Lecture 29 Flashcards
what are the components of the respiratory system?
- olfactory mucosa in nasal cavity= olfaction
- Vocal folds= phonation/speaking
- conduction and conditioning of air
- gaseous exchange= blood gas -barrier/respiratory portion
- endocrine=hormones= neuroendocrine cells
- immune functions- bronchial associated lymphoid tissue
Nasal cavity: what is the vestibule? what is the epithelium found here? what is the purpose of this area?
- cartilage framework
- Stratified squamous epithelium ( skin
- short firm hairs (vibrissae)
- sweat and sebaceous glands
Glands and vibrissae trap large particles
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Nasal cavity:
what can you find in the respiratory region?
what is the epithelium?
what is the lamina propia?
what are turbinates?
clinical clinical correlate?
- Respiratory epithelium/ pseudo stratified ciliated columnar
- Lamina propria: adhered to cartilage. vessels lined up perpendicular to the airflow—– warms the air/ conditions it.
- Clinical correlate: nasal congestion
Turbinates– increase the surface area covered by respiratory mucosa. better conditioning of air
also has the vestibule
What four cell types are found at the nasal cavity olfactory region?
Olfactory receptor cells, Brush cells, Supporting cells, Basal cells
what epithelium lines the nasal cavity?
keratinized pseudo stratified columnar epithelium
what is the histological feature and function of Olfactory receptor cells in the olfactory region?
Histology:
long thin nonmotile cilia with odor receptors.
Axons form the olfactory nerve
Function: Bipolar neurons= axon and dendritic regions.
What is the function of Brush cells?
sensory receptors
what is the histological feature and function of supporting cells?
Histo:- Apical microvilli
-Mitochrondia, sER and rER
Secretory vesicles contain odorant binding protein OBP
Function: mechanical and metabolic support to olfactory cells. Helps in odor perception
What is the histological feature and function of Basal cell?
Function: regenerate supporting and olfactory receptor cells.
What are serous olfactory glands/ Bowman’s glands found in the nasal cavity olfactory region?
secretory and found in the lamina propria, they create mucous and trap odorant particles and bring them to receptors.
- acinar cells have lipofuscin granules
serous secretion—lysozyme and IgA
How are odors sensed?
the secretion of olfactory glands trap and dissolve odoriferous particles. These then bind to OBP ( odorant binding proteins) and are delivered to receptors. Glandular secretion also wash away odor particles once sensed. Bowman’s glands will wash out the sensed smell
What is the function of the Larynx and what cartilage is it made up of??
- Skeleton of both hyaline and elastic cartilages in laryngeal
- Functions: Air conduction and phonation
larynx is always patent/ open.
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The epiglottis is made up of what kind of cartilage?
elastic cartilage
Because the vocal fold undergoes pressure what kind of epithelium is it lined by?
stratified squamous epithelium
the rest of the larynx is respiratory epithelium including ventricular fold
a cancer in the larynx/ vocal cords appears how?
as a keratin pearl or cauliflower lesion. you get hoarseness of voice and drastic loss of weight
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what kind of cartilage in the trachea?
hyaline cartilage underneath the adventitia
longitudinal elastic fibers in deep lamina propia-
LP=loose connective tissue
it has a submucosa made of loose areolar tissue where there is mucosa glands.
pseudo stratified columnar epithelium
it has a basement membrane..
posterior part of ring/ gap= has trachealis muscle (smooth) and fibroelastic membrane
adventitia: outside of cartilage layer
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in chronic cough and asthma how is the basement membrane found in the trachea ?
the basement membrane is thickened
what kinds of cells are found in the respiratory epithelium?
Lines of most of the conducting part of the respiratory system and has four cell types: Ciliated columnar, mucus Brush ( columnar and reach apical surface), small granule, and basal ( near basement membrane)
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what cells in the lungs have an endocrine function and are associated with cancer? what is the clinical correlate?
small granule cells/ Kulchitsky.
primary cells affected in small cell carcinoma of the lung
what is the job of ciliated columnar cells? clinical?
sweeping motion helps excel particles trapped in mucus
primary ciliary dyskinesia in Kartenger’s syndrome
what is the job of mucus? clinical?
secretes mucin granules which form a protective barrier.
Increased in smokers and chronic inflammation
what are basal cells?
they are near the basement membrane and they are stem cells that regenerate all other cell types
what is a brush cells?
columnar and extend to the apical surface/ short microvilli
Synapse with afferent nerves; sensory function
what syndrome do you have if cilia isn’t working but mucous is still producing?
Kartengener’s syndrome/ primary ciliary dyskinesia
the mucous clogs
what occurs to individuals with smoking and bronchitis?
their conducting respiratory duct gets narrowed, you don’t get enough oxygen so get cyanosis= blue bloater, wheezing, metaplasia, inflammation, pseudo stratified cells are now turned into stratified squamous causing metaplasia
smokers have now cilia
describe bronchioles:
1- terminal bronchioles=
larger bronchioles
2- respiratory bronchioles
they lack cartilage
they do not have mucous glands
instead of cartilage= smooth muscle
instead of mucous glands= Club muscles
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pseudostratified at upper part of bronchial
all the way down, ciliated cuboidal ells. here there are club cells.
what are club cells?
-bronchiolar exocrine cells
surfactant active agent
Club cell protein= CC16= marker for diagnosis of chronic lung disease. this indicates that epithelium is injured
what is bronchial asthma?
airway obstruction, increased mucus, increased smooth muscle, and bronchiolar wall inflammation.
what is bronchial asthma treated with?
albuterol, anticholinergic medications relax smooth muscles
corticosteroids= antiinflammatory
thickening/ hypertrophy of smooth muscle layer and hyper plasma. airway blocked by cell debris and mucus.
you find high levels of mucosa and smooth muscles are constricted
bronchiolar wall inflammation
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where is the first site that gas exchange take place?
respiratory bronchiole
what characterizes respiratory bronchiole? what epithelium?
-belongs to both conducting and respiratory bronchioles
supported by small amount of smooth muscle plates and elastic fibers,
walls are interrupted by alveoli
simple cuboidal epithelium with ciliated and club cells proximal
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Respiratory division: alveolar ducts
respiratory bronchioles transition into alveolar ducts as the number of alveolar out-pouching increase, lined by alveoli, they have bundles of smooth muscle cells found between alveolar out-pocketing ( inter alveolar septum)
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what is alveoli and what cells make up alveoli?
thin walled polyhedral terminal sacs where gaseous exchange takes place.
-Alveooli are separated from eachother by an interalveolar septum.
Cell types: Macrophages, Type I, type II pmneumocyes
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alveolar ducts terminate in what?
alveolar sacs
what is another name for macrophages?
dust cells
what is the job of dust cells/macrophages?
phagocytosis of inhaled particles, they also degrade surfactant.
they can ingest pretty much anything except tuberculosis bacteria
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1- septum macrophages
2- alveolar macrophages
what kind of epithelium are found on the Type I pneumocytes of the alveoli? where are they found?
Squamous cells that line 95% of alveolar surface
terminal cells not capable of mitosis
surface is covered by surfactant
SEE PIC
What kind of epithelium are found on Type II pneumocytes ? where are they found?
- cuboidal cells that secrete surfactant
- Found at septal junctions
they cover only 5% of alveolar surface
they have apical lamellar bodies/ foamy appearance
what kind of pneumocyte forms tight junctions?
Type I
what kind of pneumocyte forms the blood- air barrier?
Type I
type I can only give rise to Type I
what kind of pmneumocyte are stem cells ?
Type II
only this one can give rise to both Type I and II
what does SP-A do?
it regulates synthesis and secretion of surfectant and modulates an immune response
what does SP-D do?
regulates the allergic response to airborne antigens
what do SP-B and SP-C do?
regulate spreading of surfactant
adequate amount of surfectant is produced after 35th week of gestation.
regulated by cortisol, insulin, thyroxin and prolactin
what is found in the thin portion of the blood gas barrier?
- surfectant
- type I pneumocytes
- Fused basal lamina of P1 and capillary endothelium
- Endothelial cells
what is found in the thick portion of the blood gas barrier?
- surfectant
- Type I pneumocytes
- Basal lamina of P1
- Connective tissue elements
- Basal lamina capillary endothelium
- Endothelial cells
what characterizes COPD?
smoking elevates neutrophils which elevates elastase which destroys elastic fibers and causes permanent dilation of the airways
you end up losing surface area for gas exchange because of dilated airspaces
What is characteristic of emphysema?
permanent enlargement of respiratory spaces affecting airways distal to the terminal bronchioles.
- Neutrophils release proteases including elastase which break down elastic fibers..
there is a deficiency of alpha 1 antitrypsin
what is alpha 1 antitrypsin for?
counteracts elastase activity
what characterizes the appearance of a lung with emphysema?
large air spaces, large lungs.
dilated airspaces and loss of surface area for gas exchange.
see pic
what characterizes the appearance of a lung with pneumonia in imagine? what kinds of cells would you find in its histology?
consolidation, enlargement of capillaries by exudate
presence of neutrophils
what characterizes small cell lung cancer/oat cell carcinoma?
associated with smoking
origin: neuroendocrine cells. they have Cushing syndrome due to ACTH secretion
SEE IMAGE= central mass aggressive often metastasized when diagnosed
what characterizes squamous cell carcinoma ?
associated with smoking
squamous metaplasia of respiratory epithelia. Eosinophilic keratin pearl lesions
contains a central mass
SEE PIC
What characterizes adenocarcinoma?
most common in non smoking women
bronchial, bronchiolar, alveolar epithelium
bronchoalveolar carcinoma or bronchogenic
Glandular tumor
SEE PIC
has peripheral mass
