Respiratory System Flashcards
What are the three major functions of the respiratory system?
- Air Conduction
- Air Filtration
- Gas Exchange
What is a major function of the larynx?
Produces speech
What is a major function of the olfactory mucosa?
Stimulates smell
What are the three things air filtration does?
- Warm the air
- Moisten the air
- remove particulate materials
How do mucosal and serous secretions warm the air?
The air comes in close contact with the abundant capillary system beneath the epithelium which brings the air to body temperature
What tissue type makes up the respiratory epithelium? What specialized cell type is abundant?
Pseudostratified ciliated columnar epithelium
Abundant goblet and seromucous cells
Which parts of the respiratory system fall under the conduction portion? (7)
Nasal Cavity Nasopharynx Larynx Trachea Bronchi, bronchioles, terminal bronchioles
Which parts of the respiratory system fall under the respiratory portion (as opposed to conduction)?
Respiratory bronchioles
Alveolar ducts
Alveoli
Alveolar Sacs
What is the pathway of air from the nasal cavity to the alveolar sacs?
Nasal Cavity > Nasopharynx / Oralpharynx > Larynx > Trachea > Bronchi > Bronchioles > Terminal bronchioles > respiratory bronchioles > alveolar ducts > alveoli > alveolar sacs
What are the three regions of the nasal cavity?
- Nasal vestibule
- Respiratory region
- Olfactory region
What is the specialized characteristic of the nasal vestibule?
Nairs
The _____ region makes up the inferior 2/3 of the nasal cavity and the _______ region makes up the superior 1/3
Respiratory Region
Olfactory Region
What separates the nasal cavity into the respiratory and olfactory regions? It is a mixture of what two tissue types?
Nasal Septum
A mixture of hyaline cartilage and bone
What epithelium is found in the nasal vestibule? What 2 specialized glands are abundant? What other characteristic is important for filtration?
Stratified Squamous
1. Sebaceous glands
2. Sweat glands
Vibrissae = blunt hairs
What is the lateral conchae? What is its function (3)? Where is it found?
Found in the respiratory region of the nasal cavity
It is a boney structure lined with respiratory epithelium
Acts as turbinates: warm, filter, and moisten the air
How does the design of the respiratory region of the nasal cavity facilitate the warming of air?
The extensive capillary system in the lamina propria of the lateral conchae help bring the air to body temperature
What are brush cells? In what tissue type do we find them?
Have blunt microvilli with sensory function that synapse with neurons on the basal lamina
Found in respiratory and olfactory epithelium
What are basal cells? In what tissue type do we find them?
Stem cells that give rise to other cell types
Found in the basal lamina of respiratory epithelium, it gives it the pseudostratified appearance
Also found in the olfactory epithelium
What do small granule cells do? In what tissue type do we find them?
Response to O2 conditions in the environment and release hormones
Found in respiratory epithelium
What are the four cell types found in the olfactory epithelium?
- Olfactory receptor cells
- Supporting Cells
- Basal Cells
- Brush Cells
What type of epithelium does the olfactory region of the nasal cavity have?
Specialized olfactory epithelium
What type of gland does the olfactory regions of the nasal cavity have?
Olfactory (Bowman’s) Glands
What do olfactory (bowman’s) glands make? What is its function?
Make water and secretions
Solubalize olfactants and rinse out old olfactants
What do olfactory receptor cells look like? Do they extend all the way through the olfactory epithelium?
Olfactory receptor cells extend all the way through the epithelium. They have a long projection with cilia on the end that extend into the nasal cavity to capture olfactants. Then it transports those olfactants across the epithelium and distributes them onto olfactory neurons,
What are the two functions of supporting / sustentacular cells in the olfactory epithelium?
- Provide mechanical support to the ORC (olfactory receptor cell - specifically the apical most region)
- Provide nutritional support to the ORC
What is the function of basal cells in the olfactory epithelium? Are they located on the apical or basement membrane?
Make olfactory binding protein
Located in the basement membrane
What does olfactory binding protein do?
Acts as a scaffold for olfactants to bind to in order to be brought to ORC
What is the function of brush cells in the olfactory epithelium?
Sensory functions
How can there be only 350 olfactory receptors but 100,000 different smells?
Olfactants create weak/strong signals and that strength helps determine the smell
What is the polarity of olfactory neurons?
Bipolar
What 4 things does the olfactory neuron pass through to synapse with the olfactant?
Ethmoid bone
Dura Mater
Arachnoid
Pia Mater
What is a very general path that goes from olfactanct to AP being sent toward the brain?
???
What is the function of the pharynx? (3)
- Connects the nasal and oral cavities to the larynx and esophagus
- Passageway for air and food
- Resonating chamber for speech
What is the function of the epiglottis?
Epiglottis prevents food/water from entering the larynx
What are the two main functions of the larynx?
- Passageway for air between oropharynx and trachea
2. Produces sound
What does the laryngeal cartilage of the larynx do? (2)
In work with the internal skeletal muscle changes the shape of the vocal cords
In work with the external skeletal muscle does coughing and swallowing
What is the function of the hyaline cartilage in the laryngeal cartilage? What about the elastic cartilage?
The hyaline cartilage helps maintain the larynx in its open state since the larynx lacks bone
Elastic cartilage helps with recoil forces
What two components make up the laryngeal folds?
- Ventricular fold
2. True vocal cords
What are the ventricular folds in the larynx also known as?
False vocal cords
What kind of tissue are the true vocal cords made of? Why is this important?
Stratified squamous epithelium
Important because of the mechanical force and abrasion put experienced
What are the two functions of the trachea?
- Conduit for air
2. Conditions inspired air
What is found on the ventral regions of the trachea?
C rings made of hyaline cartilage
What is found on the dorsal region of the trachea?
Trachyalous muscle which is smooth muscle
What is the mucosa of the trachea composed of?
Respiratory epithelium with a thick basement membrane
What is modifying feature is abundant in the submucosa of the trachea?
Serous glands
What does the adventitia of the trachea attach to?
Esophagus
Talk me through the bronchial tree starting at the trachea
Trachea > 2 main bronchi > lobar bronchi > bronchioles > terminal bronchioles > respiratory bronchioles
What is the difference between bronchi and bronchioles?
Bronchi have smooth muscle
Bronchioles do not have smooth muscle, they do have increased reticular and elastic fibers
What part of the bronchial tree is the extrapulmonary?
2 main bronchi
What part of the bronchial tree is the conduction portion of the respiratory system?
Trachea > primary bronchi > lobar bonchi > small bronchi > terminal bronchioles
What does the mucosa of bronchi look like?
Ciliated, columnar with numerous goblet cells
What is the trend in smooth muscle size and bronchi?
Smooth muscle attenuates as bronchi get smaller
How is the cartilage around bronchi arranged? How does this change as bronchi get smaller?
Discontinuous plates of cartilage
As bronchi decrease in size, cartilage decreases
What type of glands are in the submucosa of bronchi?
Serous glands
What is the smooth muscle surrounding bronchi responsible for? What part of the NS controls the muscle?
Controls dilation and contraction based on the autonomous NS
Bronchioles; diameter size? cartilage? glands? goblet cells?
less than 1 mm in diameter
no cartilage
no glands
scattered goblet cells
How does the epithelium differ in bronchioles compared to bronchi?
Bronchioles have more simple cuboidal
What are the physical characteristics of clara cells?
Dome shaped cells, lack cillia, buldge out of epitheliuem
What is the function of Clara cells?
Make CC16 which reduces surface tension and creates a slick surface so the sides of the bronchioles don’t stick together
Why is it important to reduce surface tension in bronchi?
Without a reduction in surface tension, the lungs would collapse when empty
Where are clara cells found?
epithelium of bronchioles
What are the physical characteristics of alveolar macrophages? What is their function?
Dark yellow/brown stain
Phagocytose debris in the lower respiratory system
Talk me from terminal bronchioles through the respiratory portion of the bronchial tree
Respiratory bronchioles > alveolar ducts > alveolar sacs > alveoli > capillary network > pulmonary venule > pulmonary vein
What do we see at the transition from conducting to respiratory portions of the bronchial tree?
The respiratory wall has small spaces and Clara cells
What two cell types are the alveolar ducts composed of?
- Type I alveolar cells
2. Type II alveolar cells
What is the function of Type I alveolar cells?
Form majority of the lining of alveolus and alveolar sac
What is the function of Type II alveolar cells?
Manufacture surfactant
What transition do we see from respiratory bronchioles to the alveolar ducts?
Transition from simple columnar/cuboidal to alveoli cells
What are the three places alveoli are present?
Respiratory bronchioles
Alveolar Ducts
Alveolar Sacs
What is the interalveolar septa?
Structure between alveoli
forms air-blood barrier
What forms the air blood barrier?
Interalveolar septa
What are the three layers of the air-blood barrier?
- Then layer of surfactant
- Type I epithelial cell + basal lamina
- Capillary endothelial cell + basal lamina
Are the epithelial cells of the air-blood barrier tall or short?
Very short/flattened to allow for gas exchange
Which alveolar type is thicker I or II? Why?
Type II Alveolar Cells
They have lamellar bodies and release surfactant
Which alveolar cells are found in the inner septum? Which are found on the septal junctions?
Type I are found on the inner, thin region of the septum
Type II are found on the thicker, septal junctions
What do the lamellar bodies of type II alveolar cells contain? What is their primary function?
A mixture of phospholipids, neutral lipids, and proteins
This forms surfactant
Type I alveolar cells arise from what cell type?
progenitor cells
During what time in your life is surfactant produced?
Late gustation
What is respiratory distress syndrome? What is the cause? What are the symptoms? How can we prevent it?
Respiratory distress syndrome occurs when a baby is born before 35-week gestation, which means surfactants is not being made yet
This leads to a thicker inner alveolar septum which leads to decreased gas exchange, decreased compliance, and elasticity, and the alveolar septum are poorly vascularized
If it is known that the baby will deliver before 35-weeks it can be given steroids to induce production of surfactant
Which artery provides deoxygenated blood to alveoli?
Pulmonary Artery
Which artery provides oxygenated blood to the lung?
Bronchial Artery
What do lymphatic vessels in the lung do? (2)
- Drain parenchyma of the lung
2. Drain surface of the lung
What is Chronic Obstructive Pulmonary Disease (COPD)?
Progressive respiratory disease that is irreversiabel
What is an example of COPD we discussed in lecture?
Emphysema
What are the two types of Emphysema?
- Centracinar
2. Panacinar
What is centriacinar emphysema?
A type of COPD
Frequent irritation caused by smoking or pollutants > the continual release of elastase > decrease of antitrypsin > destruction of elastic fibers > affects the walls of the respiratory bronchioles only
What is panacinar emphysema?
A type of COPD
Genetic mutation in antitrypsin > increased elastase > affects walls of respiratory bronchioles, walls of alveolar ducts, and walls of alveoli
What is the entire mechanism of action of emphysema? (Starting with an irritant in the lungs). Comment on where this mechanism breaks down in Panacinar and Centracinar Emphysema
Irrantent in lungs > neutrophil recruitment > release of elastase into alveolar lumen > serum antitrypsin neutralized elastase to prevent it from destroying alveolar wall since the walls are only made of elastic fibers ( no hyaline cartilage)
If there is no antitrypsin = destruction of all walls that are reliant on elastic fibers (Panacinar emphysema)
If there is an excess of elastance due to constant irritation = destruction of respiratory bronchiole walls where the imbalance is occurring (centracinar emphysema)
What is cystic fibrosis? What is the cause? Symptoms?
Defect in cloride channels > no cl- leaving the cells > no water leaves the cells > cement-like mucosa > immotile cilia
The cement-like mucosa traps bacteria and also can’t move it away> helping it to expand in number > makes people with CF more prone to bacterial infactions
What cells are affected by CF?
Any cells with chloride channels
ex) pancreas, seromucosa glands, respiratory epithelium
