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CARDIOVASCULAR SYSTEM
Objectives
List the functions of the circulatory systemDescribe the heart
General features, chambers, valvesDifferentiate between the three types of bv’sDescribe the two circulations
Pulmonary vs. SystemicExplain how blood pumps through the heartDefine ECG and what P wave, QRS wave
and T wave represent
Structure and Function
• Functions of the cardiovascular system:Transports nutrients and oxygen to the body Transports waste products from the cells to
the kidneys for excretion Distributes hormones and antibodies
throughout the body Helps control body temperature and
maintain electrolyte balance
Two-sided, double pump Weighs less than a poundSlightly bigger than a fist Located between the lungs in the
thoracic cavityPositioned partially to the left of the
sternum
General features of heart
Heart Anatomy
• Four chambers of the heartAtria
Top two chambersBlood enters the heart through the atria
VentriclesLower two chambersBlood leaves the heart through the ventricles
SeptumDivides the right and left sides of the heart
Heart Anatomy
Two atriaTwo ventricles
Heart Anatomy cont.
• Four valves of the heartPrevent blood from flowing back into heartAtrioventricular
Allow blood to pass from the atria to ventricles
Semilunar valvesAllow blood to pass out of the heartSeparate the ventricles from the pulmonary
artery and aorta
Heart Anatomy cont.
Atrioventricular valves Tricuspid/right AV
valve 3 flaps
Bicuspid/mitral/left AV valve
2 flaps
Semilunar valves
Blood Vessels
The cardiovascular system has three types of blood vessels:
Arteries (and arterioles) – carry blood away from the heart
Capillaries – where nutrient and gas exchange occur
Veins (and venules) – carry blood toward the heart.
Blood Vessels (Continued)
Arteries Carry blood away from the heart
Blood is oxygenated
Have a muscular layer of tissue that helps pump blood out of the body
Aorta is the largest artery in the body, which branches into smaller arteries
ArteriolesSmaller vesselsBlood moves from arterioles to capillaries
Blood Vessels (Continued)
Capillaries Microscopic vessels that carry blood
between the arterial and venous vessels Gases, nutrients, and waste exchanged
Blood gives up oxygen
Blood flows from capillaries into venules
Blood Vessels (Continued)
Veins Venues branch together to form veins Carry blood back to the heart by gravity
Blood is deoxygenated except for pulmonary vein
Contain values that prevent blood from flowing back Have a much thinner muscular layer Superior vena cava and inferior vena cava
Largest veins
Blood Vessels
CirculationPulmonary circulation
Right side of heart pumps deoxygenated blood to the lungs
Systemic circulation Left side of the heart pumps oxygenated blood to rest
of the body Blood returns to the right side of the heart from
the body to complete the cycleHepatic circulation
Path of the blood from the intestines, gallbladder, pancreas, stomach, and spleen through the liver
Passage of Blood Through the Heart
Blood follows this sequence through the heart: superior and inferior vena cava → right atrium → tricuspid valve → right ventricle → pulmonary semilunar valve → pulmonary trunk and arteries to the lungs → pulmonary veins leaving the lungs → left atrium → bicuspid valve → left ventricle → aortic semilunar valve → aorta → to the body.
Structures of the Heart
Path of blood through the heart
Figure 11-1 Blood Flow Through the Cardiovascular System
Internal view of the heart
The Heartbeat
Each heartbeat is called a cardiac cycle.When the heart beats, the two atria
contract together, then the two ventricles contract; then the whole heart relaxes.
Systole is the contraction of heart chambers; diastole is their relaxation.
The heart sounds, lub-dup, are due to the closing of the atrioventricular valves, followed by the closing of the semilunar valves.
The Heartbeat (Continued)
Heart is the only muscle that can stimulate its own contractionsSinoatrial cells (SA node or pacemaker) in
right atriumInitiates the heartbeat and causes the atria to
contract on average every 0.85 secondsAtrioventricular node (AV node)
Sends impulse into lower portions of the heart (ventricles)
The signal for ventricles to contract travels from AV node to through the atrioventricular bundle to the smaller Purkinje fibers
Intrinsic Control of Heartbeat
The SA node sends out a stimulus, which cause the atria to contract.
When this stimulus reaches the AV node, it signals the ventricles to contract.
Impulses pass down the two branches of the atrioventricular bundle to the Purkinje fibers, and thereafter the ventricles contract
Path of Electrical Current in the Heart
Extrinsic Control of Heartbeat
A cardiac control center in the medulla oblongata speeds up or slows down the heart rate by way of the autonomic nervous system branches: parasympathetic system (slows heart rate) and the sympathetic system (increases heart rate).
Hormones epinephrine and norepinephrine from the adrenal medulla also stimulate faster heart rate.
The Electrocardiogram
An electrocardiogram (ECG) is a recording of the electrical changes that occur in the myocardium during a cardiac cycle.
Atrial depolarization creates the P wave, ventricle depolarization creates the QRS wave, and repolarization of the ventricles produces the T wave.
Electrocardiogram The P wave occurs
just prior to atrial contraction
The QRS complex occurs just prior to ventricular contraction
The T wave occurs when the ventricles are recovering from contraction.
Heart dissection on cadaver
Figure 11-5 Principal Arteries and Veins
Assessment Techniques
Measuring pulse and blood pressureListening to heart soundsDetermining cardiac output
Assessment Techniques (Continued)
Pulse Surge of blood
against the walls of the arteries
Eight pulse points on the body
Normal pulse rate for adults is 60 to 90 beats per minute
Blood pressure Force of blood
against the walls of the arteries
Systolic pressure Ventricles of the heart
contract Diastolic pressure
Ventricles relax Normal blood
pressure 120/80
Blood pressure varies greatly among people
Figure 11-6 Peripheral Pulse
Points
Assessment Techniques (Continued)
Heart soundsHeard through a stethoscopeMurmurs
Abnormal or extra soundClassified by timing, intensity, location,
pitch, and quality of the soundMay be benign or indicate a disorder
ThrillVibration felt by touch over an arteryCaused by an abnormal flow of blood
Assessment Techniques (Continued)
ElectrocardiogramMeasures graphically the pattern of
electrical activity in heart contractionsNormal and abnormal heart activities have
characteristic wave patterns
EchocardiographyUses ultrasonic waves to show the structures
and motions of the heartTransducer plots the sound echoes to produce a
graphic picture
Assessment Techniques (Continued)
Cardiac catheterizationUsed to measure the pressure in the
chambers of the heart, to take blood samples, and to view obstructions in the vessels
A tube is inserted through the blood vessels into the heart
Dye is then released and traced using x-ray
Oxygen transport
Blood
Blood
Essential Life Supportive FluidTransported in Closed System
Throughout Body Through Blood Vessels
Connective Tissue = Cells + Matrix
Physical Characteristics
ViscouspH 7.35 – 7.45Temperature: 38 degrees C; 100.4
degrees F7% - 8% of total body weightMales: 5 – 6 litersFemales: 4 – 5 liters
Functions of Blood
Transportation
Regulation
Protection
Formed Elements
Erythrocytes: (RBCs) – are produced in the red bone marrow.
Leukocytes: (WBCs) – they are formed in the bone marrow and lymph tissue.
Platelets: (Thrombocytes) – are the fragments or pieces of cells because they lack nuclei and vary in shape
General Characteristics of Formed Elements
Living blood cells2 out of 3 are NOT true cellsMost are short livedMost do not divideHematopoiesis occurs in liver,
spleen, thymus, & bone marrow
Plasma
Liquid portion: 90-92% water with fibrous proteins (fibrin)
Straw colored, sticky fluid
Plasma
ProteinsNon-protein nitrogenous
substances:NutrientsElectrolytesRespiratory gases
Functions of Plasma
Suspends blood cells & transports blood cells
Carries metabolic wastes & nutrients
Circulates hormones Maintains water content and body temperature
Maintains acid-base balance of blood
Erythrocytes
Shape: biconcave discSpectrin (fibrous protein)
flexibility to change shapeMature anucleate4 – 5.5 million per cubic
millimeterLifespan: 100 – 120 days97% is hemoglobinErythropoiesis
Leukocytes/WBCsSurveillance, Fighters,
Protectors
5 Types of WBCs
Neutrophils: granulocyteLymphocyte: agranulocyteMonocyte: agranulocyteEosinophil: granulocyteBasophil: granulocyte
Neutrophils
Phagocytize bacteria by secreting an enzyme called lysozyme
Monocytes
Phagocytize bacteria and foreign materials
Eosinophil
Remove toxins and defend the body from allergic reactions by producing antihistamines.
Basophils
Participate in the body’s inflammatory response
Produce histamine (a vasodilator), heparin (an anticoagulant)
Platelets
Platelets
Thrombocytes Involved in blood clottingSmall cytoplasmic fragments from
megakaryocyte250,000 – 400,000 per microliterLifespan: live only 10 daysAspirin inactivates the platelets
Lymphocytes
Provide immunity for the body by developing antibodies
Protect against the formation of cancer cells
Disorders of the Cardiovascular System
Disorders of the Cardiovascular System
AneurysmAn area of a blood vessel that bulges
because of a weakness in the wallAtherosclerosis
A narrowing of blood vessels caused by deposits of fatty material containing calcium and cholesterol
Cardiac arrhythmiaA disturbance of the heart’s rhythm caused
by a defect in the heart’s pacemaker cells or by damage to heart tissue
Disorders of the Cardiovascular System (Continued)
Cardiovascular disease A general term for the combined effects of
arteriosclerosis and related conditions called coronary artery disease
Congenital heart disease A group of disorders that affect about 25,000
newborns each year in the united states Congestive heart failure
The inability of the heart to pump blood adequately to meet the body’s needs
Disorders of the Cardiovascular System (Continued)
Hypertension High blood pressure
Myocardial infarction Known as a heart attack
Phlebitis An inflammation of a vein, often with
formation of a clot
Disorders of the Cardiovascular System (Continued)
Rheumatic heart disease A condition in which the heart muscle and
valves are damaged by a recurrent bacterial infection that usually begins in the throat
Varicose veinsA condition in which veins become enlarged
and ineffective
Health Careers
Health Careers
CardiologistCardiac SurgeonCardiovascular TechnicianEchocardiographerElectrocardiographic TechnicianHematologistPhlebotomistPerfusionist
Medical TermsRoot Word: cardi(o), cardi(a) – denotes
the heart.
Carditis inflammation of the heart Cardiology study of the heart Cardiac pertaining to the heart Cardiograph to record the heart Cardiogram “a” record of the heart Cardiomegaly enlargement of the heart Cardiospasm involuntary contraction of the
heart
Medical TermsRoot Word: cardi(o), cardi(a) – denotes the
heart
Cardiologist specialist of the heartBradycardia slow pace of the heartCardiopathy disease condition of the
heartTachycardia fast pace of the heart
Medical TermsRoot Word: Phleb(o) - denotes the vein
Phlebitis inflammation of the vein
Phleborrhaphy to suture the veinPhleborrhagia excessive flow
discharge in the veinPhlebotomy surgical incision of the
vein
Medical TermsRoot Words: art, arteri(o) - denotes the
artery
Arterio scler osis [age/high BP] of the artery
Arteriopathy disease condition of the artery
Arterial pertaining to the arteryArteritis inflammation in the arteryArthero scler osis disease condition of
hardening of the artery
Medical TermsRoot Words: thromb(o) – denotes the
blood clot
thrombocyte cell tissue of the blood clot Thrombosis disease condition of the
blood clot Thrombogen ic pertaining to the
production/creation of the blood clot Thromboarter itis inflammation of the artery
and blood clot Thromboectomy surgical removal of the
blood clot
Medical TermsRoot Words: thromb(o) – denotes the
blood clot
Thromboid ressembling or like of the blood clot
Thrombolysis destruction or breaking down of the blood clot
Thrombocyto penia decrease of cells of a blood clot
Thrombophleb itis inflammation of the vein of the blood clot
Thrombopathy disease condition of the blood clot
Medical TermsRoot Words: Hemo, Hema, Hemat(o) –
denotes blood
Hemostat stop of the blood Hematocrit measure of the blood Hemolysis destruction or breaking down
of the blood Hematemesis vomit of blood Hemoptysis spit of the blood Hematoma swelling or tumor of the blood Hemo phili ac pertaining to the brotherly
love and blood
Medical TermsRoot Word: emia – denotes blood
Leukemia white blood (cells)Lipemia fat in the bloodHyper glyc emia excessive sugar in the
bloodOligemia few bloodCyanemia blue blood (lack of
oxygen)Anemia without blood (low iron)
Medical TermsRoot Word: erythr(o) – red blood cells
Erythrocyte red blood cellsErythropoiesis creation or
production of red Erythroclasis fracture in the red
cellsErythroblast immature red cells
Medical termsRoot Word: cyt(o) – denotes cell
Cyto bio logy study of the life of the cell
Cyto diagn osis knowledge through the cell
Cyto meta plasia change in the form of cell
Cyto morpho logy study of form/shape of the cell
Cytoma swelling or tumor of the cell
Medical TermsRoot Word: sphygm(o)-denotes pulse or
blood pressureSphygmogram “a” record of the pulse
or blood vesselSphygmoid ressembling or like
pulse or blood vesselSphygmology study of the blood or
blood pressureSphygmopalpation feeling/pulse or
blood pressureSphygmoscopy visual examination of
the pulse or blood pressure
Medical TermsRoot word: vas(o) – denotes blood
vesselsVasomotor produce movement of the
blood vesselVasosection cut of the blood vesselVasorrhaphy to suture the blood vesselVasography to record the blood vesselVasospasm involuntary contraction of
the blood vessel
Medical TermsRoot word: angio – denotes the blood
vessel Angiectasis dilation or opening of the blood
vessel Angiostomy a moth opening of the blood
vessel Angiospasm involuntary contraction of the
blood vessel Angiogram a record of the blood vessel Angiostenosis condition of narrowing of the
blood vessel Angioplasty surgical repair of the blood
vessel
AbbreviationsE-F
E Meaning Ea Each EEG Electroencephalogram EENT Ear, Eye, Nose & Throat EKG or ECG Electrocardiogram EMS Emergency Medical Service EMT Emergency Medical Technician ENT Ear, Nose, Throat EPA Environmental Protection Agency ER Emergency Room EX Exam EXP Exploratory EXC Excision EXT Extract
AbbreviationsE-F
F Meaning F Degrees Farenheit FBS Fasting Blood Sugar FBW Fasting Blood Work FDA Food & Drug Administration Fe Iron FHB Fetal Heart Beat Fl fluids Fx Fracture FUD fever of unknown origin