Respiratory Histology Flashcards
Where does cell respiration take place?
mitochondria
Where does mechanical respiration take place?
- lungs
- trachea and bronchi
- elastic and collagen fibers
Ventilation mechanism components?
- thoracic cage
- intercostal muscles
- diaphragm
Conducting division of respiratory system?
- nasal cavity (paranasal sinuses)
- nasopharynx
- larynx
- trachea
- bronchi
- bronchioles
- terminal bronchioles
- how air gets into body
Respiratory division of respiratory system?
- respiratory bronchioles
- alveolar ducts
- alveolar sacs
- alveoli
- oxygen exchange
Functions of respiratory system?
- conduction of air to and from lungs
- Conditioning air
- cleanse
- moisten
- warm - Additional functions
- smell
- speech
- exchange of gases
Histological features of conduction?
- Hyaline cartilage
- collagen
- elastic fibers
- smooth muscles
What cleans the air?
- Vibrissae (nose hairs)
- macrophages
- mucus
What moistens the air?
serous and mucus glands
What warms the air?
-capillary network in conchae
Histological layers of conduction portion of respiratory system?
- Pseudostratified columnar epithelium with cilia and goblet cells
- smooth muscle
- serous glands
- hyaline cartilage
Cells of the Respiratory epithelium?
- Ciliated columnar cells
- goblet cells
- basal cells
Importance of cilia in respiratory?
moves particles out
Olfactory epithelium?
- Pseudostratified columnar epithelium with cilia
- no goblet cells
- cilia is immotile
- supporting (sustentacular cells)
- olfactory neuron (mature and immature)
- basal cells
Olfactory glands of Bowman?
- present under epithelium
- secrete serous fluid containing odorant binding protein (OBP)
- no mucus glands
Paranasal sinuses?
- maxillary
- frontal
- ethmoidal
- sphenoid
Histology of paranasal sinuses?
- respiratory epithelium
- fewer goblet cells
- less glands in lamina propria
- less extensive venous plexus
Surfer’s sinusitis?
- sinusitis: inflammation of mucosa lining sinus cavities
- swelling of mucus blocks the flow of mucus and pressure builds up, causing pain and inflammation
- due to salt water entering nose and paranasal sinuses
Nasopharynx histology?
- pseudostratified columnar epithelium with cilia and goblet cells
- nasal surface
Oropharynx histology?
- stratified squamous epithelium
- oral surface
Larynx function?
- produce sound
- close trachea during swallowing
Larynx histology?
- Respiratory epithelium
- except true vocal cords - Hyaline cartilage
- thyroid, cricoid, arytenoid - Elastic cartilage
- epiglottis - Lamina Propria
- loose areolar CT beneath epithelium
- seromucous glands
- mast cells (hypersensitivity leading to edema and laryngeal obstruction)
True vocal cords histology?
- stratified squamous epithelium
- vocal ligament (elastic fiber)
- vocalis muscle (skeletal muscle)
Trachea histology?
- respiratory epithelium
- 16-20 C shaped hyaline cartilage rings
- smooth muscle (trachealis- changes shape for bolus to move through)
- submucosal glands
Bronchopulmonary segment?
-gross anatomic unit of lung that can be removed surgically
Bronchi histology?
- first branch off trachea
- respiratory epithelium
- plates or cartilage (complete rings)
- smooth muscle
- glands
Transition from Bronchus (>5mm) to Bronchiole (<5mm)?
- bronchioles lack cartilage and glands
- number of goblet cells decreases distally, replaced by clara cells
- Epithelium changes
- pseudostratified columnar with cilia
- simple columnar with cilia
- simple cuboidal with cilia (terminal bronchiole)
- simple cuboidal (respiratory bronchiole)
Terminal bronchiole histology?
- simple cuboidal epithelium with cilia
- Clara cells
- Neuroepithelial cells
- Lamina propria is smooth muscle and elastic fibers
Function of Clara cells?
- produce a component of surfactant
- regulate transport of chloride ions
- produce proteins that protect the bronchiolar lining from oxidative pollutants
Function of neuroepithelial cells?
- chemoreceptors reacting to gas composition
- epithelial cell renewal
Respiratory portion function?
-exchange O2 and CO2 between inspired air and blood
Respiratory portion (pulmonary lobule) histology?
- Respiratory bronchioles
- simple cuboidal with cilia
- changes to simple cuboidal
- walls are interrupted - Alveolar ducts
- Alveolar sacs
- Alveoli
Alveolar duct and sac?
- tube consisting of alveoli
- isolated smooth muscle bundles
- individual smooth muscle fibers in alveoli sacs and alveoli
Alveoli histology?
- 2 thin squamous epithelial cells (endothelium)
- capillaries
- fibroblasts
- macrophages (dust cells)
- collagen
- elastic fibers
- alveolar pores (10-15 um)
Pneumocytes?
- Type 1
- 90% of alveolar surface - Type 2
- 10% of surface
- located in interalveolar septum
- creates surfactant (prevents collapse of alveoli)
- phospholipid film over lower aqueous phase
- less force for inspiration
- constant turnover
Blood air barrier (0.1-1.5um)?
- cytoplasm and plasma membrane or alveolar cells
- fused basal laminae of alveolar and endothelial cells (fenestrated capillaries)
- plasma membrane and cytoplasm of endothelial cell
Emphysema?
- Clinical:
- shortness of breath
- fifth decade of life
- productive cough and acute chest illness, worse in morning
- small amounts of colorless sputum from concomitant bronchitis - Histopathology
- chronic respiratory bronchiolitis
- destruction of alveolar architecture
- prominent accumulation of macrophages
- marked bronchiolitis of terminal bronchioles
Pulmonary arteries and veins?
- pump blood to lungs for O2 and back to heart
- run with bronchi toward alveoli
- artery: deoxygenated
- vein: oxygenated
Bronchial arteries function?
- nutrition to lungs
- small branches off Aorta
- eventually anastomose with small branches of pulmonary artery
- spread around alveoli
Where do bronchial veins drain into?
Azygous and Hemiazygous veins
Pleura?
- serous membrane covering lung and lining thoracic cavity
- 2 layers: parietal and visceral (mesothelial cells and CT)
- pleural cavity contains thin film of liquid for lubrication
