L1 Functions of Respiratory System PDF

Functions of respiratory system and respiratory cycle Dr. Ghada Elgarawany Assistant professor of Medical Physiology www.gmu.ac.ae Rules before lectures COLLEGE OF MEDICINE List and explain the function of respiratory system List the muscles of inspiration and expiration. Describe the role of inspir...

Functions of respiratory system and respiratory cycle Dr. Ghada Elgarawany Assistant professor of Medical Physiology www.gmu.ac.ae Rules before lectures COLLEGE OF MEDICINE List and explain the function of respiratory system List the muscles of inspiration and expiration. Describe the role of inspiratory muscle and expiratory muscles in breathing Physiological Anatomy of Respiratory system Conducting Passage Lower respiratory tract Physiological Anatomy of Respiratory system Lower Respiratory Tract Trachea Bronchi Bronchiole Terminal bronchial Respiratory bronchiole Terminal bronchioles Alveolar duct Alveolar sac Alveoli Physiological Anatomy of Respiratory system Lower Respiratory tract is divided into 23 generation as it divides 23 times 0 to 16 generation - conducting zone 0-zero generation (level) ---trachea 16 generation(level, division)—terminal bronchial 17 to 23 generation - respiratory zone 17 generation is respiratory bronchiole 23 generation is alveoli N.B: Respiratory acinus (respiratory lobule): is the functional unit of the lung. It is formed of one respiratory bronchiole and its generations. Functions of respiratory system 1- Gas Exchange : Respiratory system supplies the body with O2 and remove CO2. 2- Regulation of The PH of the blood: through regulation of CO2 excretion 3- Regulation of body temperature It responsible for 4% of heat loss at rest. Functions of respiratory system 4- Voice production (Vocalization): Voice produced through vibration of the vocal cord against the column of the expired air. 5- Smell and taste: Smell receptors are present in the olfactory membrane in the roof of the nasal cavity. Taste receptors presents in the mouth and pharynx. Functions of respiratory system 6- Metabolic functions Secretion of 1- Surfactant 2- Prostaglandins 3- Angiotensin converting enzyme (ACE) ??? What is the function of ACE Removal of Serotonin, norepinephrine and acetylcholine. Angiotensin-converting enzyme (ACE) inhibitors are 7- Defensive functions: medicines that help relax the veins and arteries to lower blood pressure 1) Immunoglobulin : Bronchial secretion contains IgA. 2) Mechanism to prevent foreign matters from reaching the alveoli. Mechanism to prevent foreign matters from reaching the alveoli Particles >10 µ removed from the hairs of the nose Particles between 6-10 µ stick to nasal mucosa and removed by → 1- SNEEZING REFLEX 2- Turbulent precipitation the air passing through the nasal passageways hits many nasal structures like the conchae (nasal turbinate)→air change its direction of movement, but the particles suspended in the air → precipitation and they are entrapped in the mucous coating and transported by the cilia to the pharynx to be swallowed. Mechanism to prevent foreign matters from reaching the alveoli Particles between 1-5 µ settled in the trachea and bronchi by gravitational precipitation, they are removed by 1- Reflex bronchial constriction. 2- Mucociliary Escalator. 3- Cough reflex Smoking cigarettes reduce the efficacy of the mucociliary escalator. Kartagener syndrome (Immotile cilia, leading to recurrent respiratory tract infections and infertility) Mechanism to prevent foreign matters from reaching the alveoli Particles < 1 µ adhere to the alveoli fluid, they are removed by pulmonary alveolar macrophages (PAMs) Particles