Anatomy and Histology of Respiratory Flashcards
What is the pathway of air?
- Entry via Nasopharynx and Oropharynx
- Convergence at Laryngopharynx and Larynx
- Down through trachea
- Lungs begin at branches at bronchi and bronchioles
- Respiratory Bronchioles, Alveolar Ducts, Alveolar Sacs
Where does lower respiratory tract begin?
What is the conduction portion?
What is the respiratory portion?
- LRT begins at larynx
- Nasopharynx to terminal bronchiole
- Respiratory bronchioles, alveolar ducts, alveolar sacs
What does the conducting portion do?
What is it stabilized by?
Function: Conducting passages deliver clean, warm and moist air; produce seromucous secretions
Stabilized by bone, cartilage or muscle
What is the lining of the conducting portion?
What is its functions?
What are the divisions in the lining?
Mucosa - Lining of a cavity in contact with the outside world
Functions as an immunolgoical and physical barrier, source of secretory products, and selective absroptive interface
Has Epithelium (Surface) and Lamina Propria (CT layer that supports epithelium)
What are the types of cells common in the respiratory epithelium? (5)
What are the functions of small granule and brush cells?
What type of epithelium is present in the general respiratory system?
Columnar, Goblet, Basal, Small Granule, and Brush cells
Small Granule likely have endocrine function
Brush have unknown function
Ciliated pseudostratified columnar
What cells are unique in the nasal epithelium?
Olfactory epithelium
Olfactory cells – Stereocilia, recognition of smells
Supporting cells – Provide nutrition to olfactory cells
Basal cells, brush cells
What is contained in the lamina propria of nasal cavity?
What role do glands and cilia have?
How can this role be inhibited?
Lamina propria – Seromucous glands, venous plexus
Role of glands and cilia to remove particulates from the mucosa (Called mucociliary escalator)
Smoking and irritants can reduce the effectiveness of this function – Cause non-stratified squamous epithelium
Also genetic syndromes can cause deficit (Congenital Immotile Cilia or Kartagener’s syndrome)
What cells are unique about the histology of the nasopharynx?
Large amount of lymph cells under the epithelium
What type of epithelium is in the larynx and why?
Which part of mucosa vibrates?
Which part of mucosa makes up the vocal ligament?
Vocal cord epithelium is non-stratified squamous – more resistant to air forces
Epithelium and superficial lamina propria vibrate in vocal cord
Vocal ligament – Deep lamina propria
What is the structural support of the trachea?
Where are seromucous glands in the trachea?
Several cartilaginous rings
Abundant seromucous glands deep to LP in submucosa
What is the structural support of bronchi?
What unique cells make up bronchi’s LP?
Plates of cartilage instead of rings
Smooth muscle cells and mast cells in LP
What are the size of bronchioles?
What supports them?
What unique cells do they have?
What is special about terminal bronchioles?
1-5 mm in diameter (Can expand and contract)
No cartilage plates, now smooth muscle supports
Special neuroendocrine cells
Last generation is terminal bronchioles which have Clara cells instead of ciliated cells
What is the defining feature of respiratory passageways?
What happens to the amount of smooth muscle cells in respiratory passages?
What types of tissue are dominant in the respiratory passageways?
All have alveoli
Smooth muscle disappears after alveolar duct
Plenty of elastic and fibrous tissue
What is the distribution of alveoli in the respiratory passages?
Respiratory bronchioles – Sparse alveoli
Alveolar ducts – Lined with lots alveoli
Alveolar sacs – Cul-de-sacs filled with alveoli
What are pulmonary lobules and acinus?
- *Pulmonary lobule** – Terminal bronchiole and the lung tissue it supplies
- *Pulmonary acinus** – Portion of the lung supplied by a respiratory bronchiole
