Circulatory System Quiz

01/07/2025

What is the circulatory system made of?

heart, arteries, veins, capillaries

Functions of the circulatory system

transport blood → carries O2 and CO2, nutrients, wastes, hormones, enzymes antibodies, heat

how many chambers in the heart

4

Cardiac muscles beat on their own. What is it called?

myogenic

Where is the eart found

middle of the chest

Fluid the protects the heart

pericardium

how does pericardium protect the heart

shock absorber

what is heat shielded by?

breast bone, sternum, ribcage

Does the right side pump oxygenated or deoxygenated blood? (and where to?)

deoxygenated, to the lungs

Does the left side pump oxygenated or deoxygenated blood? (and where to?)

oxygenated, the rest of the body

3 types of circulation

pulmonary, systemic, cardiac

pulmonary circulation

between the heart and the lungs

systemic circulation

between the heart and the rest of the body

cardiac circulation

within the heart

what are the upper and lower parts of the heart called?

upper- atria

lower- ventricles

how do the atria and ventricles work together?

atria squeeze blood into ventricles

are atria thin or thick walled? why?

thin walled (thin muscles), short distance → not much effort needed

what do the ventricles do/

pump blood away from the heart

Where do the left and right ventricles pump blood to? (are they thin/thick?)

right- to lungs (thinner)

left- the body (thicker)

what keeps the blood going in one direction/

valves

Where are the atrioventricular valves located/

between atria and ventricles

When do the AV valves close

when ventricles contract

AV valves full name

atrioventricular valves

What is the name for flaps of tissue in valves

cuspids

right vs left av valves (# of cuspids and name)

right- 3 tricuspid

left- 2 bicuspid

What holds cuspids from opening in reverse?

chordal tendinae

Semilunar valve (where, # of flaps)

between ventricles and arteries that take blood away, 3

what do the semilunar valves do?

open when ventricle contracts, then shut when it refills through suction

Do semilunar valves need chordae tendinae (why?)

no, suction does the job.

What sound does the closing of the av valves make?

lub

What sound does the closing of the semilunar valves make?

dub

what is the cardiac cycle

one heart beat

what happens during the cardiac cycle

two atria contract and two ventricles contract

What happens in systole

heart contracts- blood is squeezed out

what happens in diastole

heart relaxes- chamber fill with blood

Cardiac cycle is a full cycle …

of systole and diastole of the atria and then systole and diastole o the ventricles

What controls heart’s hearts tempo/rythm

Sinoatrial (SA) node and Atrioventricular (AV) node

What id the sinoatrial node?

bundle of nerves that initiates the heartbeat

another name of the sinoatrial node

pacemaker

What are the effects of the SA node impulses

atria contract and sends a shock to AV node

where is the SA node found

where superior vena cava enters the right atrium

What is the atrioventricular node

bundle of nerves

where is the atrioventricular node located

between right atrium and right ventricle

what does the AV node do?

impulse from SA node is sent to the bundle of HIS and then to purkinje fibers so the ventricle contract

electrocardiogram

tracks electrical impulses in the heart

What does the P wave mean on an electrocardiogram

atria contract

What does the QRS wave mean on an electrocardiogram

ventricles contract

What does the T wave mean on an electrocardiogram

ventricles relax

label the waves

What is an electrocardiogram is used for

check heart rate, detect irregularities, detect damage to heart tissue after a heart attack

what is tachycardia

heart rate too fast

what is bradycardia

heartrate too slow

what is arrythmia

irregular heart rate

EVC

extra ventricular contractions

Stress test (why and what)

bc sometimes heart condition doesn't show till pushed to the limit, EKG is done on the treadmill/bike

what does a defibrillator do

stops the heart from continuously contracting → restarts the SA node → normal rhythm

Cardiac Output

the amount of blood pumped out of the left ventricle into the body in one minute

What does the cardiac output depend on?

stroke volume and heart rate

What is stroke volume

amount of blood pushed out each beat

avg stroke volume

70ml

what is heart rate

# of beats per minute

avg heart rate

72 beats per minute

cardiac output formula

stroke volume x heart rate

what does stroke volume depend on

strength of the heart: strong heart = more squeezed out with each beat

how does a strong heart affect heart rate

lower heart rate = not as many beats needed to circulate the blood

Blood flow through the body

(a circle)

heart

aorta

arteries

arterioles

capillaries

cells of the body

capillaries

venules

veins

arteries take blood to/away from the heart

away

arteries thick/thin walls?

thick

why do arteries have thick walls

withstand high blood pressure (blood is pushed into them

arteries can constrict and relax?

yes

Constriction of arteries

vasoconstriction

relaxation of arteries

vasodilation

what keeps arteries elastic ( + what happens with time?)

collagen.

aging = lose collagen = less elastic = high blood pressure

pulse

arteries contracting and relaxing

Aneurism

a bulge formed from weakening of the artery walls

what can cause weakening of the artery walls

age, genetics, chronic high blood pressure

what happens if an aneurism bursts

internal bleeding

arteriosclerosis

build up of plaque (fat and calcium) that narrows the diameter of the artery

Effects of arteriosclerosis

high blood pressure, blood doesnt get where it needs to → heart attack, stroke (brain)

how do you treat clots and arteriosclerosis

balloon angioplasty with stent, bypass surgery

arterioles

branch out from arteries

what do arterioles do

slow down blood

What is at the end of arterioles (+ purpose)

pre-capillary sphincters, control how much blood goes into capillaries

capillaries

thin vessels (1 cell thick)

what do capillaries do (+ examples)

diffuse metabolites to and from cells, co2 ←> O2 nutrients ←> wastes

total length of blood vessels

96,000km

how far away capillaries are

2-3 cells

Venules

drain things from capillaries into veins

veins (thickness)

thinner than arteries (low blood pressure)

can veins constrict/dilate

no

veins job

bring blood back to the heart

How do veins compete with gravity

skeletal muscle contractions push blood up and one way valves

Varicose veins (what and causes)

valves fail → blood pools → weighs down the vein → bulges and twists

age, genetics, standing for a long time, crossing legs

Blood pressure

pressure on walls of arteries by blood

what measures blood pressure

sphygmomanometer

Normal heart pressure ( + what each number stands for)

120 (systolic) / 80 (diastolic)

hypertension vs hypotension

high and low blood pressure

What affects blood pressure

Blood viscosity, volume, rate, elasticity of arteries, size of arteries

Blood viscosity ( + cause and effects)

how thick blood is

genetics

smoking → thickens

Alcohol → thins

Blood volume ( + cause and effects)

How much blood is in your body

dehydrated → blood pressure down\

Salty diet → blood pressure up

haemorrhage (bleeding) → blood pressure down