ch 12 a&p

Heart

The primary muscular pump for the human body that circulates blood through a closed system of blood vessels.

Pericardium

The double-walled sac that encloses the heart.

Fibrous Pericardium

The outer layer of the pericardium composed of dense connective tissue, anchoring the heart in place.

Serous Pericardium

The inner membrane of the pericardium composed of two layers: parietal and visceral.

Epicardium

The visceral layer of the serous pericardium, which is the outer protective layer of the heart.

Myocardium

The middle layer of the heart wall, made of cardiac muscle tissue, forming the bulk of the heart.

Endocardium

The inner lining of the heart that covers the heart valves and is made of epithelial and connective tissue.

Atria

The two upper chambers of the heart that receive incoming blood.

Ventricles

The two lower chambers of the heart responsible for pumping blood out of the heart.

Interatrial Septum

The wall that separates the two atria of the heart.

Interventricular Septum

The wall that separates the two ventricles of the heart.

Atrioventricular Valves (AV)

Valves located between the atria and ventricles that prevent backflow of blood into the atria.

Semilunar Valves (SL)

Valves located between the ventricles and major arteries that prevent backflow into the ventricles.

Tricuspid Valve

An atrioventricular valve with three flaps located between the right atrium and right ventricle.

Bicuspid Valve (Mitral Valve)

An atrioventricular valve with two flaps located between the left atrium and left ventricle.

Chordae Tendinae

Cord-like structures that anchor the flaps of the AV valves to the papillary muscles in the ventricles.

Papillary Muscles

Muscles located within the ventricles that contract to prevent backflow of blood through the AV valves.

Pulmonary Semilunar Valve

A semilunar valve that prevents backflow of blood into the right ventricle from the pulmonary artery.

Aortic Semilunar Valve

A semilunar valve that prevents backflow of blood into the left ventricle from the aorta.

Pericarditis

Inflammation of the pericardium, often caused by infection, leading to reduced serous fluid production.

Cardiac Muscle

Striated, involuntary muscle that makes up the heart, contracting via the sliding filament mechanism.

Autorhythmicity

The ability of cardiac muscle fibers to contract in a coordinated fashion without external stimulation.

Intercalated Discs

Connections between cardiac muscle fibers that provide support and allow electrical impulses to travel quickly.

Cardiac Conduction System

A system of specialized cardiac muscle cells that generate and transmit electrical impulses that coordinate heartbeats.

Sinoatrial Node (SA Node)

The natural pacemaker of the heart located in the right atrium, generating impulses that initiate heartbeat.

Atrioventricular Node (AV Node)

A node that receives impulses from the SA Node and briefly delays them before passing to the ventricles.

Bundle of His

The electrical pathway that connects the atria and ventricles, allowing impulses to travel to the ventricles.

Purkinje Fibers

Fibers that carry impulses through the ventricles, allowing for coordinated contraction.

Arrhythmias

Irregular heart rhythms that can include tachycardia (fast heart rate) and bradycardia (slow heart rate).

Fibrillation

Rapid and irregular heart contractions that disrupt normal blood flow, treated with electrical shock.

Heart Sounds

Sounds produced by the closing of heart valves; includes 'Lubb' and 'Dubb'.

Systole

The phase of the cardiac cycle where the heart muscle contracts and pumps blood.

Diastole

The phase of the cardiac cycle where the heart muscle relaxes and fills with blood.

Cardiac Cycle

The sequence of events that occur during one complete heartbeat.

Electrocardiogram (ECG/EKG)

A measurement of the electrical activity of the heart, commonly used to diagnose heart conditions.

Blood Flow

The volume of blood flowing through a vessel or organ in a given period of time.

Blood Pressure (BP)

The force exerted by circulating blood on the walls of blood vessels, typically measured in mm Hg.

Resistance

The opposition to blood flow, including the friction the blood encounters as it travels through the vessels.

Blood Viscosity

The thickness of blood, which can affect circulation and blood pressure.

Hypertension

Abnormally high blood pressure, defined as BP greater than 140/95.

Congestive Heart Failure

A condition in which the heart's pumping efficiency is inadequate to meet the body's needs.

Circulatory Shock

Condition resulting when cardiac output is insufficient to supply blood to tissues.

Catheterization

A medical procedure where a catheter is introduced into a blood vessel to diagnose heart conditions.

Echocardiography

An ultrasound technique used to visualize the heart and its structures.

Coronary Circulation

The flow of blood to and from the tissues of the heart muscle itself.

Hepatic Portal Circulation

The blood flow from the digestive organs to the liver for nutrient regulation and detoxification.

Arteries

Blood vessels that carry oxygenated blood away from the heart (with pulmonary artery being the exception).

Veins

Blood vessels that carry deoxygenated blood back to the heart (with pulmonary vein being the exception).

Capillaries

Microscopic blood vessels where the exchange of gases, nutrients, and waste occurs between blood and tissues.

Valves

Structures within veins that prevent the backflow of blood.

Varicose Veins

Veins that become enlarged and twisted due to incompetent valves, often leading to discomfort or swelling.

Phlebitis

An inflammation or injury to a vein, which may result in blood clots.

Cardiac Output (CO)

The amount of blood pumped out of each ventricle per minute.

Baroreceptors

Sensory receptors that detect changes in blood pressure and send signals to the cardiovascular center in the brain.

Vasoconstriction

The narrowing of blood vessels, which increases blood pressure.

Vasodilation

The widening of blood vessels, which decreases blood pressure.

Tachycardia

An abnormally fast heart rate, typically greater than 100 beats per minute.

Bradycardia

An abnormally slow heart rate, typically less than 60 beats per minute.

Lubb

The first heart sound caused by the closure of the atrioventricular valves during ventricular systole.

Dubb

The second heart sound that occurs when the semilunar valves close at the end of ventricular systole.

Mitral Valve Prolapse

A condition where the flaps of the mitral valve become incompetent, causing inefficiency in heart function.

Pulmonary Circulation

The flow of deoxygenated blood from the right side of the heart to the lungs for oxygenation.

Systemic Circulation

The flow of oxygenated blood from the left side of the heart to the rest of the body.

Coronary Arteries

Arteries that supply blood to the heart muscle itself, branching from the aorta.

Cardiac Veins

Veins that drain deoxygenated blood from the heart muscle back to the right atrium.

Incompetent Valve

A condition where the heart valve fails to close properly, leading to backflow.

Valvular Stenosis

The narrowing of a heart valve opening, forcing the heart to work harder.

Myocardial Infarction

A heart attack caused by the death of heart tissue due to interrupted blood supply.

Stenosis

A change in valve shape that can affect blood flow.

Cardiac Arrest

A sudden stop in effective blood circulation due to failure of the heart to contract effectively.

Angina Pectoris

Chest pain caused by inadequate blood supply to the heart muscle.

Ischemia

Insufficient blood flow to an organ or tissue.

Infarction

Tissue death due to a lack of blood supply.

Stenotic Valve

A valve that has become narrowed and restricts blood flow.

Pacemaker Cells

Specialized cells in the heart that generate electrical impulses, controlling heart rhythm.

Electrocardiogram (ECG/EKG) waves

P Wave represents atrial depolarization, QRS Complex represents ventricular depolarization, T Wave represents ventricular repolarization.