Respiration

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Unit 3

• Respiration

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Functions of Respiratory System

• Carries out Gas exchange
• Forms speech sounds (Phonation)
• Defends against microbes
• Influences arterial concentrations of chemical
  messengers by removing some or adding some to
  pulmonary capillary blood
• Traps and dissolves blood clots

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Types of Respiration

• Breathing Inspiration and Expiration
• External Exchange of Carbon-di-oxide and Oxygen
  between body and environment
• Internal Exchange of gases between blood and
  tissue fluid
• Cellular Production of ATP in cells

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The respiratory tract
FYI (???) Lungs do not differentiate between
filtered and non-filtered cigarettes!!!
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        GAS INHALED   -vs-    EXHALED
            O2      20.71                14.6
            CO2     0.04                 4.0
            H2O     1.25                 5.9
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Lung organization

• Spongy appearance
• Thin-walled air sac

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Lung bronchus
Pulmonary artery
Bronchus
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Ventilation

• Inspiration or Inhalation
• Breathing in of Oxygen
• Air is filtered, warmed and moistened
• Expiration or Exhalation
• Breathing out of Carbon-di-oxide
• Air cools down and loses moisture

Why do you have a runny nose when you cry???
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Definitions to remember

• Tidal Volume
• Normal amount of air moving in and out with
  each breath
• Inspiratory Reserve Volume
• Forced inhalation to increase volume of air in
• Expiratory Reserve Volume
• Forced exhalation to increase volume of air out
• Vital Capacity
• Maximum volume of air that can be held by lungs
• Residual Volume
• After deep breath, the air that remains in lungs

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Air inhaled
Air exhaled
External Respiration
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External Respiration
Neuronal signal initiates rib cage movement
Rib muscles contract (rib cage expands)
Rib muscle relaxes (rib cage contracts)
Diaphragm contracted (moves down)
Diaphragm relaxed (moves up)
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The lung alveoli (Air sacs)
Site of gas exchange between lungs and external
environment
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• Lined with Surfactant (film of lipoprotein) to
  lower surface tension and prevent closing of the
  air sacs

Infant Respiratory distress syndrome
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Gas Exchange Diffusion of gases
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External Respiration pathway
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• H HCO3 H2CO3
  CO2 H2O
• H Hydrogen ion given up by hemoglobin
• HHb(hemoglobin) H Hb(deoxyhemoglobin)
• H2CO3 Carbonic acid mediated by enzyme
  Carbonic anhydrase
• HCO3? Bicarbonate ion
• Partial pressure of CO2 (PCO2) greater in tissue
  CO2 diffuses out of the tissue into blood
• Hb ? O2 HbO2 (Oxyhemoglobin)
• ? O2 Oxygen enters the body
• PO2 greater in blood O2 enters tissues from
  blood

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Internal Respiration

• Exchange of gases between blood and tissue fluids
• HbO2 Hb O2
• Oxyhemoglobin Deoxyhemoglobin O2
• Partial Pressure of O2 (PO2) of tissue lower than
  PO2 of blood O2 enters tissues from blood
• PCO2 of blood lower than PCO2 of tissues CO2
  leaves tissues and enters blood

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Binding capacity of hemoglobin

• Partial pressure of Oxygen
• Temperature
• pH