Human Circulatory System Quiz

Introduction to Cardiovascular System

• The cardiovascular system consists of the heart and blood vessels.
• The heart is a muscular organ that pumps blood throughout the circulatory system.
• Blood vessels form a closed system of dynamic tubes that carry blood away from the heart, transport it to the tissues of the body, and then return it to the heart.

Structure of the Heart

• The heart has four hollow chambers: two atria (right and left) and two ventricles (right and left).
• The atria are primarily receiving chambers that assist with filling the ventricles.
• The ventricles are the thick-walled discharging chambers, or actual pumps of the heart.

Blood Vessels

• Arteries carry blood from the heart to the tissues.
• Arterioles are small arteries that connect to capillaries.
• Capillaries are the site of substance exchange between the blood and body tissues.
• Venules connect capillaries to larger veins.
• Veins convey blood from the tissues back to the heart.

Right Side of the Heart

• The right side of the heart has two chambers: the upper right atrium and the lower right ventricle.
• The right atrium receives venous (deoxygenated) blood from the head, neck, and upper limbs through the superior vena cava, and from lower parts of the body through the inferior vena cava.
• The right ventricle pumps blood to the lungs through the pulmonary artery.

Left Side of the Heart

• The left side of the heart has two chambers: the upper left atrium and the lower left ventricle.
• The left atrium receives oxygenated blood from the lungs through pulmonary veins.
• The left ventricle pumps blood to different parts of the body through the systemic aorta.

Heart Valves

• Four valves enforce one-way traffic in the heart: two atrioventricular (AV) valves (tricuspid and mitral) and two semilunar (SL) valves (pulmonary and aortic).
• The valves open and close in response to differences in blood pressure on their two sides.

Layers of the Heart Wall

• The heart wall has three layers: outer pericardium, middle myocardium, and inner endocardium.
• The myocardium is formed by two types of cardiac muscle fibers: muscle fibers (contractile unit) and modified muscle fibers (pacemaker and conductive system).

Properties of Cardiac Muscle

• Excitability: the ability of cardiac muscle to respond to a stimulus with an action potential.
• Rhythmicity: the ability of cardiac muscle to produce its own impulses regularly (autorhythmicity).
• Conductivity: the ability of cardiac muscle to transmit impulses through the specialized conductive system.
• Contractility: the ability of cardiac muscle to contract (systole) and relax (diastole) after receiving a stimulus.

Introduction to Cardiovascular System

• The cardiovascular system consists of the heart and blood vessels.
• The heart is a muscular organ that pumps blood throughout the circulatory system.
• Blood vessels form a closed system of dynamic tubes that carry blood away from the heart, transport it to the tissues of the body, and then return it to the heart.

Structure of the Heart

• The heart has four hollow chambers: two atria (right and left) and two ventricles (right and left).
• The atria are primarily receiving chambers that assist with filling the ventricles.
• The ventricles are the thick-walled discharging chambers, or actual pumps of the heart.

Blood Vessels

• Arteries carry blood from the heart to the tissues.
• Arterioles are small arteries that connect to capillaries.
• Capillaries are the site of substance exchange between the blood and body tissues.
• Venules connect capillaries to larger veins.
• Veins convey blood from the tissues back to the heart.

Right Side of the Heart

• The right side of the heart has two chambers: the upper right atrium and the lower right ventricle.
• The right atrium receives venous (deoxygenated) blood from the head, neck, and upper limbs through the superior vena cava, and from lower parts of the body through the inferior vena cava.
• The right ventricle pumps blood to the lungs through the pulmonary artery.

Left Side of the Heart

• The left side of the heart has two chambers: the upper left atrium and the lower left ventricle.
• The left atrium receives oxygenated blood from the lungs through pulmonary veins.
• The left ventricle pumps blood to different parts of the body through the systemic aorta.

Heart Valves

• Four valves enforce one-way traffic in the heart: two atrioventricular (AV) valves (tricuspid and mitral) and two semilunar (SL) valves (pulmonary and aortic).
• The valves open and close in response to differences in blood pressure on their two sides.

Layers of the Heart Wall

• The heart wall has three layers: outer pericardium, middle myocardium, and inner endocardium.
• The myocardium is formed by two types of cardiac muscle fibers: muscle fibers (contractile unit) and modified muscle fibers (pacemaker and conductive system).

Properties of Cardiac Muscle

• Excitability: the ability of cardiac muscle to respond to a stimulus with an action potential.
• Rhythmicity: the ability of cardiac muscle to produce its own impulses regularly (autorhythmicity).
• Conductivity: the ability of cardiac muscle to transmit impulses through the specialized conductive system.
• Contractility: the ability of cardiac muscle to contract (systole) and relax (diastole) after receiving a stimulus.