Respiratory Histology Flashcards
Conducting Portion of breathing
Air passes these to get to Gas exchange
- Nasal Cavity
- Paranasal Sinus
- Nasopharynx —> oropharynx
- Larynx
- Trachea
- Bronchi (primary, secondary, tertiary)
- Bronchioles
- Terminal Bronchioles
Respiratory Portion of breathing
Gas exchange
- Respiratory Bronchioles
- Alveolar ducts
- Alveolar sacs
- Alveoli
Respiratory Epithelium is what
Pseudostratified columnar
+ CILIA
- has lamina Propria (Vascularized with many capillaries)
The respiratory epithelium has other cells in it
GOBLET CELLS
5%-15%
Secrete mucus into the airways
The respiratory epithelium has other cells in it
BRUSH CELLS
Short blunt microvilli
= chemosensory cells —> sensory nerve fibers
The respiratory epithelium has other cells in it
BASAL CELLS
Stem cells on the basement membrane
Non-ciliated
The respiratory epithelium has other cells in it
SMALL GRANULE CELLS
Like basal cells only have secratory granules
= endocrine cells for DNES (diffuse neuroendocrine system)
Nasal cavity 3 parts
- Nasal Vestibule = right inside nostrils (skin)
- Respiratory region = inferior 2/3 of nasal cavity (respiratory mucosa)
- Olfactory Region = at apex upper 1/3 of nasal cavity (specialized olfactory mucosa)
Nasal Cavity function
Adjust to temperature + humidity of air coming in
Turbinate bones increase SA
Paranasal Sinuses
Air-filled spaces in the bones of the walls of nasal cavity (respiratory epithelium with narrow openings to communicate with NC)
= mucus made inside —> NC
*high risk of infection after upper resp. Viral infection = drainage
Respiratory mucosa
Pseudostratified columnar ciliated
Has goblet cells, basal cells, brush cells small granule cells
Olfactory mucosa is located exactly where and what type of epithelium
Covers the superior conchae bilaterally
Pseudostratified columnar, non-motile ciliated + NO goblet cells
* Has Olfactory Bowmans glands : dissolve odors (Serous)
*Has smell receptors
Olfactory Receptory N (ORNs)
Histology and characteristics
1 dendrite
Specialized, nonmotile cilia + odorant receptor
LIGAND BINDING R.
*Brush cells : ciliated columnar ——> CN5
The Larynx histology
- Cartilage
1. Hyaline : thyroid, cricoid, inferior arytenoid cartilage
2. Elastic : epiglottis, cuneiform, corniculate, superior arytenoid cartilage - Skeletal M (movement)
Epiglottis
Function and 3 parts
Prevents swallowed food entering airway
- Core : Elastic cartilage
- Lingual surface : strat. Squamous
- Laryngeal surface : transition to ciliated Pseudostratified columnar
Larynx
Vestibular Folds
Respiratory epithelium + serous glands + LN
Superior fold - CANT move
Larynx
Vocal Folds
Nonkaritinized strat. Squamous + elastic CT (Inferior fold - MOVE) = protects from abrasion = sound and phonation * vocal lig connected to edge of folds
Laryngitis
Inflamed larynx (virus or allergy) = hoarse voice (lamina Propria edema changes shape of vocal folds)
Croup
In children and young children
Hoarseness and load harsh coughs (laryngeal mucosa edema)
7 components of nasal cavity ——> segmented bronchus (bronchi)
- Resp. Epithelium
- Goblet Cells
- SM
- Ciliated cells
- Glands
- Hyaline cartilage (decreases with each level)
- Elastic Fibers
4 components of bronchiole—> terminal bronchiole—> respiratory bronchioles
- Resp. Epithelium
- Ciliated cells (decrease each level)
- SM (decrease each level)
- Elastic Fibers
3 components of alveolar duct
- Resp. Epithelium
- Elastic Fibers
- SM (very little)
Alveolar sacs and alveoli components
Respiratory Epithelium
Elastic Fibers
Trachea basic histology
What keeps it open
Divides into
Short flexible air tube , Resp.Epithelium
Open due to stacked cartilage rings
Divides into main or primary bronchi
Trachealis muscle location
SM between the cartilage rings of trachea
esophagus is behind what and lined by what
Behind the trachea and lines by strat. Squamous non-keratinized
Trachea detailed Histology
Elastic fibers and goblet cells in = lamina Propria
Dense CT + Hyaline cartilage (C-shaped) = submucosa
Adventitia
Bronchi histology
Where does it enter and 3 parts
Resp epithelium
At Hilum of lung
Primary (main) —> Secondary (lobular) —> Tertiary (segmental)
Bronchi detailed histology
Fewer goblets
PRIMARY : complete cartilage rings
SECONDARY —> TERITIARY : more complete cartilage replaced by hyaline cartilage
Bronchioles
Start after what structure
Enters what
Branches into what
Starts after terminal branches of tertiary bronchi
Enter pulmonary lobule
5-7 TERMIAL bronchioles
Bronchioles histology large —> terminal branches
Larger : resp epithelium—> simple columnar cilia
Terminal : Simple columnar —> simple cuboidal cilia
- NO glands NO cartilage NO submucosa
- SM
Asthma
Chronic bronchiole inflammation + SM constriction = obstructs airflow
—> bronchospasm (air has hard time moving in and out from aveoli)
= eosinophils, lymph’s, mast cells fill the airway
= thick bronchiolar epithelium with HIGH GOBLETS cells + hyperplastic SM +enlarged BVs
Terminal Bronchioles Histology
And what does it secrete
Simple cuboidal + CLUB cells(no cilia + secretory granules)
- Surfactant : lipoprotein and mucins —> epithelium surface
- Detoxification : by SER of inhaled Xenobiotics
- Anti microbial peptides +cytokines : local immune defense
Terminal Bronchioles divide into
2 respiratory bronchioles
Respiratory bronchioles
Histology
Branches into
Have the alveoli on it
Simple cuboidal + elastic fibers + SM
Alveolar ducts—> alveolar rings —> alveolar sacs —> alveoli
Alveolar duct histology
Attenuated squamous cells
Alveolar rings
SM and collagen and elastic fibers forming a ring around alveolar ducts
Alveolar sacs
Clusters of +2 alveoli
Ends of alveolar ducts and along its length
Alveoli Histology
Simple squamous + BVs
- has alveolar pores : for air movement
- intralveolar septum : between alveoli
Interalveolar septum
Fibroblasts, ECM, elastic(expand and contraction) and reticular (prevent excessive distention or collapse) fibers
HIGH CAPILLARIES
Alveolar walls have what 2 types of cells
- Type 1 pneumocytes : squamous cells *gas exchange + most abundant lining the alveolus surface
- Type 2 pneumocytes : large and round, bulge + MANY CLUB cells (*make surfactant)
Macrophages in the alveoli or interalveolar septum
Dust cells
What do the walls of the alveoli help create
To keep blood out from alveoli
Blood-Air- Barrier
3 components making the BAB
- 2-3 thin highly attenuated alveolar cells
- Basal Lamina fused with capillary endothelium
- Thin endothelial capillary cells
Emphysema
What happens
Causes
Risks
Permanent enlargement of air spaces inside alveolar sacs (due to rupture of alveolar walls) distal from terminal bronchiole (enlargement of BV)
= airflow obstruction from narrowing of bronchioles + flatten
= not many alveolar walls, —> open enlarges alveolar sac only
Lost a huge part of gas exchange
Smoking, inhaling long-term coal dust or particulate materials
Pneumonia
Lung tissue inflammation
air spaces filled with WBC (neutrophils), RBC, fibrin
=enlarged capillaries with manyyy RBCs (vascular congestion)
= Red hepatization stage
* lung is red, firm, heavy (little air space)
Pulmonary and bronchiole arterial supply enter lung where and anastomoses at what level
The Hilum of the lung by the respiratory bronchioles
Difference in terminal Bronchioles and respiratory bronchioles
Terminal : have CLUB cells
Respiratory : have alveoli
Surfactant prevent alveolar collapse by
Increase SA and decrease surface tension
