Module 2: Cardiovascular/Heart

Parasympathetic innervation of the heart occurs via

CN X - Vagus

The plateau in the action potential of cardiac muscle results from the action of ________.

Ca2+ channels and an increase in contraction time

Cardiac output is normally expressed as

Liters per minute

Oxygen-poor blood enters which chamber of the heart?

Right Atrium

What is the correct order of spread of the action potential through the heart's conduction system?

SA node; AV node; AV bundle; Purkinje fibers/cell gap junctions

The P wave of the ECG coincides with ventricular filling. T/F?

True

The ventricles begin to fill during ventricular diastole. T/F?

True

Normal heart sounds are caused by which of the following events?

closure of the heart valves

A negative chronotropic drug will result in ____________.

decrease in HR

Cell-to-cell junctions, called intercalated discs, contain distinct structural features called gap junctions and

desmosomes

The external layer of the heart wall is the

epicardium

Which of the following will increase heart muscle contractility?

epinephrine

Which of the following would have a positive inotropic effect and result in an increase in stroke volume?

epinephrine

How many pulmonary veins are there?

four

The serous fluid within the pericardial cavity works to

lubricate membranes of the pericardium

A drug that decreased calcium levels in a muscle cell and thereby lowered the number of crossbridges formed during the heart's contractions would be a

negative inotropic agent

The blood in the aorta is ____________ .

oxygenated

The sinoatrial (SA) node is referred to as the _____________ of the heart.

pacemaker

Which of the cardiovascular system's circuits has deoxygenated blood in its arteries?

pulmonary circuit

Which carries oxygenated blood from the lungs to the heart?

pulmonary veins

Blood within the inferior vena cavae returns to the ________.

right atrium

Which heart chambers contain deoxygenated blood?

right atrium and right ventricle

During ventricular diastole, pressure drops and the ___________ valves close due to the backflow of blood from the arteries.

semilunar valves

In the heart, an action potential originates in the

sinoatrial node

The sequence of travel by an action potential through the heart is

sinoatrial node; atrioventricular node; atrioventricular bundle; bundle branches; Purkinje fibers

Which circuit of the cardiovascular system includes the left ventricle and aorta?

systemic circuit

________________ is persistent high heart rate in a resting adult and may result from stress, drugs, heart disease or an increase in body temperature.

tachycardia

Which is true regarding cardiac myocardium?

the myocardium is relies mostly on aerobic metabolism which makes it susceptible to failure when ischemic (oxygen is low)

Which of the following is not true for ventricular systole?

the ventricles relax

The __________ valve is between the right atrium and right ventricle.

tricuspid

The right atrioventricular valve is also called the

tricuspid valve

Which valve separates the right atrium from the right ventricle?

tricuspid valve

The _______________ carries parasympathetic innervation to the heart.

vagus nerve

The atrioventricular valves open during

ventricular diastole

The semilunar valves close during

ventricular diastole

During which event of the cardiac cycle does aortic pressure reach its maximum?

ventricular ejection

In cardiac muscle, after the plateau phase and at the beginning of repolarization,

voltage-gated potassium channels open

During the depolarization phase of cardiac muscle

voltage-gated sodium channels open

The P wave of a normal electrocardiogram indicates ________.

atrial depolarization

What variables determine the effects on cardiac output?

changes to both HR and SV

Blood within the pulmonary veins returns to the ________.

left atrium

The bicuspid valve is separates ________.

left atrium from left ventricle

Nodal rhythm is set by the ___________ and is slower?

AV node

Atrial contraction accounts for most of the ventricular filling. T/F?

False

The only arteries in the body that carry oxygen-poor blood are the coronary arteries. T/F?

False The pulmonary valves are the only arteries that carry oxygen-poor blood

The audible heart sounds are caused by the contraction of the atria and ventricles. T/F?

False sounds "lub" dub" come from the valves closing

Given that cardiac output equals ____________, there are only two ways to change it: change the heart rate or change the stroke volume.

HR x SV (Heart Rate x Stroke Volume)

Indicate whether each item would increase or decrease contractility.

Increase Contractility: -Adrenaline -Hypercalcemia -Norepinephrine -Cardiocyte hypertrophy -Acute exercise -Sympathetic stimulation Decrease Contractility: -Acetylcholine -Hyperkalemia -Hypoxia

Indicate whether each item would increase or decrease stroke volume.

Increase Stroke Volume: -Increasing EDV -Increasing preload -Increasing contractility -Increased activity of the muscular and respiratory pumps -Sympathetic stimulation -stress -Increased renal retention of water and sodium -acute exercise Decrease Stroke Volume: -Increasing afterload -Increased HR -Decreased venous return -Significant hemorrhage -Dehydration -Increased mitral valve regurgitation

Indicate whether the given factor would increase or decrease heart rate.

Increased Heart Rate: -Proprioceptive increase indicating movement of the joints -Cutting of the vagus nerve -Epinephrine -Blood Acidosis (decline in pH) -Hypercapnia (high carbon dioxide levels) -Nicotine -Thyroid hormone -Exercise -Psychological stress Decreased Heart Rate: -Vagal tone -Hyperkalemia (high potassium concentrations in the ECF) -Hypercalcemia -Acetylcholine -Parasympathetic stimulation -SA node damage -Bundle Branch Block (BBB) -Calcium channel blockers

According to the Frank-Starling law

as the volume of blood entering the heart increases, ventricular contractions become more forceful

Sympathetic innervation of the heart a: increases the heart rate b: decreases the heart rate c: increases the force of contractions d: decreases the force of contractions e: has no effect on contraction force

a, c

Which of the following will decrease heart rate?

acetylcholine

Which of the following is true concerning the heart conduction system?

action potentials pass slowly through the atrioventricular node

Just prior to atrial contraction,

all four chambers are at rest and AV valves are open

Which of the following will increase cardiac output? -Increase venous return -increase stroke volume -epinephrine -all of the above

all of the above

Which of the following would cause a decrease in cardiac output?

an increase in afterload

Norepinephrine is considered a positive chronotropic agent because it causes

an increase in the firing rate of SA node cells

What valves prevents backflow of blood into the left ventricle?

aortic semilunar

Which valve prevents the backflow of blood into the left ventricle when the ventricles relax?

aortic semilunar valve

Left ventricular contraction propels blood through which valve?

aortic valve

During ventricular diastole ___________.

blood enters the ventricles

Cardiac output is the amount of blood that is pumped

by a single ventricle in one minute