UW Biol 118 Exam 4

How blood moves through heart:

One of ____ to ____ to ____ to one of ____ to _____ to ____ to ____ to ____ to ____ to ____.

pulmonary arteries; right atrium; right ventricle; pulmonary arteries; lungs; pulmonary veins; left atrium; left ventricle; aorta; rest of body

How many chambers does the heart have?

4

List 4 chambers of heart

right atrium; left atrium; right ventricle; left ventricle

What does the aorta do?

pumps blood to body

What carry deoxygenated blood to lungs?

left and right pulmonary arteries

Where does blood enter from above heart?

superior vena cava

Where does blood enter from below heart?

inferior vena cava

blood pumps from ____ to ____

apex of heart; base of heart

Arteries take blood ____ and veins ____

away from heart; to heart

When blood goes to heart, it is ____

deoxygenated

venous blood is ____

deoxygenated

What return oxygenated blood from lungs?

left and right pulmonary veins

Heart pumps _____ and pumps ____.

100,000 times per day; 40 55-gallon drums worth of blood per day

Atriums ____ and ventricles ____. Right side of heart to ____ and left side to ____ so left side ____.

pump together; pump together; lungs; rest of body; pumps harder

What is situs inversus?

condition 1/10,000 people have where all organs flipped in opposite direction

What is the systemic circuit?

long, goes to rest of body

What is the pulmonary circuit?

short, to lungs

5 parts of systemic circuit

capillaries in head, neck, and upper limbs; systemic vein; systemic artery; systemic vein; capillaries trunk and lower limbs

3 parts of pulmonary circuit

pulmonary arteries; capillaries in lungs; pulmonary veins

The atria is ____ and ____. The ventricles are ____ and ____.

smaller, weaker; pump into ventricles; larger, stronger; pump into areteries

Pathway through right side of heart:

____ from ____ and ____ from ____ go into ____ then go through ____ to get to ____ then go through ____ to get through ____ to get to ____.

superior vena cava; upper body; inferior vena cava; lower body; right atrium; tricuspid valve; right ventricle; pulmonic valve; pulmonary artery; lungs

Pathway through left side of heart:

____ from ____ and ____ go into ____ then go through ____ to get to ____ then go through ____ to get to these 5 different places. ____ are for plumbing.

pulmonary veins; right; left lung; left atrium; mitral valve; left ventricle; aortic valve; right arm; right brain; left brain; left arm; aortic arch to lower body; coronary arteries

Regarding atria and ventricles, which direction does blood move?

atrium to ventricle

What is another name for the right atrioventricular valve?

tricuspid valve

Why is the left ventricle thicker?

has to be stronger to push blood through body

R and L valves pump ____ of blood

same volume

What are the two types of semilunar valves?

pulmonary and aortic

What are two other names for the left atrioventricular valve?

bicuspid valve; mitral valve

Name the 10 major blood vessels and valves of the heart

Superior vena cava; pulmonary arteries; pulmonary veins; right AV (tricuspid); left AV (bicuspid, mitral); inferior vena cava; descending aorta; aorta; pulmonary semilunar valve; aortic semilunar valve

Blood in superior and inferior vena cava is ____

deoxygenated

Diastole is

when a chamber is at rest and filling

Systole is

when a chamber is pumpin

When blood is moving throughout the heart it always moves ____ because ____

from high to low pressure; don't want blood moving backwards

Typically, diastole and systole refer to

ventricular system

What is happening during ventricular diastole?

ventricle at rest and filling with blood

Which valves are open and closed during ventricular diastole?

AV valves open; semilunar valves closed

Why are the semilunar valves closed during ventricular diastole?

blood flows from high to low pressure so need to close them so blood doesn't flow backwards into aorta

The aortic semilunar valves ____ when BP in the LV is ____ the min BP in the aorta.

open during systole; greater than

What is happening during ventricular systole?

ventricle ejects blood

What valves are open and closed during ventricular systole?

AV valves closed; semilunar valves open

Why are the AV valves closed during ventricular systole? Why are the semilunar valves open?

don't want blood to go from high to low pressure back into atrium; to pump blood into arteries

In ventricular systole ventricular pressure is ____ than arterial pressure and ____ than atrial pressure.

greater; greater

In ventricular diastole, ventricle pressure is ____ than artery pressure and ____ than atrial pressure.

less; less

Blood flow becomes turbulent and noisy when it ____

hits a closed valve

What are the normal heart sounds?

lub/lup; dub/dup

When is the lub sound produced?

AV valves close

When is the dub sound produced?

semilunar valves close

The systole S1 lub squirt is produced as the ____

AV fill

S1 is

when AV valves close

S2 is

when SL valves close

Cardiac muscle is made up of

red fibers rich in mitochondria and myoglobin

Cardiac muscle cells (fibers) are ____, ____, ____

short; branched; surrounded by capillaries and elastic connective tissue

In cardiac muscle cells, ____ create ____ with ____; providing ____ to prevent ____ when ____.

intercalated discs; high SA contact; adjacent cells; strength; separation between cells; heart stretches

There are ___ in intercalated discs.

gap junctions

What are gap junctions? What do they do?

tunnels between cells; allow unison contraction because signal flows through gaps

Skeletal cells are multinucleate; cardiac muscle has ____. Cardiac muscles has ____ so it relies on other ways to get ____.

one nucleus; small ER; calcium

What is a heart murmur?

when turbulent blood moves in a way it shouldn't

Why is the heart called a single motor unit?

beats by self (auto rhythmic); sends own APs

What is a motor unit?

neuron and all muscles it affects

99% of of muscles cells are ____. 1% of cells ____.

contractile cells; tell when to contract (conducting cells)

An increase in Ca2+ around myofibrils can ____

increase force of contraction

SR is ____ in cardiac muscle cells. Cardiac cells need ____.

small; extracellular Ca2+

3 stages of contractile force of cardiac muscle

rapid depolarization; plateau; repolarization

1. Rapid Depolarization:

Cause: ____

Duration: ____

Ends with: ____

Na+ entry; 3-5 msec; closure of voltage-regulated sodium channels

2. The Plateau:

Cause: ____

Duration: ____

Ends with: ____

Ca2+ entry; ~175 msec; closure of calcium channels

3. Repolarization:

Cause: ____

Duration: ____

Ends with: ____

K+ loss; 75 msec; closure of potassium channels

In skeletal muscle, APs can ____ and muscle can ____. In cardiac muscle, ____.

come one after another; stay contracted because short refractory period; heart can't do this

There is a ____ in contractile cell, so the heart can't beat ____.

longer refractory period; faster than 200 beats/min

Depolarization travels through ____.

gap junctions

What is the fibrous skeleton of the heart?

stretchy elastic material, connective tissue

What are the two functions of the fibrous skeleton of the heart?

keep valves in place; separate/isolate atria from ventricle

The ____ contract from ____ before ____ contract from ____.

atria; top-down; ventricles; bottom-up

This conducts cells at entrance of superior vena cava into R atrium; fires auto rhythmically

sinoatrial node (SA)

What is the auto rhythmic collection of conducting cells, slower than SA?

atrioventricular node (AV)

2 steps in heart AP

Ca2+ enters cell; K+ exits cell

The ____ is primary pace maker of heart because it has ____ than other heart cells.

SA node; less negative resting potential

4 steps of how the electrical signal travels across the heart

SA node (primary pacemaker) fires off into L atrium; AV node (secondary pacemaker) delays signal; AV bundle: cross fibrous skeleton into ventricle; Purkinje fibers excite ventricle muscle

The ____ at AV node allows atria to ____.

100 msec delay; continue to move blood into ventricle

What do parasympathetic neurons do to regulate the heart?

ACh increases permeability to K+ and decreases permeability to Na+, hyperpolarizing resting membrane potential so it takes longer to reach threshold

What do sympathetic neurons do to regulate the heart?

NE increases permeability to Na+ and Ca2+, depolarizing resting membrane potential so it doesn't take as long to reach threshold

What are the three waves in the heart's normal electrical pattern?

P wave; QRS wave; T wave

P wave is due to ____, QRS wave/complex is due to ____, and T wave due to ____.

depolarization of atria; depolarization of ventricles; repolarization of ventricles

What is arrhythmia?

has different heartbeat pattern (irregular heartbeat)

In the normal electrical pattern, repolarization is masked by ____.

QRS wave

What is atrioventricular block? During the block, ____ come less often because ____.

SA node can't talk to AV node, out of sync; QRS; AV isn't influenced by SA

Atrioventricular block can cause ____, which is when ____.

bradycardia; HR is less than 60 beats/min

What is tachycardia? What is it usually caused by?

when heartbeat is greater than 100 beats/min; rogue contractile cell

What is atrial fibrillation? What may happen? How to treat?

uncoordinated contraction of atria; left over blood in atrium may start to clot; anticoagulants

6 risks of atrial fibrillation

higher risk of stroke or heart attack; palpitations; shortness of breath; fatigue; fainting; chest pain

What is ventricular fibrillation? How to treat?

uncoordinated ventricle contraction; shock

Is heart pumping blood during ventricular fibrillation?

no

Which is life threatening, ventricular or atrial fibrillation?

ventricular fibrillation

5 major events during excitation of heart

SV closed and AV open; SV opened and AV closed; SV closed and AV closed; SV closed and AV open; SV closed and AV open

What causes semilunar valves to open?

decreased volume and increased pressure

Semilunar valves close when ___

pressure is greater in vessels than ventricles so SV close and atria fill with blood

AV open when ____

there's more pressure in atria than ventricles

Ventricular systole is ____. Atrial-Ventricular diastole is ____. Atrial systole is ____.

long; long; short

When ventricle relaxes, ____. It ____ as the heart ____.

it sucks up blood from atria; fills with blood by suction; relaxes and stretches

What is stroke volume?

amount of blood ejected from left ventricle

What does cardiac output equal?

heart rate times stroke volume