Histology - Respiration Flashcards
Chronic Obstructive Pulmonary Disease (COPD)
Ciliated cells: Lose synchronized beating, Decrease in #s ciliated cells Goblet cells: Increase secretion, Increase in #s goblet cells Seromucous glands: Increase secretion, Hypertrophy
Cystic Fibrosis
Defective chloride ion regulator. NaCl build up in cell, draws water from mucus. Dehydrated viscous musuc, mucociliary escalator ineffective, muscous plugs obstruct airways, chronic infections.
Kulchitsky cells (small granule cells)
Neuroendocrine cells (catecholamine, serotonin, etc.) that may participate in local reflexes regulating airway or vascular caliber (neuroepithelial bodies)
Trachea 1’ Bronchi Characteristics
Pseudostratifeid columnar, cilated & goblet cells, K cells, brush cells, basal cells, seromucus glands, hyaline cartilage
Clara cells
dome-shaped cells with short microvilli, found in the small airways (bronchioles). protect the bronchiolar epithelium, secrete lung surfactant, detoxify harmful substance, also act as a stem cell, multiplying and differentiating into ciliated cells
Smooth muscle in tracheobronchial tree
Deep, it contracts to control air velocity and distribution.
Bronchial Asthma (extrinsic)
Starts as hypersensitivity reaction. Characterized by mucus in lumen, inflammation and BM thickening, enlarged musous glands, smooth muscle hyperplasia.
Patency Support (Cartilage) in Trachea
“C” - shaped Cartiledge Rings
Patency Support (Cartilage) In 2’ & 3’ Bronchi
Discontinuous Plates
Patency Support (Cartilage) in Bronchioles (incl. terminal bronchioles):
Elastic fibers and surfactant from Clara Cells
Interalveolar Septum Occupants
- Type I alveolar cells (2) 2. Type I capillary endothelium 3. Fused basal lamina between endothelial cell & type I cell
Path of O2 (From alveolar air space to RBC)
- Cytoplasm: Type I alveolar cell (P1)
- Fused basal lamina (BM)
- Cytoplasm: Endothelial cell (E)
Surfactant functions
Surface tension, anti-bacterial-viral-fungi, inflammatory response functions
Alveolar macrophages (M)
Antigen presentation, Inflammatory response. Originate from monocytes, called dust cells.
Terminal bronchiole epithelium
Simple cuboidal, Clara cells, ciliated cells (NO alveoli)
Respiratory bronchiole epithelium
Simple cuboidal, Clara cells, Simple squamous (type I alveolar cells) lining alveoli. Bands of smooth muscle.
Alveolar duct epithelium
Simple squamous (type I alveolar cells) lining alveoli (+ other cells present in alveolus) . SLIPS of smooth muscle.
Terminal bronchiole patecy support
Elastic fibers, Surfactant (Clara cells)
Respiratory bronchiole patency support
Elastic fibers, Surfactant (Clara cells & type II cells)
Alveolar duct patency support
Elastic fibers, Surfactant (type II cells)
Alveolar sac and Alveolus Basic Characteristics
Simple squamous (type I alveolar cells) lining alveoli (+ other cells present in alveolus) . NO smooth muscle. {atency support from Eeastic fibers, Surfactant (type II cells).
GI & respiratory systems embryonic germ layer
Endoderm
smooth mm, general CT (organs), cardiac muscle, connective tissue, circulatory system (blood and lymph) embryonic orgin
visceral (splanchnic) mesoderm
Tracheoesophageal septum
Formed by fusion of two longitudinally-oriented tracheoesophageal ridges (or folds). Separates the trachea (anterior) from the esophagus (posterior).
Respiratory diverticulum
lung bud
most common Tracheoesophageal malformation
Esophageal atresia with Tracheoesophageal fistula (TEF)
Canalicular period
16 weeks = 26-28 weeks
Surfactant production begins at
20 weeks
Terminal sac period
(26-28 weeks – birth) Capillaries now associated with primitive alveoli, blood-air barrier established.
Alveolar period
More primitive alveoli develop & mature into adult alveoli. Lung takes on open, “lacy” appearance .At end of 300 million alveoli present
Trends in Respiration from Upper to Lower Tracts
Lower portions of the respiratory tract show progressive loss of the various components characteristic of the trachea; that is, less and less cartilage, progressively lower epithelium, gradual loss of goblet cells, and finally loss of cilia and smooth muscle.
Where do Clara cells begin? Where do they end?
BEGIN: Primary bronchioles
END: Alveolar ducts
Separates the trachea (anterior) from the esophagus (posterior). Formed by fusion of two longitudinally-oriented ridges (or folds).
Tracheoesophageal septum
Type I cells
(97% of alveolar surfaces) line the alveoli. Squamous; thin for optimal gas diffusion.
Type II cells
(3%) secrete pulmonary surfactant (dipalmitoyl phosphatidylcholine), which increases the alveolar surface tension. Cuboidal and clustered. Also serve as precursors to type I cells and other type II cells. Type II cells proliferate during lung damage.
Airway Submucosa Components
Loose Commective Tissue (Elastic fibers, larger blood & lymphatic
vessels.)
Smooth muscle or Glands
Most common tracheoesophogeal abnormality (90%)
VACTERL association.
Esophageal atresia with Tracheoesophageal fistula (TEF)
VACTERL
Vertebral defects
Anal atresia
Cardiac defects
TEF
Esophageal atresia
Renal defects
Limb defects
Ends 16 weeks = 4 months
- Terminal bronchioles (cuboidal epithelium)
- Capillaries present (not associated)
- No respiratory bronchi or alveoli
Pseudoglandular period
Canalicular period
16 weeks = 26-28 weeks
Terminal bronchioles (cuboidal epi.)
Respiratory bronchioles (cuboidal epi.)
Capillaries present (not associated)
No alveoli
Terminal sac period
26-28 weeks – birth
- Blood-Air-Barrier established.
- Terminal sacs or Primitive alveoli lined by simple squamous cells.
- Capillaries now associated with primitive alveoli
- Surfactant secretion greatly increases
Alveolar period
Birth - 8 - 10 years
More primitive alveoli develop & mature into adult alveoli
Lung takes on open, “lacy” appearance.
At end of alveolar period: 300 million alveoli present
Visceral Pleura Origin
Sphlanic Mesoderm
Parietal Pleura Origin
Somatic Mesoderm
Large Cell Undifferentiated Carcinoma
Mutations in stem cells of the epithelium due to persistent exposure to carcinogens (smoking)
Small Cell Carcinoma
Mutations in epithelial neuroendocrine cells from persistent exposure
Mutations of ciliated cells and mucous cells can cause…
Adenocarcinoma
