le 42-14 capillary red blood cell 15 µm tissue cell capillary net fluid movement out interstitial...
TRANSCRIPT
LE 42-14
Capillary Red bloodcell
15 µm
Tissue cell
CapillaryNet fluidmovement out
INTERSTITIAL FLUID
Net fluidmovement in
Blood pressureOsmotic pressure
Inward flow
Direction ofblood flow
Pre
ssu
re
Outward flow
Venous endArterial end of capillary
Fluid Return by the Lymphatic System
• The lymphatic system returns fluid to the body from the capillary beds
• This system aids in body defense
Blood Composition and Function
• Blood consists of several kinds of cells suspended in a liquid matrix called plasma
• The cellular elements occupy about 45% of the volume of blood
Plasma
• Blood plasma is about 90% water• Among its solutes are inorganic salts called
electrolytes• Plasma proteins influence blood pH, osmotic
pressure, and viscosity• Various plasma proteins function in lipid
transport, immunity, and blood clotting
LE 42-15
SodiumPotassiumCalciumMagnesiumChlorideBicarbonate
Osmotic balance,pH buffering, andregulation ofmembranepermeability
Plasma 55%
Constituent Major functions
Water Solvent forcarrying othersubstances
Ions (blood electrolytes)
Albumin Osmotic balance,pH buffering
Plasma proteins
Fibrinogen
Immunoglobulins(antibodies)
Clotting
Defense
Nutrients (such as glucose, fatty acids, vitamins)Waste products of metabolismRespiratory gases (O2 and CO2)Hormones
Substances transported by blood
Cellular elements 45%
Cell type Number Functionsper µL (mm3) of blood
5–6 million Transport oxygenand help transportcarbon dioxide
Leukocytes(white blood cells)
5,000–10,000Defense andimmunity
Monocyte
Basophil
Eosinophil
Lymphocyte
Neutrophil
PlateletsBlood clotting250,000–
400,000
Erythrocytes(red blood cells)
Separatedbloodelements
Erythrocytes
• Red blood cells, or erythrocytes, are by far the most numerous blood cells
• They transport oxygen throughout the body
Leukocytes
• There are five major types of white blood cells, or leukocytes: monocytes, neutrophils, basophils, eosinophils, and lymphocytes
• They function in defense by phagocytizing bacteria and debris or by producing antibodies
Platelets
• Platelets function in blood clotting
LE 42-16Pluripotent stem cells(in bone marrow)
Myeloidstem cells
Lymphoidstem cells
B cells T cells
Lymphocytes
Erythrocytes
Eosinophils
Basophils
Neutrophils
MonocytesPlatelets
Blood Clotting• A cascade of complex reactions converts
fibrinogen to fibrin, forming a clotEndothelium ofvessel is damaged,exposing connectivetissue; platelets adhere
Platelets form a plug Seal is reinforced by a clot of fibrin
Collagen fibersPlatelet plug
Platelet releases chemicalsthat make nearby platelets sticky
Clotting factors from:
PlateletsDamaged cellsPlasma (factors include calcium, vitamin K)
Prothrombin Thrombin
Fibrinogen Fibrin
Fibrin clot Red blood cell
5 µm
• One type of cardiovascular disease, atherosclerosis, is caused by the buildup of cholesterol within arteries
Connectivetissue
Smoothmuscle Endothelium
50 µmNormal artery Partly clogged artery 250 µm
Plaque
• Hypertension, or high blood pressure, promotes atherosclerosis and increases the risk of heart attack and stroke
• A heart attack is the death of cardiac muscle tissue resulting from blockage of one or more coronary arteries
• A stroke is the death of nervous tissue in the brain, usually resulting from rupture or blockage of arteries in the head
Concept 42.5: Gas exchange occurs across specialized respiratory surfaces
• Gas exchange supplies oxygen for cellular respiration and disposes of carbon dioxide
• Animals require large, moist respiratory surfaces for adequate diffusion of gases between their cells and the respiratory medium, either air or water
LE 42-19
Respiratorymedium(air or water)
Organismallevel
Cellular level
Energy-richfuel molecules
from food
Respiratorysurface
Circulatory system
Cellular respiration
CO2O2
ATP
LE 42-20a
Gills
Coelom
Tube foot
Sea star
LE 42-20b
Gill
Parapodia
Marine worm
LE 42-20c
Gills
Scallop
LE 42-20d
Gills
Crayfish
LE 42-21
Gillarch
Waterflow Operculum
Gillarch
Bloodvessel
Oxygen-richblood
Water flowover lamellaeshowing % O2
Gillfilaments
O2
Oxygen-poorblood
Lamella
15%40%
70%
100%
90%
60%
30% 5%
Blood flowthrough capillariesin lamellaeshowing % O2
Countercurrent exchange
Tracheal Systems in Insects
• The tracheal system of insects consists of tiny branching tubes that penetrate the body
Air sacs Tracheae
Spiracle
LE 42-22bBodycell
TracheoleAirsac
Trachea
Air Body wall
MyofibrilsTracheoles Mitochondria
2.5 µm
Lungs
• Spiders, land snails, and most terrestrial vertebrates have internal lungs
LE 42-23
Branchfrompulmonaryvein(oxygen-richblood)
Terminalbronchiole
Branchfrompulmonaryartery(oxygen-poorblood)
Alveoli
50 µ
m
Colorized SEMSEM
Nasalcavity
50 µ
m
Leftlung
Heart
Larynx
Pharynx
EsophagusTrachea
Rightlung
Bronchus
Bronchiole
Diaphragm
How an Amphibian Breathes
• An amphibian such as a frog ventilates its lungs by positive pressure breathing, which forces air down the trachea
How a Mammal Breathes
• Mammals ventilate their lungs by negative pressure breathing, which pulls air into the lungs
• Lung volume increases as the rib muscles and diaphragm contract
LE 42-24
Rib cageexpands asrib musclescontract
Airinhaled
Lung
Diaphragm
INHALATIONDiaphragm contracts
(moves down)
Rib cage getssmaller asrib musclesrelax
Airexhaled
EXHALATIONDiaphragm relaxes
(moves up)
How a Bird Breathes
• Birds have eight or nine air sacs that function as bellows that keep air flowing through the lungs
• Air passes through the lungs in one direction only
Anteriorair sacs
LungsPosteriorair sacs
Trachea
Air
Lungs
Air
Air tubes(parabronchi)in lung 1 mm
EXHALATIONAir sacs empty; lungs fill
INHALATIONAir sacs fill
Control of Breathing in Humans
• Breathing• control• centers
• Cerebrospinal• fluid
• Medulla• oblongata
• Pons
• Carotid• arteries
• Aorta
• Diaphragm
• Rib muscles
Concept 42.7: Respiratory pigments bind and transport gases
• The metabolic demands of many organisms require that the blood transport large quantities of O2 and CO2
Respiratory Pigments
• Respiratory pigments, proteins that transport oxygen, greatly increase the amount of oxygen that blood can carry
• The respiratory pigment of almost all vertebrates is the protein hemoglobin, contained in erythrocytes
LE 42-28
Polypeptide chain
O2 unloadedin tissues
O2 loadedin lungs
Iron atomHeme group
LE 42-29a
O2 unloaded fromhemoglobinduring normalmetabolism
O2 reserve that canbe unloaded fromhemoglobin totissues with highmetabolism
P and hemoglobin dissociation at 37°C and pH 7.4O2
P (mm Hg)O2
Tissues duringexercise
Tissues at rest
Lungs
1008060402000
20
40
60
80
100
O2
satu
rati
on
of
hem
og
lob
in (
%)
LE 42-29b
Bohr shift:additional O2 released fromhemoglobin atlower pH(higher CO2
concentration)
pH and hemoglobin dissociation
P (mm Hg)O2
1008060402000
20
40
60
80
100
O2
satu
rati
on
of
hem
og
lob
in (
%)
pH 7.2
pH 7.4