Cardiovascular system

GeneralThe cardiovascular system is a

series of tubes and a muscular pump that provides a ONE-WAY street for blood, oxygen, and nutrients.

Blood and nutrients travel through blood vessels (arteries, veins, and capillaries).

The cardiovascular system is fueled by a muscular pump called the heart. The heart is actually two pumps connected by a SEPTUM.

The right side of the heart pumps blood that is deficient in oxygen to the lungs [Pulmonary Circulation].

The left side of the heart pumps blood that is rich in oxygen to the body [Systemic Circulation].

The cardiovascular system

Roots pertaining to the cardiovascular system

Angi/oVas/o

vessel Angiogram (record)Vasospasm (twitching)

aort/o aorta Aortostenosis (narrowing)

Arterio/o artery Arteriosclerosis(condition of hardening)

Ather/o Fatty plaque Atheroma

Atri/o atrium Atrial

Cardi/o heart Cardiomegaly (enlargement)

Electr/o electric Electrocardiogram (record of electric)

Phleb/oVen/o

vein PhlebitisVenous

Thromb/o Blood clot Thrombolysis (destruction of a clot)

Ventricul/o Ventricle (brain or heart)

Interventricular septum(wall between the two ventricles)

The Heart

The heart has three distinct layers of tissue.

1. endocardium - deepest layer. 2. myocardium - muscle 3. epicardium - outermost layer

The heart is a muscular organ that pumps blood and is enclosed in a membranous sac. This sac allows the heart to beat without friction.

This sac is called the Pericardium. Peri- means “around”, cardium refers to the heart.

There are two sides of the heart.There are two vertical divisions of the

heart.The top compartments are atriaThe bottom compartments are

ventriclesTherefore, there are right and left atria

and right and left ventricles.

Heart Chambers

RightAtrium

LeftAtrium

RightVentricle

LeftVentricle

Apex

Abbreviations for chambers:

Right atrium RARight ventricle RVLeft atrium LALeft ventricle LV

The ventricles are larger than the atria. This is because the ventricles are responsible for pumping blood a farther distance than the atria.

Of the two ventricles, the left is larger than the right. This is because the left ventricle must pump blood to the entire body.

A rapid contraction of the atrium or ventricle is known as a flutter.

Atrial flutter can cause chest pain and shortness of breath (SOB).

The rule for forming plural words from the singular that end in –um is to drop the –um and add an –a.

Arteries bring blood AWAY from the heart.Veins bring blood TOWARD the heart.Arteries usually carry blood with much

oxygen.Veins usually carry blood with little

oxygen.The Right Atrium receives blood from all

tissues of the body through veins. This blood is oxygen poor.

The blood brought back to the heart comes from three sources:

1. Superior Vena Cava (Svc) brings blood from the top part of the body.

2. Inferior Vena Cava (Ivc) brings blood from the lower part of the body.

3. Coronary Sinus brings blood from the heart muscle.

All three sources empty into the Right Atrium.

Once inside the right atrium, the blood must travel to the right ventricle. In order to do this, it must pass through the Tricuspid Valve.

The function of all heart valves is to allow one way travel of blood.

It would be dangerous to have blood

backflow because of different oxygen concentrations.

Heart Valves

Apex

Left

Right

Tricuspid

Mitral

Pulmonary

Arte

ry

Aor

ta

Vena C

ava

Pulmonary Veins

Once inside the right ventricle, the blood passes through the pulmonary semilunar valve into the pulmonary arteries.

The pulmonary arteries carry oxygen-deficient blood to the lungs.

Once inside the lungs, the blood vessels branch until they reach one cell layer thick. These capillaries combine with the alveoli of the lungs for the exchange of oxygen and carbon dioxide.

The blood now has much oxygen. It returns to the heart by the Pulmonary Veins. There are four pulmonary veins that empty into the Left Atrium.

The blood then must pass through the Mitral Valve (Bicuspid Valve) into the left ventricle.

From the left ventricle the blood passes through the Aortic Semilunar Valve in the Aorta.

The aorta is the largest artery of the body.

The contraction of the left ventricle sends blood rich in oxygen all over the body.

There are three arteries that bring blood to the head, neck, and upper extremities.

There is one major vessel that brings blood to the abdomen and lower extremities.

Arteries are the large vessels that bring blood away from the heart. These vessels branch into smaller Arterioles which eventually branch into Capillaries which are only one cell thick.

The primary responsibility for initiating the heartbeat is with the Sinoatrial Node. This is located on the posterior wall of the right atrium.

Once this electric current is generated, atrial muscle contracts forcing blood into the ventricles.

Once this occurs the heartbeat moves to another region called the Atrioventricular Node.

Once this occurs, the AV node sends electrical impulses through a series of Bundle Branches ending in Purkinje Fibers that stimulate the ventricles to contract.

Blood Supply to HeartCoronary Artery System

right coronary left coronary

left anterior descendingcircumflex

The Cardiac Cycle and Heart Sounds

The Cardiac Cycle is the events that occur in one complete heartbeat.

The cardiac cycle has 2 phases:

1. contraction of the heart: Systole 2. relaxation of the heart: Diastole

SystolicThe blood pressure when the heart is contracting. It is specifically the maximum arterial pressure during contraction of the left ventricle of the heart. The time at which ventricular contraction occurs is called systole.

DiastolicReferring to the time when the heart is in a period of relaxation and dilatation (expansion).

Electrical activity of the heart can be measured by an electrocardiogram (EKG or ECG).

EKG’s are electrical tracings of each part of the cardiac cycle.

Each time a different part of the heart contracts, an electrical impulse can be recorded from different areas on the thorax.

Electrocardiogram

Clinical aspects of the cardiovascular system

Hypertension The elevation of arterial blood pressure to a level that is likely to cause damage to the cardiovascular system

Hypotension Lower than normal arterial blood pressure

Orthostatic hypotensionLow blood pressure that occurs upon standing up

Microcardia Small heart

Cardiomegaly (megalocardia) Enlargement of heart

Myocardial Infarction (MI)Heart attack

Cardiomegaly The abnormal enlargement of the heart

Cardiomyopathy The term used to describe all diseases of the heart muscle

Carditis An inflammation of the heart

Coronary arteriesSupply oxygen-rich blood to the myocardium

Coronary artery diseaseAtherosclerosis of the coronary arteries that reduces the blood supply to the heart muscle

Angiitis The inflammation of a blood or lymph vessel

Angina A condition of episodes of severe chest pain due to inadequate blood flow to the myocardium

Angiostenosis The abnormal narrowing of a blood vessel

Pericarditis An inflammation of the pericardium that causes an accumulation of fluid within the pericardial sac

Phlebitis The inflammation of a vein

Arrhythmia Describes an abnormality, or the loss of the normal rhythm, of the heart

Arteriectomy The surgical removal the surgical removal of part of an artery

Endocarditis An inflammation of the inner lining of the heart

Plaque A fatty deposit that is similar to the buildup of rust inside a pipe

Atheroma A deposit of plaque on or within the arterial wall

Arteriosclerosis Any of a group of diseases characterized by thickening and the loss of elasticity of arterial walls

The prefix “tachy-” refers to rapid.

a rapid heartbeat (pulse): tachycardia

The prefix “brady-” refers to slow.

a slow heartbeat (pulse): bradycardia

Tachycardia An abnormally rapid resting heart rate

BradycardiaAn abnormally slow resting heart rate

Cardiac arrestAn event in which the heart abruptly stops or develops a very abnormal arrhythmia that prevents it from pumping blood

Peri/cardi/ectomy - sx procedure excising the pericardium.

Peri/cardi/o/rraphy - suturing a wound of the pericardium.

My/o/cardi/um - the muscular layer of the heart.

Atherosclerosis is a form of Arteriosclerosis and is characterized by an abnormal accumulation of fat and fibrous tissue (scarring) in a blood vessel.

This leads to a narrowing of the lumen which causes a decrease in blood flow to a part of the body

This condition can lead to necrosis, or cellular death.

Atherosclerosis

Atherosclerosis

To prevent blood clots, patients may take an anticoagulant. These are agents that delay blood coagulation (clotting).

Anticoagulants are used to prevent

thrombus formation (thrombogenesis).

Thrombolysis is accomplished with thrombolytic agents or medications that destroy a clot.

Cardiac catheterizationA diagnostic procedure in which a catheter is passed into a vein or artery and then guided into the heart

Atherectomy The surgical removal of plaque buildup from

the interior of an artery

Aneurysm A localized weak spot, or balloon-

like enlargement, of the wall of an artery

There are two types of aneursym: 1. Fusiform – the wall dilates equally

resulting in a tubular swelling. 2. Sacculated – a balloon is attached

to the vessel by a narrow stalk.

Aneurysm/ectomy The surgical removal of an aneurysm

Ischemia A condition in which there is an insufficient oxygen supply due to a restricted blood flow to a part of the body

Ischemic heart diseaseA group of cardiac disabilities resulting from an insufficient supply of oxygenated blood to the heart

Thrombus A blood clot attached to the interior wall of an artery or vein

Thrombosis The abnormal condition of having a thrombus

Coronary thrombosisDamage to the heart muscle caused by a thrombus blocking a coronary artery

Deep vein thrombosisThe condition of having a thrombus attached to the wall of a deep vein

Embolism The sudden blockage of a blood vessel by an embolus

Embolus A foreign object, such as a blood clot, quantity of air or gas, or a bit of tissue or tumor that is circulating in the blood