KNS 360 - exam 3 - spring 2026 - Dr. HW

What system does the cardiovascular system work with?

The pulmonary system

What is the job at the cardiopulmonary system?

Get blood places

What is the job of the cardio respiratory system?

Oxygenate the blood

What are the two purposes of the cardio respiratory system?

Transport O2 and CO2

Regulate body temperature (vasodilation/constriction)

Adjustments of blood flow during exercise are controlled by changes in what two things

Cardiac output and blood flow

What are the four components of the cardiovascular system?

The heart

Arteries and arterioles

Capillaries

Veins and venules

What are arteries and arterioles

Away from heart

Oxygenated blood

Thick muscular walls

High pressure

What are capillaries?

Major site of O2/CO2 or waste products/nutrient exchange

What are veins and venules

To heart

Have valves (not muscular walls)

Transport unoxygenated blood

What is the order of flow of blood in the heart?

Vena cava

Right atrium (tricuspid valve)

Right ventricle (pulmonary valve)

Pulmonary arteries

Lungs

Pulmonary veins

Left atrium (bicuspid valve)

Left ventricle (aortic valve)

Aorta

What are the two different circuits of the heart and which side of the heart?

Pulmonary circuit - right side - oxygenate blood

Systemic circuit - left side - distribute blood

Where is the heart located?

thoracic cavity in mediastinum

What is the pericardium?

double-walled sac that encloses the heart

For free movement and to not get caught in vessels or nerves

What are the three layers of the heart?

epicardium, myocardium, endocardium

What is the epicardium?

Outer layer of the heart

continuous with pericardium

What is the myocardium?

Middle layer of the heart

Made of cardiac muscle (does the contract)

What is the endocardium?

Protective interlining of the chambers and valves of the heart

How does the myocardium receive blood supply?

coronary arteries

What is a myocardial infarction?

heart attack

Heart injury when coronary blood flow is disrupted leading to permanent damage to heart tissue

What is the difference in cellular junctions of heart muscle and skeletal muscle?

Heart muscle has intercalated discs which are extra junction, so the heart doesn't break itself apart because it never stops

What is the difference in energy production of heart muscle and skeletal muscle?

Heart muscle only uses aerobic

Skill to muscle uses aerobic and anaerobic

How does exercise affect those who have a heart attack?

They have a higher survival rate and they sustained less damage

What is the conduction system of the heart

The SA node starts the contraction and sends it to the AV node

there is a pause, then contraction of the atriums when the signal is sent to the bundle branches

The signal travels through the branch branches to the Perkinje fibers

There is a pause, then the ventricles contract

What are electrocardiogram tracing of electrical activity (EKG or ECG)

Records, the hearts, electrical activity

Abnormalities may indicate coronary heart disease

What are the four components of the conduction system of the heart?

1. SA node

2. AV node

3. Bundle branches

4. Purkinje fibers

What are the three portions of EKGs in order

P wave

QRS complex

T wave

What is the P wave?

atrial depolarization

(AV->SA)

What is the QRS complex?

ventricular depolarization and atrial repolarization

(Bundle branches to purkinje fibers)

What is the t wave?

ventricular repolarization

What does the ST segment of an EKG allow us to do

Make assumptions on oxygenation of ventricles

EKG labeling

What can we examine with an ECG during a GXT

Cardiac output and changes in blood pressure

What is atherosclerosis?

fatty plaque that narrows coronary arteries and reduces blood flow to myocardium

What does an S-T segment depression suggest

myocardial ischemia usually due to atherosclerosis

What is a premature ventricular contraction (PVC)?

This is when the ventricles fire before the SA node resulting in a wide and bizarre QRS complex on a ECG

Not a concern during high intensity, exercise, but is at rest

What is the default heart rate of the SA node

100 BPM

What lowers the default heart rate at rest

Parasympathetic system

What increases the default hr during exercise

Sympathetic

E and NE

How does the nervous system increase heart rate from rest to max PA

We withdrawal the parasympathetic system till 100 bpm then activate sympathetic and catecholamines

What increases heart rate after a heart transplant

More E and NE bc the nerves don't fully heal

So need extended warmup and cooldown for hormones to kick in

What are the two cardiac medications

Beta blockers (reduce E/NE, nervous system take over)

Ca channel blockers (reduce cross bridge formation -> less force production)

What could be an issue with Ca channel blockers

Affects all tissues not just heart muscle

What are the two parts of the cardiac cycle

systole (contraction) and diastole (relaxation/filling)

How much of our heart beat is systole and diastole at rest and during exercise

Rest - sys: 1/3 (0.3 secs), dia: 2/3 (0.5 secs)

Exercise - sys: (0.2 secs), dia: (0.13 secs)

What happens to pressure during systole and diastole

Sys - increase (therefore volume Dec)

Dia - decrease (therefore volume Dec)

The cardiac cycle changes with what two things

Pressure and volume

What does a swooshing sound mean when listening to heartbeat

Leaking or backflow

Common with exercise not rest

What portion of a ekg is systole and diastole

Sys - R-T

Dia - T-R

What are the two parts of blood pressure

systolic - pressure during systole

diastolic - pressure during diastole

Not the same as systole and diastole

What are the 3 classifications of blood pressure level

Normotensive (120/80)

Hypertensive (140+/90+)

Hypertensive (90-/60-)

What is pulse pressure and how is it calculated?

difference between systolic and diastolic pressure (SBP-DBP)

Avg is 40

Inc with exercise

What is the equation for mean arterial blood pressure

MAP = DBP + 1/3(SBP-DBP)

What are the two determinants of mean arterial pressure (MAP)

cardiac output

total vascular resistance

What two things regulate the short term MAP

Sympathetic

Baroreceptors in aorta and carotid arteries

Increase in BP = dec in sympathetic (vasodilation)

Dec in BP = inc in sympathetic (vasoconstriction)

How does our body detect changes in blood pressure

Baroreceptors in the aorta and carotid arteries

What is long term MAP regulated by

Kidneys (antidiuretic/aldosterone)

By blood volume

What 5 factors affect BP

SV

HR

Volume of blood

Viscosity

Peripheral vascular resistance

What is cardiac output

Amount of blood the heart pumps in 1 min

Q = heart rate x stroke volume

What is heart rate

How many times the Heart beats (contracts) per minute

What is stroke volume

Amount of blood pumped per heart beat

SV = EDV + ESV

avg 80 mL

What is end diastolic volume (EDV)?

volume of blood in each ventricle at end of ventricular diastole

Avg 100-120

What is end systolic volume (ESV)?

the amount of blood in ventricles after systole

Avg 40-60

What is average cardiac output at rest

5 L/min

even with trained (SV inc and HR Dec)

Women tend to be lower than men

What happens to cardiac output as you train

Stroke volume increases heart rate lowers bc don't need as much

Q increases at max intensity

What four factors regulate stroke volume

Venous return (bring blood back)

EDV (heart full)

Avg aortic blood pressure

Contractility

How does EDV effect SV?

Frank starling mechanism - more blood in Herat stretches muscles so contracts harder (optimal length)

What is EDV dependent on

venous return (how much blood comes back)

What is venoconstriction controlled by

Skeletal muscle pump (skeletal muscle contract to squeeze veins) (why cooldown is important cause can cause pooling in lower limbs or clots)

Respiratory pump (lungs intake air which Inc pressure and squeezes vena cava)

What is the valsalva maneuver and why is it dangerous

Holding breath during rep

Causes lungs to block vena cava

What is ejection fraction?

stroke volume/end diastolic volumE

how effective the heart is working

Avg 60%

Below 40% =0.4 sign of heart failure or HBP

How does sympathetic stimulation affect stroke volume

Increases contractility which increases stroke volume

Big picture - what modifies heart rate

Sympathetic

Parasympathetic

Hormonal response (E and NE)

Big picture what modifies stroke volume

Contraction strength (modified by Frank and symp)

EDV (modifies frank)

mean arterial pressure

What two things make up blood

cells and plasma

What is blood plasma contain

Ions proteins and hormones

Liquid portion

What are the three types of blood cells

red blood cells (contain hemoglobin to carry O2)

white blood cells (immune function)

platelets (clotting)

What is hematocrit?

percent of blood volume that is RBCs

Avg 40 (60% is plasma)

What is blood flow modified by

Pressure (directly proportional)

Resistance (directly proportional)

What is pressure in blood flow related to

difference between MAP and right atrial pressure

Where is the highest and lowest BP

Highest - left ventricle

Lowest - right atrium

HBP can make right atrium pressure too high

What three things is blood vessel resistance dependent on

Length of vessel (direct) (redirect blood)

Viscosity of blood (direct)

Radius of vessel (inverse) (most impact)

Where does th largest drop in MAP occur

At the arterioles (resistance vessels)

Where we start to reduce pressure

What happens to oxygen delivery during exercise

Cardiac output increase (HR and SV)

Blood is redistributed (from organs to muscle and skin)

Oxygen is delivered (O2 to muscles)

What are the cardiovascular changes that happen during exercise

Initially HR Inc which Inc SBP (DBP stays same)

Cardiac output has strong increase the levels out and steadily Inc (bc SV Inc rapidly to 40-50% VO2)

Once at 40-50% VO2 max HR becomes main driver of CO (which increases linearly)

What happens to blood flow distribution at rest (5L)

Mainly to organs

Only 15-20% to muscles

What happens to blood flow during exercise (25 L)

Heart stays same

Just enough to organs to not die

80-85% to muscles and skin (thermoreg)

How does arteriovenous O2 difference increase with exercise

Same as cardiac output and lactate threshold

Inc a lot then level off and steady Inc

What two things predict VO2 max (equation)

Cardiac output x A-VO2 difference = VO2 max

Can work backwards

What is arteriovenous O2 difference (A-VO2)

How well O2 is extracted from blood to tissues

What is hypertrophic cardiomyopathy?

Increase in interventricular septum size

Typically asymptomatic

Associated with sudden cardiac death

Disrupts electrical function of heart

Does the pattern of heart rates response to exercise change based on training

No but hr is at lower level for same output

There is still a increase then a steady state then a recovery

How dos the blood flow distribution to muscle and from organs happen from rest

To muscles there is drastic increase even at low int

From organs there is steady Dec

What is autoregulation of blood flow?

How the body knows where to send blood and how much

What are the 5 signals of autoregulation in increasing order

O2/CO2 tension (how much in blood)

Potassium (diffusion means doing work)

Adenine (build up from stress)

pH (Dec - build up - work; inc - no work constrict)

Nitric oxide (rogue O2 picked up by N)

What 3 things does the heart rates and blood pressures response to exercise depend on

Type, intensity and duration

Environmental condition (hot,humid)

Emotional influence

How is emotion connected to HR and BP

Emotions hooked to sympathetic nervous system

Sympathetic nervous system controls response

What is double product

HR x SBP

How hard cardiovascular system is working

Important for cardiac rehab and older adults

Tells how to scale int

Recovery of heart rate and blood pressure depends on what 3 things

Fitness level

Temerature and humidity

Duration

Is upper or lower body more demanding

Upper

because proximity to heart (closer) (inc BP) and less muscle mass (inc HE)

What happens to Q HR and SV with prolonged exercise

Q remains constant

SV decreases (cardiovascular drift)

HR inc