The Respiratory System

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29

• The Respiratory System

2
Learning Outcomes (cont.)

• 29.1 Describe the structure and function of
  each organ in the respiratory system.
• 29.2 Describe the events involved in the
  inspiration and expiration of air.
• 29.3 Explain how oxygen and carbon dioxide are
  transported in the blood.

3
Learning Outcomes (cont.)

• 29.4 Compare various respiratory volumes and
  tell how they are used to diagnose respiratory
  problems.
• 29.5 Describe the causes, signs and symptoms,
  and treatments of various diseases and disorders
  of the respiratory system.

4
Introduction

• Function
• Move air in and out of lungs
• Delivers oxygen (O2)
• Removes carbon dioxide (CO2)
• External respiration in the lungs
• Internal respiration within the hemoglobin

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Organs of the Respiratory System

• Nose
• Pharynx
• Larynx
• Trachea
• Bronchial tree
• Lungs

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Organs of the Respiratory System (cont.)

• Nasal Cavity
• Nasal septum
• Nasal conchae
• Mucous membrane warms and moistens the air
• Cilia eliminate particles

To Diagram
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Organs of the Respiratory System (cont.)

• Paranasal Sinuses
• Air-filled spaces within the skull bones
• Reduce the weight of the skull

• Equalize pressure
• Give the voice its tone

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Organs of the Respiratory System (cont.)

• Pharynx
• Larynx
• Moves air in and out of the trachea
• Produces sounds of the voice
• Cartilage and muscle
• Epiglottis

Reparatory system
Layrnx
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Organs of the Respiratory System (cont.)
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Organs of the Respiratory System (cont.)
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Organs of the Respiratory System (cont.)

• Trachea
• Tubular organ made of rings of cartilage and
  smooth muscle
• Extends from the larynx to the bronchi
• Lined with cells possessing cilia

To Diagram
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Organs of the Respiratory System (cont.)

• Vocal cords
• Between the thyroid cartilage and the cricoid
  cartilage
• Glottis the opening between the vocal cords
• Upper false cords
• Lower true vocal cords

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Organs of the Respiratory System (cont.)

• Bronchial tree branches off the trachea
• Bronchi
• Primary or main stem
• Secondary
• Tertiary
• Bronchioles branch off tertiary bronchi

To Diagram
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Organs of the Respiratory System (cont.)

• Alveoli
• Thin sacs of cells surrounded by capillaries
• Working tissue
• Cellular respiration
• Carbon dioxide released into alveoli
• Oxygen released into the blood

To Diagram
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Organs of the Respiratory System (cont.)
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Lungs

• Cone-shaped organs
• Right lung three lobes
• Left lung two lobes

The lungs contain connective tissue, the
bronchial tree, nerves, lymphatic vessels, and
blood vessels.
To Diagram
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Lungs

• Pleura
• Membranes surrounding the lungs
• Parietal pleura
• Visceral pleura
• Pleural fluid
• Surfactant keeps alveoli from collapsing

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Apply Your Knowledge
SUPER!
ANSWER

• True or False
• The nasal conchae supports the mucus
  membrane and increases the surface area in
  the nasal cavity.
• The larynx functions for both the
  respiratory and digestive systems
• Lower vocal cords produce sound and are the
  true vocal cords.
• Surfactant keeps the alveoli from collapsing
  between inspirations.
• The bronchioles are the working tissue of
  the lungs

T
F
pharynx
T
T
alveoli
F
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The Mechanisms of Breathing
Inspiration

• The diaphragm contracts and flattens
• The intercostal muscles raise the ribs
• Air rich in O2 enters the lungs

Breathing Diagram
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The Mechanisms of Breathing
Expiration

• The diaphragm relaxes
• The intercostal muscles lower the ribs
• Air rich in CO2 exits the lungs

Breathing, or pulmonary ventilation, consists of
inspiration and expiration.
Breathing Diagram
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The Mechanisms of Breathing (cont.)
INSPIRIATION
EXPIRATION
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The Mechanisms of Breathing (cont.)

• Respiratory center of the brain
• Medulla oblongata rhythm and depth of breathing
• Pons rate of breathing

• Other factors
• CO2 levels in the blood
• pH of the blood
• Fear and pain
• Inflation reflex

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The Mechanisms of Breathing (cont.)

• Causes of altered breathing patterns
• Coughing
• Sneezing
• Laughing
• Crying
• Hiccups
• Yawning
• Speaking

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Apply Your Knowledge
Indicated whether each statement refers to (I)
inhalation or (E) exhalation __ The intercostal
muscles lower the ribs __ The diaphragm contracts
or flattens __ The intercostal muscles raise the
ribs __ The diaphragm relaxes __ Air rich in O2
enters the lungs from the atmosphere __ Air rich
in CO2 exits the lungs
ANSWER
E
I
BRAVO!
I
E
I
E
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The Transport of Oxygen and Carbon Dioxide in the
Blood

• Oxygen
• Oxygen binds to hemoglobin oxyhemoglobin
• Bright red in color
• Small amount oxygen remains dissolved in plasma

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The Transport of Oxygen and Carbon Dioxide in the
Blood (cont.)

• Carbon Dioxide
• Binds to hemoglobin carboxyhemoglobin
• Most carbon dioxide goes into the plasma
• RBCs convert it to carbonic acid used to regulate
  the pH of the blood

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Apply Your Knowledge
Describe what happens to carbon dioxide in the
blood.
ANSWER Carbon dioxide can combine with
hemoglobin and form carboxyhemoglobin. Most is
converted to carbonic acid by RBCs.
Super!
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Respiratory Volumes

• Different volumes of air move in and out of lungs
  with different intensities of breathing
• Measured to assess health of respiratory system

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Respiratory Volumes (cont.)
Amount of air that moves in or out of the lungs
during a normal breath
Amount of air that can be forcefully inhaled
following a normal inhalation
Amount of air that can be forcefully exhaled
following a normal exhalation
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Respiratory Volumes (cont.)
Volume of air that always remains in the lungs
even after a forceful exhalation
Amount of air that can be forcefully exhaled
after the deepest inhalation possible
The total amount of air the lungs can hold
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Apply Your Knowledge
Match the following
ANSWER
C

• ___ Amount of air that moves during a normal
  breath.
• ___ Amount of air that always remains in the
  lungs.
• ___ Total amount of air the lungs can hold.
• ___ Amount of air forcefully exhaled after
  deepest inhalation possible.

• A. Total lung capacity
• B. Residual volume
• C. Tidal volume
• D. Vital capacity

B
A
D
Good Job!
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Common Diseases and Disorders of the Respiratory
System

• Snoring
• Due to vibration of soft tissues when muscles of
  the palate, tongue, and throat relax
• Affects approximately 50 of men and 25 of women
  over the age of 40
• Causes daytime sleepiness
• Severity of snoring

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Common Diseases and Disorders (cont.)
Disease Description
Allergic rhinitis Hypersensitivity reaction to various airborne allergens
Asthma A condition in which the tubes of the bronchial tree become obstructed due to inflammation
Atelectasis Collapsed lung one symptom is dyspnea
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Common Diseases and Disorders (cont.)
Disease Description
Bronchitis Inflammation of the bronchi often follows a cold one type of COPD
Chronic obstructive pulmonary disease (COPD) A group of lung disorders that limit airflow to lungs and usually cause enlargement of the alveoli
Emphysema A chronic condition associated with smoking that damages the alveoli one type of COPD
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Common Diseases and Disorders (cont.)
Disease Description
Influenza A viral disease that attacks the respiratory system commonly called the flu
Laryngitis An acute inflammation of the larynx causing hoarseness (dysphonia)
Legionnaires disease Acute bacterial pneumonia caused by Legionnaire bacteria that usually grows in the standing water of air conditioning systems
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Common Diseases and Disorders (cont.)
Disease Description
Lung cancer Cancer closely associated with smoking and exposure to second-hand smoke four types of lung cancers
Pleural effusion A buildup of fluid in the pleural cavity
Pleuritis / Pleurisy Inflammation of the membranes that cover the lungs, known as pleura
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Common Diseases and Disorders (cont.)
Disease Description
Pneumoconiosis Lung diseases that result from years environmental or occupational exposure to different types of dust
Pneumonia/ Pneumonitis An inflammation of the lungs that is most often caused by a bacterial, viral, or fungal infection
Pneumothorax A collection of air in the chest around the lungs, which may cause atelectasis
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Common Diseases and Disorders (cont.)
Disease Description
Pulmonary edema A condition in which fluids fill spaces within the lungs, making it very difficult for the lungs to oxygenate the blood
Pulmonary embolism A blood clot (embolism) that travels usually from the legs and blocks an artery in the lungs
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Common Diseases and Disorders (cont.)
Disease Description
Respiratory distress syndrome (RDS) Syndrome in which a lack of surfactant in the lungs allows the alveoli to collapse on exhalation, resulting in poor oxygenation
Severe acute respiratory syndrome (SARS) A viral respiratory disease that is very contagious and sometimes fatal
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Common Diseases and Disorders (cont.)
Disease Description
Sinusitis An inflammation of the membranes lining the sinuses of the skull
Sudden infant death syndrome (SIDS) A syndrome without characteristic signs or symptoms usually a baby with this disorder simply goes to sleep and never wakes up
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Common Diseases and Disorders (cont.)
Disease Description
Tuberculosis Primarily a respiratory disease caused by various strains of the bacterium Mycobacterium tuberculosis
Upper respiratory (tract) infection (URI) Coryza, or the common cold
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Apply Your Knowledge
Correct!
ANSWER

• Matching
• Syndrome caused by a lack of
  surfactant.
• Obstruction of bronchial tree due to
  inflammation.
• May cause daytime sleepiness.
• Coryza
• A collection of air in the chest.
• Disorders that limit airflow to the lungs.
• An accumulation of fluid in the pleural
  cavity.

1. Snoring
2. Asthma
3. COPD
4. Pneumothorax
5. Pleural effusion
6. RDS
7. URI

F
B
A
G
D
C
E
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In Summary

• 29.1 The function of the respiratory system is
  to move air in and out of the lungs in a process
  known as ventilation, respiration, or breathing.
  
• The larynx contains the vocal cords, which
  stretch between the thyroid and cricoid
  cartilages.
• The lungs contain connective tissue, the
  bronchial tree, nerves, lymphatic vessels, and
  blood vessels.
• The bronchial tree consists of the primary,
  secondary, and tertiary branches of the bronchi,
  the bronchioles, and the alveoli.

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In Summary (cont.)

• 29.2 During inspiration, the diaphragm contracts
  and the intercostal muscles raise the ribs,
  increasing the space in the thoracic cavity.
• This decreases the pressure within the cavity so
  that the air outside the body passively flows
  into the thoracic cavity.
• During expiration, the diaphragm relaxes,
  pushing up into the thoracic cavity, and the
  intercostal muscles lower the ribs, forcing the
  air to flow out of the body.
• Breathing is controlled by the respiratory
  center of the brain, located in the pons and
  medulla oblongata

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In Summary (cont.)

• 29.3 Most of the oxygen in the bloodstream binds
  to the hemoglobin within red blood cells,
  resulting in oxyhemoglobin, although a small
  amount does not bind to hemoglobin and remains
  dissolved in the plasma.
• Carbon dioxide binds to hemoglobin, resulting in
  carboxyhemoglobin. Most of the carbon dioxide
  that enters the blood reacts with water in
  plasma and cerebrospinal fluid to form carbonic
  acid. As carbonic acid ionizes, it releases
  hydrogen and bicarbonate ions, which attach to
  hemoglobin making its way back to the lungs to
  be exhaled.

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In Summary (cont.)

• 29.4 Respiratory volumes are measured to check
  the health of the respiratory system.
• The volumes are tidal volume, inspiratory and
  expiratory reserve volumes, residual volume,
  inspiratory capacity, functional residual
  capacity, vital capacity, and total lung
  capacity. The normal capacities are found in the
  chapter

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In Summary (cont.)

• 29.5 The diseases and disorders of the
  respiratory system are many and varied, as are
  the causes and treatments of these diseases.
• Many of the more common respiratory disorders
  with their individual causes and treatments are
  discussed in detail in the pathophysiology
  section of this chapter.

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End of Chapter 29
The air of ideas is the only air worth
breathing. Edith Wharton