Chapter 47 Lecture

7/22/2019 Chapter 47 Lecture

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Circulatory SystemsChapter 47



Function

TransportationRegulationProtection



Transportation

Materials required for metabolism◦ Respiratory

oxygen and carbon dioxide◦ Nutritive

Breakdown products of digestion(liver to cells

◦ ExcretoryMetabolic waste, water, ions, etc…



Regulation

Hormonetransport◦ From endocrine

glands to targetorgans

Temperatureregulation◦ Vasoconstriction

and vasodilation◦ Countercurrent

heat exchange



Protection

Blood clotting◦ Platelets

Immune defenseLeukocytes



Types of Circulatory Systems

Gastrovascular cavities

Open systems

Closed systems



Gastrovascular Cavity

Cnidarians andmany flatwormsExchange occurs

across surface ofbody cavityLarge surface areafacilitatesexchange



Open Circulatory SystemsNo distinctionbetween circulatingfluid andextracellular body

fluidBasic components◦ Hemolymph◦ Vessels◦ One or more hearts

Arthropods(Crustaceans,Insects), Molluscs



Open Circulatory Systems

Pros◦ Metabolically

inexpensive◦

Movement enhancescirculation

Cons◦ Cannot be

selectively deliveredto specific tissues



Closed Circulatory SystemsBlood and interstitialfluid are physicallyseparated

Allows for greaterpressure to beachieved

◦ Facilitates distributionto all tissues in largeanimals

Earthworms,Cephalopods, allVertebrates



Closed Circulatory Systems

Features◦ Blood remains in vessels◦ One or more heart◦

Contain disease fightingcells and molecules◦ Adjustable to meet

metabolic demands◦

Facilitates self healing◦ Continually grows with

organism



Closed Circulatory Systems -Types

Single circulation◦ fish

Double circulation◦ crocodiles, birds, and mammalsCombination◦ Amphibians and most reptiles





Double Circulation – PartialSeparation

Amphibians andReptiles

◦ Oxygenated bloodfrom the lungs is keptrelatively separatefrom thedeoxygenated bloodfrom the rest of thebody due toincomplete divisionswithin the heart.

PulmocutaneouscirculationSystemic circulation

◦ Lungs and skincarryout gas exchange

Ventricle

Lung

O 2

O 2

CO 2

O 2 CO 2

Skin

Pulmocutaneous circulation

Systemic circulation

Amphibian (frog)

Heart

Rightatrium

Mostly O 2-rich blood

Moderatepressure

Mostlymixedblood

Leftatrium

Lowpressure

Lowpressure

Bodytissues

CO 2



Cutaneous Respiration

•Both atria dump into singleventricle•Internal structure keeps 2oxygenated and deoxygenatedblood mostly separated•Some mixing does occur reducing

efficiency



Double Circulation – CompleteSeparation

Two distinct circuits◦ Pulmonary◦ Systemic

Four Chambered heart◦ 2 atria◦ 2 ventricles

Two pressure systems

O 2 CO 2

(c) Double circulation in birds and mammals

Mammal

Systemic circulation

Veins Arteries

Lungs

O2

CO 2

Heart

Bodytissues

Lowpressure/low O 2

Rightatrium

Rightventricle

Leftatrium

Leftventricle

Pulmonarycirculation

Highpressure/high O 2

Mixed blood

Mostly mixed blood

Direction of blood flow

KEYO2-rich blood

O2-poor blood

Mostly O 2-rich blood



17

Blood

Fluid connectivetissueCells and cell

fragmentsSolution of watercontainingdissolved nutrients,proteins, gases,and othermolecules

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Plasma



Major Components

PlasmaLeukocytesErythrocytesPlatelets or thrombocytes



Plasma

Water and solutes◦ Metabolites, wastes, hormones

Ions

Na, Cl, bicarbonate◦ Proteins (most from liver)

Primary Function◦

pH buffering, water balance and immunecell transport



Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

CH

CH

N N

N N

Fe

Heme

Red bloodcell

Hemoglobin proteinwith 4 subunits

CH 2CH 2COOHCH

2CH

2COOH

CH 3 CH 3

O2

CH 2

CH 3 CH 2

CH 3

Erythrocytes

Hematocrit(volume) ~ 45%Primary Function

◦ Oxygen transport using

hemoglobinProduced in bonemarrowSome enucleated



Leukocytes

Primary function◦ Defense

Can leave the

blood streamNucleated2 classes◦ Granular◦ Agranular

http://www.youtube.com/watch?v=PXUNEJkjQt4

http://www.youtube.com/watch?v=WEGGMaRX8f0&NR=1







Platelets and Thrombocytes

Platelets (inmammals)◦ Cell fragments

Thrombocytes◦ In tact cells

Primary Function◦

Blood clottinghttp://www.youtube.com/watch?v=HFNWGCx_Eu4

http://www.youtube.com/watch?v=--

bZUeb83uU

http://www.youtube.com/watch?v=HFNWGCx_Eu4


http://www.youtube.com/watch?v=--bZUeb83uU









Blood Vessels

From the Heart◦ Arteries◦ Arterioles

Return flow◦ Capillaries◦ Venules◦ Veins



Arteries

Carry blood away from the heartThick walled, greater resistance



Capillaries

No muscle tissue◦ 8μ m diameter

Gas exchange◦

1 layer



Veins

Carry blood to the heartThin walled, less resistanceVenus pump

◦ Venus valves



27

Arteriole

Capillary

Venule

Low pressureHigh protein

High pressureHigh protein

H2O andsolutesleavecapillary.

Interstitial fluid(low pressure+ low protein)

H2O andsolutesentercapillary.

Excess H 2O andsolutes enterlymph vessels.

Excess H 2O(with solutes) isreturned to blood.

Lymphvessel

To otherregionsof tissue



Mammalian Heart

four-chambered heart with two separateatria and two separate ventricles.



The Cardiac Cycle

The heart has two pairs of valves.◦ Atrioventricular (AV) valves guards the opening

between the atria and the ventricles.right - tricuspid valveleft - bicuspid valve

◦ Semilunar valves guard the exits from theventricles to the arterial system.

right - pulmonary valveleft - aortic valve

http://www.youtube.com/watch?v=rguztY8a

qpk

http://www.youtube.com/watch?v=rguztY8aqpk






The Cardiac Cycle

Valves open and close as the heartgoes through the cardiac cycle of rest(diastole) and contraction (systole).

Measuring arterial blood pressure◦ Systolic pressure is peak pressure during

ventricular systole (contraction).◦ Diastolic pressure is minimum pressure

between heartbeats.Blood pressure is written as a ratio of systolicover diastolic pressure.



Measurement of BloodP ressure

http://www.youtube.com/watch?v=2A_wy8r93os

http://www.youtube.com/watch?v=ElCbQMiBC6A&NR=1








Electrical Excitation andContraction of the Heart

Contraction ofheart muscle isstimulated bymembranedepolarization.

◦ Depolarizationtriggered bysinoatrial (SA) node.

Acts as a pacemakerfor the rest of the heartby producingdepolarizationimpulsesspontaneously at a



Electrical Excitation andContraction of the Heart

Atrioventricular(AV) node allowsdepolarization topass to theventricles.◦ Depolarization is

conducted rapidlyover both ventricles

by atrioventricularbundle (bundle ofHis).

transmitted by Purkinjefibers

http://www.youtube.com/watch?v=te_SY3

MeWys&feature=related

http://www.youtube.com/watch?v=te_SY3MeWys&feature=related




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Chapter 47 Lecture