Respiratory Histology Flashcards
What are the two divisions of the respiratory system and their associated parts?
1. CONDUCTING PORTION : Nasal cavity Nasopharynx Larynx Trachea Bronchi Bronchioles Terminal bronchioles 2. RESPIRATORY PORTION : Respiratory bronchioles Alveolar ducts Alveolar sacs and Alveoli .
What are the four major functions of the conducting portion?
FUNCTIONS OF CONDUCTING PORTION :
- Conduit for delivering air to the lungs .
- Conditions incoming air by cleansing , moistening and warming it as it moves towards the lungs .
- Olfaction ~ a small area of conducting portion possesses the sensory receptors and other specializations necessary for olfaction .
- Sound production , the vocal folds in the larynx are specialized for this function .
The main cell type of the conducting portion of the respiratory epithelium is?
Pseudostratified columnar ciliated with goblet cells
Toward the end of the conducting portion the cells transition into ______ and then finally change to _______?
simple columnar and finally simple cuboidal epithelium
Nonkeratinized stratified squamous epithelium is present at which areas of the respiratory system?
Nonkeratinized stratified squamous epithelium is present in areas either exposed to rapid airflow (e.g vocal folds) or prone to other abrasions (e.g epiglottis)
What are the 5 cell types associated with the respiratory epithelium in order?
- Ciliated columnar cells
- Goblet cells
- Brush cells
- Basal (stem) cells
- Small granule cells
What are the roles of the 5 cell types of the respiratory epithelium?
- Ciliated columnar cells : most numerous cells .Each cell has hundreds of cilia on its apical surface that move mucus along the epithelial surface.
2.Goblet (mucous) cells : produce & secrete mucous. The apical region of the cell is filled with polysaccharide- rich mucous droplets.
This is the second most numerous cell type .The number of goblet cells decreases in deeper portions of the conducting portion of respiratory system .
3.Brush cells : so named because their apical surface is covered with microvilli. These cells are thought to be sensory receptors . - Basal (stem) cells : small somewhat rounded cells that sit on the basal lamina. These cells are regenerative cells , capable of dividing and differentiating into other cell types of the epithelium .
- Small granule cells : are the cells of diffuse endocrine system that are located on the basal lamina and have numerous granules. Granules are hormone like substance secreted by the cell that may regulate the mucous and serous secretions of other cells .
What is the definition of Squamous Metaplasia?
The change from pseudostratified ciliated columnar to stratified squamous epithelium. This can lead to precancerous cell dysplasia in the tissue.
Describe the histological characteristics of the nasal cavity.
Vestibule: portion where air enters first
Nares: the anterior dilated portion lined by skin with vibrissae, sweat glands, and sebaceous glands.
Describe the histological characteristics of the nasal septum
Hyaline cartilage that divides the vestibule into right and left halves.
Describe the histological characteristics of the nasal conchae and its functions.
there are 3 shelf like folds in the bony lateral walls of the nasal cavity. This increases the surface area exposed to the air disrupting the air flow.
Respiratory epithelium covers the middle and inferior portion and olfactory epithelium covers the superior.
What are the three types of olfactory cells?
- Olfactory cells and nerves that pass through the cribriform plate of the ethmoid bone and join other nerve fiber bundles.
- Sustentacular cells are there to support and electrically insulate the olfactory cells (these are the most numerous of olfactory cells) Each cells has microvilli and oval nucleus in the apical third of the cytoplasm
- Basal cells which is one of the few instances where adults can have nerve cells replaced. They can replace both olfactory and sustentacular cells.
What is the function of the olfactory glands or bowman’s gland?
They are to produce a serous secretion that traps and dessolves odiferous substances. the secretory portion can be found in the lamina propria deep to the olfactory epithelium.
Where are the four paranasal sinuses located and how do their cilia work? What happens if the cilia stops functioning?
The four sinuses are located at the frontal, ethmoid, sphenoid and maxilla bones and are relatively large, blind cavities. The cilia beats in such a way that it moves the mucus layer above it. When they stop working the mucus can no longer move and you can get sinusitis.
The larynx forms a passageway for between the _________ and ______. it is also the organ involved in what?
Oropharynx and Trachea.
It is used in producing sounds for speech.
What is special about the larynx and its cartilage and muscle?
Larynx possesses several irregularly shaped cartilaginous plates some of which are hyaline while others are elastic cartilage. These plates are joined by ligaments and are moved with respect to one another by intrinsic skeletal muscle of the larynx.
