8. Respiration and Circulation.pdf

All Notes related to the chapter- Respiration and Circulation
Human Respiratory system.
Gases Exachange

1. Respiration and Circulation
RESPIRATION IN PLANTS AND ANIMALS
AKASH K. BAGADE
CSIR-NET, MH-SET and GATE
WELCOME –BIO-GEEK

2. RESPIRATION
Tostayalive,animalsmusttakeinoxygenandreleaseexcesscarbondioxide.
➢Mostanimalcellsrequireacontinuoussupplyofoxygenforcellularrespiration.
➢Braincellsmaybedamagedbeyondrepairiftheiroxygensupplyiscutoffforonlyafew
minutes.
➢Theexchangeofgasesbetweenanorganismanditsenvironmentiscalledrespiration.
‘Itisabiochemicalprocessofoxidationoforganiccompoundsinanorderlymannerforthe
liberationofchemicalenergyintheformofATP’.
Equation-
Forthis,theprocessofgaseousexchangetakesplacebetweenorganismandtheenvironment.The
siteofgaseousexchangeiscalledtherespiratorysurface.

3. Respiratory exchange is simple physical process.
Respiratory surfaces should have some features for efficient gaseous exchange.
1.It should have large surface area.
2.It should be thin, highly vascular and permeable to allow exchange of gases.
3.It should be moist.

4. GASEOUS EXCHANGE IN PLANTS
➢The shape and structure of plants facilitate gaseous exchange by diffusion.
➢A terrestrial flowering plants has many air spaces between the cells of stem, leaf and
leaves. These air spaces are continuous.
➢Oxygen diffuses into the air spaces through stomata (i.e. pores on leaves and young
stems.) , carbon dioxide and water vapour diffuse out. In aerated soil, the oxygen
dissolves in the film of moisture of water around the root tissue and enters it by
diffusion.
➢Woody flowering plants tree and shrubs have external impervious bark.
➢Gaseous exchange occurs through small pores in the stem surface called lenticels.

5. RESPIRATION IN ANIMALS
➢Ascomparedtoplantsanimalsshowswidevarietyofrespiratorysurfacesororgans.
➢Dependinguponcomplexityoforganizationandsurroundingmedium,certainpartsof
thebodyhavebecomespecializedintodifferenttypesofrespiratoryorgans.
Respiration
Aerobic
Direct
Indirect
Anaerobic

6. Airisabetterrespiratorymediumthanwater

7. Protist, sponges and coelenterates-
1.Habitat-Aquatic
2.Respiratory surface/ organ in these animals is plasma membrane.

8. Flatworms like planaria.
Annelida-earthworm, nereis and leech
Amphibians-frog.
Habitat-aquatic and semi-aquatic
Respiratory surface and organ-plasma membrane, general body surface moist skin

9. Insects-
Habitat-Terrestrial
Respiratory surface/organ-Tracheal tubes and spiracles.
Arachnids-Spiders and scorpions-
Habitat-terrestrial
Respiratory surface/organ-Book lungs

10. Limnus-Arthorpoda
Habitat-Aquatic
Respiratory surface/ organ-Book gills
Amphibian-tadpoles of frog, salamander and newts
Habitat-Aquatic
Respiratory surface/ organ-External gills

11. Fish
Habitat-Aquatic
Respiratory surface/ organ-
Internal gills
Turtle
Habitat-Aquatic
Respiratory surface/ organ-
Cloaca

12. Reptiles, birds and mammals
Habitat-terrestrial
Respiratory surface/ organ-Lungs

13. HUMAN RESPIRATORY SYSTEM
➢The respiratory system brings about inspiration, expiration and exchange of
gases in the lungs.
➢The respiratory system can be divided into on upper respiratory system having
external nares, nasal cavities, internal nares, nasopharynx throat and associated
structures.
➢The lower respiratory system refers larynx, trachea, bronchi , bronchioles and
lungs.

14. Nose
➢The nose has a pair of slits like openings called external nares or nostrils for entry of the air into the nasal
cavity.
➢The nasal cavity is divisible into right and left nasal chambers by a mesethemoid cartilage.
➢Each nasal chamber is further divided into 3 regions.
1.Vestibule-
➢It is the proximal of the nostrils.
➢Skin has hair for filtering air and trapping dust and suspended particles in the inhaled air.
2. Respiratory Part-
➢Called as conditioner.
➢The middle thin walled highly vascular part for warming and moistening the inhaled air.
3. Olfactory or Sensory Chamber-
The uppermost part is lined by olfactory epithelium for detection of smell.

15. Pharynx
➢Itisdivisibleintothreeparts.
➢Thenasopharynxistheuppermostpartfromthenasalchamberitleadsintooropharynxi.e.
commonpassageforfoodandair.
➢Continuesbelowasthelaryngopharynx.
➢Betweenthenasopharynxandoropharynxisthepalatebone.
➢Thepharynxhasasetoflymphoidorganscalledtonsils.

16. Larynx
➢Itiscalledvoicebox.
➢Itcontainsvocalcordsforproducingsound.
➢Thelarynxextendsfromlaryngopharynxandthehyoidbonetothe
trachea.
➢Itishollow,tubularstructure.
➢Itswallmadeupofcartilageplatesheldbymembranesandmuscles.
➢Internallyitislinedbyapairoffoldsofelasticvocalcordstruevocal
cords
➢Voiceisproducedbypassageofairbetweenthevocalcordsand
modulationscreatedbytongue,teeth,lipsandnasalcavity.
➢Thelarynxopensintothelaryngopharynxthroughaslitlikeopening
calledglottis.
➢Thisopeningofthetracheaorwindpipeisguardedbyaleaflike
calledepiglottis.
➢Itpreventstheentryofthefoodintotrachea.

17. Trachea
➢It is long tube –10-12 cm in length.
➢It runs through the neck in front of the esophagus and extends into and up to the
middle of the thoracic cavity.
➢It is supported by C shaped 16-20 rings of cartilage which prevents the collapse
of trachea.
➢Internally lined by ciliated, pseudostratified epithelium and mucus gland that
trap the unwanted particles preventing entry into the lungs.

18. Bronchi and Bronchioles
➢Thetracheadividesintorightandleftprimarybronchiasitreachesthemiddleof
thethoraciccavity.
➢Thebronchiaresupportedinternallyby‘C’shapedincompleteringsofcartilage.
➢Theprimarybronchidividestoformsecondaryandtertiarybronchiwhichlead
intoterminalbronchiolesendingintoalveoli.

19. Lungs
➢Thesearethemainrespiratoryorgansofthehuman.
➢Onepairofspongyandelasticlungsarepresentinthethoraciccavity.
➢Eachlungisenclosedandprotectedbydoublepleuralmembrane,outerparietalandinner
visceralmembrane.
➢Betweenthetwopleuraisapleuralcavityfilledwithalubricatingfluidcalledpleuralfluid.
➢Itissecretedbythemembranes.
➢Therightlungislargeranddividedinto3lobes,whileleftlungisdividedinto2lobes.
➢Eachlobeofthelunghastheterminalbronchiolesendinginabunchofairsacs,eachwith10-
12alveoli.

20. Alveoli
➢These are thin walled lobulated structures, like a bunch of grapes.
➢Each alveolus is surrounded by a network of capillaries of pulmonary arteries and veins.
➢These have highly elastic wall made up of a single layer of squamous epithelium resting on
basement membrane of connective tissue.
➢There are about 700 million alveoli in the lungs and they provide the surface area for exchange
of gases.

21. Diaphragm
➢It is a muscular septum that separates the thoracic and abdominal cavity.
➢It is dome shaped and on contraction it becomes flattened.

22. Mechanism of respiration.
Respiration is a physical process involving exchange of gases
between the atmosphere and the lungs and it results in the
formation of ATP.
It includes the following processes.
1.Breathing
2.External respiration
3.Internal respiration
4.Cellular respiration

23. 1.Breathing-
➢It is a physical process by which gaseous exchange takes place between the
atmosphere and the lungs.
➢It involves inspiration and expiration.
➢Both these steps involved parts of the thoracic cage, the ribs, sternum and the
intercostal muscles and muscles of the diaphragm.

24. Inspiration-
➢During inspiration the atmospheric air is taken in to the lungs.
➢It is occurs due to the pressure gradient formed between the lungs and the atmosphere.
➢It is an active process in which the diaphragm becomes flat and goes downward, the external
intercostal muscles contracts so the ribs and sternum move upward and outward.
➢This leads to an increase in the thoracic volume and a decrease in pressure of thorax and the
lungs.
➢The equalize the low pressure inside the lungs, air from atmosphere rushes into lungs.
➢This is inspiration.

25. Expiration-
➢During expiration, the thorax contracts causing air to be exhaled.
➢The diaphragm relaxes and is pushed upwards.
➢It is becomes dome shaped. The intercostal muscles also relax pulling the rib cage inward and
downward.
➢This causes a decrease in thoracic volume and leads to increase in pressure on the thorax and
the lungs as compared to the atmospheric pressure.
➢So air from the lungs rushes out this is expiration.
➢One inspiration and one expiration is one breath.

26. External respiration/ exchange of gases at the alveolar level
➢Analveolusconsistofalayerofsimplesquamous
epitheliumrestingonbasementmembrane.
➢Itissurroundedbydensenetworkofcapillaries.
Thecapillarywallisalsomadeupofsimple
squamousepitheliumrestingonthinB.M.
➢Bothstructurearesimilarandhavethinmembrane.
➢Togethertheymakeuptherespiratorymembrane
throughwhichgaseousexchangeoccursi.e.
betweenthealveolarairandtheblood.
➢Diffusiontakesplaceanddependsonpartial
pressureofgases.
➢ThepartialpressureofCO2ofbloodenteringthe
pulmonarycapillariesis45mmHgwhilepartial
pressureofCO2inalveolarairis40mmHg.
➢DuetothisdifferenceCO2diffusesfromthe
capillariesintothealveolus.
➢PartialpressureofO2inpulmonarycapillariesis
40mmHgwhileinalveolarairis104mmHg.
➢Duetothisdifferenceoxygendiffusesfromalveoli
tothecapillaries.

27. Lung/Pulmonary volume and lung/Pulmonary capacities
➢While at rest, a healthy adult averages 12 breaths a minute, with each inhalation and exhalation moving about 500
mL of air into and out of the lungs.
➢The volume of one breath is called the tidal volume (VT). The minute ventilation (MV )—the total volume of
air inhaled and exhaled each minute—is respiratory rate multiplied by tidal volume:
MV 12 breaths/min 500 mL/breath
6 liters/min
✓The apparatus commonly used to measure the volume of air exchanged during breathing and the respiratory rate is
a spirometer (spiro-breathe; meter measuring device) or respirometer. The record is called a spirogram.

28. Image take from-Principles of Anatomy and Physiology By G. Tortora 12
th
edition

29. Internal respiration-
ThetwocomponentsofbloodinvolvedintransportofgasesthatisRBCsandplasma.
1.TransportofOxygen-
➢Oxygendoesnotdissolveeasilyinwater,so3%Oxygenistransportedinadissolvedstateby
plasmaand97%OxygenboundwithhemoglobinpresentinRBC.
➢Hemoglobinactastherespiratorycarrier.IthashighaffinityforO2andcombinesittoform
oxyhemoglobin.Oxygenandhemoglobinbindinaneasilyreversiblereactiontoform
oxyhaemoglobin:
➢OnemoleculeofHbhas4Fe++,eachofwhichcanpickupamoleculeofoxygen.
Oxyhaemoglobin is transported from lungs to the tissue where is readily dissociate to release
O2

30. The degree of saturation of Hb with O2 depends on the O2 tension i.e. PO2.
❑100 percent saturation is rare.
❑Maximum saturation of 95 to 97 percent is at PO2 in alveoli is 100mmHg.
❑Degree of saturation decreases with drop in PO2. this begins the dissociation of HbO2.
❑At 30mmHg of PO2, only 50 percent saturation can be maintained.
❑The relationship between HbO2 saturation and oxygen tension PO2 is called oxygen
dissociation curve.
❑The Oxygen dissociation curve is a sigmoid curve and it shifts towards the right due to
increased in H+ concentration, increase in PCO2 and rise in temp. and rise in DPG, 2,3
diphosphoglycerate. It lowers the affinity of hemoglobin for oxygen.
Bohreffect-shiftofoxyhemoglobindissociationcurvedueto
changeinpartialpressureofCO2inblood.
Haldaneeffect-Oxyhemoglobinfunctionasanacid.Itdecreases
PHofblood.DuetoincreaseinH+ions,HCO3-changesinH2O
andCO2

34. Transportof Carbon dioxide

37. Regulation of respiration

42. Transportation in living organism
➢Alllivingorganismshowandimportantpropertyofexchangeifmaterialwiththeirsurroundingaswellas
betweenvariouspartofthebody.
➢Organismtakeupoxygenandnutrientsfromthesurrounding,thesearecirculatedwithinbodyforvarious
metabolicactivities.
➢Thewastegeneratedwithinaregivenoutintosurrounding.
➢Transportationinorganismandanimasoccursbydiffusionandbyactivetransportbetweenthecells,when
surfaceareaifthebodyislargeandthedistancebetweenbodypartsisextremelysmall.
➢Cyclosis-thestreamingofmovementodthecytoplasm.Ex.Paramecium,AmoebaroothaircellsandWBCs.
➢Itistransportationwithincellsorintracellulartransportation.
➢Inspongesandcoelenteratesthesurroundingwateriscirculatedthroughbodycavity.
➢Inflatwormsthereisparenchymalcirculation.
➢Inroundwormstherearenobloodvesselsandbodyfluidismovedaroundviscerabycontractionofbodywall
andmuscles.Thisisextracellulartransport.

43. CIRCULATION IN ANIMALS
Inhigheranimalsthecirculationiscarriedoutbyspecialfluidsbloodandlymph.
BloodVascularSystem-
HigheranimalsfromAnnelidatoChordatahavespecialcirculationfluid,thebloodwhichis
pumpedtothetissuesbytheheartthroughthebloodvessels.
TypesofBloodvascularsystem-
1.OpenCirculation-
✓Bloodiscirculatedthroughthebodycavities.
✓Visceralorgansarelieinthebloodfilledbodycavity.
✓Exchangeofmaterialtakesplacedirectlybetweenbloodandcellsortissueofthebody.
✓Bloodflowswithlowpressure.
✓Doesnotcontainrespiratorypigment.

44. Closed circulation-
✓Blood is circulated all over the body through a network of blood vessels.
✓In this blood flows within the vessels and does not come in contact with cell of
tissue.
✓Exchange o material between blood and body tissue through and intermediate
fluid called lymph.
✓Blood flows with high pressure.
✓It contain respiratory pigment.
Closed circulation divide into two types-
1.Sigle circulation
2.Double circulation.

45. Single Circulation DoubleCirculation

46. CIRCULATORY SYSTEM IN HUMAN
The human circulatory system is composed of blood vascular system and lymphatic system.
1.BLOOD VASCULAR SYSTEM -
In human beings it consist of blood heart and blood vessels.
It is responsible for various functions like
Transport
Homeostasis
Protection

47. BLOOD AND BLOOD COMPOSITION
BLOOD
➢Specialized connective tissue consisting fluid matrix.
➢It is mesoderm in origin.
➢An average adult has about 4-6 lit. of blood.
➢Study of blood is called hematology.
➢It is red in coloured.
➢It is slightly alkaline, salty and viscous fluid.
➢It is heavier than water.

48. COMPOSITION OF
BLOOD
Plasma
Formed
Elements
Blood cells
Erythrocytes Leucocytes
Granulocytes
Neutrophils
Basophils
Eosinophils
Agranulocytes
Monocytes Lymphocytes
B-lymphocytesT-lymphocytes
Blood
Platelets

49. PLASMA
Plasma is the straw colored , viscous fluid forming matrix of the blood.
It is slightly alkaline is nature.
Composition of plasma-
1.water-90-92% of plasma is water.
2.Proteins-They constitute about 6-8 % of it. Fibrinogen, globulins and
albumins are the major plasma proteins.
a. fibrinogen-important clotting factor produced by liver.
b. Globulins-primarily involved in defense mechanism. They are
grouped as alpha, beta and gamma globulins.
c. Albumins-help in osmotic balance. They maintain osmotic
pressure. So helps in maintaining blood volume and pressure.
3. Minerals-plasma contains small amount of minerals like Na+, Ca++,
Mg++, HCO3-, Cl-etc.
4. glucose, amino acids, lipids etc. Dissolved gases. These substances
enter and leave the plasma at regular intervals. hormones, enzymes,
vitamins, cholesterol anticoagulants wastes etc. are also present in the
plasma.

50. Erythrocytes Red Blood cells
✓Itismostabundantofallcellsinblood.
✓Ahealthyadultmanonanaveragehas5.1-5.8millionofRBCsmm-3ofbloodandfemale-4.3-5.2million
mm-3
✓Shapeandstructure-Mammals-biconcaveandwithoutnucleus.Camelandllamaareovalandare
nucleated.
✓TheprocessofformationofRBCsiscallederythropoiesis.
✓RBCsareproducedfromhemocytoblast/reticulocytes.
✓Theerythropoieticorganofthefoetus-liverandspleenandintheadultitismainlyinthebonemarrow.
✓VitaminB12,folicacidandhemeproteinarerequiredforRBCsforproduction.
✓TheoldandwornoutRBCsaredestroyedinSpleen.i.e.graveyardofRBCs.
✓Polycythemia-
✓Erythrocytopenia-
✓Thehormoneerythropoietinproducedbythekidneyandstimulatesthebonemorrowforerythropoiesis.
✓RBCcontainanenzymeCarbonicanhydrous.
FunctionofRBC-
✓1.ResponsibleforthetransportofrespiratorygasesO2andCO2.
✓2.MaintainingpHandviscosityofblood.
❑ThehaemocritistheratioofthevolumeofRBCstototalbloodvolumeofblood.
❑Itisdifferentformenandwomen.

51. White blood cells/ leucocytes
Leucocytesarecolorless,nucleatedandamoeboid
cellslargerthanRBCs.
Duetotheiramoeboidmovementtheycanmoveout
thecapillarywallbyaprocesscalleddiapedesis.
Anormaladulthasonanaverage5000-11000WBCs
permm3ofblood.
DecreaseinnumberofWBCcalledleucopenia.
IncreaseinWBCnumbercalledleukocytosis.
UncontrolledincreaseinnumberofWBCsisatypeof
bloodcancercalledleukemia.
Leucocytesaremainlyconcernedwithdefense
mechanismi.e.protection.
TypesofWBCs-
Thesearecolorless,irregularnucleatedcellsthatshow
polymorphism.Theyclassifiedintotwomaintypes.
Leucocytes
Granulocytes
Neutrophil
s
Basophils
Eosinophils
Agranulocytes
Monocy
tes
Lymphocytes
B-
lymphocytes
T-
lymphocytes

52. Granulocytes-
WBCswithgranularcytoplasm.
Alsocalledaspolymorphonuclearleucocytes.
Theyhavelobulatednucleiindifferentshapes.
Granulocytesareformedfrommyeloidstemcellsandonceformeddonotdivide.
Granulocytesconstituteabout72percentoftotalWBCs.
Granulesareactuallysecretaryvesicleswhichcontainvarioussecretion,enzymesetc.
Dependinguponstainingpropertyofthegranulestheseareclassifiedinto3typesasneutrophils,
basophilsandacidophils.

54. Thrombocytes/Platelets-
Thrombocytesarecellularfragmentsformedfromlargecellscalledmegakaryocytes.
Theseareproducedinbonemarrow.
Theyareverysmallovalshapedcellfragmentswithoutnucleus.
Normalcountofthrombocytesinhumanbloodisabout2.5-4.5lakh/mm3ofblood.
Ifnumberofplateletsdecreasethannormalconditioniscalledthrombocytopenia.
Thisconditioncausesinternalbleeding.
Plateletssecreteplateletfactorswhichareessentialinbloodclotting.
Theyalsosealtherupturedbloodvesselsbyformationofplateletplug/thrombus.
Theysecreteserotoninalocalvasoconstrictor.

55. BLOOD CLOTTING
Bloodflowsfromcutorwoundbutaftersometimeitstopsautomatically,itiscalledclottingof
blood.
Bleedingtime-1-3min.
Clottingtime-2-8min.
Sometimeclotsformedarealsoformedinintactbloodvesselswhichareof2types.
1.THROMBUS CLOT-
✓Staticclotwhichgrowbiggerandbiggerandultimatelyblockthebloodvessels.
✓Ifthisclotisformedinthecoronaryvesselsthenitiscalledcoronarythrombuswhichcan
causeheartattack.
✓Iffoundinbrainthencalledcephalicthrombuscausesparalysis.
2.AMBOLUSCLOT-
✓Movingclotswhichflowwithbloodandultimatelydissolveinblood.
✓Moreharmfulduetoitsmovingnature.

56. CLOTTING MECHANISM
ENZYME CASCADE THEORY
This theory is proposed by Macfarlane and Co-worker.
According to this theory there are 3 steps.
1.Releasing of Thromboplastin
Injured tissue, synthesize exothromboplastinand platelets synthesize endothromoplastin.
Both this thromboplastin react with plasma protein in the presence of Ca++ ions to form
Prothrombinase enzyme i.e. Thrombokinase.
This enzyme inactivate heparin.
2. Conversion of prothrombin into thrombin.
Prothrombinase enzyme convert inactive prothrombin into active thrombin in the presence of
Ca++ ion.
3.Conversion of fibrinogen into fibrin.
Fibrinogen is the soluble protein of plasma. Thrombin protein polymerize monomer of fibrinogen
to form insoluble fibrous protein fibrin.

58. STRUCTURE OF HUMAN HEART