Cardiovascular System: Anatomy, Circulation, and Function

Comprehensive practice flashcards covering cardiovascular anatomy, blood circulation, vessels, blood composition, the cardiac cycle, and hemodynamics during rest and exercise.

What are the three primary functions of the cardiovascular system regarding blood transport?

The transport of $O_2$ to tissues and removal of waste, the transport of nutrients to tissues, and the regulation of body temperature.

What is the wall called that divides the right and left halves of the heart?

The septum.

What is the average resting heart rate and the average volume expelled per beat by the heart?

The heart averages $70\text{ beats per minute}$ and expels $70 - 100\,\text{ml}$ per beat.

How is pulmonary circulation distinguished from systemic circulation?

Pulmonary circulation is a closed loop of vessels carrying blood between the heart and lungs, whereas systemic circulation is a circuit of vessels carrying blood between the heart and organ systems.

What is the protective sac surrounding the heart, and what fluid does it contain?

The pericardium, which contains pericardial fluid.

Where are the four one-way valves of the heart located?

The right atrioventricular (tricuspid) and left atrioventricular (bicuspid/mitral) valves are between the atria and ventricles; the aortic valve is between the left ventricle and aorta; and the pulmonary valve is between the right ventricle and pulmonary artery.

What type of blood does the right side of the heart receive, and where does it pump this blood?

The right side of the heart receives deoxygenated blood from the body and sends it to the lungs.

What type of blood does the left side of the heart receive, and where does it pump this blood?

The left side of the heart receives oxygenated blood from the lungs and sends it to the body.

Which blood vessels represent the unique exceptions to the typical oxygenation rules for arteries and veins?

The pulmonary artery is the only artery that carries deoxygenated blood, and the pulmonary vein is the only vein that carries oxygenated blood.

What is the sequential pathway of blood flow through the heart chambers and major vessels?

$\text{Body} \rightarrow \text{Vena Cava} \rightarrow \text{Right Atrium} \rightarrow \text{Right Ventricle} \rightarrow \text{Pulmonary Artery} \rightarrow \text{Lungs} \rightarrow \text{Pulmonary Vein} \rightarrow \text{Left Atrium} \rightarrow \text{Left Ventricle} \rightarrow \text{Aorta} \rightarrow \text{Body}$.

What are the structural characteristics and primary functions of arteries?

Arteries carry blood away from the heart, provide the pressure force for blood when the heart relaxes, have elastic properties within their thick, strong walls (with a smooth muscular lining), and have a pulse.

What are arterioles?

Arterioles are the numerous branches formed when a small artery reaches the organ it is supplying.

What is the primary physiological function of capillaries?

Capillaries are the site where all gaseous exchanges occur in tissue cells, permitting the diffusion of oxygen and nutrients into tissues and waste products (such as carbon dioxide) into the blood.

What structural features distinguish veins from arteries, and how is venous return assisted?

Veins have thinner walls, are much less elastic, and contain one-way valves to prevent backflow; during exercise, skeletal muscle contraction assists in returning blood to the heart under low pressure.

What are the proportions of the major components of whole blood?

Plasma makes up $55\%$, red blood cells make up $45\%$, and white blood cells and platelets make up $< 1\%$.

What are the characteristics and composition of blood plasma?

Plasma is the liquid component of blood, consisting of a yellowish, watery fluid made up of $90\%$ water, which contains nutrients, electrolytes, proteins, wastes, and hormones.

What is the lifespan and site of manufacture of red blood cells?

Red blood cells are manufactured in the red bone marrow and last an average of $120\text{ days}$.

How does hemoglobin transport oxygen within red blood cells?

Hemoglobin contains iron ($\text{Fe}$) and protein; oxygen binds specifically to the heme group on the hemoglobin molecule.

How is anemia defined in the lecture notes?

A reduction below normal in the $O_2$ carrying capacity of the blood (low hematocrit), which is categorized into 6 different types.

What are the five distinct types of white blood cells?

Neutrophil, Eosinophil, Basophil, Monocyte, and Lymphocyte.

What is the primary role of platelets in the blood?

Platelets are small cell fragments that arrest bleeding from broken vessels (stop hemorrhage) and assist in tissue repair via blood constriction, platelet plugs, and blood clotting.

What occurs during the diastole and systole phases of the cardiac cycle?

During diastole, the atria and ventricles relax and fill; during systole, the atria and ventricles contract and empty.

What serves as the normal pacemaker of the heart, and at what intrinsic rate does it fire?

The sinoatrial (SA) node, which sets a normal pace of $70 - 80\text{ beats per minute}$.

What is the sequential pathway of electrical conduction through the heart?

$\text{SA node} \rightarrow \text{Internodal pathways} \rightarrow \text{AV node} \rightarrow \text{Bundle of His} \rightarrow \text{Bundle branches} \rightarrow \text{Purkinje fibers}$.

What is the mathematical formula for cardiac output ($Q$)?

$Q = \text{Stroke volume} \times \text{heart rate}$.

What are the average values for cardiac output ($Q$) at rest versus during exercise?

Cardiac output averages $5\,\text{L/min}$ at rest ($HR = 72\,\text{bpm}$, $SV = 70\,\text{ml}$) and $27\,\text{L/min}$ during exercise ($HR = 180\,\text{bpm}$, $SV = 150\,\text{ml}$).

What is stroke volume and its typical resting range?

Stroke volume is the amount of blood pumped into the body with each heartbeat, averaging $60 - 100\,\text{ml/beat}$ at rest.

What formula is used to predict maximum heart rate?

$\text{Predicted maximum HR} = 220 - \text{age}$.

What three variables regulate arterial blood pressure, and what is considered an average reading?

Cardiac output, total peripheral resistance, and blood volume regulate arterial blood pressure; an average reading is $120/80\,\text{mm Hg}$ (systolic over diastolic pressure).