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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!