Histology - Respiratory System (1) Lecture Notes PDF

Histology - respiratory Respiratory system ( ) LECTURE (1) Respiratory system (1) Dr. M. Shalaby Histology - respiratory Respiratory system ( ) STRUCTURAL 1. Upper respiratory trac...

Histology - respiratory Respiratory system ( ) LECTURE (1) Respiratory system (1) Dr. M. Shalaby Histology - respiratory Respiratory system ( ) STRUCTURAL 1. Upper respiratory tract. CLASSIFICATION 2. Lower respiratory tract. CONDUCTING PORTION RESPIRATORY PORTION  Conduction of air to and from  For Gas exchange (respiration). lung  Conditioning of air ① Nasal cavities & sinuses. ① Respiratory bronchioles. FUNCTIONAL ② Nasopharynx. ② Alveolar ducts. CLASSIFICATION ③ Larynx. ③ Alveolar sacs. ④ Trachea. ④ Alveoli. ⑤ Bronchi. ⑥ Bronchioles. ⑦ Terminal bronchioles. Dr. M. Shalaby Histology - respiratory Respiratory system ( )  External dilated part.  Lined by thin skin –sweat glands – VESTIBULE sebaceous glands – short coarse vibrissae for filtration of air.  Separated into: 2 NASAL ① Respiratory region. FOSSAE ② Olfactory region. RESPIRATORY REGION OLFACTORY REGION  Inferior 2/3 of nasal fossae.  Upper 1/3 of nasal fossae (roof). CONSTITUTES  Middle and inferior conchae  Superior conchae LINED BY  Respiratory mucosa  Olfactory mucosa  Pseudo-stratified columnar  Neuroepithelium: 3 types of cells: ciliated epithelium with goblet ① Sustentacular (supporting) EPITHELIUM cells. cells. ② Olfactory (sensory)cells. ③ Basal Cells.  Dense fibroelastic CT.  Bowman's glands: secrete serous CORIUM  Swell bodies: large venous fluid, acts as a solvent for odorous plexuses. gases. Dr. M. Shalaby Histology - respiratory Respiratory system ( ) SUSTENTACULAR CELLS OLFACTORY CELLS BASAL CELLS OTHER Supporting Sensory NAME Small, conical CELLS Columnar Bipolar nerve cells At basal lamina NUCLEUS Oval Oval  On their free surface are  Bipolar neurons.  Responsible for microvilli submerged in a  Nuclei between those of regeneration. fluid layer. the supporting cells and  Bind to adjacent the basal cells. olfactory cells by  The luminal dendrite is a junction complexes. knoblike with long +  Express abundant ion nonmotile cilia act as channels to maintain a chemoreceptors. microenvironment for  The basal axons leave olfactory function and the epithelium and unite survival. in the lamina propria as very small nerves Dr. M. Shalaby Histology - respiratory Respiratory system ( ) DEF  The first part of the pharynx. LINED BY  Respiratory epithelium  Pseudo-stratified columnar ciliated EPITHELIUM epithelium with goblet cells. CORIUM  Pharyngeal tonsils (adenoids). DEF  Rigid short tube () pharynx & trachea. STRUCTURE  Pseudo-stratified columnar ciliated with goblet Cells except vocal cords, EPITHELIUM anterior (lingual) surface of epiglottis.  Infiltrated with lymphocytes and in certain sites  Lymphatic nodules (laryngeal tonsil).  Laryngeal cartilages: CORIUM ① Large cartilages (thyroid, cricoid and most of the arytenoids) are hyaline cartilage. ② Smaller cartilages (epiglottis, cuneiform, corniculate and tips of the arytenoids) are elastic cartilage. Dr. M. Shalaby Histology - respiratory Respiratory system ( ) SITE  Projects from upper rim of larynx. STRUCTURE  Lingual surface: stratified squamous non keratinized epithelium. EPITHELIUM  Laryngeal surface: pseudo-stratified columnar ciliated epithelium. CORIUM  Contains glands.  Acts as a valve to prevent swallowed food or fluid from entering FUNCTION trachea. DEF  2 pairs of mucosal folds that extend into the lumen. TYPES  The upper pair. FALSE  Protect larynx from foreign bodies.  Lined by pseudostratified columnar ciliated epithelium.  The lower pair. TRUE  For phonation.  Lined by stratified squamous non keratinized epithelium. Dr. M. Shalaby