Respiratory Histology Flashcards
1
Q
What are brush cells?
A
- Cells in the respiratory epithelium with short blunt microvili
- Chemosoensory cells that are connected to sensory nerve fibers
2
Q
What are small granule cells?
A
- Resemble basal cells but have secretory granules
- Belong to DNES
3
Q
What are basal cells of the respiratory epithelium?
A
- Non ciliated stem cells on t he basement membrane
4
Q
what are the three regions of the nasal cavity?
A
- Nasal vestibule: inside nostrils lined by skin
- Respiratory region: inferior 2/3 of nasal cavity lined with respiratory mucosa
- Olfactory region: apex (upper 1/3) lined by specialized olfactory mucosa
5
Q
what is the function of the nasal cavity?
A
- Adjust temp and humidity of inspired air
- Enhanced by large surface area provided by turbinate bones
6
Q
What are the paranasal sinuses?
A
- Air filled spaces in the walls of hte nasal cavity
- Extensions of respiratory region of nasal cavity lined by repiratory epithelium
- Sinuses communicate with nasal cavities through narrow openings onto respiratory mucosa
7
Q
Top and bottom?
A
- Top is the nasal vestibule made of keratiniezed strat squam
- Respirtory region on bottom with psuedostratified columnar ciliated epi
8
Q
Describe the olfactory mucosa?
A
- Dramatically thicker than nasal epithelium and lacks goblet cells, also has non motile cilia
- PSCE
- covers superior conchae bilaterally and contains receptors for sense of smell
- Contains Olfactory (Bowmans) glands serous secretions that dissolve odorant molecules
9
Q
What are ORN’s?
A
- Neurons with single dendritic process
- Specialized non motile cilia with odorant receptors
- Ligand binding causes the AP
10
Q
What ccells are in contact with trigeminal nerve?
A
Brush cells, allows pain sensation of olfactory mucosa
11
Q
What do sustentacular cells provide to the ORN’s?
A
Mechanical and metabolic support
12
Q
What cartilage makes up the larynx?
A
- Hyaline including thyroid, cricoid, inferior arytenoid cartilages
- Elaseic including epiglottis, cuneiform, corniculate, superior arytenoid cartilages
13
Q
Describe the epiglottis
A
- Core of elastic cartilage
- Lingual surface is Strat squam
- Laryngeal surface transitions to PSCE
- Mixed mucous and serous glands in lamina propria
14
Q
What are vestibular folds?
A
- Respiratory epithelium with seromucous glands and lymphoid nodules
- they are suprior and immovable
15
Q
What are vocal folds?
A
- Nonkeratinized strat squam epi that protects from abrasion and desiccation
- Used for phonation
- dense regular bundle of elastic CT makess up the vocal ligament which supports the free edges of each fold
16
Q
What is laryngitis?
A
- Inflammation of larynx due to allergies or viral infection
- Edema of LP changes shape of vocal folds causing loss of voie or hoarseness
17
Q
What is croup?
A
- Similar to laryngitis found in young children
- Edema of laryngeal mucosa causes hoarsness and loud harsh coughs
18
Q
What keeps the trachea lumen open?
A
- Stacked cartilaginous C shaped rings that are open on the posterior side
- The trachealis musclce spans the posterior side
19
Q
What is this
A
20
Q
Bronhi mucosa, submucosa and adventitia?
A
Mucosa:
- PSCE with cells shorter in height and fewer goblet ccells
- Primary bronchi have ompelete cartilage rings gradually repalced with hyaline cartilage as lumen decreases
- Abundant mucous and serous glands
- LP has spiral bundles of SM mm and increasing elastic fibers
Submucosa:
- loose CT with glands
Adventitia:
- moderatly dense CT continuous with surrounding structures
21
Q
A
Bronchi
22
Q
A
23
Q
Trachea mucosa submucosa and adventitia?
A
Mucosa:
- ciliated PSCE
- LP has elastic fibers, goblet cells and BALT
Submucosa:
- slightly denser CT than Lp has incomplete C shaped hyaline rings
- rich in submucosal glands
Adventita:
- composed of CT and binds trachea to adjacent structures
24
Q
What are bronchioles?
A
- Arise from terminal branches of the tertiary bronchi, it will form five to seven terminal bronchioles
25
Q
Describe bronchioles epithelium
A
- PSCE found in larger bronchioles and transitions to ciliated simple columnar to simple cuboidal epithelium (terminal bronchioles)
- NO cartilage or mucosal glands
- NO submucosa
- Muscularis prominent sm mm with dense CT
26
Q
What is asthma?
A
- Recurrent obstruction of airflow due to bronchiole inflammation and sm mm constriction called bronchospasm
- Invasion of WBC’s into bronchiolar wall by eosinophils, lymphocytes, and mast cells
- This thickens the epithelium and increases goblet cells, the sm mm can become hyperplastic
27
Q
What is the terminal bronchioles epithelium?
A
- simple cuboidal epithelium consisting o club cells with non ciliated dome shaped apical ends with secretory granules
28
Q
What are the exocrine functions of club cells?
A
- Secretion of surfactant lipoproteins and mucins on epithelial surfacec
- Detoxification of inhaled xenobiotic conpounds by enzymes of SER
- Secretion of antimicrobial peptides and cytokines for local immune defense
29
Q
What other cells are present in the terminal bronchioles besides club cells?
A
- Brush cells
- DNES small granule cells
- Stem cells
30
Q
what are respiratory bronchioles?
A
- Terminal bronchioles subdivides into respiratory bronchioles which have a alveoli
- First part of respiratory region
- Simple cuboidal epi with elastic fibers and sm mm
31
Q
What are the components of the respiratory bronchioles?
A
- Respiratory bronchiole
- Alveolar ducts:
- lined by the opening of alveoli lined with attenuated squamous cells ending in alveolar sacs
- Alveolar sac:
- large clusters of 2+ alveoli form the ends of the alveolar ducts distally and occur occasionally along their length
- Alveoli:
- saclike evaginations from respirartory
32
Q
What are alveolar rings?
A
- Aggregates of sm mm, collagen, and elastic fibers, that form rings around the alveolar ducts
- Help to hold alveoli open but not directly involved with gas exchange
33
Q
What are alveoli and the components?
A
- Blind ended sacs lined with simple squamous epi supporting tissue and blood vessels
- Contains alveolar pores which are small openings that permit movement of air btw alveoli
- Interalveolar septum found btw alveoli
34
Q
What is found in the interalveolar septum?
A
- Scattered fibroblasts and sparse ECM
- vascularized with the richest capillary networks in the body
- Elastic fibers permit expansion with inspiration and passive contraction with expiration
- Reticular fibers prevent collapse and excessive distension
35
Q
What are the cells found within the alveolar walls and their function?
A
- Type one pneumocytes:
- squamous cells line the entire alveolus surface and participate in gas exchange
- Type two pneumocytes:
- lines portions of each alveolus, rounded large cells that bulge into alveolus, similar to club cells, and produces surfactant
- Alveolar macrophages (dust cells):
- may be ofund in alveoli or interalveolar septa
36
Q
What makes up the respiratory membrane’s Blood air barrier?
A
- 2-3 highly attenuated thin cells lining the alveolus (usually a type one cell)
- Fused basal laminae of these cells and capillary endothelium
- Thin endothelial capillary cells
37
Q
What is emphysema?
A
-
Permanent enlargement of air spaces distal to terminal bronchiole
- Chronic obstruction of airflow due to narrowing of bronchioles accompanied by destruction of alveolar wall
- Results in significant area for gas exchange being lost
- Smoking & chronic inhalation of particulates can lead to this
38
Q
What is pneumonia?
A
- Inflammation of lung tissue, filling airspaces with exudate containing WBC, RBC, and fibrin
- Enlarged capillaries are congested with RBCs
- Red hepatization stage
- Lung appears red, and firm due to lack of air spaces and heavy due to the exudate
39
Q
What parts of the respiratory tract contain Respiratory and Stratified Squamous epitheium?
A
- Larynx
- Nasopharynx and posterior oropharynx
40
Q
What parts of respiratory tract contain only respiratory epithelium?
A
- Most areas of nasal cavity
- Trachea
- Bronchi
