Lecture 5: Respiratory Histology Flashcards
What is the function of the conduction portion of the lungs?
Warms and filters air passing through
-no gas exchange!
What portions of the respiratory tract compose the conduction portion of the lungs?
Nasal Cavity to Terminal Bronchioles
What is the function of the respiratory portion of the lungs?
Pass air to alveoli for gas exchange
What portions of the respiratory tract compose the respiratory portion of the lungs?
Respiratory Bronchioles to Alveolar sacs
The wall of the larynx is reinforced by what types of cartilage?
Hyaline and small elastic cartilage
What type of epithelium is found in true vocal folds?
What is the main function?
Non-keratinized stratified squamous epithelium
-protects mucosa from abrasions
What type of epithelium is respiratory epithelium?
Pseudostratified ciliated columnar epithelium
What is the function of respiratory epithelium?
Protect airway via mucus production
Transport mucus out of tract via cilia
What type of cells are found in respiratory epithelium?
Ciliated cells
Goblet cells: secrete and synthesize mucus
Basal cells
What are the four layers of the trachea? (superficial to deep)
1) Mucosa: Respiratory epithelium w/ elastic lamina propria
2) Submucosa: dense CT
3) Cartilaginous: c-shaped hyaline cartilage rings
4) Adventitia: CT that binds trachea to adjacent structure - trachealis muscle
What are some defining histological features of bronchi?
Cells short in height Fewer goblet cells Increased elastic fibers Full cartilage rings Loose/areolar CT
What are some defining histological features of bronchioles?
Transition b/t simple ciliated columnar to simple cuboidal Few goblet cells Increased elastic fibers No submucosa NO CARTILAGE
What are club cells?
Cells found in terminal bronchioles
- prevent luminal adhesion w/ airway collapse during expiration
- detoxifies inhaled materials
- secretes antimicrobial peptides
What do respiratory bronchioles branch into?
Alveolar ducts –> alveolar sacs –> alveoli
What are some defining histological features of respiratory bronchioles?
Simple cuboidal
Club cells
Elastic fibers
What type of epithelium is found in alveolar ducts, rings, and sacs?
Simple squamous epithelium
What are alveolar rings?
Aggregates of smooth muscle, collagen, and elastic fibers that surround alveolar ducts
What lines alveoli sacs?
Type I and Type II Pneumocytes
What type of epithelium is found in pneumocytes
Simple squamous epithelium
What is the function of Type I pneumocytes?
Surface for gas exchange
What is the function of Type II pneumocytes?
Secrete surfactant to reduce surface tension w/in alveoli to prevent collapse during respiration
What is the precursor for Type I and Type II pneumocytes?
Type II Pneumocytes
Type I pneumocytes are ____ shaped while Type II Pneumocytes are _____ shaped.
Type I Pneumocytes: Squamous (flat)
Type II Pneumocytes: Cuboidal/round
What fluid is found in the pleural cavity?
Serous fluid
