Overview of the Circulatory System and Its Functions

Heart

Muscle pump located behind the sternum.

Pulmonary Arteries

Carry deoxygenated blood to the lungs.

Pulmonary Veins

Transport oxygenated blood from lungs to heart.

Lungs

Facilitate gas exchange for blood.

Blood Vessels

Transport blood throughout the circulatory system.

Blood

Circulatory fluid carrying oxygen and nutrients.

Lymphatic System

Auxiliary system assisting in waste removal.

Heart Size

Approximately the size of a clenched fist.

Heart Location

Two-thirds on the left side of the chest.

Heart Rate

Normal range is 60-100 beats per minute.

Lub Sound

First heart sound from atrioventricular valve closure.

Dub Sound

Second heart sound from semilunar valve closure.

SA node (sinoatrial node)

node initiates heart muscle contractions.

AV node (atrioventricular node)

node relays impulses to ventricles.

First-Degree Heart Block

Momentary delay at the AV node.

Second-Degree Heart Block

Intermittent failure of impulses to ventricles.

Third-Degree Heart Block

Complete failure of impulse transmission, can be fatal.

PACs

Premature contractions from the atria.

PVCs

Premature contractions from the ventricles.

Arteries

Carry oxygenated blood away from the heart.

Veins

Return deoxygenated blood to the heart.

Capillaries

Site of gas and nutrient exchange.

Venules

Small vessels merging to form veins.

Circulation Types

Includes pulmonary, systemic, and portal circulation.

Systemic Circulation

Blood flow from left ventricle to body organs.

Aorta

Main artery distributing blood from the heart.

Common Iliac Arteries

Branches of aorta at fourth lumbar vertebra.

Femoral Artery

External iliac artery's continuation down the leg.

Tibial Branch

Continuation of femoral artery into the lower leg.

Arterioles

Small branches of arteries leading to capillaries.

Deoxygenated Blood

Blood that has released oxygen and gained carbon dioxide.

Inferior Vena Cava

Major vein returning blood from lower body.

Superior Vena Cava

Major vein returning blood from upper body.

Right Atrium

Heart chamber receiving blood from vena cavae.

Portal Circulation

Blood flow from digestive organs to liver.

Plasma

Liquid component of blood, mostly water.

Red Blood Cells (RBCs)

Erythrocytes carrying oxygen and carbon dioxide.

Hemoglobin

Protein in RBCs that binds oxygen.

White Blood Cells (WBCs)

Leukocytes defending against infections.

Granulocytes

WBCs with granules, including neutrophils, eosinophils, basophils.

Agranulocytes

WBCs without granules, including lymphocytes and monocytes.

Platelets

Thrombocytes aiding in blood clotting.

Blood Types

Classification based on antigens on RBCs.

Antigen

Protein on RBC surface determining blood type.

Substance that triggers antibody production in blood.

Antibody

Protein in plasma reacting to specific antigens.

Rh Factor

Protein affecting blood compatibility in transfusions.

Rhesus Factor

Antigen in red blood cells, affects transfusions.

Antibodies

Proteins produced against foreign antigens.

Cholesterol

Blood substance from fat metabolism, forms plaque.

Plaque

Accumulation of cholesterol in blood vessel linings.

Low-Density Lipoprotein (LDL)

Known as 'bad' cholesterol, increases heart disease risk.

High-Density Lipoprotein (HDL)

Known as 'good' cholesterol, protects against heart disease.

Triglycerides

Fats in food, high levels indicate disease risk.

Arteriography

X-ray of arteries post-contrast medium injection.

Cardiac Catheterization

Inserts catheter to visualize heart and arteries.

Dobutamine Stress Test

Cardiac stress test combined with echocardiogram.

Doppler Ultrasonography

Uses sound waves to evaluate blood flow.

Echocardiogram

Imaging test using sound waves to assess heart.

Electrocardiograph (EKG/ECG)

Records electrical activity of the heart.

Holter Monitor

24-hour ECG monitoring for irregular heart activity.

Heart Scan

CT scan diagnosing plaque and coronary occlusion.

MUGA Scan

Evaluates heart motion after isotope injection.

Myocardial Perfusion Imaging

Measures blood flow to heart muscle using radioactivity.

Venogram

X-ray of deep veins using contrast medium.

Deep Vein Thrombosis

Blood clot in deep veins, often in legs.

Aneurysm

Abnormal blood vessel bulge, risk of rupture. Ballooning of an artery wall.

Coronary Occlusion

Blockage in coronary arteries, restricts blood flow.

Anemia

Condition indicating lack of elements in blood.

Iron-deficiency anemia

Anemia caused by insufficient iron levels.

Aplastic anemia

Injury to bone marrow affecting blood cell formation.

Blood loss anemia

Low red blood cell count from prolonged blood loss.

Cerebral aneurysm

Aneurysm occurring in the brain.

Thoracic aneurysm

Aneurysm located in the chest.

Abdominal aneurysm

Aneurysm found in the abdomen.

Angina

Severe chest pain radiating to the left arm.

Arrhythmia

Abnormal heart rhythm changes.

Arteriosclerosis

Hardening of arteries and arterioles.

Atherosclerosis

Fatty material buildup in artery linings.

Cardiac Arrest

Sudden cessation of heart action.

Carditis

Inflammation of the heart from infections.

Cerebrovascular Accident (CVA)

Sudden blood flow impairment to the brain.

Congestive Heart Failure (CHF)

Cardiac dysfunction causing circulatory congestion.

Coronary Artery Disease

Disease affecting arteries supplying the heart.

Embolism

Circulation of foreign matter in bloodstream.

Heart Failure

Heart's inability to pump sufficient blood.

Heart Replacement

Replacing a diseased heart with a donor heart.

Hypertension

Consistently high blood pressure above 140/90.

Hypertrophic Cardiomyopathy

Thickening of heart ventricle walls.

Hypotension

Blood pressure below normal range.

Leukemia

Malignant disease of bone marrow or lymph tissue.

Murmur

Abnormal heart sounds from leaking valves.

Myocardial Infarction

Heart attack from artery blockage.

Phlebitis

Inflammation of a vein causing clot formation.

Sickle Cell Anemia

Congenital anemia with sickle-shaped red blood cells.

Stasis Ulcer

Ulcer from chronic venous insufficiency.

Thrombophlebitis

Vein inflammation with blood clot formation.

Varicosities

Dilated veins due to valve weakness.