practical

Human Respiratory System

Trachea
Bronchi
Bronchioles
Alveoli

The Respiratory System

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Nasal Cavity – Where air enters the body

Mouth – Where air enters the body
Pharynx
Larynx – Voice Box

CS in Trachea

CS in Trachea

• Trachea

• Mucosa
• Sub mucosa
• Cartilage &muscle layer
• Adventitia
•

• Trachea

• Mucosa
• Respiratory Epithelium
• -Pseudo stratified ciliated columnar.
• Cells-Ciliated columnar cells
• - Goblet cells
• - Basal cells
• Lamina propria - Elastic fibre, Lymphocyte, Mast cells, Blood vessels
•

• Trachea

• Sub mucosa-
• Loose connective tissue
• Tracheal glands-Mixed (serous &mucus) glands
• Blood vessels.
• Cartilage &smooth muscle layer-
• ”C” Shaped hyaline cartilage having perichondrium and chondrocytes
• Ends of cartilage connected by smooth muscles
• Adventitia-fibro elastic tissue

The Trachea

Figure 21.7a, b

CS in Trachea

CS in Tracahea

CS in Trachea

LS in Trachea

Bronchi

Mucosa: respiratory epithelium as seen in trachea
Smooth muscle band between submucosa and mucosa
Submucosa: seromucous glands
Hyaline cartilage.
Adventitia.
• Innervated by the sympathetic and parasympathetic systems

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Bronchioles

Mucosa: lined by respiratory epithelium with Clara cells replacing goblet cells
Epithelium gradually become mostly clara cells with cuboidal rather than ciliated epithelium as the terminal bronchioles.
Clara cells( bronchiolar cells) surfactant secretion
Smooth muscle layer
No cartilage
Adventitia






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Type I

Type II

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•

• Trachea
• Bronchi
• Bronchiole
• Epithelium
• Pseudostratified
• Pseudostratified
• Cuboidal
• Goblet cells
• +++
• ++
• Absent
• Clara cells
• Absent
• Absent
• +
• Mucous glands
• +++
• ++
• Absent
• Cartilage
• +++
• ++
• Absent
• Alveoli
• Absent
• Absent
• +