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RESPIRATION

RESPIRATION - Warner Pacific Collegeclasspages.warnerpacific.edu/BDuPriest/BIO 102/Lecture 21... · Cutaneous respiration (integumentary ... (frog; only adults are adapted to dry

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Text of RESPIRATION - Warner Pacific Collegeclasspages.warnerpacific.edu/BDuPriest/BIO 102/Lecture 21... ·...

  • RESPIRATION

  • RESPIRATION

    Respiratory system

    Functions

    O2 uptake

    CO2 expulsion

    2

  • Atmospheric Gasses

    Nitrogen (N2)

    78%

    PN2 593 mmHg

    Oxygen (O2)

    21%

    PO2 160 mmHg

    Carbon dioxide (CO2)

    0.05%

    PCO2 0.4 mmHg

    760 mm Hg

    3

  • Elements of Gas Exchange

    Movement directed by concentration &

    pressure gradients

    Diffusion

    Concentration: [high] [low]

    Pressure: H L

    Factors affecting rates of diffusion

    Temperature

    Moisture

    4

  • Mechanisms of Gas Exchange

    Cutaneous respiration (integumentary

    exchange)

    E.g., Annelida, Platyhelminthes, Amphibia

    5

  • Mechanisms of Gas Exchange

    Tracheal respiration

    E.g., Insecta

    6

  • Mechanisms of Gas Exchange

    Gills

    E.g., mollusks, aquatic arthropods, fish,

    amphibians

    7

  • Gills

    FISH GILL

    water flows

    over gills,

    then out

    mouth

    open

    operculum

    closed mouth

    closed

    operculum

    open

    8

  • Gills

    gill arch

    filament

    of gill

    Countercurrent flow

    Efficient O2 uptake

    direction

    of water

    flow

    surface for gas

    exchange

    direction

    of blood

    flow

    9

  • Mechanisms of Gas Exchange

    Lungs

    Compromise efficiency for water retention

    Gas exchange requires pressure differential

    inside / outside body

    E.g., mammals, birds, reptiles, amphibians (most)

    10

  • Lungs

    Slide 10

    Fig. 41.8, p. 713

    AMPHIBIAN

    (salamander;

    still rather like

    fishes, early

    amphibians)

    REPTILE

    (lizard;

    adapted

    to dry

    habitats)

    AMPHIBIAN

    (frog; only

    adults are

    adapted

    to dry

    habitats)

    MAMMAL

    (human;

    adapted to

    dry habitats)

    11

  • Quick Quiz: The primary function of

    the respiratory system of any animal

    is

    A) Gas Exchange

    B) Removal of wastes from the body

    C) Breathing

    D) Circulation

    12

  • Mechanics of Breathing

    Boyles Law

    The pressure of a gas varies

    inversely with its volume

    volume, pressure

    = inhalation

    volume, pressure

    = exhalation

    13

  • Amphibian Respiratory System

    frog_respiration 14

  • Avian Respiratory System

    air

    sacs

    trachea

    air

    sacs

    Structures

    Lungs

    Air sacs

    Oxygenated air

    continually passes

    over lungs

    Need for increased

    efficiency?

    bird_respiration 15

  • Human Respiratory System

    Primary structures

    Oral / Nasal cavities

    Pharynx

    Larynx

    Epiglottis

    Vocal folds

    Trachea

    Bronchi

    Bronchioles

    Alveoli

    human_respiration 16

  • Human Respiratory System

    Other structures

    Hyaline cartilage

    Ciliated epithelia

    Mucus cells

    Diaphragm

    17

  • Mechanics of Breathing

    Inhalation

    Diaphragm contracts

    Moves downward

    External intercostals

    contract

    Elevates rib cage

    Effect

    Volume pressure

    Air forced into lungs

    INWARD BULK

    FLOW OF AIR

    18

  • Mechanics of Breathing

    Exhalation

    Diaphragm relaxes

    Moves upward

    Internal intercostals contract

    Depresses rib cage

    Recoil properties of lungs

    Effect

    Volume pressure

    Air forced out of lungs

    OUTWARD BULK

    FLOW OF AIR

    breathing 19

  • Quick Quiz: Breathing depends on

    A) Changing pressure inside the chest cavity

    B) Changing volume of the chest cavity

    C) The contraction and relaxation of the

    diaphragm

    D) All of the above

    20

  • Lung Capacities

    Total lung capacity

    6 L (adult male)

    Tidal volume

    Normal breath

    0.5 L

    Vital Capacity

    Max. inhale & exhale

    5 L

    Residual volume

    Air not forcibly exhaled

    1 L

    21

  • Gas Exchange & Transport

    The surface of the lung

    Alveoli

    Capillaries

    22

  • Gas Exchange & Transport

    O2 transport

    Red blood cells

    Binds to hemoglobin (98%)

    4 O2 / Hb

    CO2 transport

    Red blood cells

    Some binds to hemoglobin ( 30%)

    Most converted to bicarbonate ion

    Plasma

    Free CO2 ( 10%)

    Bicarbonate ( 60%)

    Buffer 23

  • Gas Exchange &

    Transport

    Movement based on

    partial pressure

    gradients for O2 &

    CO2

    alveolar sacs

    cells of body tissue

    MOIST

    EXHAILED AIR

    120 27

    pulmonary

    arteries

    40 45

    start of

    systematic

    veins

    40 45

    DRY

    INHAILED AIR

    160 0.03

    pulmonary

    veins

    100 40

    start of

    systematic

    capillaries

    100 40

    more than 45 less than 40 24

  • Quick Quiz: Oxygen moves to the

    tissues because

    A) Oxygen concentration is higher in the blood

    than in the tissues

    B) Oxygen concentration is lower in the blood

    than in the tissues

    C) Oxygen partial pressure is higher in the

    blood than in the tissues

    D) Oxygen partial pressure is lower in the

    blood than in the tissues 25

  • Respiratory Control

    Voluntary

    Diaphragm (skeletal muscle)

    Involuntary

    Respiratory centers in medulla oblongata & pons

    Control rate & depth of breathing

    Influenced most by [CO2]

    26

  • Respiratory Disease

    27

  • Environmental Effects on Respiration

    Altitude

    pressure ( PO2)

    Less O2 available

    pressure differential

    Decreased force of diffusion

    28

  • Altitude

    Effects (short term)

    Breathing difficulty

    Muscular / neurological dysfunction

    Altitude sickness (>8,000 ft; ~2,400 m)

    29

  • Altitude

    Acclimatization

    Change in breathing patterns

    2-3 L/min

    Increase cardiac output

    Increased rbc production

    Increased lung & heart mass

    30

  • Environmental Effects on Respiration

    Depth

    external pressure

    1 atm / 10 m (33 ft)

    Human divers

    SCUBA

    Maintain alveolar pressures relative to water

    pressure

    Nitrogen narcosis & the bends

    Descent of 100 ft or more

    N2 forced into blood tissues

    CNS intoxication

    Rapid ascent

    N2 rapidly released from tissues & bubbles 31

  • Depth

    Diving mammals Sperm whales

    Submerge > hour

    Depths > 1,000 m

    Mechanisms Increased O2 storage

    Increased rbc / hemoglobin content

    O2 bound to myoglobin (muscle)

    Decreased O2 usage

    Decreased metabolic rate

    Shunting (selective use)

    Anaerobic metabolism

    32

  • Quick Quiz: Changes in altitude are

    detrimental because

    A) Your ears pop and that makes the oxygen

    come out of your lungs

    B) The blood cant get oxygen out of the air

    C) Air is too dense

    D) Oxygen partial pressure in the lungs are

    different than they are at sea level

    33