Nonrespiratory Functions of the Lungs: Khundmiri Flashcards
what are the other functions of the lungs besides gas exchange?
to maintain low fluid volume: lungs has its own mucosal associated tissues
Mucosa Associated Lymphoid Tissue (MALT)
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What are the Three tier defense mechanisms of the lung
Mucociliary clearance that moves inhales and trapped particles cephalad toward the mouth
Phagocytic and inflammatory cells that destroy inhaled substances
Specialized mucosal immune system
What is the function of the mucocialry and what are the three components?
to protect the lower respiratory system
Three major components (two fluid layers)
Sol – Periciliary Fluid
Gel Phase – Viscoelastic Mucus Layer
Cilia – Surface of the epithelial cells and embedded in the periciliary fluid
Describe the Periciliary Fluid
very important for the rhythmic beating of cilia
- epithelial sodium channels ENaC
- cystic fibrosis transmembrane receptors (cholride channel) - CFTR
- aquaporin (ADP) which are conducting water
sodium concentration allows what to occur
osmosis taking water from one portion of the cell to the other
If you add an inhibitor of sodium channel amiloride, what happens?
you are not transporting sodium inside the cells
given to HTN pts to inhibit sodium reabsorption in kidneys, thus lung volume should increase but that doesn’t happen because your system probably??????
you are building up osmolarity in the ???
increase ???
If you inhibit aquaporins
stops movement of water under physiological conditions because you don’t want to fill up the lungs with water
What is on top of the periciliary fluid?
-mucus layer
Functions to:
-to entrap inhaled substances
-Low viscosity and highly elastic
because of the glycoproteins that are present
make about 100 mL and are recyled out??
What are the four types of cells that make mucus?
?????
Goblet cells
secrete neutral or acidic glycoproteins
in pts who smoke or with chronic bronchitis produce large amount of mucus due to increased proliferation of goblet cells
Submucosal tracheobronchial glands
secrete acidic glycoproteins
they also contain enzyme with the function of killing bacteria
size and number increase in bronchitis
What are the differences between properties of submucosal glands serous and mucous cells?
granules are end close particles that contain digestive enzymes
mucus has no substance P
both are muscarinic
Clara cells
- Located in the epithelium if bronchioles
- Contribute to mucus secretion
- Secrete non-mucinous material containing carbohydrates and proteins
- Play important role in bronchial regeneration after injury: these cells can act as stem cells causing regeneration of the bronchial cells after injury; injury due to infection or trauma
What is the sputum clincally?
-Expectorated mucus
Serum proteins, lipids, electrolytes, Ca, DNA from degenerated white cells
Also contains extrabronchial secretions – nasal, oral, lingual, pharyngeal, and salivary secretions
Color of sputum correlates with presence of infection and how long it has remained in the lower respiratory tract
What causes the movement of mucus and clearing of??
cilia
What are cilia?
- originate from the basal body of epithelial cells
- are covered by an outcropping of the plasma membrane
- Ciliary movement is dependent upon ATP and also require Calcium and Magnesium
Describe cilia movement
- the cilia go into the mucus layer during forward movement
- present in the preciliar fluid during reverse beat
- nasopharynx beat in the direction to move mucus into the pharynx
- trachea propel mucus upward toward pharynx where it is swallowed
genetic disorders caused by changes in ciliary function
cycstic fibrosis
Kartagner syndrome
cycstic fibrosis
wrong cilia due to chloride channel CFTR
preci fluid maintained but inward movement of sodium and outward movement of Chloride
there is a decrease in the ACTIVITY of CFTR because the proteins are not going to the membrane —-NOT the number
there are NO changes in the transcription and translation of CFTR just sits inside cells and eventually gets degraded
and thus sodium is just moving inside the cells increasing osmolarity and thus water precilary fluid is decreased (it will not move)
if ENaC was disrupted there would be increased preciliry fluid
pts have recurrent pulmonary infections
Kartagner syndrome
genetic disorder due to mutations in a protein called kinesin structural proteins which keep the dynein arms together
there is disruption in the dynein arms
in this case the pt would have Bronchiectasis, Chronic Sinusitis, Situs Inversus Totalis
males are infertile because ciliar are important for locomotion of sperm
being bombarded with different particles causing particle deposition which is dependent on the
size of particle
if larger than 10 um they will impact nasal passages and will not penetrate the lower respirtaory tract
2-10 um – deposited in the lower respiratory tract by initial impaction and turbulent flow in the nasopharynx, trachea, and bronchi due to inertia
0.2-2 um – deposited by sedimentation secondary to gravity – depends on airway diameter
Less than 0.2 um particles are deposited by Brownian motion – depends on particle’s diffusion coefficient – come in contact with epithelium where there are no cilia and mucociliary transport
Elongated shaped particles like asbestos and silica are deposited by interception – particle’s center of gravity:
Deposition of silica
especially people who used silica in mining and photography industries the silica in these individuals would get phagocytosed by macrophages
because the silica cannot be metabolize it punctures the macrophages and damages the alveoli
(terminal ends of the bronchial tree is the achilles heel region)
eventually going into the lung interstitium
what are the metabolic functions of lungs?
they metabolism based on active needs
the most important ones are : angiotensin I
angiotensin made in liver is converted to angiotensin I in the lungs by an enzyme made in kidney, renin
what are other substances metabolized in the lungs?
- serotonin
- endothelial cells
The lungs DO NOT metabolize
Epinephrine Dopamine Histamine Isoproterenol Angiotensin II Substance P
The lungs has its own immune system
for the lung to know which substances are or are not harmful for it
inflammation causes removal of particles but also causes disruption in normal physiological activity
What are the two types of immune cells
innate and adaptive?
CHART
????
MALT
The respiratory system together with gastrointestinal system and the urinary system has mucosal immune system
This system is unique – adaptive immune response is initiated only after the insulting agent has bypassed the innate immune response
The most important function of MALT or BALT in lungs
limits sensitization only to the mucosal tissue
???He said something about macrophages
BALT help make antibodies IgA
IgA
plasma cells in the lungs secrete IgA
once formed binds to receptors on epithelial cells
gets endocytosed
??????
all these things require movement from ER tubular structures and move along the dynein fibers inside the cells; all dependent on calcium concentration
DO NOT bind to the complement system
-limits pro-inflammatory properties ?????
Allergic Lung Diseases - Asthma
normally your lungs are producing IgA to combat infect
in cases of allergy your lungs will switch over to IgE
- in the IgE case, your immune response will take about 4-6 hours
two disease responbile for pulmonary responsible ????
Goodpasture’s syndrome is an autoimmune response to the lung basement membrane that results in hemorrhagic disease; abs are produce against your own lung
IgA deficiency is the most common inherited immunoglobulin deficiency and is frequently associated with chronic lung disease.
What are the types of adative and innate immune cells?
TCR - preferentially localize to mucosal sites : first line of defense against
What are the function of the natrual killer cells
engulf and kill target
release enzymes that poke holes in the plasma membrane of viruses or bacteria due to activty of cytokines: IL-4, IL-5, IL-3, IFN, and TNF
NK cell number and activity increases in asthma
first nonepithelial cells to respond to foreign substances
Dendritic and Alveolar Macrophages
Dendritic and Alveolar Macrophages????
when it pass through??
bind to dendrites which get primed ??
naive T cells to get activated
move into pulmonary ??
once released bind to effector T cells to ????
Alveolar Macrophages
common in immune disorders or inflammatory diseases of the lungs
chemotaxis: engulf bacteria because of high oxygen radials they will kill the pathogen
Suppress T cell activity – secretion of NO, PGE2, IL-10, TGF-beta????
Toll-Like Receptors (TLRs)
response to nonpathogenic substances
they are single chain polypeptides present in the PM
when they are bound to the nonpatho sub activating a huge signaling cascade that will activate Nkappa B????
this will go to induce transcription of proteins that will go to destroy the pathogens???
Are age related diseases
emhysema and bronchitis
What are features of emphysema?
caused mostly by smoking casuing inflammatory cells to ???????
elastase cause not only damage to bacteria or inflammatory cells but digest elastin fibers which are normal in your lungs thus
alpha 1-antitripsin is inhibitor of elastase
smoking decreases alpha 1-antitripsin
some people are resistant to smoking as they have higher than normal activity of alpha 1-antitripsin
people with lower alpha 1-antitripsin are more susceptible to emphysema
What are features of bronchitis ?
????
Pulmonary embolism
hypoxic vasoconstriction
causes pulm HTN, V/Q imbalances, increases dead air space, chest pain,
