cardiovascular system · the cardiovascular system (also called the circulatory system) can be...

CARDIOVASCULARSYSTEM

Khaleel Alyahya, PhD, MEdwww.khaleelalyahya.net

RESOURCES

Mosby’s Dictionary

By Mosby

Essential of Human Anatomy and Physiology

By Elaine Marieb and Suzanne Keller

Mastering Medical Terminology

By Sue Walker, Maryann Wood and Jenny Nicol

Information, tables and figures of this lecture were taken from the following books:

▪ The cardiovascular system (also called the circulatory system)can be thought of as the transport system of the body.

▪ It is a closed system which consists of the heart and a network ofvessels that carry blood to the body tissues.

▪ With each heartbeat, blood is sent through the body, carryingoxygen and nutrients to all the cells.

▪ Cardi/o comes from the Greek word kardia, meaning heart, andvascular comes from the Latin word vasculum, meaning smallvessel.

▪ The functions of the cardiovascular system are very closelylinked with the functions of many other body systems such as therespiratory system.

▪ A healthy cardiovascular system is essential to good health.

▪ If this important system ceases its work, the body will fail.

INTRODUCTION

By Khaleel Alyahya, PhD, MEd

▪ The cardiovascular system is also known as the circulatorysystem, and consists of the heart and the blood vessels:

• Arteries

• Arterioles

• Capillaries

• Venules

• Veins

▪ This system plays a vital role in moving blood around the body toensure that every cell, organ and muscle receives oxygen andnutrients and that waste products are removed.

• It is a transportation system which uses the blood as the transportvehicle.

• It carries oxygen, nutrients, cell wastes, hormones and many othersubstances vital for body homeostasis.

• It provides forces to move the blood around the body by the beatingHeart.

FUNCTIONS


COMBINING FORM

▪ Check page 169-170 from the book “Mastering Medical Terminology” for the

complete list of combining form.


PREFIX


SUFFIX


PRONUNCIATION

Check page 171 from the book “Mastering Medical

Terminology” for the complete list of pronunciation.


ABBREVIATIONS

Check page 172 from the book “Mastering Medical

Terminology” for the complete list of abbreviation.


▪ The heart is made up of cardiac muscle.

▪ Approximately the size of a closed adult fist, it is located within thethoracic cavity between the lungs and behind the sternum.

▪ The main function of the heart is to act as the pump whichcirculates the blood in the body.

▪ The heart has three layers:

• A smooth inner lining, known as the endocardium

• A muscular middle layer, called the myocardium

• The outer layer, which is a sac of fluid called the pericardium(epicardium).

HEART


▪ It is located in the thoracic cavity in a place known as the MiddleMediastinum between the two pleural sacs.

▪ Enclosed by a double sac of serous membrane (Pericardium).

▪ 2/3 of the heart lies to the left of median plane.

▪ The outer wall of the heart is made up of three layers:

• Epicardium.

• Myocardium (muscle of the heart).

• Endocardium.

▪ The heart is a hollow, cone shaped muscular pump that keepscirculation going on.

▪ It has:

• Apex

• Base

• Surfaces

o Diaphragmatic & Sternocostal

• Borders

o Right, Left, Inferior.

LOCATION


▪ Within the heart are two upper chambers known as the right and leftatria, and two lower chambers called the right and left ventricles.

▪ It is important to remember that when talking about right and left inrelation to the heart that the person is in the anatomical position.

▪ Separating the right and left sides of the heart is a thick muscle knownas the septum.

▪ The right atrium receives deoxygenated blood returned from theupper part of the body through the superior vena cava and from thelower body through the inferior vena cava.

▪ In addition, blood from the heart itself enters the right atrium throughthe coronary sinus.

▪ The blood then flows into the right ventricle through the rightatrioventricular valve (also known as the tricuspid valve because it hasthree cusps or leaves).

▪ The heart valves act to ensure that the blood can only flow in onedirection.

▪ The right ventricle then pumps the blood through the pulmonary valveand into the lungs via the right and left pulmonary arteries where it isreoxygenated.

▪ These pulmonary arteries are unique in that they are the only arteriesto carry deoxygenated blood.

CHAMBERS


▪ The blood from the left ventricle, being full of oxygen, is pumpedto all the cells in the body to ensure they can function optimally.

▪ Blood from which the oxygen has been drawn is extracted fromthe cells and returned to the right atrium and then passes to theright ventricle.

▪ This continuous cycle of oxygenation–pumping to body cells–return of deoxygenated blood’ is known as the cardiac cycle.

▪ The cycle includes systole (contraction) and diastole (relaxation)of the left and right atria and ventricles.

▪ The two atria contract simultaneously.

▪ As they relax, the ventricles contract.

▪ The ventricles then relax and the atria again contract.

▪ This cycle repeats continuously.

CHAMBERS


▪ They are two (Right & Left).

▪ Superior in position.

▪ They are the receiving chambers.

▪ They have thin walls.

▪ The upper part of each atrium is the Auricle.

▪ The Right Atrium receives the venous blood coming to the heart.

▪ Left Atrium receives arterial blood coming from the lungs.

ATRIA


▪ The inferior chambers.

▪ They are two (right & left).

▪ They have thick walls.

▪ They are the discharging chambers (actual pumps).

▪ Their contraction propels blood out of the heart into thecirculation. VENTRICLES


▪ Atrioventricular Valves:

• Valves between atria & ventricles.

• They allow the blood to flow in one direction from the atria tothe ventricles.

• Right AVV (Tricuspid).

• Left AVV (Bicuspid).

▪ Semilunar Valves (Aortic & Pulmonary):

• Between the right and left ventricles and the great arteriesleaving the heart.

o Aortic Semilunar Valve

o Pulmonary Semilunar Valve

• They allow the flow of blood from the ventricles to thesearteries.

VALVES


▪ As the blood is pumped around the body, it exerts pressure on thewalls of the arterial vessels.

▪ This is known as blood pressure and is measured as acomparison of systolic (maximum) pressure as the heart pumpsblood over diastolic (minimum) pressure as the heart relaxesbefore its next beat.

▪ Normal blood pressure is around 120/80 mmHg although thisvaries from individual to individual and from time to time in the oneperson according to the body’s requirements.

▪ The rhythmic beating of the heart is controlled by the sinoatrialnode located in the right atrium.

▪ This node controls the contraction of heart muscle by generatingimpulses which cause other heart cells to contract in an orderlysequence that forces blood to be pumped around the heart.

▪ Normal heart rhythm is known as sinus rhythm.

BLOOD PRESSURE


▪ The sympathetic division of the autonomic nervous system cantransmit messages to the sinoatrial node, instructing it to increasethe heart rate in response to a need for additional oxygen in thebody cells, such as during exercise or times of stress.

▪ By contrast, the parasympathetic division has the opposite effect,instructing the heart to slow.

▪ The number of times the heart beats in a minute can be felt ascontractions in the arteries.

▪ This is known as the pulse and is measured by feeling asuperficial vessel against a bone, most commonly the radial arteryin the wrist.

▪ A normal resting heart rate is between 60 and 80 beats per minutebut this is affected by level of fitness, activity or relaxation, bodyweight and heart health.

▪ An abnormally fast heart rate is known as tachycardia and aslower than usual heart rate is called bradycardia.

NEURONAL STIMULI


▪ What makes the heartbeat?

▪ Unlike skeletal muscle cells, which must be stimulated by nerveimpulses before they will contract, cardiac muscle cells can anddo contract spontaneously and independently, even if all nervousconnections are severed.

▪ Moreover, these spontaneous contractions occur in a regular andcontinuous way.

▪ Although cardiac muscle can beat independently, the muscle cellsin different areas of the heart have different rhythms.

▪ Atrial cells beat about 60 times per minute, but ventricular cellscontract more slowly (20–40 times per minute).

▪ Therefore, without some type of unifying control system, the heartwould be an uncoordinated and inefficient pump.

HEARTBEAT


▪ Two systems act to regulate heart activity.

▪ One of these involves the nerves of the autonomic nervoussystem, which act like brakes and gas pedals to decrease orincrease the heart rate, depending on which division is activated.

▪ The second system is the intrinsic conduction system, or nodalsystem, that is built into the heart tissue and sets its basic rhythmlike a drummer sets the beat for a rock band playing a song.

▪ The intrinsic conduction system is composed of a special tissuefound nowhere else in the body; it is much like a cross betweenmuscle and nervous tissue.

▪ This system causes heart muscle depolarization in only onedirection from the atria to the ventricles.

▪ In addition, the intrinsic conduction system enforces a contractionrate of approximately 75 beats per minute on the heart; thus, theheart beats as a coordinated unit.

INTRINSIC CONDUCTION SYSTEM


▪ One of the most important parts of the intrinsic conduction systemis a crescent-shaped node of tissue called the sinoatrial (SA)node, located in the right atrium.

▪ Other components include the atrioventricular (AV) node at thejunction of the atria and ventricles, the atrioventricular (AV) bundleand the right and left bundle branches located in theinterventricular septum, and finally the Purkinje fibers, whichspread within the myocardium of the ventricle walls.

SINOATRIAL NODE


▪ The SA node is a tiny cell mass with a mammoth job.

▪ Because it has the highest rate of depolarization in the wholesystem, it starts each heartbeat and sets the pace for the wholeheart.

▪ Therefore, the SA node is often called the pacemaker.

▪ From the SA node, the impulse spreads through the atria to theAV node, and then the atria contract.

▪ At the AV node, the impulse is delayed briefly to give the atriatime to finish contracting.

▪ It then passes rapidly through the AV bundle, the bundlebranches, and the Purkinje fibers, resulting in a “wringing”contraction of the ventricles that begins at the heart apex andmoves toward the atria.

▪ This contraction effectively ejects blood superiorly into the largearteries leaving the heart.

SINOATRIAL NODE


▪ In a healthy heart, the atria contract altogether.

▪ Then, as they start to relax, the ventricles begin to contract.

▪ Systole and diastole mean heart contraction and relaxation,respectively.

▪ Because most of the pumping work is done by the ventricles,these terms refer to the contraction and relaxation of the ventriclesunless otherwise stated.

▪ The term cardiac cycle refers to the events of one completeheartbeat, during which both atria and ventricles contract and thenrelax.

▪ The average heart beats approximately 75 times per minute, sothe length of the cardiac cycle is normally about 0.8 second.

CARDIAC CYCLE


▪ Atrial diastole (ventricular filling)

• Our discussion begins with the heart completely relaxed.

• Pressure in the heart is low, the AV valves are open, and blood isflowing passively through the atria into the ventricles.

• The semilunar valves are closed.

▪ Atrial systole

• The ventricles remain in diastole as the atria contract, forcing blood intothe ventricles to complete ventricular filling.

▪ Isovolumetric contraction

• Atrial systole ends, and ventricular systole begins.

• The initial rise in intraventricular pressure closes the AV valves,preventing backflow of blood into the atria.

• For a moment, the ventricles are completely closed chambers.

CARDIAC CYCLE


▪ Ventricular systole (ejection phase)

• The ventricles continue to contract, causing the intraventricularpressure to surpass the pressure in the major arteries leavingthe heart.

• This causes the semilunar valves to open and blood to beejected from the ventricles.

• During this phase, the atria are again relaxed and filling withblood.

▪ Isovolumetric relaxation

• As ventricular diastole begins, the pressure in the ventriclesfalls below that in the major arteries, and the semilunar valvesclose to prevent backflow into the ventricles.

• For another moment, the ventricles are completely closedchambers and intraventricular pressure continues to decrease.

• Meanwhile, the atria have been in diastole, filling with blood.

• When atrial pressure increases above intraventricular pressure,the AV valves open, and the cycle repeats.

CARDIAC CYCLE


▪ When using a stethoscope, you can hear two distinct soundsduring each cardiac cycle.

▪ These heart sounds are often described by the two syllables “lub”and “dup,” and the sequence is lub-dup, pause, lub-dup, pause,and so on.

▪ The first heart sound (lub) is caused by the closing of the AVvalves.

▪ The second heart sound (dup) occurs when the semilunarvalves close at the end of ventricular systole.

▪ The first heart sound is longer and louder than the second heartsound, which tends to be short and sharp.

HEART SOUND


▪ Cardiac output (CO) is the amount of blood pumped out by each sideof the heart (each ventricle) in 1 minute.

▪ It is the product of the heart rate (HR) and the stroke volume (SV).

▪ Stroke volume is the volume of blood pumped out by a ventricle witheach heartbeat.

▪ In general, stroke volume increases as the force of ventricularcontraction increases.

▪ If we use the normal resting values for heart rate (75 beats perminute) and stroke volume (70 ml per beat), the average adultcardiac output can be easily calculated:

• CO = HR (75 beats/min) × SV (70 ml/beat)

• CO = 5250 ml/min = 5.25 L/min

▪ The normal adult blood volume is about 6,000 ml, so nearly the entireblood supply passes through the body once each minute.

▪ Cardiac output varies with the demands of the body.

▪ It rises when the stroke volume is increased or the heart beats fasteror both; it drops when either or both factors decrease.

CARDIA OUTPUT


▪ In healthy people, stroke volume tends to be relatively constant.

▪ However, when blood volume drops suddenly or when the hearthas been seriously weakened, stroke volume declines, andcardiac output is maintained by a faster heartbeat.

▪ The following are the factors:

• Neural (ANS) controls.

o Sympathetic

o Parasympathetic

• Hormones and ions.

o Epinephrine

o Thyroxine

o Levels of sodium and calcium

• Physical factors.

o Age

o Gender

o Exercises

o Body temperature

FACTORS MODYFING BASIC HEART RATE


▪ There are three types of vessels in the human body, known asarteries, veins and capillaries.

▪ Arteries are elastic vessels responsible for carrying oxygenatedblood away from the heart to the rest of the body.

▪ There are two main types of arteries: pulmonary arteries andsystemic arteries.

• The pulmonary arteries are responsible for taking blood from the heartto the lungs to collect oxygen.

• These are the only arteries in the body to carry deoxygenated blood.

• The reoxygenated blood is then returned to the heart via the pulmonaryveins, the only veins in the body to carry oxygen rich blood.

• The systemic arteries, of which the aorta is the largest, transport theblood to the remainder of the body.

• The aorta originates in the heart but branches out into smaller vesselsto supply the head, the heart itself and the lower body.

• As the arteries branch out, they get smaller and smaller.

• The smallest branches are called arterioles, and these are involved inthe circulation of blood to the body tissues via the capillaries and fromthe tissues to the capillaries via venules, the smallest branches of theveins.

ARTERIES


▪ There are three main types of veins: pulmonary veins,

• Systemic veins

• Portal veins

▪ As noted above, the pulmonary veins transport the oxygenatedblood from the lungs to the left atrium of the heart, while thesystemic veins are responsible for returning the deoxygenatedblood from the tissues back to the heart.

▪ Portal veins drain the gastrointestinal tract carrying nutriments tothe liver.

▪ The largest systemic veins are the inferior and superior venaecava, collectively called venae cavae.

▪ Some veins are located close to the surface of the body and arecalled superficial veins.

▪ Deep veins are those that are found in deep muscle tissue andare usually co-located with a corresponding artery.

▪ Within the veins are valves that prevent blood from moving in thewrong direction.

VIENS


▪ Capillaries are tiny blood vessels that are so small that red bloodcells can only pass through them in single file.

▪ The capillaries exist in a network like a web that connects thearteries and veins.

▪ Oxygen, carbon dioxide, nutrients and wastes pass through thethin walls of capillaries.

▪ Capillaries also have a role in regulating temperature within thebody.

▪ When body temperature rises, the temperature of blood also rises.

▪ The heated blood travels in the capillaries to the body tissueswhere the heat is released.

▪ This causes, for example, a flushed look on the faces of peoplewho are feeling hot.

CAPPILARIES


▪ The aorta is the largest artery of the body.

▪ It leaves the left ventricle of the heart, and it decreases onlyslightly in diameter as it runs to its terminus.

▪ Different parts of the aorta are named for either their location ortheir shape.

▪ Branches of the aorta;

• Ascending aorta

• Arch of aorta

• Descending aorta

MAJOR ARTERIES


MAJOR ARTERIES


▪ Ascending aorta• Left coronary artery

• Right coronary artery

▪ Arch of aorta

• Left Subclavian.

o Vertebral arteries

o Axillary arteries

o Brachial arteries

o Ulnar arteries

o Radial arteries

o Palmar arches

• Left Common Carotid.

o Internal carotid arteries

o External carotid arteries

• Brachiocephalic Trunk.

o Right Subclavian.

o Right Common Carotid.

▪ Descending aorta

• Thoracic aorta

o Intercostal arteries

• Abdominal aorta

o Celiac trunk

o Superior mesenteric arteries

o Inferior mesenteric arteries

o Renal arteries

o Gonadal arteries

o Right and left common iliac trunk

▪ Internal iliac arteries

▪ External iliac arteries

✓ Femoral arteries

✓ Popliteal arteries

✓ Tibial arteries

✓ Fibular arteries

✓ Feet arteries

▪ Although arteries are generally located in deep, well-protectedbody areas, many veins are more superficial, and some are easilyseen and palpated on the body surface.

▪ Most deep veins follow the course of the major arteries, and with afew exceptions, the naming of these veins is identical to that oftheir companion arteries.

▪ Major systemic arteries branch off the aorta, whereas the veinsconverge on the venae cavae, which enter the right atrium of theheart.

▪ Veins draining the head and arms empty into the superior venacava, and those draining the lower body empty into the inferiorvena cava.

MAJOR VEINS


MAJOR VEINS


▪ Superior Vena Cava• Internal jugular veins

✓ Dural venous sinuses

• External jugular veins

✓ Anterior jugular veins

• Subclavian veins

o Veins of hands

o Radial vines

o Ulnar veins

o Brachial veins

o Axillary veins

o Cephalic veins (superficial)

o Basilic veins (superficial)

▪ Inferior Vena Cava• Common iliac veins

o Internal iliac veins

o External iliac veins

• Tibial veins

• Fibular veins

• Popliteal veins

• Femoral veins

• Great saphenous (superficial)

• Short saphenous (superficial)

o Gonadal veins

o Renal veins

o Inferior mesenteric veins

o Superior mesenteric veins

MAJOR ARTERIES & VEINS


Check page 177-183 from the book

“Mastering Medical Terminology”

for the complete list of pathology and diseases

PATHOLOGY

AND

DISEASES

▪ Angina pectoris is the medical term used to describe thetemporary chest pain that occurs when the heart is not gettingenough blood.

▪ It presents as a severe steady pain and constriction around theheart, typically radiating from the chest to the left shoulder anddown the left arm, creating a feeling of pressure in the chest.

▪ The patient will often be very pale and will experience dyspneaand have a variable raised blood pressure.

▪ An attack of angina pectoris will last a few seconds to a fewminutes.

▪ It is relieved by removing the stressor and/or taking sublingualnitroglycerin..

ANGINA PECTORIS


▪ Congestive cardiac failure (CCF) is a condition in which theheart cannot pump enough blood, and consequently enoughoxygen around the body.

▪ It can result from coronary artery disease such as stenosis,scarring from a previous myocardial infarction, hypertension,damaged heart valves, cardiomyopathy or an infection such asendocarditis.

▪ The failing heart keeps working but not as efficiently as it should.

▪ People with CCF cannot exert themselves because they becomefatigued and short of breath very easily.

▪ Peripheral edema occurs due to this venous stasis.

▪ Sometimes fluid collects in the lungs and interferes withbreathing, causing shortness of breath, especially when a personis lying down.

▪ Diagnosis is by clinical examination, electrocardiogram,echocardiogram and blood tests.

▪ Treatment includes reduction of salt and fluid intake,medications such as diuretics, and a cocktail of cardiac specificmedications.

CONGESTIVE CARDIAC FAILURE


▪ Coronary Artery Disease (CAD) occurs when the arteries thatsupply blood to heart muscle (the coronary arteries) becomehardened and narrowed.

▪ This is due to atherosclerosis which is the buildup ofcholesterol-rich plaque, on the inner walls of the vessels.

▪ Over time, this plaque hardens and may rupture.

▪ Hardened plaque narrows the coronary arteries and reduces theflow of oxygen-rich blood to the heart.

▪ This reduced blood supply to the heart muscle is calledischemia.

▪ When the heart muscle doesn’t get enough blood, chest painknown as angina may occur.

▪ Angina is the most common symptom of CAD.

▪ As the disease progresses, CAD can lead to ischemic heartdisease.

▪ CAD may also result in myocardial infarction which isdiscussed elsewhere in this section.

▪ Coronary artery disease is also called coronary heart disease.

CORONARY ARTERY DISEASE


▪ Endocarditis is a bacterial infection of the endocardiumresulting in valvular deformity.

▪ It most commonly occurs in susceptible patients whosecirculatory system has been breached in some way such asthrough insertion of a central venous line, recent dental work,drug injections, or previous cardiac surgery.

▪ Long-term intravenous antibiotics are required, and replacementof heart valves may be necessary.

ENDOCARDITIS


▪ An aneurysm is a localized dilation or ballooning of an arterialwall due to weakness in the wall of the blood vessel.

▪ The aorta, cerebral and mesenteric arteries are mostcommonly affected.

▪ If the aneurysm ruptures it becomes a life-threateningemergency.

▪ Surgery may be performed to repair the defect or minimallyinvasive treatment involving placement of coils or stentsintroduced through other arteries of the body or neck and guidedinto the affected vessel may be performed.

ANEURYSM


▪ Arteriosclerosis is a general term for a hardening andthickening of arterial walls with a subsequent loss of elasticityand diminished blood flow to the heart, extremities andcerebrum.

▪ It is commonly referred to as hardening of the arteries.

▪ Arteriosclerosis may be present in any artery of the body, butthe disease is most concerning when it attacks the coronaryarteries and threatens to cause a myocardial infarction.

▪ This process gradually restricts the blood flow to one's organsand tissues and can lead to severe health risks brought onby atherosclerosis, which is a specific form of arteriosclerosiscaused by the buildup of fatty plaques, cholesterol, and someother substances in and on the artery walls.

▪ Atherosclerosis is the primary cause of coronary arterydisease (CAD) and stroke, with multiple genetic andenvironmental contributions.

ARTERIOSCLEROSIS


▪ Hypertension is more commonly known as high bloodpressure.

▪ There are two main types of hypertension.

▪ Essential (also called primary) hypertension accounts for about90% of all cases.

▪ There is no known cause, but risk factors includehypercholesterolaemia, hypernatremia, obesity and familyhistory.

▪ The other type is secondary hypertension which occurs whenthe patient has another disease such as a complication ofpregnancy or kidney disease which causes the hypertension.

▪ Treatment of the original condition will often reduce thehypertension to normal levels.

HYPERTENSION


▪ Varicose veins are enlarged, twisted veins that are often dark incolor.

▪ They have a ropey appearance and are usually thick andenlarged.

▪ While any vein can be affected, the veins in the lower legs andthighs have a greater tendency to varicose.

▪ This is due to leaking valves in the leg veins which allow blood toflow backwards, resulting in poor venous return to the heart.

▪ Over time this causes veins to varicose, becoming dilated andswollen.

▪ Varicose veins can be aggravated by many other conditions suchas long periods of standing, obesity, pregnancy, advanced age,and chronic constipation causing straining.

▪ As well as being a causative factor for VVs, straining to pass abowel motion can also result in the formation of hemorrhoids,which are varicose veins located in the anorectal area.

VARICOSE VEINS




for the complete list of tests and procedures.

TESTS

AND

PROCEDURES

TESTS AND PROCEDURES

EXERCISES



for the complete exercises.

EXERCISES

[email protected]?

cardiovascular system · the cardiovascular system (also called the circulatory system) can be...

Documents