Flashcards in Colombo: Respiratory System Deck (67):
What structures make up the conducting zone?
nose, pharynx, larynx, trachea, bronchi, bronchioles and terminal bronchioles
What structures make up the respiratory zone?
respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
What structures are considered part of the upper respiratory tract?
nasal cavity through the start of the larynx
Which structures are considered part of the lower respiratory tract
larynx through the lungs
What are the functions of the nasal passage?
1. warm and humidify air2. removal of retention of pathogens/particulate matter3. olfaction4. trap to drain out paranasal sinuses and lacrimal ducts
How does the nasal passage serve to warm and humidify inspired air?
Air flows in through the turbinates, which are bone shelf projections that force air into a steady flow over mucosal surfaces. This mucosa has a lamina propria layer that has a complex capillary loop system that releases heat into the inspired air. Seromucus glands release water to humidify the air and they produce mucous to trap particulate air impurities.
What antibody is produced in the nasal passageway?
What are the two types of epithelium in the nasal passageway?
1. respiratory epithelium2. Olfactory epithelium
Where is the respiratory epithelium in the nasal passageway?
It covers the middle and inferior turbinates as well as rest of conducting portion of the system.
Where is the olfactory epithelium located in the nasal passageway?
It covers the superior turbinate and roof of nasal cavity.
What are the 5 components of the olfactory epithelium in the nasal cavity and tell me about them?
1. Olfactory neurons: ciliated bipolar olfactory neurons with membrane chemoreceptors2. Supporting cells: pseudostratisfied columnar cells that support the olfactory cells3. basal cells: they are stem cells that replace the olfactory nerve every 2-3 months4. brush cells: columnar cells with microvilli. They have afferent connections to CN V5. Lamina Propria: contains Bowman's glands (olfactory glands) that produce liquid to facilitate odor detection.
Why is it important for the larynx to be lined with cartilage?
protection and it also helps participate in sound production
What is the lingual surface of the larynx made of?
stratified squamous epithelium
The vestibular folds of the larynx also contain what two histological features?
1. glands2. lymphoid nodules
What covers the vocal cords?
stratified squamous epithelium
What type of epithelium is in the region of the vestibules of the nasal cavity?
Stratified squamous, keratinized to non-keratinized Sebaceous/sweat glands
What type of muscle and skeletal support are in the vestibules of the nasal cavity?
what is the main function and other features of the vestibules of the nasal cavity?
Vibrissae (stiff hairs) and moisture both filter and humidify air.
What type of epithelium is in most areas of the nasal cavity?
respiratory seromucous glands
What type of muscle and skeletal support is in most areas of the nasal cavity?
Bone and hyaline cartilage
What are the major functions of most areas of the nasal cavity and what are other features that accompany those?
Rich vasculature and glands warm, humidify, and clean the air.
What type of epithelium is in the superior areas of the nasal cavity?
Olfactory serous glands (Bowmans glands)
What type of muscle and skeletal support is in the superior part of the nasal cavity?
What is the function of the superior nasal cavity?
solubilize and detect odorant molecules in the air.
What type of epithelium line the nasopharynx?
Respiratory, stratified squamous, and seromucous glands
What type of muscle and skeletal support are in the nasopharynx?
Bone and skeletal muscle
What is a function of the nasopharynx and what are some key features in the nasopharynx?
To conduct air to larynx; pharyngeal and palatine tonsils
What is the epithelium found in the larynx?
respiratory, stratified squamous, mucous glands
What muscle and skeletal support are in the larynx?
elastic and hyaline cartilage, ligaments, skeletal muscle
What are the functions of the larynx?
1. site for phonation2. epiglottis closes while swallowing
What is the epithelium that lines the trachea?
respiratory, mucous glands (goblet cells), Basal Cells (progenitor cells)
What type of muscle and skeletal support are in the trachea?
cartilage rings of hyaline cartilage, smooth muscle (trachealis)
What is the function of the trachea and what is a major feature of the trachea?
To conduct air to primary bronchi; mucous associated lymphatic tissue
How many C shaped hyaline cartilage rings are there in the trachea?
How long is the trachea? What is its diameter?
100-120 mm long; 25 mm diameter
what is the muscle that pulls the anterior part of the cartilage rings together?
What are the three layers of the trachea and what are they made of?
1. Mucosa: respiratory epithelium2. Lamina propria (tunica fibromusculocartilaginea): Mixed seromucus glands are located in this submucosa.3. Tunica adventitia: CT
What are the two purposes for the trachealis muscle?
1. To more easily allow for swallowing2. To narrow the opening so air can be expelled more forcefully like in a cough.
How many times does the bronchial tree branch?
What is the range of diameter in the bronchial tree?
25 mm at the trachea and 0.5 mm and terminal bronchioles
As one descends down the respiratory tract, what histological trends will you find (5)?
1. Epithelium height will decrease2. Cartilage rings will be replaced by isolated blocks or irregular plates then go away altogether at level of bronchioles.3. Trachealis muscle is replaced with bundles of smooth muscle that spiral around the airways4. Amount of elastic fibers and smooth muscle proportionally increases.5. Goblet cells and glands proportionally decrease.6. Bronchus associated lymphatic tissue will increase (BALT)
What are the three layers of the lamina propria and what are they made of?
1. Mucosa: Resp. epithelium, but as it descends it becomes simple ciliated columnar.2. Lamina Propria: Smooth muscle, elastic tissue, (in primary) cartilage rings that give way to plates in secondary bronchi and down.3. Tunica Adventitia: CT
What type of epithelium are in the bronchioles?
ciliated cuboidal epithelium with some goblet cells
Where does cartilage stop in the respiratory tract?
What is the most predominant tissue in the bronchioles?
What type of epithelium and cells are in terminal bronchioles?
simple cuboidal ciliated cells, also club cells
What are club cells?
club shaped, non-ciliated cells found in terminal bronchioles. They have secretory granules and secrete surfactant and antimicrobial peptides. They are also progenitor cells.
What is different about the smooth muscle tissue in terminal bronchioles vs higher-up bronchioles?
There is not as much smooth muscle here.
How many alveoli are there in the lungs?
300 million per lung
What is the transition zone and where is it located?
The area that separates the conduction zone from the respiration zone. This occurs as the terminal bronchioles become respiratory bronchioles.
What type of epithelium are in the alveoli?
simple squamous epithelium
What separates alveoli?
How are alveoli connected to each other?
By alveolar pores also known as pores of Kohn.
What are some pros and cons of alveolar pores?
Pros: 1. They can distribute air evenly and equalize pressure2. They will help prevent total loss of ventilation in event of bronchiole being blockedCons: can allow the spread of bacteria and neoplasms
What are the 3 types of alveolar cells?
1. Type 1 pneumocyte2. Type II pneumocyte3. Dust cell
How are type I pneumocytes joined together?
How much of the alveolar surface do type I pneumocytes make up?
What do type I pneumocytes do?
Make a very thin wall for gas exchange.
What do type II pneumocytes look like?
Larger cuboidal cells
What do type II pneumocytes do?
Make surfactant and serve and progenitor cells for tissue renewal.
What do dust cells do?
They are macrophages and eat "stuff"
How far down in the respiratory tract does epithelium go?
All the way
How far down in the respiratory tract do goblet cells go?
They end right before terminal bronchioles
How far down in the respiratory tract do ciliated cells go?
They end in respiratory bronchioles
How far down in the respiratory tract do glands go?
They end right before terminal bronchioles
How far down in the respiratory tract does hyaline cartilage go?
They end right before bronchioles