Cardiovascular System(Circulatory (Circulatory

System)System)

Blood From the BodyDeoxygenated blood enters the RIGHT ATRIUM

from the VENA CAVA

Atrium Contracts forcing the blood through the TRICUSPID VALVE

Into the RIGHT VENTRICLE

Ventricle contracts pushing blood through SEMILUNAR VALVE

Blood flows through either the RIGHT or LEFT PUMONARY ARTERY

                                                                                             

Click here for a Flash version of this illustration.

A heartbeat is a two-part pumping action that takes about a second. As blood collects in the upper chambers (the right and left atria), the heart's natural pacemaker (the SA node) sends out an electrical signal that causes the atria to contract. This contraction pushes blood through the tricuspid and mitral valves into the resting lower chambers (the right and left ventricles). This part of the two-part pumping phase (the longer of the two) is called diastole.The second part of the pumping phase begins when the ventricles are full of blood. The electrical signals from the SA node travel along a pathway of cells to the ventricles, causing them to contract. This is called systole. As the tricuspid and mitral valves shut tight to prevent a back flow of blood, the pulmonary and aortic valves are pushed open. While blood is pushed from the right ventricle into the lungs to pick up oxygen, oxygen-rich blood flows from the left ventricle to the heart and other parts of the body.After blood moves into the pulmonary artery and the aorta, the ventricles relax, and the pulmonary and aortic valves close. The lower pressure in the ventricles causes the tricuspid and mitral valves to open, and the cycle begins again. This series of contractions is repeated over and over again, increasing during times of exertion and decreasing while you are at rest. The heart normally beats about 60 to 80 times a minute when you are at rest, but this can vary. As you get older, your resting heart rate rises. Also, it is usually lower in people who are physically fit.

Blood Enters the LungsEnters the Lung (either right or left lung)

Blood is deoxygenated

Oxygenation is accomplished in the air sacs of the lungs at the same time the CO2 is being expelled

Oxygenated Blood is returned to heart via RIGHT or Left Pulmonary Vein. This is the only place where a vein carries oxygenated blood

Oxygenated Blood from the Lungs

Enter the LEFT ATRIUM which contracts

Blood is pushed through the BICUSPID Valve

Blood enters the Left Ventricle

Ventricle acts as the pump for the newly oxygenated blood

Blood is sent through the AORTIC SEMILUNAR VALVE

Blood then flows from the heart via the AORTA

Coronary Circulation

Myocardium must have blood to sustain is pumping

Right and Left Coronary arteries branch off the AORTA just above the heart

Branches of these arteries encircle the heart muscle delivering O2 and nutrients

Deoxygenated blood from these arteries return via CORONARY VEINS to RIGHT ATRIUM

Deoxygenated blood enters the atrium via the CORONARY SINUS

Systemic CirculationOxygenated

blood leaves the heart via the AORTA

As it leaves the anterior portion of the heart it forms the AORTIC ARCH

Circulation to Head

                                                                                                                

Arteries of the Head and Upper Torso

Ascending AortaAORTIC ARCH branches into 3 Main arteries

carry blood to arms, neck and head

Left Common Carotid Artery Brachiocephalic Artery – Right Common

Carotid, Right SubclavianLeft Subclavian Artery – left axillary, left

brachial

Descending Aorta

Coronary Artery – feeding the heartMore Branches feeding the body wall,

stomach, intestines, liver, etc.THORACIC AORTAABDOMINAL AORTAETC.

Types of Vessels

Arteries carry oxygenated blood away from

the heart (one exception)

Types of Vessels

BLOOD FLOW THROUGH VESSELS - Arteries

Transport blood under high pressure

Walls are elastic, muscular and thick

3 layers from interior to exterior

Tunica interna, media, and externa

Arteries branch into arterioles

Arterioles give rise to capillaries

Capillaries

Types of Vessels

CapillariesSmallest of blood vessels – microscopicConnect arterioles to venulesWalls thin to allow selective permeability of

various cells and substances – Nutrients and O2 pass out to surrounding tissueWaste CO2 and metabolic waste may enter to be

excreted Tiny opens allow WBC to leave the bloodstream

and enter tissue to help destroy invading bacteriaPlasma;a diffuses out of the bloodstream and into

tissue spaces (interstitial fluid) that is returned to the bloodstream in the form of lymph via lymph vessels

Diameter so small RBC “march” single file

VeinsCarry deoxygenated

blood and other waste products for

excretion

Types of Vessels

VeinsVeins similar is size to arteriesLess elastic and muscularWalls much thinner – blood pressure lowerThin walls – will collapse easily when not filled with

bloodContain one – way valves – prevent reflux or back

flow of bloodMore valves in lower extremities because of gravitySkeletal muscle also assist in Venous returnVenous blood returns to the heart via the Superior

and Inferior Vena Cava

Blood Pressure

Heart Pumps Blood into ArteriesSurge creates pressure on artery walls Pressure at the moment of ventricular

contraction is the systolic pressureAverage Systolic Pressure 120 mm/HgLessened pressure at ventricular

relaxation is diastolic pressureAverage Diastolic Pressure 80mm/Hg

120/80

BLOOD PRESSURE DISORDERS

Hypertension – “High Blood” – When BP is constantly greater than 140/90

Sometimes called the SILENT KILLERLeads to strokes, heart disease and kidney

failureTreated with diet, medication and weight loss 1 out of 5 American have hypertension

Hypotension – “Low Blood” – When Systolic BP is constantly lower than 100mm/Hg

Treated with fluids, medication

Disorders of Blood VesselsAneurysm – ballooning out of an artery –

thinning wall and weakening of the blood vessel

Sometimes pain and pressure sometimes no symptoms

Sometime surgically correctedRupture can be life threatening if in brain

or a large vessel like abdominal aorta

ArteriosclerosisArtery walls thicken – loss of elasticity

usually due to old ageNarrowing of artery – interfering with blood

supplyCan cause hypertension or cardiac infarct

AtherosclerosisDeposits of fatty substances form along the

walls of the arteries Narrowing of artery – interfering with

blood supplyCan cause hypertension or cardiac infarct

GangreneDeath of body tissue due to insufficient

blood supply caused by disease (diabetes) or injury

Pain and darkening skin and underlying tissue

Attempt to treat with antibioticsUsually must amputate affected area

PhlebitisInflammation of the lining of a vein,

accompanied by clotting of blood in the vein

Symptoms can include edema, pain and redness

Treat with medication, elevation and elastic stockings

EmbolismTraveling blood clotPulmonary embolism is clot in lung that can

cause respiratory arrest

Varicose VeinsSwollen veins resulting

from slowing down of blood flow back to heart

Blood backs up; distending the vein and valves

Usually caused by hereditary weakness

Age and pregnancy

HemorrhoidsVaricose veins in the walls of the lower

rectum and the tissues around the anus

Cerebral hemorrhageBleeding from blood vessels with the brainCan be caused by arteriosclerosis, disease,

aneurysm, or injuryCan cause permanent damage to brain

tissue and/or death

Peripheral Vascular DiseaseBlockage of arteries usually in legs

Symptoms – pain and cramping in the legs or buttocks while walking – claudicating

Must be treated or can progress where amputation is necessary

Treatments: medication, diet

Transient Ischemic Attacks (TIA)

Temporary interruption of the blood flow (ischemia) to the brain or part of the brain

Can be caused by narrowing of carotid artery

Symptoms include dizziness, weakness or temporary paralysis

Cerebral Vascular Accident (CVA) Stroke

Sudden interruption of blood supply to the brain

Loss of O2 to brain causing impairment of the brain tissue and/or death

3rd leading cause of death in USRisk factors include smoking, hypertension,

heart disease and family HX90% are caused by blood clots10% by bleeding into brain when vessel

ruptures

                                                          

         

 TYPES OF STROKE                                                             

ISCHAEMIC STROKE

HAEMORRHAGIC STROKE

Conduction of the HeartCardiac Cycle – one complete heart beat

Conduction System of the HeartHeart Rate (HR)

Heart must contract rhythmically

Each cycle or beat is about 0.8 seconds

Average rate of heart in an adult is 72-75 beats/min

Tachycardia – fast rate – usually over 100

Bradycardia – slow rate – usually under 60

SA Node – Pacemaker of the Heart

Conduction System initiates beats in intrinsic by distributing electrical impulses

Begins with the SA (Sinoatrial) node

Located in the superior wall of right atrium

Send the beginning of the electrical impulse over both atria causing them to contract simultaneously

Causes blood to flow downward from upper atrial chamber to AV opening

Bicuspid and Tricuspid valves open

Conduction System Semilunar valves closed at this time - no

blood to enter the pulmonary artery or aorta

Ventricles will relax at this time allowing them to fill with blood

Brief pause to allow atria time to complete contraction

Depolarizes the AV (atrioventricular) node

AV Node Located in the lower portion of the right atrium

AV node stimulates contraction of both ventricles

Contraction start at the apex and moves toward the atria

Send impulse down Bundle of His through the ventricular septum

Bundle divides in right and left branch that further subdivide sending messages up the ventricular walls by way of the Purkinje fiber network

Semilunar valves open allowing blood to move into the lungs via the pulmonary artery and out to body via aorta

Atrium then relax and AV valves close

Cycle continuesVentricles relax

Semilunar valves closed to prevent the blood flowing back in to the ventricles

SA Node signals again

Electricity gone haywire

Conduction Defects

Conduction AbnormalitiesHeart Block – AV damage – SA impulse

doesn’t reach ventricle – ventricles will beat at their own rate – slower

Damage to SA node – slower heart rate – sometimes need artificial pacemaker – defibrillation or “shocking” patient

Ischemia can lead to Fibrillation – rapid uncoordinated shuddering of heart muscle

Cardiac arrest – stopping of conduction

Autonomic Nervous System

Neural Control

Autonomic Nervous SystemHeart enervated by autonomic nervous

system – controls speed of contractions

Sympathetic NS will speed it up temporarily In times of physical or emotional stress Will increase availability of O2 and glucose

to cells

Parasympathetic NS will slow it temporarilyPrimarily the vagus nerve

Hormones and IonsHormone Thyroxine and epinephrine can also

increase heart rate

IonsLow calcium – depresses the heartToo much calcium can stop the heartLow K+ causes feeble or abnormal

beatingLow Na+ depress heart

Other FactorsAge- faster in babies – gradually decreases

through out life in normal heart

Gender – faster in females

Temperature – fever and exercise increase HR due to increase in metabolic rates; cold decreases HR

Medication – chemically stimulating or decreasing heart; intentional or side affect

Diet – digestion increase HR

Cardiac Cycle Mid to late Diastole

We will begin with the heart at complete relaxation

Pressure in heart is lowBlood flowing passively into atrium from the

pulmonary and systemic systemsSemilunar valves closed AV valves openAtria contract and force blood into ventricles

Cardiac Cycle Ventricular Systole

Shortly the ventricles will begin to contract and pressure increases rapidly

Pressure closes AV valves

When intraventricular pressure higher than in large vessels leaving heart - semilunar valves open

Blood rushes out of ventricles to vessels

Atria will be relaxed at this time and their chambers are filling

Cardiac CycleEarly Diastole At the end of Systole ventricles relax

Semilunar valves snap shut – preventing black flow

Intraventricular pressure drops

AV valves forced open

Ventricles beginning to refill rapidly

Cycle complete

Cardiac CycleNormally atria contract simultaneously as the

ventricles relax

Ventricles contract while atria relax

Diastole – phase of relaxation

Systole – phase of contraction

One cycle consists of systole and diastole of both atria and the systole and diastole of both ventricles

Timing Cycle lasts 0.8 seconds

First 0.1 seconds, the atria contract and ventricles relax

0.3 seconds atria are relaxing and ventricles contracting

Last 0.4 seconds is quiescent period – all chambers in diastole – heart resting

Heart SoundsFirst sound – Lub – is closing of the AV

valves – louder and stronger sound

Second sound – dup – closing of the semilunar valves at the end of systole – sound tends to be short and sharp

Pause

Heard with stethoscope

Heart MurmursAbnormal or unusual heart sounds

Blood flow silent unless strikes obstruction

Fairly common in children and elderly

Usually indicate valve problems

Medication can help some

Surgery required in severe cases

Blood Pressure

Pressure exerted at moment of contraction of ventricles – Systolic Blood Pressure – top number

Lessened force of the blood when ventricles relax – Diastolic Blood Pressure – bottom number

Pressure highest in the arteries close to initial surge of blood and gradually decreases as it it travels further from heart

Average BP in adult is 120mmHg/80mmHg

Directly related to CO and peripheral resistance

Blood PressurePeripheral Resistance – amount of friction

encountered by the blood as it flows through the blood vessels

Increase by constriction of blood vessels-by SNS or atherosclerosis

Increased by increased blood volume or blood viscosity

Blood PressureANS – sympathetic division causes vasoconstriction

Loss of blood

Gravity after sitting or laying down and rising suddenly

Exercise – vasoconstriction except in muscles vasodilatation

Never cause vasoconstriction of blood vessels in heart or brain

Blood Pressure

Kidneys – alters blood volume

Increases liquids excretion when BP goes up – decrease blood volume – decrease BP

Temperature – cold causes vasoconstriction

Chemicals

Epinephrine – increase HR – increases BP

Nicotine – increases HR – increases vasoconstriction - Increases BP

Alcohol – vasodilator – decrease BP

Blood Pressure DisordersHypotension – low BP

Systolic below 100

Usually no cause for concern under normal circumstances

Orthostatic hypotension – postural changes – increase with old age

Chronic Low BP can indicate poor nutrition and inadequate levels of blood proteins

Circulatory Shock- not enough blood volume in vessels

Blood Pressure DisordersHypertension – high blood pressure

Pathologic – sustained BP of 140/90 or higher

People can be asymptomatic for first 10-20 years – slowly causing unknown damage – silent killer

Increase resistance causes heart to work harder – over stretching the heart muscle

Can be affected by diet, obesity, heredity, race and stress

Pulse Pulse throbs at pressure points throughout body

Alternating expansion and contraction of an artery as blood flows through it

Brachial- near crook of elbow

Common carotid – neck

Dorsalis pedis – anterior foot

Temporal – temples on sides of face

Radial - wrist

Femoral – groin

Popliteal – behind knee Posterior tibial - ankle

Cardiac Output - COAmount of blood pumped out of each side of the heart in

one minute

Product of the heart rate (HR) and the stroke volume (SV)

CO = HR X SV

Stoke Volume is amount of blood pumped out of ventricles with each contraction

Normal CO = HR (75b/m) X SV (70 ml/beat)CO = 75 X 70CO = 5250 ml/min

Cardiac OutputAverage adult has 5000 ml of blood in the

entire system

Entire volume of blood passes through the heart (therefore through the body) in 1 minute

Cardiac Output will vary with demands

Increase with increase volume

Increases with increased rate

Cardiac OutputStroke Volume – volume of blood pumped

from the ventricles with each contraction

Healthy heart pumps 60% of the blood that enters it – 70 ml or 2 ounces – with each contraction

CO – Starling’s Law of the Heart

SV controlled by how much the cardiac muscle cells are stretched just before they contract

Increased stretching = stronger contraction

Amount of stretching affected by venous return- amount of blood entering

Stroke Volume Things that affects it

Slow heart rate allows more time for filling and stretching

Strong contracting of skeletal muscles affecting venous return – exercise

Rapid heart rate decreases filling time

Severe blood loss lowers venous return

Cardiac muscle weakening or damage decrease SV

Heart will try to maintain CO by increasing HR

Pumping Efficiency ProblemsCongestive Heart Failure – efficiency is decreased so

that circulation is inadequate to meet tissue demands

Usually progressive

Weakening of heart muscle due to MI, arteriosclerosis or persistent hypertension

Pulmonary congestion occurs when left heart fails – can lead to pulmonary edema

Peripheral congestion when right side fails

If one side fails more stress to other side can lead to total heart failure

Cardiovascular Disease

Disease of the Heart

Infections/InflammationsPericarditis Infection in the pericardium – the outer layer of

the heartSymptoms include pain, cough, dyspnea, rapid

pulse and fever

MyocarditisTreated with medications Inflammation of the cardiac muscleSymptoms and treatment same as pericarditis

Infections/InflammationsEndocarditis Inflammation of membrane lining the heart

and covering valvesCan lead to blood clot Can lead to valve difficulties

Rheumatic Heart Disease Antibodies fighting rheumatic fever or strep

throat can attack the valves and the lining of the heart

Can cause valves to stop closing properly

Coronary Artery DiseaseAngina pectoris

Severe chest pain caused by not enough O2 to heart myocardium

Not a disease but symptoms of narrowing of coronary arteries

Treat with medication – nitroglycerine – to dilate arteries

Secondary with by-pass surgery

Myocardial InfarctionMI or Heart attack – lack of blood supply to heart

muscle causing death of tissue

Can be caused by narrowing of arteries or blood clot

Amount of damage will determine mortality and/or resulting long term problems

Prevention is the best treatment

After damage done- medication can strengthen contraction and or dissolve clots

Invasive Treatment

Cardiac Surgery

Angioplasty“balloon surgery”

Small deflated balloon threaded into coronary artery to reach blockage

Balloon inflated to push blockage against artery wall

Balloon deflated and removed

If doesn’t work by-pass surgery may be needed

StintsSmall device threaded

into coronary arty to try to hold the vessel open after successful angioplasty

Not always successful long term

Tries to prevent Heart Attacks or MI from reoccurring

Coronary Artery By-PassSurgery to detour or by pass the blockage

in a coronary artery

Healthy blood vessel used

Not as successful in increasing longevity as once thought

Heart TransplantsIndividual’s heart can no longer function

properly

Due to damage or disease or in some congenital heart defect

Must “match” body tissue to prevent rejection by the recipient's own body

Donor must “die” for someone needs a transplant

Artificial HeartsLast ditch effort

Used only for short periods of time until a donor heart can be found

Pacemaker and Implantable DefibrillatorPacemaker to take over the work of the SA

node

Defibrillator – implanted to shock heart back into a regular rhythm – for those at risk or have a history of ventricular tachycardia

The River of Life

Blood

BloodSpecialized connective

tissuePumped by the heartCarried by the blood

vesselsComposed of:Blood cellsPlasmaPlatelets

BloodTransports O2 to cells for metabolismTransports CO2 back to lungsCarries nutrients, ions and water from the digestive

tract to all cellsTransports waste for cells to sweat glands and kidneys

for excretionTransports hormones from endocrine glands to target

organsTransports enzymes to cells to regulate chemical

processes and chemical reactionsHelps regulate pH through buffers and amino acidsHelps regulate body temperature by helping to regulate

H2O content of cells through Na ions (osmosis)Clotting mechanism helps prevent fluid lossHelps protect the body from foreign microorganisms

and toxins

Blood Cells - Erythrocytes Red Blood cells – contain no nucleus 95% of blood volume Hematopoiesis – formation – in red bone

marrow Come from stem cells – live for about 120

days Appear as biconcave discs- edges thicker

than center Composed of:1. Protein (stoma& cytoplasm)2. Lipids including cholesterol3. Hemoglobin

Erythrocytes - HemoglobinCombine with O2 in the lungs and transport it to

various tissuesCombine with CO2 in tissues and transport it to

the lungs for expulsion Hemoglobin is a protein – globin and a pigment –

hemeHeme combines with O2 – Globin combines with

CO2Normal Hemoglobin blood level is 4.8 million

RBCS/mm3 in women to 5.4 in men

Blood Cells - LeukocytesWhite Blood CellsContain no pigment and have a nucleusGeneral function – combat inflammation and

infectionLarger than RBCHave ability to leave blood and move into

tissue 5000 – 90000/mm3Live only a few days normally but only a few

hours during an infection2 sub categories – granular and non-granular

Leukocytes - GranularNeutrophils – most common leukocytesMost active Move into cells and phagocytize (consume)

foreign substances and secrete lysozyme which helps destroy certain bacteria

Pus consists of dell debris, fluid and dead neutrophils

Leukocytes - GranularEosinophils – combat irritants, such as pollen

that cause allergiesProduce antihistaminesAlso can attack some worm parasites

Leukocytes - GranularBasophiles – combat irritantsRelease heparin (an anticoagulant)

histamine (an inflammatory substance) and serotonin (vasoconstrictor) into the tissues

Leukocytes – Non - GranularMonocytes – phagocytoticLargest leukocytesWhen they leave the blood they increase in

sizePhagocytize bacteria, dead cells and/or

cellular debris

Non GranularLymphocytes – involved in production of

antibodiesPlay a crucial role in the immune system’s

responseSmallest of leukocytesInvolved in controlling cancer cells,

destroying microorganisms and rejecting foreign tissue implants

Blood Cells - ThrombocytesPlatelets

Disc shaped cellular fragments with a nucleus

Prevent fluid loss when blood vessels are damaged by clotting

Life span about 1 week

Produced by red bone marrow

PlasmaFluid part of the blood

91% of plasma is water

7% proteins- albumin and fibrinogen and globulins

Rest is solutes such as ions, nutrients, waste products, gases, enzymes and hormones

Albumin

Initiates osmotic pressure

Helps control water balance between blood and tissues

Plasma Proteins - Globulins

Some act as transport molecules for hormones and carry them to target organs

Some are antibodies – important in the immune system

Plasma Proteins - FibrinogenVital in blood clotting

Clotting of the BloodCoagulation –

the process of the clotting of the blood

Must occur to stop bleeding

Unnecessary clotting can clog a vessel

Clotting of the BloodVessel damage – leakage occursThromboplasin produced (needs Vit K) As blood platelets flow over the roughened area

they disintegrate, releasing thromboplasinThromboplasin + Ca = ThrombinThrombin + fibrinogen = fibrinFibrin are gel-like threads that layer themselves

over the cut, creating meshlike networkNetwork traps RBC, platalets and plasma

creating a blood clotSerum oozes out of the cut – slowly drying

creating a crust (scab) over the treadsClotting time is 5-15 min in adults

Blood Types4 major types – A, B, AB and OBlood type is inheritedDetermined by the presence or absence

of the blood glyoprotein called antigen located on the surface of the RBC

A has A antigenB has B antigenAB has bothO has neither

Blood Groups - AntibodiesProtein in the plasma

called antibody

A has “b” antibodies

B has “a” antibodies

AB has no antibodies

O has both

Blood TypesImportant to know type when receiving

transfusionAntibodies can react with antigens of

the same type – clumping of blood cellsA must receive A or O bloodB must receive B or O bloodAB can receive all typesO can donate to all types (universal

donor)

Rh factorAntigen found on the surface of the RBC

If someone has it they say they are Rh+

If someone does not have it Rh-

Important to know in transfusions

Important to know if Mother is Rh- and unborn baby is Rh+

Blood Disorders

Blood types

Blood Disorders - HemophiliaHereditary disorder

Blood clots slowly or abnormally

Only in males

Can be treated with clotting factors

Avoid trauma

Blood Disorders - LeukemiaCancerous or malignant condition

Abnormally high production of WBC that do not fight infection

Displace the normal # of RBC- thus interfering with amount of O2 circulating in the blood

Treatment – radiation, and/or chemotherapy

Blood Disorders - AnemiaDeficiency of RBC and amount of hemoglobin

Varying degree of dyspnea, pallor, palpitations and fatigue

Can be caused by bleeding or extreme destruction of malformation of RBC

Types: Pernicious – Vit B-12 deficiencyAplastic – bone marrow doesn’t produce enough

RBC and WBC

Sickle Cell DiseaseChronic disease inherited

from both parents

RBC form in crescent shapes that carry less O2

Almost exclusively in blacks

Treatment drugs and transfusions

Sickle Cell Trait is when only one parent is affected

Blood Disorders - SepticemiaPresence of a pathogen or toxin in the blood

Blood infection Treated with antibiotics

Can cause death if untreated or not treated quickly enough

Blood Disorders - Thalassemia

Also called Cooley’s anemia

Defect in RBC formation

Fatigue, enlarged spleen, bone deformaties

Medication and transfusions

Affects blacks and Mediteranian descent

Blood Disorders - MalariaInfectious diseaseCaused by protozoan

parasiteTropical climates – by

mosquitoCause symptoms of

anemia, tachycardia, fever, chills, nausea flu like symptoms, and coma and death

Blood Disorders - Mononucleosis

Mono – Kissing Disease – Glandular FeverCaused by Epstein Barr Virus (EBV)Symptoms fever, malaise, sore throat, enlarged glandsIncrease number of WBC - lymphocytes Spread by person-to-person contact Saliva is the primary method of transmitting Coughing or sneezing, causing small droplets of

infected saliva and/or mucus to be suspended in the air which can be inhaled by others.

Sharing food or beverages from the same container or utensil

Can lead to liver damage or spleen rupture

Interaction with Other Body Systems

IntegumentaryBlood flows to the skin to aid in the temperature

control for the body

Blood flow to skin brings O2 and nutrients to and are moves wastes from skin and glands

Dilation of vessels in the dermis occurs when we are embarrassed; resulting in “blushing”

Skin absorbs sunlight to indirectly allow for the production of Ca needed in muscular contraction of the heart

Muscular SystemExercising muscles receive increase blood flow

delivering O2 and nutrients and removing wastes

Cardiac and smooth muscles contractions maintain blood flow and blood pressure

Exercise helps prevent cardiovascular disease

Diaphragm contraction allows breathing sending O2 to lung for blood to pick it up for delivery to body

Heart is a muscle

Blood delivers O2 and nutrients for health and function of muscles and connective tissues

Skeletal SystemBones store and release calcium to maintain blood

levels – cardiac muscle needs Ca to contract

Bones are site of hematopoisesis

Bones (sternum and ribs) protect the heart

Long bones protect important arteries

Blood provides O2 and nutrients for health and function of the bones and removal of wastes

Nervous SystemBrain and spinal cord depend on blood flow

for survival

ANS regulates heartbeat and blood pressure

Pain felt in “heart attacks” help send signals to the person that they need to seek medical attention

Blood flow aids in waste removal from nervous system cells

Respiratory SystemRespiratory system provides the

exchange of O2 and CO2 with the red blood cells

Respiratory movements aid in venous blood return to heart

Heart provides the O2 and nutrients for health of the respiratory cells and for waste removal

Digestive SystemDigestive system breaks down food and

nutrients into forms that can be absorbed and transported in the blood stream

Iron and B vitamins are provided by the digestive system for red blood cell formation

Heart provides the O2 needed to maintain digestive function and metabolism and for waste removal

Reproductive SystemIncreased blood volume allows penis to maintain

erection

Increased blood volume during sexual arousal in both sexes allow sexual “readiness”

Estrogen helps maintain vascular health in females

Blood provides O2 and nutrients for health and function of reproductive organs and for waste removal

Excretory SystemKidneys filter the blood of wastes and excess

electrolytes and water

Kidneys help control blood volume and blood pressure

Blood pressure helps maintain kidney function

Blood provides nutrients and O2 for cells of the excretory system and for waste removal

Endocrine SystemBlood stream transports hormones to

target sites

Epinephrine , thyroxin and antidiuretic hormones effect blood pressure

Epinephrine , thyroxin effect heart rate

Blood supplies O2 and nutrients for health and function of endocrine glands and for waste removal