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Chapter 15 Respiratory System. 1. Components ---nose ---pharynx ---larynx ---trachea ---bronchi ---lung. 2. Trachea and main bronchi. three layers 1) Mucosa : ---epithelium: pseudostratified ciliated columnar epithelium ---lamina propria: CT, contain LC, PC, MC, BV, LV.
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1. Components ---nose ---pharynx ---larynx ---trachea ---bronchi ---lung
2. Trachea and main bronchi three layers 1)Mucosa: ---epithelium: pseudostratified ciliated columnar epithelium ---lamina propria: CT, contain LC, PC, MC, BV, LV
Pseudostratified ciliated columnar epi. • ciliated cell: columnar, cilia • goblet cell • basal cell: -pyramidal, basally-located -undifferentiated cell→ciliated cell or goblet cell
brush cell: -columnar, microvilli, -EM: RER, no g. -function: not very clear, may be i.become into ciliated cell ii.receive sensory stimuli-epitheliodendritic synapse
diffuse neuroendocrine cell: -less, pyramidal -EM: dense-core g.-small granule cell neuroepithelial body: cell + NF -Function: secret hormones to regulate contract of SM and secretion of gland i. 5-hydroxytryptamine(serotonin) ii. calcitonin iii. enkephalin * clear basement membrane
2) Submucosa: LCT, with BV, LV and N • tracheal gland: mixed • diffuse LT and LN * S Ig A = secretory component (secreted by epi. cell) + Ig A ( produced by plasma cell)
3) Adventitia: • cartilage ring: 16-20 “C ” shaped • circular ligament: elastic F • SM- posterior part( membrane part): SM, elastic F, tracheal gland
3. Lung ---paired organ, located in thoracic cavity
1) General structure: ---capsule: visceral layer of pleura- serous membrane-CT + mesothelium ---parenchyma: all branches of bronchi and alveoli( right 3, left 2) ---interstitia: CT, BV, LV, N
* branchi →intrapulmonary bronchial tree( lobar bronchial tree, segmental bronchi and small bronchi) D < 1mm D < 0.5 mm →bronchioles →terminal bronchioles →respiratory bronchioles →alveolar duct →alveolar sac → alveoli * pulmonary lobule: one bronchioles and its all branches and all alveoli • cone or pyramidal-shaped: apex pointed toward the hilum and basal(1.0 cm in D) faced the surface • more CT between them
2) Conducting portion ① from lobar bronchi to small bronchi ---Regulation of simplification: (gradually) • mucosa: -epi. : become thinner -goblet cell ↓ -lamina propria: thinner, SM ↑ • submucosa: gland ↓ • adventitia: cartilage→cartilage →decreasing
② bronchiole: D < 1mm ---continuous to change • goblet cell, Gland, cartilage ↓ or disappear • smooth muscle ↑,circular mucosa plica ↑
③ terminal bronchiole: D < 0.5 mm ---goblet cell, gland, cartilage disappear ---SM: form a whole layer of circumferential SM ---Wall: • simple columnar epi.: two types of cells • A layer of SM
i. ciliated cell ii.secreting cell: Clara cell EM: • dome-shaped apical • SER • Secreting G: contains proteolytase and oxidase function: • dissolve the mucus • biological thansformation • undifferentiated cell → ciliated cell
3) respiratory portion ①respiratory bronchiole ---similar to terminal bronchioles: • simple ciliated columnar epi. • smooth muscle ---place where connect with alveoli: gradual changing • simple cuboidal epi. →simple squamous epi. • less SM, elastic F
②alveolar duct: 20-60 alveoli connect with it ---wall: hard to see- opening part between two alveoli • simple cuboidal epi. or squamous epi. • SM: single, EF- knob-liked structure
③alveolar sac: ---many alveoli open to it ---no proper wall, no knob-liked structure
④alveoli: ---polygonal, with opening sac- 0.2mm in D, 300-400 million/per lung, total area: 70-80mm2 ---wall: • epi. and basal lamina • alveolar septum: CT with BV, EF
alveolur epi: ---type I alveolar cell: LM: flattened, 0.2um, N: round EM: • plasmalemmal vesicles • tight junction Function: constitute the blood-air barrier
---type II alveolar cell: scattered, 5-8/per alveoles LM: • cuboidal or round, with round N • paler- stained, foamy cytoplasm
EM: • secreting granules: Osmiophilic multilamellar body -0.1-1.0 um -contains: phospholipid, glycosaminoglycan and protein • microvilli, mito, lysosome, RER, Golgi Function: i. secreting surfactant ii.differentiated into type I alveolar cell
b. alveolar septum: CT • EF • Fibroblast, macrophage, plasma cell, mast cell • LV, N • capillary: endothelium + basement membrane
* Blood-air barrier: the structure through which the gaseous exchange takes place ---0.2-0.5 um ---components: • a layer of liquid • type I alveolar cell and basement M • CT • capillary endothelial cell and BM
c. alveolar pore: 10-15 um ---equalize( balance) the air-pressure between alveoli ---lober pneumonia- bacteria or inflammatory spread through the pore
d. alveolar marcophage: monocytes- MPS ---dust cell: macrophage which phagocytose carbon or duct particles ---heart failure cell: when lung congested(edema), the alveolar marcophage phagocytose RBC, digest the hemoglobin into hemosiderin(pigment) and accumulated them within macrophage