L1 Respiratory System PDF

Module 3B  respiratory system histology (Conducting portion 1) Dr. Shereen Hamed Lecturer of Medical Histology [email protected] Learning Outcomes text text Identifiy the conducting por...

Module 3B  respiratory system histology (Conducting portion 1) Dr. Shereen Hamed Lecturer of Medical Histology [email protected] Learning Outcomes text text Identifiy the conducting portion. Identify histological structure of nose. Identify histology of olfactory mucosa, nasopharynx and larynx  Learning Outcome 1 Identify the conducting portion. Identify histology of olfactory mucosa, nasopharynx and larynx  RESPIRATORY SYSTEM Conducting part Respiratory part part responsible for: -conduction of air to and from the lung -conditioning of air  RESPIRATORY SYSTEM Respiratory Conducting part part 1- Nasal cavities and nasal sinuses. 2- Nasopharynx. 3- Larynx. 4- Trachea. 5- Bronchi. 6- Bronchioles. 7- Terminal bronchioles  Learning Outcome 2 Identify histological structure of nose.  Nasal Cavity The 2 Nasal vestibule fossae Respiratory Olfactory region region external part lined by thin skin : - sweat glands - sebaceous glands - short coarse vibrissae (hairs) for filtration of air.  Respiratory region Olfactory region Site Inferior 2/3 of the Upper 1/3 of the nasal nasal fossae. fossae (roof). middle and inferior superior conchae conchae Covering Respiratory mucosa Olfactory mucosa Mucosa  Respiratory mucosa Olfactory mucosa Epith. Pseudost. Col. Ciliated Neuroepithelium with goblet cells. Corium Dense fibroelastic Dense fibroelastic CT CT Swell bodies: which Bowman's glands. are large venous Secrete serous fluid plexuses which acts as a solvent for the odorous gases. Every 20–30 minutes, the swell bodies on one side become temporarily engorged with blood Respiratory region  Learning Outcome 3 Identify histology of olfactory mucosa, nasopharynx and larynx  Olfactory mucosa Epith. Neuroepithelium Corium Dense fibroelastic CT Bowman's glands. Secrete serous fluid which acts as a solvent for the odorous gases.  Olfactory epithelium Supporting Olfactory Basal Cells cells neurons  Olfactory epithelium Supporting cells - columnar, with broad apexes and narrower bases. -On their free surface are microvilli submerged in a fluid layer. -bind to the adjacent olfactory cells by junctional complexes. -express abundant ion channels to maintain a microenvironment for olfactory function and survival. Olfactory epithelium Olfactory neurons  Olfactory epithelium Olfactory neurons - bipolar neurons. - Nuclei between those of the supporting cells and the basal cells. -The luminal dendrite is a knoblike with long nonmotile cilia act as chemoreceptors. -The basal axons leave the epithelium and unite in the lamina propria as very small nerves Olfactory epithelium Basal Cells Small Conical At basal lamina Stem cells for other types  Paranasal sinuses Bilateral cavities frontal, maxillary, ethmoid Epithelium and sphenoid bones of skull. Thin resp. epith. Few goblet  Nasopharynx Epithelium Corium pseudo-st. Pharyngeal col. ciliated tonsils with goblet (adenoids). cells  Larynx a rigid short tube between the pharynx and trachea. Epithelium Corium pseudo-st. col. Laryngeal tonsils ciliated with cartilages goblet cells (reinforces its Except ….. wall).  Corium of larynx Infiltrated with lymphocytes and in certain sites lymphatic nodules (laryngeal tonsil). laryngeal cartilages. Large cartilages (thyroid, cricoid and most of the arytenoids) are hyaline cartilage. Smaller cartilages (epiglottis, cuneiform, corniculate and tips of the arytenoids) are elastic cartilage.  Epiglottis It projects from the upper rim of larynx. It acts as a valve to prevent swallowed food or fluid from entering the trachea. Epithelium Corium Laryngeal The lingual surface: contains glands surface: stratified squamous pseudo-st. col. non keratinized ciliated with epithelium. goblet cells  Vocal cords 2 pairs of mucosal folds that extend into the lumen False vocal cords True vocal cords -upper pair -lower pair. - Protect from -phonation F.B. -St. sq. non -Pseudost. Col. keratinized ciliated  References Principles of histology, (student book of Histology & Cell Biology Department, faculty of medicine, Mansoura university) Basic Histology, text book of histology & cell biology Internet sources Discussion Feedback  References Principles of histology, Semester 3 (student book of Histology & Cell Biology Department) Basic Histology, text book of histology & cell biology