Ch. 36 Energy and Metabolism III: Circulation

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Ch. 36 Energy and Metabolism III Circulation

• Kenneth Wong, Period 1

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BLOOD

• Blood chemical highway connecting cells
• Delivers nutrients oxygen
• Carries away wastes (urea, CO2)
• Has hormones, enzymes, antibodies

Blood is 8 of your body weight!
www.colorado.edu/epob/ epob1220lynch/11blood2.html

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• Blood is 60 plasma and 40 red white blood
  cells platelets
• Blood Type of connective tissue

www.lima.ohio-state.edu/.../Blood20400X.jpg
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Plasma

• Almost all molecules in blood are dissolved in
  plasma (except O2 and CO2)
• Straw-colored liquid
• Has plasma proteins
• Make osmotic potential of blood than that of
  surrounding interstitial fluid
• Prevents excessive loss of fluid from bloodstream
  to tissues
• Transport fats, cholesterol, insoluble
  molecules

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It might seem like plasma is less important than
the blood cells it carries. But that would be
like saying that the stream is less important
than the fish that swims in it. You can't have
one without the other.
Quote and pic. from
sln.fi.edu/ biosci/ blood /plasma.html
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The 3 Types of Plasma Proteins
distance.stcc.edu/BIOL102 /images/albumin.jpg

• ALBUMIN
• Maintains
• high osmotic
• potential
• FIBRINOGEN
• Blood clotting - - - - - - ?
• GLOBULINS
• Include
• antibodies

Campbell Biology 6th Edition Images CD
www.microscopies.com/.../ Plaquettes327-FG.jpg
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RED BLOOD CELLS

• (aka Erythrocytes) specialized for O2 transport
• No nucleus, mitochondria, or other structures
• Filled with hemoglobin
• Short life span, but can fold in vessels
• New ones made in bone marrow

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Fact 2 million red blood cells in your body are
dying each second (but new ones are made in
bone marrow _at_ same rate)
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http//images.encarta.msn.com/xrefmedia/sharemed/t
argets/images/pho/35a5c/35A5C297.jpg
WHITE BLOOD CELLS

• aka Leukocytes
• Much less common than red blood cells

• Defend body against foreign particles (ex-
  viruses bacteria)
• Move by pseudopodia many are phagocytic

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WHITE BLOOD CELLS (continued)

• Formed in spleen, bone marrow, other tissues
• Often destroyed when fighting infection (ex- pus)
• Not confined to blood vessels

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PLATELETS (the 4th component of blood)

• Colorless, sometimes oval shape, smaller than red
  blood cells
• Fragments of large cells of bone marrow
• Little bags of chemicals that start blood clotting

www.mcl.tulane.edu/.../ Blood/Platelets.html
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Blood Clotting Process
http//www.irvingcrowley.com/cls/clotting.gif
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http//www.irvingcrowley.com/cls/clotting.gif
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http//www.irvingcrowley.com/cls/clotting.gif
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HEMOPHILIA

• Group of genetically determined diseases that
  affect clotting
• In most common type, one of factors (Factor VIII)
  involved in chain of reactions is defective
• Blood doesnt clot
• Hemophiliacs lacking this must be treated with
  Factor VIII taken from normal blood

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THE CARDIOVASCULAR SYSTEM ( heart vessels)

• Systems through which blood transported in
  animals vary in complexity structure
• Earthworm closed system, but hearts little
  more than larger muscular vessels
• Mollusks chambered heart, open circulatory stem
• Vertebrate chambered heart, blood vessels form
  closed system

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Open and closed circulatory systems
Campbell Biology 6th Edition Images CD
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The Blood Vessels

• Heart ? large arteries ? smaller branching
  arteries ? smallest arteries (arterioles) ?
  capillaries ? small veins (venules) ? larger
  veins ? heart
• Aorta 2.5 cm largest artery
• Vena cava 3 cm largest vein

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Blood Vessels (continued)
http//www.sirinet.net/jgjohnso/vesselstructure.j
pg
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Arteries vs. Veins

• Arteries
• Have thick strong walls of 3 layers
• Inner layer endothelium
• Middle layer is smooth muscle elastic tissues
• Outer layer is made of collagen is elastic
• Stay open when empty
• Veins
• Also have 3 layers
• Thinner, less elastic, more pliable
• Collapse when empty

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Capillaries and Diffusion

• Walls of capillaries only 1 layer of cells
• Gases, hormones, other materials are exchanged
  by diffusion

web.buddyproject.org/ web019/web019/Capimage.html

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Evolution of the Heart

• Fish
• Single heart divided into atrium (receiving area
  of blood) ventricle (pumping area from which
  blood expelled)
• Blood pumped to capillaries in gills
• Gets O2 blood flows slowly to tissues

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The structure and function of fish gills
Campbell Biology 6th Edition Images CD
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• Amphibians
• 2 atria ? one receives oxygenated blood, one
• receives deoxygenated
• Both empty into single ventricle
• Vessels leading through lungs also carry some of
  deoxygenated blood to moist skin
• Major site of gas exchange in amphibians is the
  skin

www.mypkhome.com/ frog/frog-7.jpg
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Birds Mammals

• Heart separated into right heart and left heart,
  each with an atrium ventricle
• Right heart receives blood pumps to lungs
• From lungs, oxygenated blood returns to left
  heart pumped to body
• FULL separation of 2 types makes high metabolic
  rate possible ? constant body temp. high level
  of activity

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Different Cardiovascular Systems of Vertebrates
Campbell Biology 6th Edition Images CD
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The Human Heart

• Made of cardiac muscle
• Returning blood enters right atrium through 2
  large veins superior inferior venae cavae
• Blood returning from lungs enters left atrium
  through pulmonary veins
• Atriums contract simultaneously
• Blood goes through valves into ventricles
• Right ventricle pushes blood to lungs
• Left ventricle propels blood into aorta
• Valves close to prevent backflow

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www.edu.pe.ca/westroyalty/ web2001/6A/Monique.htm
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• Cardiac output total volume of blood
• pumped by heart per
  min.
• Heart rate
  (beats/min)
• x
• Stroke volume (L /
  beat)
• Heart also serves as a hormone-secreting
• organ (ex. hormone- cardiac peptide)

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Regulation of Heartbeat

• Sinoatrial node pacemaker
• Specialized cardiac muscle cells that
  spontaneously initiate own impulse contract
• Impulse spreads through heart, especially through
  gap junctions that connect cytoplasm of cells

http//www.cardioweb.co.uk/ecg/ecgimages/page22/pa
ge22small.jpg
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• Traveling impulse stimulates 2nd area of nodal
  tissue, the atrioventricular node
• Impulses are carried from this node to bundle of
  His
• This bundle is only electrical bridge between
  atria ventricles
• Atrioventricular node consists of slow-conducting
  fibers
• This creates delay between contractions of atrium
  ventricles

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• Electrocardiogram asses hearts capability of
  initiating and transmitting impulses

http//www.manbir-online.com/grafics4/ecg-stress-1
.gif

• Parasympathetic stimulation- slows
• Sympathetic stimulation- increases rate
• Adrenaline also increases heartbeat

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Vascular Circuitry

• Pulmonary Circuit
• Right ventricle ? pulmonary arteries (fully
  deoxygenated) ? both lungs ? capillaries aveoli
  ? pulmonary veins (fully oxygenated) ? left
  atrium of heart
• Remember An artery is only a vessel that pumps
  away from heart. Not necessarily oxygenated.
  (Conversely, a vein is a vessel that goes to the
  heart. Not necessarily unoxygenated.)

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http//www.unis.org/UNIScienceNet/Alveoli_cap.jpg
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Vascular Circuitry (continued)

• Systemic Circuit
• Much larger than pulmonary circuit
• Subdivisions
• Coronary arteries- bring oxygen to heart
• Another artery provides oxygen to brain
• Several portal systems blood flows through 2
  
• distinct capillary beds (ex- gut
  liver)

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Blood Pressure

• Blood pressure measure of force per unit
• area with which
  blood
• pushes against
  walls of
• blood vessels
• Described in terms of how high it can push column
  of mercury
• Systolic blood pressure- when ventricles contract
  
• Diastolic blood pressure- when ventricles relax

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BLOOD PRESSURE (continued)

• Rate of blood flow directly proportional to blood
  pressure
• Fluid flow through a tube is proportional to the
  4th power of the radius of the tube (r4)
• Diameter of arterioles can be altered by rings of
  smooth muscle in vessel walls
• Rate of blood flow dependent on requirements of
  animal
• As blood flows through vascular circuitry,
  pressure gradually drops

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Valves in veins prevent backflow of blood
Campbell Biology 6th Edition Images CD
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Diseases of Heart Blood Vessels

• 55 of cardiovascular deaths caused by heart
  attacks
• Result of insufficient supply of blood to area of
  heart muscle
• Cardiac cells die
• Caused by blood clot or blockage of blood vessel

http//www.centenarycardiology.com
/Conditions/heartattack.gif
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• Angina pectoris- heart muscle receives
• insufficient blood
  supply
• Stroke- interference w/ blood supply to
• brain
• Atherosclerosis- linings of arteries thicken
• inner surfaces become roughened by
• deposits
• Hypertension- chronically increased
• arterial blood pressure

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CAUSES OF THESE DISEASES

• High blood pressure
• High cholesterol
• Relative proportioins in which it is carried in
  bloodstream
• HDLs- protectect against atherosclerosis
• LDLs- contribute to disease process
• Cigarette smoking
• Lack of physical activity
• Bad Diet
• Hereditary factors

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Cardiovascular Regulating Center

• Center located in medulla (part of brain)
• Integrates reflexes that control blood pressure
• Blood-pressure reflex
• example of negative feedback
• When pressure falls, heart rate increases blood
  vessels constricted to raise pressure

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Lymphatic System

• When excessive amounts of fluid are lost, tends
  to pool producing swelling called edema
• Fluids (lymph) lost from blood to tissues are
  collected by lymphatic system
• Lymph moved by contractions of muscles
• Lymph nodes
• Where lymphocytes made
• Clean lymph before it enters the blood

http//www.med.umich.edu/opm/ newspage/images/lymp
h20system.gif