to the

right and left lungs

the left ventricle pumps blood to the

aorta

When a bld clot forms on a ruptured plaque in a coronary artery, the condition is known as

coronary thrombosis

the muscle layer of the heart is

myocardium

Oxygen is added to blood as it flows through the...

pulmonary circuit

What part of the condition system initiates the depolarizing impulse which spreads throughout the heart?

SA node

What does the ECG wave tracing represent?

electircal activity in the heart

What does the QRS complex represent in the ECG wave tracing?

ventricular depolarization

Contraction of the atria results from which wave of depolarization on the ECG tracing?

P wave

Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles?

AV node

Different between cardiac and skel muscle is

Cardiac muscle cant be tatanized

In cardiac muscle, the fast depolarization phase of the action potential is the result of

increased membrane permeability of sodium ions

The long plateau phase of the cardiac muscle action potential is due to

calcium channels remaining open

The normal pacemaker of the heart is located in the

sinoatrial node

If the pacemaker cells in the SA node become more permeable to potassium ions

heart rate will decrease and cells will hyperpolarize

In the connection between the SA node and AV node becomes blocked

the ventricles will beat more slowly

The P wave of the electrocardiogram is a signal from

depolarization of the atria

During the T wave of the ECG, ventricles are

both repolarizing and relaxing

Pacemaker cells in the SA node

can spontaneously depolarize

A slower than normal heart rate is called

bradycardia

faster than normal heart rate is called

tachycardia

isovolumetric relaxtion and ventricular filling take place during

ventricular diastole

Filling od ventricles

passively in the ventricles through open AV valves

describe pressures in the atria and ventricles that would cause the opening of the AV valves

pressure in atria would be greater than the pressure in ventricles

What causes the aortic semilunar valve to close

greater pressure in the aorta than in the left ventricle

Phases of cardiac cycle in order

ventricular filling, contraction, ventricular ejection, isovolumetric relaxtion

Increased pressure in the ventricles would close what valves

AV valves only

What is the relaxed state of the ventricle called?

diastole

the one way nature of the left AV valve prevents blood flow from

the left ventricle of the left atrium

Majority of the ventricular filling occurs while the ventricles and atria are in what state?

relaxed, ventricular and atrial diastole

What describes the end diastolic volume?

the volume of the ventricle when it is most full

left ventricle filling occurs

while the AV valve is open

Decrease in left ventricular pressure at the end of ventricular systole causes

the semilunar valve to close

First heart sound is heard when the

AV valves close

During ventricular systole

AV valves are closed

With each ventricular systole

blood pressure increases

Contraction phase of the cardiac cycle is called

systole

Which would increase cardiac output to the greatest extent?

increased heart rate and increased stroke volume

What would increase heart rate?

epinephrine and norepinephrine

How would an increase in the SNS increase stroke volume?

increased contractility

How would decrease in blood volume affect stroke volume and cardiac output?

volume and no change in cardiac output

heart rate is controlled by neurons of the cardiovascular center located in the

medullae oblongata

Cardiac output is increased by

sympathetic stimulation

Drugs that block the beta one adrenergic receptors will

decrease heart rate

activation of which kind of receptor causes rate to increase

beta one receptor