human circulatory system. circulatory systems open system vs. closed system –both have a pump...

HUMAN CIRCULATORY HUMAN CIRCULATORY SYSTEMSYSTEM

Circulatory SystemsCirculatory Systems

Open system vs. closed systemOpen system vs. closed system– Both have a pumpBoth have a pump– Open system has no blood vessels to hold Open system has no blood vessels to hold

bloodblood– Closed system has blood contained within Closed system has blood contained within

vesselsvessels

Circulatory systemsCirculatory systems

The simplest of organisms do not have a The simplest of organisms do not have a circulatory systemcirculatory system

Rely on diffusion/osmosis for regulationRely on diffusion/osmosis for regulation

Circulatory systemsCirculatory systems

Other simple organisms rely on the flow of Other simple organisms rely on the flow of water to exchange nutrients and wasteswater to exchange nutrients and wastes

Open vs. Closed Circulatory Open vs. Closed Circulatory systemssystems

Closed circulatory systemsClosed circulatory systems

Vary in complexityVary in complexity

Human HeartHuman Heart

Cardiac muscleCardiac muscle

Structure of the heart wallStructure of the heart wall

Structure of the heart wallStructure of the heart wall

HUMAN CIRCULATORY SYSTEMHUMAN CIRCULATORY SYSTEM

Artery and VeinArtery and Veinstructural comparisonstructural comparison

ArteryArtery

Walls are thickWalls are thick– MuscularMuscular– Elastic, so they can stretch when heart Elastic, so they can stretch when heart

contractscontracts– Must withstand higher pressure than veinsMust withstand higher pressure than veins

AtherosclerosisAtherosclerosis

VeinVein

Thin-walled (less muscle, less elastic Thin-walled (less muscle, less elastic tissue)tissue)

Contain VALVESContain VALVES

to prevent back-flowto prevent back-flow

CapillariesCapillaries

Blood vessels with the smallest diameter Blood vessels with the smallest diameter and thinnest wallsand thinnest walls

Capillary BedsCapillary Beds

Exchange of carbon dioxide, oxygen, and Exchange of carbon dioxide, oxygen, and nutrients occurs in the capillary bedsnutrients occurs in the capillary beds

BLOOD PRESSUREBLOOD PRESSURE

Measurement of both the pressure under Measurement of both the pressure under which the heart contracts (which the heart contracts (systolesystole), as well ), as well as the pressure under which the heart fills as the pressure under which the heart fills ((diastolediastole))

BLOOD PRESSUREBLOOD PRESSURE

Blood pressure is checked in your arm, Blood pressure is checked in your arm, using a using a sphygmomanometersphygmomanometer

Blood PressureBlood Pressure

The pressure generated by your heart can The pressure generated by your heart can be measured in your arm because the be measured in your arm because the pressure is transmitted through the pressure is transmitted through the muscular, elastic arteriesmuscular, elastic arteries

Blood PressureBlood Pressure

Measured in mm HgMeasured in mm Hg

Reported as two numbers:Reported as two numbers:systolic pressuresystolic pressure

diastolic pressurediastolic pressure

Systolic blood pressureSystolic blood pressure

Pressure transmitted when the left Pressure transmitted when the left ventricle contractsventricle contracts– It is the pressure under which the blood is It is the pressure under which the blood is

being forced out of the left ventricle into the being forced out of the left ventricle into the aortaaorta

Diastolic blood pressureDiastolic blood pressure

Is the filling pressure of the heartIs the filling pressure of the heart

Sounds of KorotkoffSounds of Korotkoff

Sounds of KorotkoffSounds of Korotkoff

Sounds of Korotkoff (are caused by Sounds of Korotkoff (are caused by turbulence in arterial blood flow.turbulence in arterial blood flow.– A well-trained examiner can hear 5 different A well-trained examiner can hear 5 different

Korotkoff sounds, which vary slightly in qualityKorotkoff sounds, which vary slightly in quality– The first and fifth Korotkoff sounds are used The first and fifth Korotkoff sounds are used

to define blood pressureto define blood pressure

Pulse PointsPulse Points

Blood PressureBlood Pressure

Generally measured over Generally measured over

the brachial arterythe brachial artery

Why is blood pressure important?Why is blood pressure important?

Blood pressure must remain in a normal Blood pressure must remain in a normal range so that tissues can receive range so that tissues can receive adequate blood flow in order to exchange adequate blood flow in order to exchange gases, nutrients, and wastes efficientlygases, nutrients, and wastes efficiently

HYPERTENSIONHYPERTENSION

Elevation in blood pressureElevation in blood pressure

Fairly common: about 30%Fairly common: about 30%– almost 1 in 3 adults!almost 1 in 3 adults!

HTN more common in HTN more common in – African AmericansAfrican Americans– Obese peopleObese people

HypertensionHypertension

High blood pressure can damage the heart High blood pressure can damage the heart and blood vesselsand blood vessels

Increases the chances of having a strokeIncreases the chances of having a stroke

Cause is multi-factorialCause is multi-factorial

Can be treated with medication; Can be treated with medication; sometimes with diet and exercise alonesometimes with diet and exercise alone

Regulation of blood pressureRegulation of blood pressure

Conduction System of the HeartConduction System of the Heart

ElectrocardiogramElectrocardiogram

Useful tool for studying the conduction of Useful tool for studying the conduction of impulses through the heartimpulses through the heart

ElectrocardiogramElectrocardiogram

P wave represents depolarization of the P wave represents depolarization of the atriumatrium

QRS complex represents depolarization of QRS complex represents depolarization of the ventriclesthe ventricles

T wave represents repolarization T wave represents repolarization (“recharging” for the next beat(“recharging” for the next beat

Normal ElectrocardiogramNormal Electrocardiogram

ECG abnormalitiesECG abnormalities

After a myocardial infarction (heart attack, After a myocardial infarction (heart attack, “MI”), the damaged areas of the heart no “MI”), the damaged areas of the heart no longer have normal conduction of longer have normal conduction of impulsesimpulses– Results in a change in the normal waveformsResults in a change in the normal waveforms

ECG abnormalitiesECG abnormalities

ECG abnormalitiesECG abnormalities

ECG abnormalitiesECG abnormalities

Atrial fibrillationAtrial fibrillation

ECG abnormalitiesECG abnormalities

Acute myocardial infarction (heart attack)Acute myocardial infarction (heart attack)

COMPOSITION OF BLOODCOMPOSITION OF BLOOD

Blood is made up of a fluid portion and a Blood is made up of a fluid portion and a cellular portioncellular portion

PLASMAPLASMA

Made up of water, proteins, ions, amino Made up of water, proteins, ions, amino acids, sugarsacids, sugars

Carries carbon dioxide (released from Carries carbon dioxide (released from tissues)tissues)

Carries nutrients from the digestive Carries nutrients from the digestive system, hormonessystem, hormones

Cells in the BloodCells in the Blood

Erythrocytes: Red Blood Cells, RBC’sErythrocytes: Red Blood Cells, RBC’s

ErythrocytesErythrocytes

Contain hemoglobinContain hemoglobin– A proteinA protein– Transports OxygenTransports Oxygen

ErythrocytesErythrocytes

Hemoglobin structureHemoglobin structure

ErythrocytesErythrocytes

Live about 120 daysLive about 120 days

Produced in the bone marrowProduced in the bone marrow

Productions is regulated by a hormone Productions is regulated by a hormone from the kidneys-from the kidneys-– erythropoetinerythropoetin

Blood CellsBlood Cells

Leukocytes = White Blood CellsLeukocytes = White Blood Cells– Function in the immune systemFunction in the immune system– Form a second line of defense against Form a second line of defense against

bacteria and virusesbacteria and viruses– Larger than RBC’sLarger than RBC’s

LeukocytesLeukocytes

GranulocytesGranulocytes– NeutrophilsNeutrophils– BasophilsBasophils– EosinophilsEosinophils

LymphocytesLymphocytes

MacrophagesMacrophages

GranulocytesGranulocytes

NeutrophilNeutrophil– Greatest in numberGreatest in number– Has a segmented nucleusHas a segmented nucleus– Functions in bacterial infectionsFunctions in bacterial infections– Short-livedShort-lived

NeutrophilsNeutrophils

BasophilBasophil

Also a granulocyteAlso a granulocyte

Very few in numberVery few in number

Function is not completely understoodFunction is not completely understood

Contain granules that are important in Contain granules that are important in immune responseimmune response

EosinophilEosinophil

Granulocyte containing very large Granulocyte containing very large granulesgranules

Important in allergiesImportant in allergies

Few in number (far less than neutrophils Few in number (far less than neutrophils but more than basophils)but more than basophils)

EosinophilEosinophil

LymphocytesLymphocytes

Important in immune systemImportant in immune system– Making of antibodiesMaking of antibodies– Fighting viral infectionsFighting viral infections

Has a large, dark-staining nucleusHas a large, dark-staining nucleus

LymphocyteLymphocyte

MacrophagesMacrophages

Phagocytes: engulf and destroy cellular Phagocytes: engulf and destroy cellular debris and bacteria/virusesdebris and bacteria/viruses

Lifespan is months to yearsLifespan is months to years

Larger than a lymphocyteLarger than a lymphocyte

MacrophageMacrophage

Other Blood ComponentsOther Blood Components

PlateletsPlatelets– Involved in blood coagulation (clotting)Involved in blood coagulation (clotting)– Sticky; form a plug at the site of bleedingSticky; form a plug at the site of bleeding– Small and numerousSmall and numerous

Blood clotting is a very complex processBlood clotting is a very complex process– Involves many proteins (factors)Involves many proteins (factors)– Cascade eventCascade event

PlateletsPlatelets

PlateletsPlatelets

What protein forms the “threads” that trap What protein forms the “threads” that trap the platelets when forming a clot??the platelets when forming a clot??

Blood disordersBlood disorders

ANEMIA: qualitative or quantitative ANEMIA: qualitative or quantitative reduction in hemoglobinreduction in hemoglobin– Most common is iron deficiency anemiaMost common is iron deficiency anemia

Caused by low levels of iron: causes may be Caused by low levels of iron: causes may be dietary, chronic blood loss from gutdietary, chronic blood loss from gut

– Vitamin B6, folic acid deficienciesVitamin B6, folic acid deficiencies– Aplastic anemiaAplastic anemia

HemoglobinHemoglobin

Iron Deficiency AnemiaIron Deficiency Anemia

Iron Deficiency anemiaIron Deficiency anemia

Unusual symptomsUnusual symptoms– GlossitisGlossitis– Pica: geophagia (compulsive eating of dirt), Pica: geophagia (compulsive eating of dirt),

pagophagia (compulsive eating of ice)pagophagia (compulsive eating of ice)

Iron Deficiency anemiaIron Deficiency anemia

Blood smearBlood smear

Iron Deficiency anemia: Iron Deficiency anemia: treatmenttreatment

Treatment depends on the causeTreatment depends on the cause– Iron supplementIron supplement– Dietary changesDietary changes– In severe cases, blood transfusionIn severe cases, blood transfusion

Sickle Cell anemiaSickle Cell anemia

Inheritable disorder (co-dominance)Inheritable disorder (co-dominance)– Mutation in the hemoglobin molecule (HgbS)Mutation in the hemoglobin molecule (HgbS)– RBC’s form a sickle shapeRBC’s form a sickle shape– Reduces oxygen carrying capacity of the Reduces oxygen carrying capacity of the

bloodblood– African descentAfrican descent– Confers resistance to malariaConfers resistance to malaria

Sickle Cell anemiaSickle Cell anemia

Sickle Cell CrisisSickle Cell Crisis

Caused by a variety of things: stress, Caused by a variety of things: stress, fever, illness, alcohol & drug use, fever, illness, alcohol & drug use, dehydrationdehydration

Causes severe pain in tissues, bones, Causes severe pain in tissues, bones, jointsjoints

Can be life-threateningCan be life-threatening

Sickle Cell CrisisSickle Cell Crisis

Symptoms due to sickle cells blocking Symptoms due to sickle cells blocking capillary flowcapillary flow

Treatment: fluids, pain medicine, other Treatment: fluids, pain medicine, other treatments for specific problems (i.e. heart treatments for specific problems (i.e. heart attack, stroke, blindness)attack, stroke, blindness)