,Respiratory system,Respiratory system,Nasal cavity, pharynx & larynx. Trachea & bronchi. Lung.,一、trachea,trachea (HE),Mixed gland,EM: epithelium of trachea,4. Small granule C,1.Ciliated C,2.Brush C,3.Goblet C,5.Basal C,The wall of trachea,1. Mucosa=epithelium+lamina propria pseudostratiated ciliated columnar Ciliated C, goblet C, brush C, basal C, small granular C. 2. Submucosa=CT+ mixed glands 3. Adventitia=16-20 C shaped hayline cartilage rings.,atmosphere & alveoli alveoli & blood (blood & tissue),Gas exchange,二、lung,Lung Low power,lung,parenchyma: bronchial trees & alveoli . Principal bronchi(Br)lobular、segmental Brsmaller Brbronchioleterminal bronchiolerespiratory bronchiolealveolar duct、alveolar sacalveoli. Conduction portion : above terminal bronchioles. Respiratory portion :respiratory bronchiole to alveoli. Pulmonary lobule: bronchiole and its ramifications.,Conduction portion lobular Br & small Br,Epithelium Goblet C Glands Cartilage plate SMC,Conduction portion bronchiole & terminal brochiole,Simple ciliated columnar. Goblet C （） Gland （） Cartilage plate （） SMC,Rules of structural variance in conducting portion,Respiratory portion Respiratory bronchiole,The wall is interrupted Simple cuboidal Epi, clara C SMC,Respiratory portion Alveolar duct & alveolar sac,The wall, many alveoli SMC* Simple cuboidal, squamous,Alveolar duct,Alveolar sac,No SMC*,Respiratory portionalveolus,肺泡管,Simple alveolar Epi.,(1) Respiratory portion,#constituents：respiratory bronchiole，alveolar duct，alveolar sac，alveolus。 1.Respiratory bronchiole The wall, few alveoli open into. Simple cuboidal Epi,SMC.,(2) Respiratory portion,2.Alveolar duct & alveolar sac The wall, many alveoli open into. Knobs in the wall of alveolar duct Knobs is sphincter-like SMC.,(3) Respiratory portion,3. alveolus: type I alveolar C type II alveolar C alveolar septum.,Type II alveolar C,macrophage,Elastic fiber,type I alveolar C,Type II alveolar C,Osmiophilic Multilamellar bodies,blood-air barrier,Alveoli,Type I cell squamous, covered most surface of the alveoli .,Type II cell LM: round or cuboidal, cell body protrude into the lumen. EM: osmiophilic multilamellar body, with abundant phospholipids. Functions: secret surfactant, reduce surface tension, stabilize alveoli.,Alveolar septum: continuous Cap., elastic fiber. macrophage dust C. blood-air barrier includes: 1.mucus layer on surface of alveoli 2.type I alveolar C 3.BM of alveolar C 4.delicate layer of CT 5.continuous Cap. BM 6.continuous Cap. Endothelium.,Terminal bronchiole,Respiratory bronchiole,Alveolar duct,Alveolar sac,1,2,3,4,Rules of structural variance in respiratory portion,Alveolar epithelial cell,Type I cell can not regenerate. Type II cell can differentiate into Type I cell .,*,keypoints,The basic structure of trachea. Histologic structure of conduction portion. Histologic structure of respiratory portion. Esp. the alveolar epithelium,Thank you !,