RESPIRATORY ORGANS It includes: Nose. Pharynx. Larynx. Trachea. Bronchi and bronchioles. Lungs and alveoli. NOSE It opens externally on the face by the nostrils (external nares). The nasal cavity is divided by the midline nasal septum. It is separated from the oral cavity by the palate. LINING MUCOSA The olfactory mucosa is in the superior part of the nasal cavity. The rest of the mucosa is respiratory. LINING MUCOSA The nasal mucosa has a a rich network of veins to: 1. warms the air. 2. The sticky mucous secretion moistens the air. 3. Traps bacteria and foreign bodies. NASAL CAVITY The ciliated cells of the nasal mucosa move the mucous backwards to the throat where it is swallowed. CONCHAE They are three mucous-covered projections in the lateral wall of the nasal cavity. They increase the surface area of the mucosa exposed to the air. PHARYNX (THROAT) It is a muscular tube. It is a common pathway for food and air. It is continuous with the nasal cavity through the internal nares. It terminates in the esophagus. PHARYNX It passes behind. (1) The nasal cavity (Nasopharynx). (2) Oral cavity (Oropharynx). (3) Larynx (Laryngopharynx PHARYNX It has clusters of lymphoid tissue. The pharyngeal tonsil (Adenoid): in the nasopharynx. Palatine tonsil :in the oropharynx. Lingual tonsil : at the base of the tongue. NASOPHARYNX It is continuous with the nasal cavity through the internal nares. It receives the openings of the pharyngotympanic tubes to connect with the middle ear. LARYNX Functions : 1. It directs food and air into their proper channels. 2. It has a role in speech. It is formed of (8) hyaline cartilages The Thyroid cartilage is the largest. LARYNX Thyroid cartilage: is the largest. Epiglottis: Is a single flap of elastic cartilage VOCAL (TRUE VOCAL) FOLDS They are made of the mucous membrane of the larynx. They vibrate with the expelled air and produce sounds. The passage between them is the glottis. TRACHEA It begins from the larynx. It ends at the level of T (5). It is (10-12) cm. Its walls are reinforced with C shaped hyaline cartilages. TRACHEA The open parts of the rings allow the oesophagus to expand anteriorly during swallowing. The rigid parts keep the trachea patent. MAIN BRONCHI Right main bronchus: Wider. Shorter. Straighter. (than the left) It is the more common site to lodge foreign bodies. I LUNGS They are paired organs. They lie in the thoracic cavity on each side of the mediastinum. LUNGS Each lung has : Apex : It is narrow and located deep to the clavicle. Base : Broad and rests on the diaphragm. Fissures : Two in the right lung and one in the left. LUNGS Lobes : The right lung has three lobes (upper,middle and lower). The left lung has two lobes (upper and lower). PLEURA Visceral : A serous membrane covering the lung. Parietal : It lines the thoracic walls. RESPIRATORY TREE 1. primary (main) bronchi. 2. Secondary. 3. Tertiary. 4. Terminal Bronchioles. 5. Respiratory bronchioles. 6. Alveolar ducts. 7. Alveolar sacs. RESPIRATORY ZONE It is the only site for gas exchange in the lungs. It consists of: 1. Respiratory bronchioles. 2. Alveolar ducts. 3. Alveolar sacs. 4. Alveoli. Millions of alveoli make up the bulk of the lung which are mostly air spaces. CONDUCTING ZONE It conduits air to and from the respiratory zone. It consists of : 1. Nose. 2. Pharynx. 3. Larynx. 4. Trachea. 5. Bronchi. 6.Terminal bronchioles.