The Respiratory System

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The Respiratory System

• Chapter 17

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Introduction

• Organs nose, pharynx, larynx, trachea, bronchi,
  lungs
• Respiration exchange of O2 / CO2 between
  atmosphere, blood and cells
• Cardiovascular and respiratory systems work
  together to supply O2 to and remove CO2 from cells

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The Anatomy and Functions of the Nose
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The Anatomy and Functions of the Nose (contd.)
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The Anatomy and Functions of the Nose (contd.)

• External nares openings into the nose
• Internal nares connect nose and pharynx
• Coarse hairs line the vestibules
• Filter large dust particles

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The Anatomy and Functions of the Nose (contd.)

• Three shelves formed by turbinate bones
• Superior, middle and inferior meatus
• Olfactory receptors located in the superior
  meatus
• Functions of internal nose
• Warm and moisturize air, smell, speech tone

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The Structure and Functions of the Pharynx
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The Structure and Functions of the Pharynx
(contd.)

• Functions
• Passageway for food
• Passageway for air
• Resonating chamber for speech

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The Structure and Functions of the Pharynx
(contd.)

• Divisions
• Nasopharynx internal nares and Eustachian tubes
• Oropharynx connection to mouth (fauces)
• Laryngopharynx connects with esophagus and
  larynx

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The Larynx or Voice Box
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The Larynx or Voice Box (contd.)

• Supporting cartilage
• Thyroid cartilage largest, Adams apple
• Epiglottis prevents food and liquids from
  entering trachea
• Cricoid connects with first tracheal ring

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The Larynx or Voice Box (contd.)

• Supporting cartilage
• Arytenoid attach to vocal cords and laryngeal
  muscles
• Corniculate and cuneiform connect epiglottis to
  arytenoid cartilage

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The Larynx or Voice Box (contd.)

• Form and function
• Mucous membrane two pairs of folds
• False vocal cords
• True vocal cords
• Glottis opening over true vocal cords
• Sound produced by air vibrating vocal cords

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The Larynx or Voice Box (contd.)
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The Trachea or Windpipe
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The Trachea or Windpipe (contd.)

• Tubular passageway for air
• Anterior to esophagus
• Extends from cricoid cartilage to fifth thoracic
  vertebra
• Pseudostratified epithelium with cilia and goblet
  cells
• Smooth muscle and connective tissue

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The Trachea or Windpipe (contd.)

• Supporting cartilage stack of Cs
• Cough reflex stimulated by foreign object
• Tracheostomy done if object cannot be expelled
• Usually done between second and third tracheal
  cartilages
• Can be closed when object removed

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The Bronchi and the Bronchial Tree
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The Bronchi and the Bronchial Tree (contd.)
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The Bronchi and the Bronchial Tree (contd.)

• Trachea branches into left and right primary
  bronchi
• Primary bronchi branch into secondary bronchi
• Secondary bronchi branch into tertiary bronchi

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The Bronchi and the Bronchial Tree (contd.)

• Tertiary bronchi branch into bronchioles
• Bronchioles branch into terminal bronchioles

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The Anatomy and Function of the Lungs
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The Anatomy and Function of the Lungs (contd.)

• Pleural membrane encloses and protects lungs
• Parietal pleura outer
• Visceral pleura inner
• Pleural cavity between pleura, prevents friction
• Pleurisy inflammation of parietal pleura

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The Anatomy and Function of the Lungs (contd.)

• Segments supplied by each tertiary bronchi
• Lobules
• Wrapped in elastic connective tissue
• Each has lymphatic, arteriole, venule,
  bronchioles
• Terminal bronchioles subdivide into respiratory
  bronchioles

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The Anatomy and Function of the Lungs (contd.)

• Respiratory bronchioles divide into alveolar
  ducts
• Alveoli surround the alveolar ducts
• Grapelike outpouching
• Surrounded by capillary network

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The Anatomy and Function of the Lungs (contd.)

• Respiratory gases pass through alveolar-capillary
  membrane
• Coated with surfactant reduces surface tension

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The Respiration Process
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The Respiration Process (contd.)

• Ventilation or breathing
• Inhalation
• Diaphragm and intercostal muscles contract
• Pressure decreases in lungs air rushes in
• Exhalation
• Diaphragm and intercostal muscles relax
• Pressure increases in lungs air rushes out

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The Respiration Process (contd.)

• External respiration
• Exchange of gases between lungs and blood
• Internal respiration
• Exchange of gases between blood and body cells

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The Respiration Process (contd.)

• Partial pressure of gas
• Amount of pressure gas contributes to total
  pressure
• Directly proportional to concentration of gas
• Gas diffuses from high partial pressure to low
  partial pressure

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The Respiration Process (contd.)

• Lung capacity
• Functional residual capacity volume of gas in
  lungs at the end of a normal tidal volume
  exhalation
• Inspiratory capacity maximum volume of gas that
  can be inhaled from end of resting exhalation

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The Respiration Process (contd.)

• Lung capacity
• Total lung capacity volume of gas in lungs at
  end of maximum inspiration
• Vital capacity maximum volume of air that can be
  expelled at normal rate of exhalation after a
  maximum inspiration

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Animation Respiration
Click Here to Play Respiration Animation
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Animation Intercostal Retractions

• The following animation illustrates how a
  restricted airway reduces pressure within the
  chest cavity, causing the intercostal muscles to
  move inward, or retract

Click Here to Play Intercostal Retractions
Animation
35
Animation Asthma

• Read the Health Alert on Asthma in your textbook.
• Now watch the asthma animation.

Click Here to Play Asthma Animation
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Summary

• Named the organs of the respiratory system and
  their functions
• Discussed the parts of the nose, the pharynx, the
  larynx and the trachea
• Described the bronchial tree

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Summary (contd.)

• Discussed the structure and function of the lungs
  including gas exchange
• Described the respiratory process