W1. Cardiovascular A & P Review

Parts 1-4 ✅ Complete

What are the two main overall functions of the cardiovascular system?

• Transport of substances

• Regulation of internal body conditions

What are the primary transport roles of the cardiovascular system?

• Deliver oxygen, nutrients, and hormones to tissues

• Remove carbon dioxide and metabolic wastes

What body processes does the cardiovascular system help regulate?

• Body temperature

• Acid–base balance (pH)

• Fluid/blood volume balance

What is ischemia and how does it relate to cardiovascular dysfunction?

Ischemia is localized tissue damage caused by decreased blood flow

What is hypoxemia and when can it occur?

Systemic low oxygen levels that can occur when the heart pumps inefficiently

How is the cardiovascular system organized functionally?

As a closed-loop circulation consisting of heart, arteries, capillaries, and veins

What is the role of the heart in the cardiovascular system?

It acts as the central pump that generates the pressure to move blood

What is the function of arteries?

Distribution vessels that carry blood away from the heart under high pressure

What is the function of capillaries?

Exchange sites for gases, nutrients, hormones, and metabolic waste

What is the function of veins?

Collection and return of blood back to the heart under low pressure

Describe blood flow from the left ventricle to the body

Left atrium → mitral valve → left ventricle → aortic valve → aorta → systemic circulation

Describe blood flow returning from the body to the right side of the heart

Body → vena cava → right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary arteries → lungs

What is the complete pathway of blood through both circulations?

Pulmonary veins → left atrium → left ventricle → aorta → body → vena cava → right atrium → right ventricle → pulmonary arteries → lungs → pulmonary veins

What are the main roles of the atria?

They act as reservoirs, ensure complete ventricular filling, and improve pumping efficiency

Why are atria important for efficient heart function?

They allow smooth, complete filling of ventricles and prevent turbulent, inefficient flow

What clinical analogy explains the importance of the atria?

They are like chambers that prevent air bubbles in a water pump, keeping flow smooth

What is the role of the septum?

It separates deoxygenated blood on the right from oxygenated blood on the left and prevents mixing

Which valves produce the S1 heart sound?

Closure of the mitral and tricuspid valves

During what phase does S1 occur?

At the start of systole

Which valves produce the S2 heart sound?

Closure of the aortic and pulmonary valves

When does S2 occur?

At the end of systole

What are structural features of arteries?

Thick, muscular, elastic walls with prominent tunic media to handle high pressures

What are functional characteristics of arteries?

They carry blood away from the heart, have palpable pulses, and tolerate high pressure

What is unique about capillary anatomy?

Microscopic vessels with a single epithelial layer where RBCs pass single file

What major exchanges occur at capillaries?

• Oxygen/carbon dioxide exchange

• Nutrient delivery

• Waste removal

What are defining features of veins?

• Thin walls

• Low pressure

• One-way valves

• Reliance on skeletal muscle pump

What are veins designed for?

Capacitance - holding large volumes of blood rather than generating pressure

How much blood volume is held in veins at rest?

About 65%

What mechanisms assist venous return?

• Venous valves

• Smooth muscle contraction

• Skeletal muscle pump

What happens to the cardiovascular system at rest?

Arterioles are constricted and many precapillary sphincters are closed, so perfusion is minimal

What happens to capillaries during exercise?

Arterioles dilate and precapillary sphincters relax, increasing recruitment

What is angiogenesis?

Formation of new capillaries as an adaptation to chronic exercise

Explain the skeletal muscle pump mechanism

Muscle contraction compresses veins and pushes blood forward;

relaxation allows refill while valves prevent backflow

Why is the muscle pump clinically important?

• Prevents blood pooling

• Reduces edema

• Enhances venous return

Where is vessel surface area highest?

In the capillaries

Why is blood velocity lowest in capillaries?

Their large combined cross-sectional area slows flow to optimize exchange

What results from venous valve dysfunction?

Increased hydrostatic pressure causing pooling and varicose veins

Why are varicose veins most common in the legs?

Gravity, dependent positioning, and superficial location with less muscle support

What are varicose veins?

Dilated superficial veins caused by valve incompetence, often uncomfortable

What is phlebitis?

Inflamed superficial veins, commonly associated with varicose veins

Why are superficial vein clots low risk?

Smaller diameter and indirect route to heart limit migration and embolization

What are typical signs of superficial thrombophlebitis?

Localized redness, warmth, and tenderness;

rarely life-threatening

Why are deep vein clots dangerous?

• Large diameter

• Faster flow

• Direct path to lungs allow embolization

Why is the muscle pump dangerous if a DVT is present?

Contractions can dislodge a deep clot and send it to pulmonary arteries

What can result from a DVT?

Pulmonary embolism and serious cardiopulmonary complications

What PT screening signs suggest DVT?

Unilateral leg swelling, warmth, redness, and calf pain

What fundamental concept explains cardiovascular flow?

Pressure gradients drive blood flow, and vessels are structured accordingly

Summarize exercise effects on the cardiovascular system.

Exercise improves tissue perfusion, oxygen delivery, venous return, and long-term capillary growth

What drives heart valve movement?

Valves open and close because of pressure differences, not because of muscle contraction

During late diastole, what happens at the end of the filling phase?

The atria contract to deliver the final volume of blood to the ventricles, called the “atrial kick.

Which valves are open during atrial contraction?

The tricuspid and mitral valves remain open while blood moves from atria to ventricles

Why is the atrial kick clinically important?

It boosts ventricular filling, especially in older adults or in hearts with decreased compliance

What occurs during isovolumetric contraction?

Ventricles begin contracting, pressure rises, and the mitral and tricuspid valves close while all valves are shut

What happens to chamber volume in isovolumetric contraction?

The volume stays constant because no blood is entering or leaving the ventricles

Which heart sound corresponds to isovolumetric contraction?

S1 (“lub”) occurs when the mitral and tricuspid valves close.

What marks the ventricular ejection phase?

Pulmonary and aortic valves open when ventricular pressure exceeds arterial pressures

Where does blood move during ventricular ejection?

From the right ventricle to pulmonary circulation and from the left ventricle into the aorta and systemic circulation

What defines isovolumetric relaxation?

Ventricles relax, pressure falls, and the pulmonary and aortic valves close with all valves again shut

What happens to volume during isovolumetric relaxation?

Ventricular volume remains constant because the valves prevent backflow from arteries

Which heart sound matches isovolumetric relaxation?

S2 (“dub”) occurs when the aortic and pulmonary valves close.

What allows the next cycle of filling to begin?

Ventricular pressure drops below atrial pressure, causing the mitral and tricuspid valves to reopen

What is systole?

The period of ventricular contraction and highest cardiac pressure that reflects the work of the heart

What is diastole?

The period of ventricular relaxation when the heart refills and blood pressure reflects peripheral resistance

Which valves are closed during diastole?

The pulmonary and aortic valves remain closed while ventricles fill

Why does the left side of the heart fail more often?

It must generate much higher pressures than the right side

Which valves most commonly develop pathology?

The mitral and aortic valves because they function under higher systemic pressures

What happens to blood pressure in elastic, healthy vessels?

Peripheral resistance is lower and overall blood pressure decreases with more efficient flow

What occurs with stiff or diseased arteries such as in atherosclerosis?

Peripheral resistance increases and both systolic and diastolic blood pressures rise

How does atherosclerosis increase systolic BP?

Plaque narrows the lumen and reduced elasticity makes ventricular ejection harder

How does atherosclerosis affect diastolic pressure?

Loss of arterial recoil prevents efficient pressure drop, so diastolic BP also increases

What is orthostatic hypotension?

A drop in blood pressure and symptoms like dizziness or fainting when standing

Why are veins important in orthostatic hypotension?

They hold most of the blood volume, which can pool in the legs if not assisted by muscle activity

What happens when a person stands still for too long?

Minimal muscle pump activity reduces venous return, lowering cardiac output and BP—risking syncope

What are risk factors for orthostatic hypotension?

Dehydration, blood loss, medications, prolonged standing, locked knees

How does chronic hypertension affect the heart?

The heart pumps against high resistance and develops left ventricular hypertrophy

Why is heart hypertrophy risky compared with skeletal muscle hypertrophy?

The heart never truly rests, so thickening eventually decreases efficiency

What long-term outcome can result from untreated hypertension?

Progression to decreased cardiac efficiency and ultimately heart failure

What medications are commonly used to manage hypertension?

Diuretics, beta blockers, and calcium channel blockers

How do these medications help the heart?

They reduce cardiac contractility and decrease systemic blood pressure

What lifestyle changes help manage hypertension?

Regular exercise, weight loss, stress management, reduced sodium and alcohol intake

What is the PT role in hypertension management?

Patient education and safe exercise prescription

How does resistance exercise affect BP?

Both systolic and diastolic pressures rise, especially with high intensity, large muscle groups, or Valsalva

How does steady-state aerobic exercise affect BP?

Systolic BP increases with workload, but diastolic BP stays relatively constant

Why does diastolic BP remain constant during aerobic exercise?

Vasodilation and capillary recruitment increase surface area and lower peripheral resistance

What is post-exercise hypotension?

A temporary drop in blood pressure below resting levels after moderate to intense endurance exercise

Why can post-exercise hypotension occur?

Sustained vasodilation plus decreased muscle pump activity lower peripheral resistance and cardiac output

Is post-exercise hypotension beneficial for some patients?

Yes—particularly individuals with moderate hypertension, as regular aerobic exercise improves long-term BP control

Why does upper-body exercise raise BP more than lower-body exercise?

Arms have less muscle mass and smaller total cross-sectional area, producing greater resistance

What PT precautions apply to upper-body exercise in cardiac patients?

Monitor BP closely, progress cautiously, avoid Valsalva, and favor rhythmic low-resistance movements

Which type of exercise reflects peripheral vascular resistance?

Diastole primarily reflects the resistance properties of the arteries

Compare embolization risk between superficial and deep veins

Superficial issues cause local inflammation, while deep vein problems create systemic cardiopulmonary risk

What is the overall PT “big picture” takeaway?

Understand valve response to pressure gradients and recognize how different activities influence blood pressure

What are the coronary arteries’ origins?

The right and left coronary arteries branch off the upper ascending aorta

When does the heart receive its own blood supply?

Primarily during diastole, not systole

Why does coronary perfusion occur mainly in diastole?

Ventricular relaxation allows aortic back pressure to push blood into coronary arteries

What happens to coronary flow when the aortic valve closes?

Back pressure in the aorta redirects blood into the coronary circulation

Key principle of coronary circulation

Coronary perfusion is pressure-driven during ventricular relaxation, not during contraction

Main arteries supplying the heart

Right Coronary Artery (RCA) and Left Coronary Artery (LCA)

What regions does the RCA supply?

Right atrium, right ventricle, and a major portion of the myocardium

What regions does the LCA supply?

Left atrium, left ventricle, and a small portion of the right ventricle