7 2 MAIN FUNCTIONS OF THE CONDUCTING PORTION To provide a conduit through which air can travel to and from lungs To provide a conduit through which air can travel to and from lungs To condition the inspired air To condition the inspired air –Cleansed –Moistened and warmed by: –Respiratory ephitelium –Mucous and serous glands –A rich vascular network
12 Mechanism of smell Odor molecules stimulate receptors Transduction process Toward the central nervous system OLFACTORY EPHITELIUM ORGANIZATION
13 PARANASAL SINUSES Frontal Frontal Maxillary Maxillary Ethmoid Ethmoid Sphenoid Sphenoid Thinner resp. epithelium Thinner resp. epithelium Few goblet cells Few goblet cells Few small glands Few small glands Thinner lamina propia periost Thinner lamina propia periost –Sinusitis : Inflammatory process of the sinus Acute Chronic
14 PHARYNX Nasopharynx Nasopharynx –Respiratory type epithelium Oropharynx Oropharynx –Squamous type epithelium
18 2 Pairs of Mucous Folds The upper pair: The upper pair: –False vocal cords: (vestibular folds) The lower pair: The lower pair: –True vocal cords: Vocal ligament (elastic fiber) Vocal ligament (elastic fiber) Stratified squoamous epith. Stratified squoamous epith.
19 TRACHEA Respiratory epith. Respiratory epith. C-shape rings of hyaline cartilage (pars. cartilaginea) C-shape rings of hyaline cartilage (pars. cartilaginea) Pars membranacea: Pars membranacea: –Fibroelastic ligament –Smooth muscle –Mixed mucous-serous glands
21 Bronchial tree Bronchi extra pulmonal Bronchi extra pulmonal Bronchi intra pulmonal Bronchi intra pulmonal Bronchioli Bronchioli (terminal bronchioles) (terminal bronchioles)
22 Bronchi Folded appearance of the bronchial mucous (observed in histologic section) Folded appearance of the bronchial mucous (observed in histologic section) Respiratory epith. Respiratory epith. Mucous and serous gland Mucous and serous gland Spirally arranged smooth muscle Spirally arranged smooth muscle Rings / isolated plate of hyaline cartilage Rings / isolated plate of hyaline cartilage
24 Bronchiole Diameter of 5 mm/less Diameter of 5 mm/less Ciliated pseudostratified columnar ciliated simply columnar / cuboidal epith. Ciliated pseudostratified columnar ciliated simply columnar / cuboidal epith. Smooth muscle + elastic fiber in the lamina propria Smooth muscle + elastic fiber in the lamina propria Have neither cartilage nor glands in their mucous layer Have neither cartilage nor glands in their mucous layer
26 Bronchiale Asthma The musculatur (both the bronchi and the bronchioles) is under the control of the vagus nerve and the sympathetic N.S. The musculatur (both the bronchi and the bronchioles) is under the control of the vagus nerve and the sympathetic N.S. Stimulation of The vagus contraction The vagus contraction The parasympathetic relaxation The parasympathetic relaxation
27 Asthma Attacks Dispnoe (increased airway resistance) Dispnoe (increased airway resistance) Wheezing sounds Wheezing sounds –Decreases the diameter of the lumen –Hypersecretion of the mucous / serous glands + goblet cells
30 Alveolar Ducts Squamous alveolar cells Squamous alveolar cells Smooth muscle cells Smooth muscle cells Matrix of elastic and collagen Matrix of elastic and collagenAtria Alveolar sac.
32 ALVEOLI Terminal portions of the bronchial tree Terminal portions of the bronchial tree Inter alveolar septum: Inter alveolar septum: –Capillaries –Fibroblast –Elastic and collagen fibers –Macrophages Blood: Blood: –Air barrier –Cytoplasm of the alveolar cells –Fused basal laminae –Cytoplasm of the endothelial (continuos type)
34 2 TYPE OF ALVEOLAR CELLS Type I cells (squamous alveolar/ Pneumocyte type I) Type II cells (Septal cells/ Pneumocyte type II) Thin/squamous Permeable to gases Cuboidal Vesicular cytoplasm Secretory cells Pulmonary surfactant (to lower alveolar surface tension)
35 ALVEOLAR PORES m in diameter m in diameter Connecting neighboring alveoli Connecting neighboring alveoli Equalize pressure in the alveoli Equalize pressure in the alveoli Enable the collateral circulation Enable the collateral circulation