Good Morning!

Welcome to a Lecture on Internal Transport!

Chapter 42Power point slides will be available on the course website.

Any Questions? My office is Miller 23, Ext. 3605.

I. Meeting the Metabolic Needs of a Multicellular Organism Requires:

• A delivery system for nutrients, minerals, gases and wastes so cells can exchange with their environment.

• A closed circuit that minimizes the diffusion distance.

• Extensive communication with other systems: Respiratory, Digestive, Urinary and Lymphatic.

• Maintenance of Homeostasis.

II. The Vertebrate Circulatory Systemaka Our Cardiovascular System

• Continuous closed circuit under pressure.

• Components: Transporting Medium = Blood Plumbing = Blood Vessels Pump = 4 chambered Heart

• 3 functions: Transportation, Protection and Regulation

• The health of this system is vital to all other organ systems. Cardiovascular disease is the leading cause of untimely death in the US.

The Closed Circuit and its Pump

The 4 chambered Mammalian heart

III. The Transporting Medium

5-6 liters in circulation

Red Gold

A Blood Smear

Figure 42-4Page 811

Whole blood

Plasma Cellcomponents

Plasmaproteins

Lipoproteins Albumins Globulins Fibrinogen

Clottingproteins

WaterSalts

Dissolvedgases

HormonesGlucoseWastes

Granularleukocytes

Agranularleukocytes

7 µmRed blood cells(erythrocytes)

1 to 2 µmPlatelets

Whiteblood cells

(leukocytes)

10 to 14 µm

Eosinophil

15 to 20 µmMonocyte

8 to 10 µmLymphocyte

10 to 14 µmNeutrophil

10 to 14 µmBasophil

Figure 42.4

Table 42-1

‘NLMEB’

250 million Hb molecules/RBC

55% 45%

Credit: © Dr. Dennis Kunkel/Visuals Unlimited

Erythrocytes

Red and white blood cells within an arteriole. Arteries branch into arterioles within organs and deliver blood to the capillaries. SEM X6130.

900019

Credit: © Dr. Richard Kessel & Dr. Randy Kardon/Tissues & Organs/Visuals Unlimited

WBC Phagocytosis

WBC’s leaving circulationto begin the inflammatory response

Injury toblood vessel

Wall of vesselcontracts

Platelets adhereto collagen fibersof damaged vesselwall

More permanentclot forms

Blood flow Blood flowdecreases

Blood flowdecreases Platelet

plugBlood flow

ceases

Damaged cells and plateletsrelease substances thatactivate clotting factors

Prothrombin activator

Thrombin

Fibrinogen

Fibrin threads (clot)

Prothrombin

Ca2+

Ca2+

1 2 3 4

Figure 42.5

STOP THE BLEEDING!

Blood Clot. Red blood cells are trapped in a clot of fibrin. Damage to the connective tissue in blood vessels triggers a series of events that leads to the conversion of fibrinogen (an inactive sealant in our blood) to be converted to fibrin. SEM X4005.

900021

Credit: © Dr. Richard Kessel & Dr. Randy Kardon/Tissues & Organs/Visuals Unlimited

IV. Blood Vessels

Outer coat(connective tissue)

VEIN

Smooth muscle Endothelium

ARTERY

Outer coat(connective tissue)

Endothelium

CAPILLARY

25 µm

Figure 42.6

3 Types of Blood Vessels

Lymphatic Vein

Artery

Venule

Arteriole

Lymphnode

Movement ofinterstitial fluid

Lymphcapillaries

Figure 42.6

Capillary Bed

•Organization of the circuit•Direction•Pressure (s)•Oxygen levels•Exchange•BP/BV regulation

ConstrictionDilation

Lymphatic System involvement

Key Points:

Figure 42-20Page 827

Arterial endof capillary

Bloodpressure

(+40)

Osmoticpressure

of plasma(- 28)

Bloodpressure

(+15)

Osmoticpressureof plasma

(- 28)

Osmoticpressure

of interstitialfluid(+3)

Osmoticpressure

of interstitialfluid(+3)

(40 + 3) - 28 = +15

Net filtration(15 + 3) - 28 = - 10

Net absorption

Venous endof capillary ‘Proteins and Pressures’

Figure 42-19Page 827

Arteriole

Valve Plasma

Venule

Red blood cells

Connectivetissue fibers

Capillarybed

Lymph

Plasma

Figure 42.19

Now tie in the Lymphatic System (again)

Rightlymphatic

duct

Rightsubclavian

vein

Axillarylymphnodes

Lymphaticsof breasts

Superficiallymphatics

of upperlimb

Tonsil

Cervicallymphnodes

Leftsubclavianvein

Thoracicduct

Spleen

Thymus

Superficiallymphatics

of lowerlimb

Figure 42.18

Spider Woman???No, It’s Lymphatic Woman!

ApplicationFigure, Page 822

500 µm 500 µm

Normal ArteryAtherosclerosis

Myocardial Infarction, Cerebrovascular Accident

Credit: © Carolina Biological/Visuals Unlimited

A heart attack waiting to happen

V. Behold the Heart

A. Lub Dub provides us with……..• Circulation of 5-35 liters of blood/minute• Through at least 60,000 miles of blood vessels• 1 heartbeat (lub dub) in 0.8 seconds• Heartbeats of 100,000 times /day• 2.5 billion times over our lifetime• Pumping 300 million liters (80 million gallons)

over our lifetime• Ever faithful….if we identify risk factors and

modify our lifestyles.

B. Those Risk Factors for the #1 Killer = Cardiovascular Disease

• SMOKING• Hypertension• Couch Potato Lifestyle • Poor Diet• Obesity• High cholesterol, Trigylcerides and LDL

levels; Low HDL levels• Diabetes mellitus

Your heart: Your hardest working muscle of all!

C. Your heart is a Double Pump with a Double Circuit:

•Systemic Circulation (blood to the body)

•Pulmonary Circulation (blood to lungs for oxygen)

Figure 42-16Page 824

Systemic circulationCapillary network

Brain

Carotidartery

Pulmonaryartery

Superiorvenacava

Pulmonarycirculation

Pulmonaryartery

Leftlung

AortaRight lung

LA

Pulmonaryvein

Inferiorvena cava

Pulmonaryvein

To lower partsof the body

Capillarynetwork

RA

RV LV

Appreciate the Circuitry

Figure 42.16

Right pulmonaryarteries

Pulmonary valve

Right atrium

Pulmonary veins

Tricuspid valve

Right ventricle

Inferior vena cava

Aorta

Left pulmonary arteries

Pulmonary artery

Pulmonary veins

Left atrium

Mitral valve

Aortic valve

Chordae tendineae(“heartstrings”)

Papillary muscles

Left ventricle

Interventricular septum

Aorta

Superior vena cava

Figure 42.9

D. By design: 4 Chambers, Valves and Vessels

E. Let’s follow a drop of blood through the heart.

Large Veins (Superior, Inferior Vena Cava)Right Atrium

ValveRight Ventricle

ValvePulmonary Arteries

LungsPulmonary Veins

Left AtriumValve

Left VentricleAorta

Dissection of pericardium and heart in situ, interior of left atrium and left ventricle.

Credit: © L. Bassett/Visuals Unlimited 303794

Notice the thicker, stronger walls of the left ventricle

A superior view of the valves

Figure 42-10aPage 818

SA node orpacemaker

Rightatrium

AV node

Rightventricle

Purkinjefibers

Left atrium

AV bundle

Left ventricle

Right and leftbranchesof AV bundle

Figure 42.10

Electrical Cells :Slow Sodium, Fast Calcium channelsContractile Cells: Fast Sodium, Slow Calcium Channels

Intrinsic Conduction System

F. And the beat goes on….

Credit: © Mediscan/Visuals Unlimited 3202

Electrocardiography: Placing electrodes on the body to monitor the electrical activity of the heart.

And if the pacemaker is broken we can fix it!

G. The Cardiac Cycle

• Follows the electrical message (Action Potential).• Makes up one complete heartbeat.• Takes. 0.8 seconds.• Involves contraction = SYSTOLE

and relaxation = DIASTOLE of the heart chambers.• Systole and Diastole are monitored when we have

our Blood Pressure taken (120/70).• ‘Lub-dub’ heart sounds during the cycle result from

the valves closing.• Valve problems are diagnosed as heart murmurs.

Right atriumTricuspid valve

Inferior vena cava

Superiorvena cava

Aorta Pulmonaryartery

Semilunar valves

Pulmonary vein

Left atriumMitral valve

Rightventricle

Leftventricle

Heartsounds

Beginning ofventricular systole

Period of risingpressure

Atrial systole1

2

3Beginning ofventricular diastole

4

5 Period of fallingpressure

Figure 42.11

The CARDIAC CYCLE

Figure 42-14

Blood volume

Bloodviscosity

Blood pressure= X

Blood flowPeripheralresistance

Cardiacoutput

Vaso-constriction

Systolic PressureDiastolic Pressure

115/70

H. Blood Pressure reflect how healthy we are and how hard our heart has to work

Highest in the arteries due to systole

The reason why we need to exercise!Similar to Figure 42-15

on page 823(Low pressure in veins.)

Figure 42-12Page 820

Stressors andother stimuli

Hypothalamus

Cardiac centersin the medulla

Brain

Increasedvenousreturn

Adrenalglands

Sympatheticnerves

(accelerator nerves)

Parasympatheticnerves(vagus)

Increasein body

temperature

Epinephrineand

NorepinephrineNorepinephrine

Acetylcholine

STROKEVOLUME

HEARTRATE

CARDIACOUTPUTX =

Increases

Decreases

Figure 42.12

I. Extrinsic regulation From 2 systems:

Nervous System &Endocrine System

(~5 L/min)

A Review For You!

• Pump Your Blood

Just in case you need some words of encouragement today….

Have a wonderful day!