The Cardiovascular System and Its Control

150 vocabulary flashcards covering essential concepts from the cardiovascular system and its control, based on lecture notes.

What are the major functions of the cardiovascular system?

Delivers oxygen and nutrients, removes carbon dioxide and waste, transports hormones, maintains temperature balance, regulates fluid balance, maintains acid-base balance, and supports immune function.

What are the three major elements of the cardiovascular system?

A pump (heart), channels or tubes (blood vessels), and a fluid medium (blood).

What is the primary function of the heart?

To generate pressure to drive blood through vessels.

What are the four chambers of the heart?

Right atrium, left atrium, right ventricle, left ventricle.

What type of blood does the right heart pump?

Deoxygenated blood from the body to the lungs.

What type of blood does the left heart pump?

Oxygenated blood from the lungs to the body.

What is the myocardium?

The cardiac muscle responsible for heart contraction.

What structural adaptation occurs in the left ventricle with exercise?

Hypertrophy of the left ventricle walls.

What type of muscle fiber is found in the myocardium?

It is similar to type I skeletal muscle fibers.

What are intercalated discs?

Connections between cardiac muscle fibers that include desmosomes and gap junctions.

How do cardiac muscle fibers differ from skeletal muscle fibers?

Cardiac fibers are smaller, branched, and have one nucleus, while skeletal fibers are large, unbranched, and multinucleated.

What is unique about the contraction of myocardial cells?

They have continuous, involuntary rhythmic contractions.

What are the components of the cardiac conduction system?

Sinoatrial (SA) node, Atrioventricular (AV) node, AV bundle (bundle of His), and Purkinje fibers.

What is the function of the SA node?

It initiates the electrical impulses that cause heart contractions.

What is a key characteristic of the AV node?

It delays and relays the signal to the ventricles.

What role do Purkinje fibers play in the heart?

They spread the electrical signal throughout the ventricles and stimulate contraction.

How does the parasympathetic nervous system influence heart rate?

It releases acetylcholine which decreases heart rate and the force of contraction.

What effect does the sympathetic nervous system have on heart rate?

It releases norepinephrine to increase heart rate and force of contraction.

What is the mean arterial pressure (MAP)?

Average arterial pressure in the circulatory system; calculated as DBP + 1/3(SBP-DBP).

What is stroke volume (SV)?

The volume of blood pumped in one heartbeat.

What is ejection fraction (EF)?

The percent of end-diastolic volume (EDV) pumped during each heartbeat.

What is cardiac output (Q)?

Total volume of blood pumped per minute; calculated as HR x SV.

What is the role of arterioles in the cardiovascular system?

Control blood flow and feed capillaries.

What is the process of hemodynamics?

The study of blood flow and the forces that influence it.

What factors influence blood viscosity?

The thickness of blood increases with the number of red blood cells.

What mechanisms assist venous return?

One-way venous valves, muscle pumps, and the respiratory pump.

What is the blood volume in a typical adult male and female?

5 to 6 L in males; 4 to 5 L in females.

What are formed elements in blood?

Components of blood including red blood cells, white blood cells, and platelets.

How does training affect plasma volume?

Plasma volume can increase by 10% with training.

What is hematocrit?

The percentage of blood volume composed of formed elements.

What is the lifespan of a red blood cell?

Approximately 4 months.

What is the primary component of hemoglobin?

A protein that carries oxygen in red blood cells.

How do changes in heart rate affect an ECG?

It reflects the electrical activity and rhythm of the heart.

What does the P wave in an ECG represent?

Atrial depolarization.

What does the QRS complex represent in an ECG?

Ventricular depolarization.

What does the T wave indicate in an ECG?

Ventricular repolarization.

What is the intrinsic heart rate (HR)?

Approximately 100 beats per minute without neural or hormonal influence.

What is an important role of baroreceptors?

They detect changes in blood pressure and relay signals to the brain.

What is the effect of vagal tone on heart rate?

It decreases heart rate below intrinsic levels.

What is atherosclerosis?

A condition characterized by the buildup of plaque in the coronary arteries.

How do metabolic mechanisms control blood flow?

By responding to increased oxygen demand and local metabolic by-products.

What is the function of the venous reservoir?

To store and release blood back to the heart as needed.

What does the respiratory pump do?

It assists venous return during inhalation by changing pressure in the chest cavity.

What are the effects of dehydration on blood volume?

It can lead to a decrease in blood volume by up to 10%.

What are the primary functions of blood?

Transportation, temperature regulation, and acid-base balance.

What is the relationship between cardiac output and exercise intensity?

Cardiac output increases significantly during heavy exercise.

What happens to blood flow during heavy exercise?

Increased blood flow to exercising muscles and decreased flow to less active organs.

What is the difference between ventricular systole and diastole?

Systole is the contraction phase, while diastole is the relaxation phase.

What physiological changes occur during ventricular diastole?

The ventricles relax and fill with blood as the atrioventricular valves open.

What structural changes occur in the heart with long-term endurance training?

Increased size and efficiency of the heart, known as cardiac hypertrophy.

How does blood pressure relate to cardiovascular health?

High blood pressure can lead to heart disease and other health issues.

What cardiovascular adaptations occur with regular exercise?

Increased cardiac output, stroke volume, and improved blood flow regulation.

What physiological mechanisms control arteriolar diameter?

Intrinsic factors: metabolic, myogenic, and vasodilation/vasoconstriction by the nervous system.

How is the cardiovascular system regulated during rest versus exercise?

Different regulatory mechanisms ensure optimal blood flow based on activity level.

What role do gap junctions play in the heart?

They enable rapid conduction of electrical signals between cardiac muscle cells.

What is the significance of the coronary arteries?

They supply blood to the heart muscle itself.

What is the average resting heart rate for adults?

Between 60 to 80 beats per minute.

What is the primary hormone released by the sympathetic nervous system during stress?

Norepinephrine.

What is the primary purpose of the cardiac cycle?

To encompass all mechanical and electrical events during one heartbeat.

What is the impact of a cardiac output of 25 L/min?

Indicates elevated demand for cardiovascular function, such as during maximal exercise.

What is the result of increased blood viscosity on circulation?

Potentially impaired blood flow and reduced oxygen transport.

What happens to the heart during endurance training?

Increased stroke volume and slower resting heart rate due to improved efficiency.

What are the roles of endothelial cells in arterioles?

They release substances that help regulate vascular tone and blood flow.

How does the heart's electrical conduction system maintain rhythm?

Through intrinsic pacing and coordination of contraction.

What clinical index reflects heart contractility?

Ejection fraction.

What is the primary means by which blood is redistributed during exercise?

By vasodilation of arterioles supplying active muscles.

What is coronary artery disease?

A condition caused by reduced blood flow to the heart muscle due to plaque buildup.

What is the relationship between heart rate, stroke volume, and cardiac output?

Cardiac output equals heart rate times stroke volume.

How is blood pressure primarily regulated?

Through autonomic nervous system reflexes and baroreceptor feedback.

What is the main consequence of excessive sympathetic stimulation on blood vessels?

Increased vasoconstriction leading to elevated blood pressure.

What are two forms of heart adaption to regular exercise?

Cardiac hypertrophy and improved vascular response.

What is the main protective mechanism in the vascular system?

Baroreceptors that adjust blood pressure as needed.

How does the cardiovascular system adapt to higher altitude conditions?

By increasing red blood cell production and improving oxygen delivery.

What are the signs of overtraining in regard to the cardiovascular system?

Altered resting heart rate and recovery patterns.

What is an ECG used for?

To monitor and diagnose heart rhythms and electrical activity.

What are the effects of regular endurance training on heart structure?

Enlargement of the heart chambers and increased myocardial thickness.

What is the significance of atrial contraction in the cardiac cycle?

To maximize ventricular filling before contraction.

What is the relationship between venous return and stroke volume?

Higher venous return increases stroke volume due to the Frank-Starling mechanism.

How does exercise impact blood pressure?

Moderate exercise typically lowers blood pressure in the long term.

What is the average blood pressure reading for a healthy adult?

Approximately 120/80 mmHg.

What is an abnormal response to exercise in terms of heart rate?

Failure to increase heart rate adequately during physical activity.

What is the primary effect of dehydration on cardiovascular function during exercise?

Increased heart rate and decreased stroke volume.

What does systolic pressure represent?

The pressure in arteries during heart contraction.

What does diastolic pressure indicate?

The pressure in arteries during heart relaxation.

How do exercise and hydration status interact to affect heart performance?

Proper hydration optimizes heart function and performance during exercise.

What adaptation occurs in blood vessels with prolonged endurance training?

Improved endothelial function and increased capillary density.

What is the impact of acute stress on heart rate?

It typically causes an increase in heart rate and blood pressure.

What role does the autonomic nervous system play during exercise?

It adjusts heart rate and contraction strength according to demand.

How does cardiovascular fitness influence aerobic capacity?

Higher cardiovascular fitness results in enhanced maximal oxygen uptake.

What modality can help track cardiovascular adjustments over time?

Fitness testing with ECG monitoring.

How does temperature affect cardiovascular function?

Heat increases heart rate and alters blood flow distribution for cooling.

What is the significance of aerobic exercise for heart health?

It strengthens the heart and improves blood circulation.

What is the role of nitric oxide in the cardiovascular system?

It acts as a vasodilator, improving blood flow and reducing blood pressure.

What is venoconstriction?

The constriction of veins to facilitate increased venous return.

How do high altitude conditions affect heart rate?

They typically increase heart rate due to lower oxygen availability.

How does chronic exercise impact heart disease risk?

It significantly lowers the risk of developing cardiovascular disease.

What is a key benefit of regular physical activity on heart muscle?

It enhances the strength of cardiac contractions.

What does a high ejection fraction indicate?

Good cardiac function and efficiency.

How is blood flow prioritized during exercise?

Blood is diverted to working muscles while restricting flow to non-essential regions.