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单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,#,Respiratory System Disorders,Respiratory System Disorde,1,Pediatric pulmonary diseases account for almost 50%of deaths in children under age 1 year and 20%of all hospitalization of children under age 15 years.,Pediatric pulmonary diseases a,2,Bryce et al.WHO estimates of the causes of death in children.Lancet 2005,Bryce et al.WHO estimates of,3,Respiratory tract infections represent the most common infections of childhood and range from trivial to life threatening illness.Other diseases of this system include asthma,disorders of pleura or pleura cavity,lung tumor,congenital abnormality.,Respiratory tract infections r,4,Anatomy and Physiology of Respiratory System,The knowledge of basic respiratory physiology and anatomy is one of the basic requirements for correct interpretation of symptoms and physical signs and in the attainment of an age appropriate differential diagnosis.There are a number of significant anatomic and physiological differences between children and adults that have impact on assessment and management.The child is not only physically smaller but also has immature respiratory systems with fewer reserves than those of the adult.,Anatomy and Physiology of Resp,5,Normal anatomy,Respiratory system is divided into upper respiratory tract and lower respiratory tract by cricoid cartilage.,upper respiratory tract:nose,nasal sinuses,pharynx,pharyngotympanic tube,epiglottis,larynx,lower respiratory tract:trachea,bronchus,bronchiole,respiratory brochiole,alveolar ductules,alveolus,Normal anatomy,6,Nasal passage is shorter,no vibrissa,mucosa has a rich vascularity-liable to infection,Nasal passage is narrow-liable to obstruction,resulted dyspnea.,Nasal sinus ostia is large-nasosinusitis.,pharyngotympanic tube is broader,straighter,shorter and horizontal-otitis media.,pharyngeal tonsils:start to enlarge at the end of 1 year,peak at 4 to 10 year-old,degeneration at 1415 years old-tonsillitis rarely occurs in infants.,Larynx is in a shape of funnel and narrow,cartilage is flexible,mucosa is tender and rich of vessel-laryngeal edema and narrow,Nasal passage is shorter,no v,7,Trachea and bronchus are narrower than those of adult;cartilage is flexible,lack of elasticity tissue,supporting action is weak,Airway wall account for 30%of Airway wall area in children,15%in adult.mucosa is tender and rich of vessel.,The right main bronchus is more vertical and broader than the left and it offers an easier passage for aspirated foreign bodiers.,Bronchiole has not cartilage-easy to collapse,result to retention of gas and effect the exchange of gas.,The amount and size of alveolus is less and small.,Chest is shorter and in a barrel shape,has a smaller scope of activities,Trachea and bronchus are narro,8,The airway are lined with an epithelial membrane that gradually changes from ciliated pseudostratified columnar epithelium in the bronchi to a ciliated cuboidal epithelium near the gas-exchanging units.The three lobes(upper,middle and lower)of right lung has separated by the horizontal and oblique fissures,respectively.,The airway are lined with an e,9,The left lung has two major lobes(upper and lower)separated by an oblique fissure,and the upper lobe is itself divided into upper and lingular lobes.The right lung and the left lung project low down behind the dome of the diaphragm and peak behind the clavicles.,The left lung has two major lo,10,Normal physiology,The principal function of the lung is to carry through gas exchange,which is to enrich the blood with oxygen and cleanse it of carbon dioxide.An essential feature of normal gas exchange is that the volume and distribution of ventilation are appropriate.,Normal physiology,11,The extrathoracic components of the respiratory tree trend to collapse inwards during inspiration and open during expiration.Therefore,if the extrathoracic airway is obstructed,the obstruction is first evident during inspiration and,as the airway further narrows,obstruction occurs during both phases of breathing.,The extrathoracic components o,12,By the action of respiratory muscles the intrathoracic airways are actively opened during inspiration.In addition,surfactant reduces the surface tension of the alveoli,thereby reducing the effort to keep the alveoli open during inspiration.During expiration,the airways tend to collapse because of the natural elasticity of the lung.Therefore,partial obstruction of the intrathoracic airways causes earlier closure of the airways during expiration and results in air-trapping with eventual over inflation of the lung.,By the action of respiratory m,13,Acute upper respiratory tract infection,Acute upper respiratory tract,14,The upper respiratory tract comprises the nose,throat,tonsils,pharynx,and sinuses.Acute upper respiratory infection(also called common cold syndrome)is very common in all paediatric age groups.The nose and pharynx are the most common sites of infection.,The upper respiratory tract co,15,Etiology
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