Respiratory Systems Chapter 37. Respiratory Systems 2Outline Gas Exchange Surfaces Water Environments Gills Land Environments Lungs Human Respiratory

Respiratory Systems

Chapter 37

Respiratory Respiratory SystemsSystems 2

OutlineOutline

Gas Exchange SurfacesGas Exchange SurfacesWater EnvironmentsWater EnvironmentsGillsGills

Land EnvironmentsLand Environments LungsLungs

Human Respiratory SystemHuman Respiratory System Inspiration versus ExpirationInspiration versus Expiration

Respiration and HealthRespiration and HealthRespiratory DisordersRespiratory Disorders


Gas Exchange SurfacesGas Exchange Surfaces

Respiration:Respiration:

The events associated with gas The events associated with gas exchange between the cells and the exchange between the cells and the external environmentexternal environment

Consists ofConsists of

VentilationVentilation

External RespirationExternal Respiration

Internal RespirationInternal Respiration


Gas Exchange SurfacesGas Exchange SurfacesFor diffusion to be effective, gas-For diffusion to be effective, gas-exchange regions must be:exchange regions must be:

MoistMoist

ThinThin

Relatively largeRelatively large

Effectiveness of diffusion is enhanced Effectiveness of diffusion is enhanced by vascularizationby vascularization

Delivery to cells is promoted by Delivery to cells is promoted by respiratory pigments (like respiratory pigments (like hemoglobin)hemoglobin)


Water EnvironmentsWater Environments

Gasses of air can dissolve in waterGasses of air can dissolve in water

HoweverHowever

When saturated, water contains small When saturated, water contains small fraction of the Ofraction of the O22 in same volume of in same volume of air, andair, and

Water is much more viscous than airWater is much more viscous than air

Aquatic animals expend more energy Aquatic animals expend more energy to breathe than do terrestrial animalsto breathe than do terrestrial animals


Gas ExchangeGas ExchangeHydras and planariansHydras and planarians

Small animals with large surface areaSmall animals with large surface areaMost of their cells exchange gases Most of their cells exchange gases directly with the environmentdirectly with the environment

Larger aquatic animalsLarger aquatic animalsOften have gillsOften have gills Finely divided vascularized outgrowths Finely divided vascularized outgrowths of inner body surfaceof inner body surfaceGills of bony fishesGills of bony fishes

Outward extensions of pharynxOutward extensions of pharynx Ventilation is brought about by combined Ventilation is brought about by combined action of the mouth and gill covers action of the mouth and gill covers (operculum)(operculum)

Countercurrent ExchangeCountercurrent Exchange

7Animal Shapes and Gas Exchange

8Anatomy of Gills in Bony Fishes

Respiratory Respiratory SystemsSystems 9Land Environments:Land Environments:

TracheaeTracheae

Insects and other terrestrial Insects and other terrestrial arthropodsarthropods

A respiratory system consists of A respiratory system consists of branched tracheaebranched tracheae

Oxygen enters tracheae at spiraclesOxygen enters tracheae at spiracles

Tracheae branch until end in Tracheae branch until end in tracheoles that are in direct contact tracheoles that are in direct contact with body cellswith body cells

10Tracheae of Insects

Respiratory Respiratory SystemsSystems 11Land Environments:Land Environments:

Lungs of VertebratesLungs of VertebratesTerrestrial vertebrates have evolved lungsTerrestrial vertebrates have evolved lungs

Vascular outgrowths from lower pharyngeal Vascular outgrowths from lower pharyngeal regionregion

Lungs of amphibiansLungs of amphibians Possess a short tracheae which divides into two Possess a short tracheae which divides into two bronchi that open into lungsbronchi that open into lungs

Many also breathe to some extent through skinMany also breathe to some extent through skin ReptilesReptiles Inner lining of lungs is more finely divided in Inner lining of lungs is more finely divided in reptiles than in amphibiansreptiles than in amphibians

Lungs of birds and mammals are elaborately Lungs of birds and mammals are elaborately subdividedsubdivided

All terrestrial vertebrates, except birds, use a All terrestrial vertebrates, except birds, use a tidal ventilation systemtidal ventilation system Air moves in and out by the same routeAir moves in and out by the same route

12Ventilation in Frogs

Respiratory Respiratory SystemsSystems 13Ventilation inVentilation in

Terrestrial Vertebrates Terrestrial Vertebrates Inspiration in mammalsInspiration in mammalsCreate negative pressure in lungsCreate negative pressure in lungs

The rib cage is elevated The rib cage is elevated The diaphragm lowersThe diaphragm lowers Thoracic pressure decreases to less than Thoracic pressure decreases to less than atmospheric pressureatmospheric pressure

Atmospheric pressure forces air into the Atmospheric pressure forces air into the lungslungs

Expiration in mammalsExpiration in mammalsCreate positive pressure in lungsCreate positive pressure in lungs

The rib cage is lowered The rib cage is lowered The diaphragm risesThe diaphragm rises Thoracic pressure increases to more than Thoracic pressure increases to more than atmospheric pressureatmospheric pressure

Forces air out the lungsForces air out the lungs


LungsLungs

Birds use a one-way ventilation Birds use a one-way ventilation mechanism in lungsmechanism in lungs

Results in a higher partial pressure of Results in a higher partial pressure of oxygen in the lungsoxygen in the lungs

Oxygen uptake with each breath is Oxygen uptake with each breath is greater than in other vertebratesgreater than in other vertebrates

15Respiratory System in Birds


Human Respiratory SystemHuman Respiratory System

As air moves through upper As air moves through upper respiratory systemrespiratory system

It is filtered to free it of debrisIt is filtered to free it of debris

Warmed, andWarmed, and

HumidifiedHumidified

When air reaches lungsWhen air reaches lungs

It is at body temperature, andIt is at body temperature, and

Its humidity is 100%Its humidity is 100%

17The Human Respiratory Tract


Human Respiratory SystemHuman Respiratory SystemAir passes from pharynx through glottisAir passes from pharynx through glottis

Larynx and trachea Larynx and trachea

Permanently held open by cartilage ringsPermanently held open by cartilage rings

Facilitates movement of airFacilitates movement of air

When food is swallowedWhen food is swallowed

The larynx rises, andThe larynx rises, and

The glottis is closed by the epiglottisThe glottis is closed by the epiglottis

Backward movement of soft palate Backward movement of soft palate covers the entrance of nasal passages covers the entrance of nasal passages into the pharynxinto the pharynx


Human Respiratory SystemHuman Respiratory System

Trachea dividesTrachea divides

Forms two primary bronchiForms two primary bronchi

Bronchi enter the right and left lungsBronchi enter the right and left lungs

Bronchi branch until there are a great Bronchi branch until there are a great number of tiny bronchiolesnumber of tiny bronchioles

Each bronchiole terminates in an Each bronchiole terminates in an elongated space enclosed by alveolielongated space enclosed by alveoli


VentilationVentilation

Humans breathe using a tidal Humans breathe using a tidal mechanismmechanism

Volume of thoracic cavity and lungs is Volume of thoracic cavity and lungs is increased by muscle contractions that increased by muscle contractions that lower the diaphragm and raise the ribslower the diaphragm and raise the ribs

Create negative pressure in the thoracic Create negative pressure in the thoracic cavity and lungs, and then air flows into cavity and lungs, and then air flows into the lungs during inspirationthe lungs during inspiration

21Inspiration Versus Expiration

22External and Internal respiration

23Hemoglobin


Gas Exchange and TransportGas Exchange and Transport

Breathing stimulusBreathing stimulus Increased HIncreased H++ and CO and CO22 concentrations in the concentrations in the bloodblood

Not affected by ONot affected by O22 levels levelsOxygen diffuses into pulmonary Oxygen diffuses into pulmonary capillariescapillariesMost combines with hemoglobin in red Most combines with hemoglobin in red blood cells to form oxyhemoglobinblood cells to form oxyhemoglobin

COCO22 diffuses out of pulmonary capillaries diffuses out of pulmonary capillariesMost carbon dioxide is transported in the Most carbon dioxide is transported in the form of bicarbonate ionform of bicarbonate ion

Some carbon dioxide combines with Some carbon dioxide combines with hemoglobin to form carbaminohemoglobinhemoglobin to form carbaminohemoglobin

25Hemoglobin Saturationin Relation to Temperature and

Acidity


Respiration and HealthRespiration and Health

Upper Respiratory Tract InfectionsUpper Respiratory Tract Infections

Strep ThroatStrep Throat

Streptococcus pyogenesStreptococcus pyogenes

SinusitisSinusitis

Infection of sinusesInfection of sinuses

TonsillitisTonsillitis

Infection of tonsilsInfection of tonsils

LaryngitisLaryngitis

Infection of larynxInfection of larynx

27CommonBronchial and Pulmonary

Diseases


Respiration and HealthRespiration and HealthLower Respiratory Tract InfectionsLower Respiratory Tract Infections

Acute bronchitisAcute bronchitis

Infection of primary and secondary Infection of primary and secondary bronchibronchi

PneumoniaPneumonia

Viral or bacterial infection of the lungs Viral or bacterial infection of the lungs where bronchi and alveoli fill with fluidwhere bronchi and alveoli fill with fluid

Pulmonary tuberculosisPulmonary tuberculosis

Caused by tubercle bacillusCaused by tubercle bacillus


DisordersDisorders

Pulmonary fibrosisPulmonary fibrosis

Fibrous connective tissue builds up in Fibrous connective tissue builds up in the lungsthe lungs

Chronic bronchitisChronic bronchitis

Airways inflamed and filled with mucusAirways inflamed and filled with mucus

EmphysemaEmphysema

Alveoli are distended and walls are Alveoli are distended and walls are damaged reducing surface area damaged reducing surface area available for gas exchangeavailable for gas exchange


DisordersDisorders

AsthmaAsthma

Airways are unusually sensitive to Airways are unusually sensitive to specific irritantsspecific irritants

When exposed to the irritants, the When exposed to the irritants, the smooth muscles in the bronchioles smooth muscles in the bronchioles undergo spasmsundergo spasms

Lung CancerLung Cancer

Begins with thickening and callusing Begins with thickening and callusing of the cells lining the airwaysof the cells lining the airways


ReviewReview

Gas Exchange SurfacesGas Exchange SurfacesWater EnvironmentsWater EnvironmentsGillsGills

Land EnvironmentsLand Environments LungsLungs

Human Respiratory SystemHuman Respiratory System Inspiration versus ExpirationInspiration versus Expiration

Respiration and HealthRespiration and HealthRespiratory DisordersRespiratory Disorders

Respiratory Systems

Ending Slide Chapter 37

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Respiratory Systems Chapter 37. Respiratory Systems 2Outline Gas Exchange Surfaces Water Environments Gills Land Environments Lungs Human Respiratory