BIOL204 Spring 2025 Exam 2

The heart is located in the...

mediastanum

3 multiple choice options

Atrium

thin-walled upper chambers that receive blood returning to the heart through veins

1 multiple choice option

Ventricle

thick, muscular lower chambers that pump blood out of the heart through arteries

1 multiple choice option

(Atria/Ventricles) receive blood in the heart

atria

1 multiple choice option

Atria/Ventricles pump blood away from the heart

ventricles

1 multiple choice option

Blood returns to the heart via (veins/arteries)

veins

1 multiple choice option

Blood is pumped out of the heart via (veins/arteries)

arteries

1 multiple choice option

What is the purpose of hear valves?

to allow one-way flow of blood

Semilunar Valves

prevent backflow of blood into the ventricles when they are relaxing

1 multiple choice option

Atrioventricular Valves

prevent backflow of blood into the atria when the ventricles are contracting

1 multiple choice option

Semilunar valves include...

pulmonary and aortic valves

3 multiple choice options

Atrioventricular valves include...

tricuspid and mitral valves

3 multiple choice options

The mitral valve is also called the...

biscuspid valve

3 multiple choice options

Pulmonary Valve

valve positioned between the right ventricle and the pulmonary artery

3 multiple choice options

Aortic Valve

valve positioned between the left ventricle and aorta

3 multiple choice options

Tricuspid Valve

valve positioned between the right atrium and right ventricle

3 multiple choice options

Mitral Valve

valve positioned between the left atrium and left ventricle

3 multiple choice options

Cardiac Skeleton

a layer of connective tissue that stabilizes the positions of the four valves and prevents overdilation

Chordae Tendineae

thin bands of fibrous tissue that attach to the valves in the heart and prevent them from being pushed into the atria during systole

Papillary Muscles

enlarged muscles within the ventricular wall that are attached to chordae tendineae

Which valves have chordae tendineae?

the atrioventricular valves

1 multiple choice option

Pericardium

a sac-like membrane surrounding the heart

What are the two parts of the pericardium?

fibrous and serous pericardium

Fibrous Pericardium

tough, white fibrous connective tissue that is the outer layer of the pericardium

Serous Pericardium

thinner portion of the pericardium that is split into the parietal and visceral layers

Parietal Layer of Serous Pericardium

adheres to surface of fibrous pericardium

Visceral Layer of Serous Pericardium

outer layer of the heart

The visceral layer of the serous pericardium is also called the...

epicardium

2 multiple choice options

Heart Wall

epicardium, myocardium, endocardium

Coronary blood vessels travel through which layer of the heart wall?

epicardium

2 multiple choice options

Myocardium

Thick middle muscle layer of the heart

Endocardium

inner lining of the heart

Pericardial Cavity

contains pericardial fluid that reduces friction

Cardiomyocytes

heart muscle cells

Cardiomyocytes are...

branched

1 multiple choice option

Cardiomyocytes are...

striated

1 multiple choice option

Intercalated Discs

specialized adhesive junctions that connect adjacent cardiac muscle cells

Desmosomes

Anchoring junctions that prevent cells from being pulled apart

Gap Junction

protein channels that connect the cytoplasm of neighboring cells, allowing passage of materials between cardiac cells

Cardiomyocytes are dependent on _____ metabolism

aerobic

1 multiple choice option

Cardiac Action Potential

repeated cycle of depolarization and repolarization

Phase 0 of Cardiac AP

rapid depolarization due to rapid sodium influx

3 multiple choice options

Phase 1 of Cardiac AP

transient potassium channels open, and potassium efflux begins to return the membrane potential to normal

3 multiple choice options

Phase 2 of Cardiac AP

influx of calcium ions balances the potassium efflux, creating the plateau phase

3 multiple choice options

Cardiac Plateau Phase

lengthens cardiac action potentials; ensures ventricles have enough time to squeeze all blood out with each beat

Phase 3 of Cardiac AP

calcium channels close and rectifier potassium channels remain open, allowing the membrane potential to return to normal

3 multiple choice options

Phase 4 of Cardiac AP

potassium rectifier channels maintain the resting membrane potential

3 multiple choice options

Absolute Refractory Period

the minimum length of time after an action potential during which another action potential cannot begin

1 multiple choice option

Relative Refractory Period

the period of time following an action potential, when it is possible, but difficult, for another action potential to fire

1 multiple choice option

Fibrillation

a state of rapid and disorganized contraction

Cardiac Cycle

the sequence of events that occur during one complete heartbeat

The cardiac cycle consists of two phases called...

diastole and systole

Systole

contraction; blood leaves the chamber

Diastole

relaxation; chamber refills

(Atria/Ventricles) fill with blood first

atria

1 multiple choice option

What is the first step of the cardiac cycle?

atrioventricular valves open and ventricles fill passively

3 multiple choice options

What is the second step of the cardiac cycle?

atrial systole and ventricular diastole

3 multiple choice options

What is the third step of the cardiac cycle?

first phase of ventricular systole; atrioventricular valves close, but not enough pressure for semilunar valves to open

3 multiple choice options

What is the fourth step of the cardiac cycle?

second phase of ventricular systole; semilunar valves open, pushing blood into pulmonary and systemic circuits

3 multiple choice options

What is the fifth step of the cardiac cycle?

ventricular diastole; semilunar valves close and ventricles relax

3 multiple choice options

What is the sixth step of the cardiac cycle?

all valves are closed, and blood passively fills the atria

3 multiple choice options

Isovolumetric Contraction

the initial phase of ventricular contraction where the muscle fibers contract but the valves remain closed, resulting in no change in ventricular volume; builds tension, preparing to eject blood

3 multiple choice options

Isovolumetric Relaxation

the ventricles relax, but the valves remain closed, resulting in no change in ventricular volume

3 multiple choice options

Ventricular Ejection

the phase of ventricular contraction where the aortic and pulmonary valves open, allowing blood to be ejected from the ventricles into the aorta and pulmonary artery

3 multiple choice options

End-Diastolic Volume

the amount of blood in the ventricle at the end of diastole

3 multiple choice options

What causes the sound associated with heartbeat?

the turbulence of blood hitting a closed valve or rapidly filling a chamber

S1 Sound

"lub;" AV valves closing

3 multiple choice options

S2 Sound

"dub;" semilunar valves closing

3 multiple choice options

S3 Sound

very faint ventricular filling sound

3 multiple choice options

S4 Sound

normally inaudible "atrial gallop"

3 multiple choice options

Valve Regurgitation

leaking of blood through a closed valve

Valve Stenosis

when valves become narrower than normal, impeding the flow of blood

Pacemaker Cells

heart cells that regularly produce spontaneous electrical impulses

3 multiple choice options

Purkinje Fibers

fibers in the ventricles that transmit impulses to the right and left ventricles, causing them to contract

3 multiple choice options

What type of muscle cell is found in the walls of blood vessels?

smooth

2 multiple choice options

What type of cells line the inner surface of the heart and blood vessels?

endothelial

3 multiple choice options

Fibroblasts

cells that produce and maintain the extracellular matrix

3 multiple choice options

Cardiomyocytes

cardiac muscle cells responsible for contracting and pumping blood

3 multiple choice options

Auto-Rhythmicity

cardiac muscle's ability to contract at its own pace independent of neural or hormonal stimulation

Conducting Cells

nerve-like conduction pathways through the myocardium

The Sinoatrial Node

sets the rate of the heartbeat due to having the fastest rate of depolarization

3 multiple choice options

The sinoatrial node is also called the...

pacemaker

What is the first step of the electrical conduction for a heart contraction?

the sinoatrial node generates an electrical impulse which spreads through the atria

3 multiple choice options

What is the second step of the electrical conduction for a heart contraction?

the impulse reaches Bachmann's bundle, helping to spread it to the left atrium

3 multiple choice options

What is the third step of the electrical conduction for a heart contraction?

the impulse reaches the atrioventricular node, delaying the impulse

3 multiple choice options

What is the fourth step of the electrical conduction for a heart contraction?

the delayed impulse travels through the bundle of His

3 multiple choice options

What is the fifth step of the electrical conduction for a heart contraction?

the impulse travels through the Purkinje fibers to the ventricles, causing them to contract

3 multiple choice options

Bachmann's Bundle

the structure that relays the electrical impulse from the SA node to the left atrium in a normal heart

3 multiple choice options

Bundle of His

a bundle of modified muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles

3 multiple choice options

Atrioventricular Node

a node of specialized heart muscle located in the septal wall of the right atrium

3 multiple choice options

What is the difference between the action potential in the atria and ventricles vs the pacemaker?

the pacemaker action potential has pacemaker potential, responsible for the spontaneous repetitive depolarization

Electrocardiogram

records the sum of all electrical potentials generated by all of the cells of the heart at any given time

P Wave

atrial depolarization

Label the P Wave

QRS Complex

ventricular depolarization

Label the QRS Complex

T Wave

ventricular repolarization

Label the T Wave

Heart Rate

calculated from R wave to R wave; beats per minute

2 multiple choice options

What is a normal resting heart rate?

60-100 bpm

3 multiple choice options