17 Respiratory System

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17 Respiratory System

• I. Overview
• II. Larynx
• III. Trachea
• IV. Bronchi
• V. Bronchioles
• VI. Alveoli

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I. Overview

• A. Nasal cavity
• 1. olfactory epithelium
• 2. respiratory epithelium
• B. Pharynx
• C. Epiglottis
• D. Larynx
• E. Trachea
• F. Bronchi
• G. Lungs / bronchial tree

http//www.nlm.nih.gov/medlineplus/ency/images/enc
y/fullsize/9828.jpg
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II. Larynx

• A. Mucosa
• 1. PSCC epithelium with goblet cells (17.2)
• 2. strat. squamous epith.
• a. vocal cords

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II. Larynx

• Respiratory epithelium (PSCC)
• TEM 17-3, SEM 17-4

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II. Larynx

• A. Mucosa
• 3. lamina propria (17.6)
• a. seromucous glands
• b. laryngeal cartilages
• 1) hyaline elastic
• 2) perichondrium
• c. laryngeal musculature
• 1) skeletal muscle

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III. Trachea

• General organization
• Atlas 12-3
• Mucosa
• lamina propria
• seromucous glands
• C-shaped cartilage ring
• Trachealis muscle
• Adventitia

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III. Trachea

• A. Mucosa
• 1. PSCC epithelium (17.6)

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III. Trachea

• A. Mucosa
• 2. lamina propria (17.6)
• a. seromucous glands
• b. tracheal rings
• 1) hyaline cartilage
• 2) perichondrium
• c. trachealis muscle
• 1) smooth muscle

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IV. Bronchi

• A. Mucosa
• 1. similar to trachea (17.7,17.8)
• 2. lamina propria
• a. seromucous glands
• b. layer of smooth muscle
• c. cartilaginous plates

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IV. Bronchi

• LM of smooth muscle in lamina propria 17-9
• LM of MALT 17-10

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V. Bronchial tree

• Trachea (17.1)
• Primary bronchi
• Secondary (lobar) bronchi
• Tertiary bronchi
• Bronchioles ..
• Terminal bronchioles
• Respiratory bronchioles
• Alveolar duct
• Alveolar sac
• Alveoli (lab)

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V. Bronchial tree

• A. Bronchioles (17.7)
• 1. PSCC - simple col./cub. cil. epith.
• a. few goblet cells
• 2. no cartilage
• 3. no glands
• 4. lamina propria
• a. smooth muscle
• b. elastic fibers

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V. Bronchial tree

• B. Terminal/respiratory bronchioles (17.14)
• 1. simple col./cub. cil. epith.
• 2. smooth muscle fibers

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V. Bronchial tree

• Terminal bronchiole to alveolar duct 17-18

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V. Bronchial tree

• Terminal bronchiole 17-13

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V. Bronchial tree

• C. Respiratory bronchioles / alveolar duct
  (17.16)
• 1. walls interrupted by alveoli

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VI. Alveoli

• A. Alveolar ducts (17.16)
• B. Atria / Alveolar sacs

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VI. Alveoli

• C. 200 mm diameter, 300 million, 140 m2 surf.
  area (17.11), may be collapsed in some specimens
• D. Simple squamous epithelium
• E. Interalveolar septum
• 1. capillaries
• 2. fibroblasts
• 3. elastic reticular fibers
• 4. macrophages (dust cells)

17-19
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VI. Alveoli

• F. Blood-air barrier
• 1. epithelial cell (17.20,17.21)
• 2. fused basal laminae
• 3. endothelial cell
• 4. thickness0.1 to 1.5 mm

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VI. Alveoli

• G. Capillary endothelial cells (17.21,17.22)
• 1. continuous capillary
• 2. flattened endothelial cells

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VI. Alveoli

• H. Type I (squamous alveolar) cells
• 1. 97 of alveolar surface (17.21,17.24)
• 2. tight jxns

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VI. Alveoli

• I. Type II (great alveolar/septal) cells
• 1. cuboidal (17.22,17.26)
• 2. foamy cytoplasm
• 3. secretion forms pulmonary surfactant
• 4. lowers surface tension
• 5. keeps alveoli from collapsing

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VI. Alveoli

• J. Dust cells (17.23)
• 1. macrophages developed from monocytes
• 2. location
• a. interalveolar septum
• b. alveolar surface

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Smokers Lungs

• A smoker's lung is black because of the deposits
  of bi-products from cigarettes. Bi-products such
  as tar and carbon are deposited into the lung
  tissue, affecting its ability to function
  properly.
• Macrophages in the lung digest the bi-products
  and prevent them from depositing into the lung
  tissue. Inclusions can be seen in the macrophage
  if there is too much bi-product to digest.

http//www.medlabweek.homestead.com/organ.html
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Emphysema

• Emphysema is a lung disease involving damage to
  the air sacs (alveoli).There is progressive
  destruction of alveoli and the surrounding tissue
  that supports the alveoli. With more advanced
  disease, large air cysts develop where normal
  lung tissue used to be. Air is trapped in the
  lungs due to lack of supportive tissue which
  decreases oxygenation.

http//www.nlm.nih.gov/medlineplus/ency/imagepages
/17055.htm
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Emphysema
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Emphysema

• Emphysema Normal lung

http//henson1.salisbury.edu/agdigiov/334/Manual/
emphys06.htm
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COPD

• What is COPD?COPD stands for chronic obstructive
  pulmonary (lung) disease. COPD is a general term
  used for several lung diseases. The most common
  diseases in this group are chronic bronchitis and
  emphysema. Chronic asthma may also be included in
  this group. While some patients with COPD have
  only chronic bronchitis or emphysema, most
  patients have a combination of both. COPD worsens
  gradually, causing limited airflow in and out of
  the lungs.
• EmphysemaEmphysema is the destruction, or
  breakdown, of the walls of the alveoli (air sacs)
  located at the end of the bronchial tubes. The
  damaged alveoli are not able to exchange oxygen
  and carbon dioxide between the lungs and the
  blood. The bronchioles lose their elasticity and
  collapse when you exhale, trapping air in the
  lungs. The trapped air keeps fresh air and oxygen
  from entering the lungs.
• What causes COPD?The two primary causes of COPD
  are cigarette smoking and alpha1-antitrypsin
  (AAT) deficiency. Air pollution and occupational
  dusts may also contribute to COPD, especially
  when the person exposed to these substances is a
  cigarette smoker.
• Cigarette smoke causes COPD by irritating the
  airways and creating inflammation that narrows
  the airways, making it more difficult to breathe.
  Cigarette smoke also causes the cilia to stop
  working properly so mucus and trapped particles
  are not cleaned from the airways. As a result,
  chronic cough and excess mucus production
  develop, leading to chronic bronchitis

http//www.cchs.net/health/health-info/docs/2400/2
416.asp?index8709