Animal Histology - Respiratory Notes

8/12/2019 Animal Histology - Respiratory Notes

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Respiratory System Notes:

General Overview:

wiki.medpedia.com/Formoterol
http://wiki.medpedia.com/Formoterolhttp://wiki.medpedia.com/Formoterol


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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

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Animal Histology - Respiratory Notes