The Cardiovascular System

Medical Terminology Chapter 5

Word Parts

cardi/o = heartvascul/o = blood vessels -ar = pertaining to (same as –al,

-ic, -ac)cardiovascular = term for

pertaining to the heart and blood vessels

Word Roots: thromb/o = blood clot arteri/o = artery phleb/o = vein ven/o = vein ventricul/o = ventricle atri/o = atria, atrium Endo- = within ather/o = plaque; fatty substance angi/o = vessel

heart, blood vessels, blood = major structures of the cardiovascular system.

This consists of arteries, veins, venules, arterioles, capillaries.

Structure of the Heart

peri/cardi/um – the double-walled sac around the heart.

pericardial fluid – the fluid between the layers that prevents friction when the heart beats.

The walls of the heart are made up of three layers:

epicardium – outside or external layer of the heart (epi = upon).

myocardium – the middle and thickest of the three layers; consists of the cardiac muscle.

endocardium – the inner lining of the heart; comes in contact w/blood

coronary – another word pertaining to the heart.

Examples of using:coronary arteries, coronary

bypass, having a “coronary”

The Heart Chambers

atria, atrium – the two upper chambers of the heart, aka

“receiving” chambers – all blood vessels coming into the heart enter here. A right and a left atrium.

ventricles – the two lower chambers; all vessels leaving the heart emerge from these chambers.

Heart Valves

tricuspid valve – controls the opening between the right atrium and the right ventricle. Tricuspid means ‘having three points’.

pulmonary valve – between the right ventricle and the pulmonary artery. Sometimes called the “semilunar valve” – like a half moon.

mitral valve – also known as the ‘bicuspid’ valve; located between the left atrium and the left ventricle. Bicuspid means ‘having two points’.

aortic valve – between the left ventricle and the aorta.

Blood Supply

The myocardium is specialized muscle that beats constantly and must have a continuous supply of oxygen and nutrients and prompt removal of waste.

coronary arteries and veins – supply the blood needs of the myocardium. If this blood supply is disrupted, the myocardium in the affected area dies. This is known as “myocardial infarction” or MI.

Two circulation systems:systemic circulation – blood flow

to all parts of the body except the lungs.

pulmonary circulation – blood flow between the heart and lungs. (Pulmonary = lungs).

arteries, capillaries, veins – three major types of blood vessels in the body.

lumen – the opening within these vessels through which the blood flows.

arteries – large blood vessels that carry blood away from the heart to all regions of the body. The walls of the arteries are composed of three layers; this makes them both muscular and elastic, so they can expand and contract with the pumping heart beat.

aorta – the largest of all arteries.arterioles – smaller, thinner

arteries; carry blood to the capillaries.

capillaries – connect the arterial and venous circulatory systems. Only one epithelial cell in thickness; the smallest vessels in the body.

venules – small veins that form to form larger veins

veins – large vessels that carry blood from all parts of the body back to or toward the heart.

Thromboses and Embolisms

thrombosis – abnormal condition of having a blood clot in a vessel.

thrombus – the blood clot attached to the interior wall of a vein or artery.

thrombotic occlusion – when the thrombus blocks the lumen of an artery or vein.

embolus – a foreign object, such as a blood clot, air, gas, or tissue that is circulating (moving) in the bloodstream.

embolism – the blockage of a vessel by an embolus.

What is an aneurysm?

An aneurysm is a localized weak spot or balloon-like enlargement of the wall of an artery.

The Heartbeat

To pump blood effectively throughout the body, the contraction and relaxation (beating) of the heart must occur in exactly the correct sequence.

The rate and regularity is determined by electrical impulses from nerves that stimulate the myocardium.

These electrical impulses are controlled by the:

sinoatrial (S-A) nodeatrioventricular (A-V) nodeBundle of His

S-A Node

Located in the posterior wall of the right atrium near the entrance of the superior vena cava.

Because it establishes the basic rhythm, it is called the natural pacemaker of the heart.

Electrical impulses from the S-A node start each wave of muscle contraction in the heart.

The impulse in the right atrium spreads over the muscles of both atria, causing them to contract simultaneously.

This contraction forces blood into the ventricles.

A-V Node

S-A node impulses also travel to the A-V node.

Located near the interatrial septum.

It transmits the impulses on to the Bundle of His.

Bundle of His

Named for Wilhelm His, 19th century physician.

Located in interventricular septum

Branches of the bundle of His carry impulses to the right and left ventricles and the Purkinje fibers.

Purkinje fibers

Stimulation of the Purkinje fibers cause the ventricles to contract simultaneously, forcing blood into the aorta and pulmonary arteries.

Electrical Waves

On an electrocardiogram (ECG / EKG)

P wave – due to the contraction of the atria

QRS complex – shows the contraction of the ventricles, as the atria relax.

T wave – relaxation of ventricles

Heart Sounds

Two distinct sounds are heard:“lubb dupp” lubb = the tricuspid and mitral

valves closingdupp = shorter and higher

pitched. Caused by closing of the aortic and pulmonary valves

Arrhythmias (or dysrhythmias)

An irregularity or the loss of a normal rhythm of the heart beat.

Bradycardia = slow heartbeat; less than 60 beats per minute (bpm)

Tachycardia = fast heartbeat; greater than 100 bpm.

Paroxysmal tachycardia - sudden onset of tachycardia.

Flutter = atrial contractions are rapid but regular. On an EKG, it looks like a sawtooth pattern.

Palpitation = a pounding or racing heart with or without an irregular rhythm.

Fibrillation – a rapid, random and ineffective contractions of the heart.

Is like a “quivering” movementAtrial fibrillation – atria beat

faster than ventricles, but can cause a very rapid ventricular heartbeat.

Ventricular fibrillation – life threatening. Fatal unless reversed by electrical “defibrillation”.

Pulse and Blood Pressure

Pulse = rhythmic expansion and contraction of an artery produced by the blood moving through the artery.

Blood pressure = the measurement of pressure exerted against the walls of the vessels.

Systolic pressure = occurs when the ventricles contract; is the highest pressure against the walls of the blood vessels.

Diastolic pressure = occurs when the ventricles relax. Is the lowest pressure against the vessel walls.

Blood pressure is recorded as systolic over diastolic; is measured in mm of mercury (Hg).

Word Practice

card/itis inflammation of the heartendo/card/itis inflammation of the inner layer

of the heartmyo/card/itis inflammation of the myocardium

peri/card/itis inflammation of the pericardium

(surrounding the heart)mitral stenosisabnormal narrowing of mitral

valveNote: when a valve does not

function properly, it may allow blood to flow back into the heart chamber; the sound of this is called a heart murmur.

arter/itis inflammation of an arterypoly/arter/itis inflammation of several arteriesarterio/sclerosishardening of the arteries

Pathology of the CV System

Ischemia = deficiency in blood supply to an area

ischemic heart disease – inadequate blood supply to the heart, causing a group of cardiac problems

Angina pectoris – sometimes just called “angina”. Severe episodes of spasmodic choking or suffocating chest pain. Usually due to interference with the supply of oxygen to the myocardium.

myocardial infarction – also known as a heart attack or “MI”. Is the occlusion (closing off) of a coronary artery resulting in an infarct (tissue necrosis, tissue death) of the affected myocardium. This can impair the heart’s ability to pump blood throughout the body.

coronary artery disease (CAD) – atherosclerosis of the coronary arteries that may cause angina, myocardial infarction, and sudden death.

congestive heart failure (CHF) – heart is unable to pump enough blood to meet the body’s needs for oxygen. Fluid pooling in legs, ankles, lungs. Kidneys also retain fluid.

hypertension – high blood pressure.

Can be classified as primary or essential, secondary (caused by a kidney disorder or tumor on the kidney), and malignant (sudden onset, life-threatening).

Cholesterol Info

cholesterol – consists of lipids (fatty substances) that travel in the blood in packages called “lipoproteins”. It becomes pathologic when present in excessive amounts.

Low-density lipoprotein (LDL) – “bad” cholesterol. Contributes to plaque build up in arteries.

high-density lipoprotein (HDL) – “good” cholesterol. It carries unneeded cholesterol back to the liver for processing and does not contribute to plaque buildup. It actually “protects” our heart.

triglycerides – combinations of fatty acids that are also found normally in the blood in limited quantities.

Hyperlipidemia – a general term for high levels of cholesterol, triglycerides and lipoproteins.

The Blood

Composed of 55% liquid plasma; 45% “formed elements”.

Formed elements = red blood cells (RBCs), white blood cells (WBCs), and platelets.

Plasma

91% water; 9% proteins, including clotting proteins.

Straw-colored.Fibrinogen and prothrombin =

clotting proteins; important in clot formation to control bleeding.

Serum = plasma without clotting proteins.

Erythr/o/cytes

Red blood cellsProduced by red bone marrowShaped like a doughnutHemoglobin – iron-containing

pigment that transports oxygenReticulocyte – immature RBC;

meshlike pattern of threads

The normal life of an RBC is about 120 days. After this, macrophages in the spleen, liver and bone marrow destroy RBCs that are no longer useful.

Leuk/o/cytes

White blood cellsProtect the body against

invaders such as bacteriaNeutrophils – most prevalent

WBC that fight infection by “phagocytosis”

This is the process of engulfing and swallowing germs (phago = eat)

On a blood test, an elevated neutrophil count indicates a bacterial infection.

Basophils – promote the inflammatory response.

An elevated basophil count may indicate an allergic condition.

Eosinophils – increase in response to an allergic reaction.

Lymphocytes – formed in red bone marrow, spleen, lymph nodes. Protect the body against disease.

Monocytes – protect body against disease; an elevated count usually indicates a chronic infection.

Thromb/o/cytes

PlateletsSmallest of the formed elements Important in the clotting of

blood.When a blood vessel is damaged,

platelets are activated.Once activated, they become

sticky and clump together and form a clot.

Blood Types

Four major typesA, AB, B, OBased on the presence of the A

and/or B antigens on red blood cells.

In type O, both antigens are missing.

Blood has to be typed and cross-matched for a transfusion.

Donors and Recipients

A can donate to A or AB, and can receive from A or O only.

B can donate to B or AB only, and can receive from B or O only.

AB = the universal recipient; can donate to AB only, and can receive from A, B, AB or O

O = the universal donor; can donate to A, B, AB, O, and can receive from O only.

Hematologist = specializes in diagnosing and treating diseases and disorders of the blood and blood-forming tissues.

Hemat/o = blood.

Rh Factor

RBCs also contain the Rh antigenNamed for Rhesus monkeys

where they were first foundEach individual is either positive

or negative for the Rh factor.About 85% of Americans are Rh

+; they have the Rh antigen.

The remaining 15% = Rh -.They do not have the Rh antigen.The Rh factor causes difficulties

when an Rh + infant is born to an Rh – mother.

New Word Roots and Suffices

angi/o = blood vessel.phleb/o = vein.You already know arteri/o =

artery.ech/o = ultrasound. -emia = blood or blood

condition. -penia = decreased; lack of; too

few

Blood Disorders

erythro/cyt/osis – abnormal condition of red blood cells; it is an abnormal increase in RBCs.

thrombo/cyto/penia = abnormal decrease of platelets (thrombocytes).

leuko/penia – abnormal decrease of WBCs (leukocytes)

leukemia – a malignancy characterized by a progressive increase of abnormal leukocytes.

anemia – a disorder of lower than normal levels of RBCs in the blood. an- = without; -emia = blood condition.

Diagnostic Procedures of the CV System

pulse oximeter – placed on finger; measures amount of oxygenated blood in the circulatory system; normal = 96-100%.

angiography, angiocardiography, phlebography – x-ray study of vessels after injection of a contrast medium. (-grams are the films).

cardiac catheterization – a catheter is passed into a vein or artery and guided into the heart. A contrast medium is injected into the catheter; the dye travels through the heart and shows how well the heart is working.

echocardiography – use of ultrasound of the heart to show the structures and motion of the heart. Result = echocardiogram.

Treatment Procedures

Percutaneous transluminal coronary angioplasty (PTCA) – also called balloon angioplasty. A small balloon on the end of a catheter is used to open a partially blocked coronary artery by flattening the plaque deposit; then the balloon is deflated and the catheter removed.

In a similar technique, a stent is implanted in a coronary artery to provide support to the arterial wall to prevent re-stenosis. (re-narrowing).

The expanded stent is presses plaque against the artery wall, and the stent stays expanded.

atherectomy – surgical removal of plaque from the interior lining of an artery.

After the catheter and balloon are in place, the balloon is inflated and a cutting tool is used to shave off pieces of the plaque buildup.

endarterectomy – (end = within, arter = artery, -ectomy = surgical removal).

the surgical removal of the lining of an artery that is clogged with plaque.

carotid endarterectomy – the surgical removal of the lining of a portion of the carotid artery, leading to the brain.

The artery may be reinforced with a piece of vein taken from the leg. This procedure is done to reduce the risk of stroke by ensuring the blood flow to the brain.

Coronary artery bypass graft – (CABG) – also known as bypass surgery.

It requires opening the chest (sternotomy). A piece of vein from the leg is implanted on the heart to bypass a blockage in a coronary artery to improve the flow of blood to the heart.

valvuloplasty – or ‘valvoplasty’ – surgical repair of heart valve; could also mean surgical replacement of a heart valve.

pacemaker – an electronic device that may be attached externally or implanted under the skin, with connections leading into the heart to regulate the heartbeat. Usually for bradycardia or atrial fibrillation.

Defibrillation or ‘cardioversion’. The use of electrical shock to

restore the heart’s normal rhythm.

This can be performed externally as an emergency procedure or a device may be implanted to control severe arrhythmias. These are called ICDs, or internal (or implanted) cardiac defibrillators.

Cardiopulmonary Resuscitation – CPR. An emergency procedure for life support consisting of artificial respiration and manual external cardiac compression.