CHAPTER 6 BIO - HEART DISEASE

Myocardium

The muscular layer of the heart that contracts to pump blood.

Endocardium

The smooth lining of the heart chambers and valves.

Pericardium

The double-layered sac surrounding the heart.

Atrium

An upper heart chamber that receives blood.

Ventricle

A lower heart chamber that ejects blood.

Interatrial septum

The partition separating the right and left upper heart chambers.

Interventricular septum

The partition separating the right and left lower heart chambers.

Mitral valve

The two-cusped valve between the left atrium and left ventricle.

Tricuspid valve

The three-cusped valve between the right atrium and right ventricle.

Pulmonary semilunar valve

The valve controlling flow from the right ventricle into the pulmonary artery.

Aortic semilunar valve

The valve controlling flow from the left ventricle into the aorta.

Diastole

The relaxation and filling phase of a heart chamber.

Systole

The contraction and ejection phase of a heart chamber.

Cardiac cycle

One coordinated sequence of heart-chamber contraction and relaxation.

Systolic blood pressure

The upper arterial-pressure number, associated with ventricular contraction.

Diastolic blood pressure

The lower arterial-pressure number, associated with ventricular relaxation.

Coronary arteries

Vessels arising from the aorta that supply blood to the heart muscle.

Sinoatrial node (SA node)

The normal pacemaker that initiates heartbeats in the right atrium.

Atrioventricular node (AV node)

The conduction region that delays and relays atrial impulses toward the ventricles.

Bundle of His

The conduction pathway carrying impulses from the AV node toward the ventricular bundle branches.

Bundle branches

Right and left conduction pathways carrying impulses toward the ventricular walls.

Purkinje fibers

Rapid-conducting fibers that distribute impulses through the ventricular myocardium.

Vagus nerve

A parasympathetic nerve that slows the heart rate.

Systemic circulation

Blood flow between the left heart, body tissues, and right heart.

Pulmonary circulation

Blood flow between the right heart, lungs, and left heart.

Aorta

The largest artery, carrying blood from the left ventricle to the body.

Superior vena cava

The large vein returning upper-body blood to the right atrium.

Inferior vena cava

The large vein returning lower-body blood to the right atrium.

Artery

A vessel carrying blood away from the heart.

Arteriole

A small artery that regulates resistance and blood delivery to tissues.

Capillary

A microscopic, thin-walled vessel where gases, nutrients, and wastes are exchanged.

Venule

A small vessel collecting blood from capillaries and delivering it to larger veins.

Vein

A vessel carrying blood toward the heart.

Endothelium

The cell layer lining the inside of blood vessels.

Lumen

The interior space through which blood flows in a vessel.

Auscultation

Listening to internal body sounds with a stethoscope.

Electrocardiogram (ECG)

A recording of the heart's electrical activity.

Echocardiography

Ultrasound imaging of heart structures and their movement.

Doppler echocardiography

Ultrasound assessment of blood-flow direction and velocity within the heart and major vessels.

Exercise tolerance test

Monitoring of ECG and blood pressure during exertion to detect problems that may be absent at rest.

Cardiac catheterization

Insertion of a catheter through vessels into the heart to measure pressures, sample blood, or perform procedures.

Angiocardiography

Contrast x-ray imaging of cardiovascular structures.

Coronary arteriography

Contrast imaging of the arteries supplying the heart to detect narrowing or blockage.

Lipoprotein

A particle that transports cholesterol and other fats through blood.

Low-density lipoprotein (LDL)

The major cholesterol carrier to tissues; elevated levels promote arterial plaque.

High-density lipoprotein (HDL)

A cholesterol carrier involved in returning excess cholesterol toward the liver.

Triglyceride

A major form of fat storage and transport whose elevated blood level can increase cardiovascular risk.

Hyperlipidemia

Abnormally elevated blood lipids.

Hypercholesterolemia

Abnormally elevated blood cholesterol.

Arteriosclerosis

Thickening and hardening of arterial walls with loss of elasticity.

Atherosclerosis

Accumulation of lipid-rich plaques in arterial walls, causing narrowing and increased clot risk.

Fatty streak

An early, flat lipid deposit in an arterial wall.

Fibrous atheromatous plaque

An arterial-wall lesion with a lipid core and fibrous covering.

Thrombosis

Formation of a blood clot within a vessel.

Thrombus

A blood clot at its site of formation within a vessel.

Embolus (plural: emboli)

Material traveling through blood that can lodge in and obstruct a distant vessel.

Embolism

Obstruction of a blood vessel by material that traveled from another location.

Ischemia

Inadequate blood supply to tissue.

Infarction

Tissue death caused by prolonged or severe loss of blood supply.

Necrosis

Death of cells or tissue.

Carotid arteries

Major vessels supplying the head and brain.

Peripheral arterial disease (PAD)

Reduced blood flow through arteries outside the heart, commonly affecting the legs because of atherosclerosis.

Intermittent claudication

Leg-muscle pain during walking or exertion that improves with rest.

Raynaud disease

Episodes of small-artery spasm causing cold, numb, and color-changing fingers or toes.

Vasospasm

Sudden contraction of vessel smooth muscle that narrows its opening.

Aortic aneurysm

Abnormal dilation of the body's main systemic artery due to wall weakness.

Fusiform aneurysm

A symmetrical, spindle-shaped widening involving the vessel's circumference.

Saccular aneurysm

A pouchlike bulge arising from one side of a vessel wall.

Abdominal aortic aneurysm

Dilation of the main systemic artery in the abdomen, often below the kidneys.

Thoracic aortic aneurysm

Dilation of the main systemic artery within the chest.

Cerebral aneurysm

A localized bulge in the wall of an artery supplying the brain.

Hypertension

Sustained elevation of arterial blood pressure.

Prehypertension (textbook category)

An older category: systolic pressure 120–139 or diastolic pressure 80–89 mm Hg.

Stage 1 hypertension (textbook category)

An older category: systolic pressure 140–159 or diastolic pressure 90–99 mm Hg.

Stage 2 hypertension (textbook category)

An older category: systolic pressure at least 160 or diastolic pressure at least 100 mm Hg.

Essential hypertension

Persistently elevated blood pressure without a single identified underlying disease; also called primary hypertension.

Secondary hypertension

Persistently elevated blood pressure resulting from an identifiable condition, such as kidney disease.

Varicose veins

Dilated, twisted superficial vessels associated with venous pooling and ineffective valves, usually in the legs.

Spider veins

Small red or blue networks of visible superficial blood vessels.

Surgical vein stripping

Removal of a diseased vein segment, with remaining ends tied off.

Compression sclerotherapy

Injection of an irritating solution to close selected diseased veins, followed by external pressure.

Chronic venous insufficiency (CVI)

Impaired venous return from the legs, causing pooling, swelling, skin changes, and sometimes ulcers.

Venous thrombosis

Formation of a blood clot within a vein.

Deep vein thrombosis (DVT)

Formation of a clot in deeper veins, commonly in the legs.

Coronary heart disease (CHD)

Reduced blood supply to the myocardium, usually from atherosclerotic narrowing of its arteries.

Angina pectoris

Chest discomfort caused by inadequate myocardial oxygen supply without necessarily causing tissue death.

Palpitations

Awareness of a racing, pounding, fluttering, or irregular heartbeat.

Myocardial infarction (MI)

Death of heart-muscle tissue caused by prolonged inadequate blood supply.

Cardiac arrest

Loss of effective heart pumping and circulation.

Angioplasty

Balloon-catheter expansion of a narrowed artery.

Stent

A small scaffold placed inside a vessel to help keep it open.

Restenosis

Renarrowing of an artery after it has been opened by a procedure.

Coronary artery bypass grafting

Creation of an alternate blood-flow route around a blocked artery supplying the heart.

Myocarditis

Inflammation of the heart's muscular layer.

Cardiomyopathy

Disease of the heart muscle that impairs its structure or function.

Dilated cardiomyopathy

Enlargement of ventricular chambers with weakened contraction.

Hypertrophic cardiomyopathy

Abnormal thickening of heart muscle, often involving the ventricles.

Restrictive cardiomyopathy

Stiff ventricular walls that impair relaxation and filling.

Infective endocarditis

Infection of the heart's inner lining or valves, commonly caused by bacteria.

Vegetation

A clump attached to the endocardium or valves, often containing fibrin, platelets, and microorganisms in infective disease.