1. Physiological Anatomy of the Respiratory System The respiratory system is divided into two zones: المحاضرة الثانية

2. Includes : nose, nasopharynx, larynx, trachea and 2 main bronchi one for each lung, and smaller bronchioles. I- The Conducting Zone: Function of the conducting part: 1.Conducting air into the respiratory zone. 2.Air conditioning 3.Humidification 4.Filtration 5.Protective reflexes a- Sneezing reflex b- Cough reflex 6.Non respiratory function

3. II- Respiratory Zone : Consists of respiratory units each of which composed of respiratory bronchioles which subdivided into alveolar ducts which end in clusters of small thin walled air sacs called alveoli

4. Respiratory Passages 1-The nose The nasal cavity is subdivided into there zones a) The vestibule b) The respiratory area C- The olfactory area

5. The olfactory area is lined by olfactory mucosa which consists of: (A) Olfactory epithelium: consists of three types of cells: 1- Sustentecular (supporting) columnar cells 2- Olfactory (sensory) cells 3- Basal cells (B) Corium Diagram of a section of the olfactory mucosa