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Respiratory System Notes:
General Overview:
wiki.medpedia.com/Formoterol
http://wiki.medpedia.com/Formoterolhttp://wiki.medpedia.com/Formoterol8/12/2019 Animal Histology - Respiratory Notes
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Respiratory System
Conducting Zone Respiratory Zone(site of gas exchange)
(Nose, Pharynx, Larynx, Bronchi (bronchioles, alveolarand Bronchioles) ducts/saccules, alveoli)
http://webanatomy.net/histology/respiratory/respiratory_zones.jpg
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*Note: respiratory epithelium(AKA pseudostratified ciliated columnar epithelium w/Goblet Cells)*
Conducting Zone:
I. Nose/Nasal Septum2 nasal cavity separated by a cartilaginous (hyaline) nasal septum w/a mucus
membrane.
http://calder.med.miami.edu/pointis/normbr.html
1. inside cavities: EPITHELIUM changesto stratified squamous non-keratinized pseudostratified ciliatedcolumnar type with goblet cells in the inner respiratory region.
a. epithelium sits on a lamina propri a with serous and mucusglands , and HYALINE cartilage
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2. cavities also lined with olfactory epithelium (ciliated):a. Cells = sustenacular cells, olfactory cells, basal cellsb. Glands of Bowman and Ducts
Blue arrow - Sustantacular cell;Red arrow - Olfactory Cell (Bipolar Neuron);Green arrow - Basal Cell
3. bony projections from wall of nasal cavity = nasal conchae a. covered by respiratory epithelium (pseudostratified ciliatedcolumnar with goblet cells)b. with a lamina propri a containing numerous coll apsed veins
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II. Epiglottisflap-like projection, covered by a mucus membrane; sits on top of the larynx
(Be able to identify the laryngeal from the pharyngeal side)
1. epithelium = stratified squamous non-keratinized EXCEPT for a
smaller circular patch of respiratory epithelium(in the laryngeal opening) 2. core of ELASTIC cartilage and mixed glands = in lamina propria onthe (laryngeal side)
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III. Larynxconnects the pharynx and trachea; contains hyaline cartilages bound together by
connective tissue and the vocal cordsBe able to identify true from false vocal chords
1. Al l lined with :a. pseudostratif ied cil iated columnar = (i.e. larynx including
false vocal cords (sit superior to true vocal cords))
EXCEPT
b. stratified squamous non-keratinized epithelium = true vocal cords
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2. TrueVocal chords = folds in the mucus membrane, covered by stratifiedsquamous non-keratinized epithelium
a. layer of fibroelastic connective tissuesAND
b. a core of skeletal muscle
Vocal Chords Conti nued:
Red arrow True Vocal Chords;Blue arrow - Transition from False to True Vocal cords
Yellow arrow - True Vocal Cords (Non-keratinized stratified squamous) GreenArrow - False Vocal Cord (Psuedostratified Ciliated); Black arrow - TransitionPoint; Red arrow Cilia; Orange arrow - Skeletal Muscle (True Vocal Cords)
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IV. Tracheaconnects larynx and bronchi; shares an adventitia with the esophagus
3 Major Layers:
1. M UCUS M EM BRANE = respiratory epithelium (pseudostratified ciliatedcolumnar epithelium w/goblet cells), a lamina propria and a distinct elastic lamina
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2. SUBMUCOSA = respiratory epithelium, lamina propria w/mucus glands, elasticlamina, hyaline cartilage and mucus and mixed glands
*NOTE: hyaline cartilages = horseshoe shaped;between ends of cartilages ring = fibroelastic connective tissue and smooth
muscle
3. ADVENTITIA= connective tissue shared with the esophagus
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Bronchial TreeIV. Bronchi (Overview)
Note: Cartilage Rings = Hyaline Cartilage (as continued from the trachea)
**Will ONLY See 3 0 Bronchi in LAB**
Trachea ends - dividing into 3 branches:1 0 or Extrapulmonary Bronchi
2 o or L obar Br onchi
3 0 or Segmental Br onchi .
1 0 Bronchi enter the lungs, and branch to each lobe =2 o or L obar Br onchi.
2 o Bronch i will branch and enter the lungs as3 0 or Segmental Br onchi .
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1. Primary (Extrapulmonary Bronchi): extension of trachea(found outside lungs)
Same histology as the tracheaa. smaller diameterb. a continuous ring of cartilage
2. Secondary (Lobar Bronchi): (extending from inside to outside of lungs)
Same as primar y bronchi EXCEPT
a. walls = irregular shaped cartilageb. a complete layer of smooth muscle around the tube
Red dotted Line Bronchus; Yellow arrow - Plates Of Cartilage
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3. Tertiary (Segmental Bronchi): (found deepest in lung) a. folded respiratory epithelial lining (contraction of smooth muscle)b. mucus glands are found between the muscle and segmented
cartilage
White dotted line - BronchusBlue arrow - Cartilage Plate
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A. Primary (Preterminal): folded layer of epithelium
B. Secondary (Terminal): flattened epithelial layer
Red arrow - Respiratory Bronchiole; Blue arrow - TerminalBronchiole
Red arrow - Terminal Bronchiole;Blue arrow - Respiratory Bronchiole
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C. Tertiary (Respiratory): walls of bronchioles becomediscontinuous
a. outpocketings in walls lead to areas of gas exchangeb. free terminations open into straight spaces (alveolar ducts)
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II. Inside Respiratory Zone:
A. Alveolar Ducts: straight spaces continuous with the free terminations orthe respiratory bronchioles
Green arrow - Alveolar Duct; Blue arrow - Alveolar Sac
B. Alveolar Saccules: round spaces (like a bunch of grapes)communicating with the ducts and the alveoli
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C. Alveoli : spur-like partitions around periphery of saccules
1. Interalveolar wall : contains capillary endothelial cells
3 Cell Types:
a. Pneumocyte Type I: very thin squamous cell type;Function = gas exchange
b. Pneumocyte Type II: rounded cell with cytoplasmic granulesFunction = produces pulmonary surfactant
c. Alveolar Phagocytes (Dust Cells): seen at surface of the wall/ or inthe free space
Function = lung macrophages