Examination of Respiratory System — Anatomy OmpathStudy

Respiratory System Examination — Complete Study Guide CLINICAL METHODS – RESPIRATORY SYSTEM Carey F. Okinda October/Nov 2011 TOPIC 1: REVIEW OF ANATOMY AND PHYSIOLOGY OF THE RESPIRATORY SYSTEM OBJECTIVES At the end of the session the learner should be able to 1. Take appropriate history of respiratory system disorders 2. Describe the key symptoms of respiratory disease 1.0 ANATOMY AND PHYSIOLOGY 1.1 Introduction Living organisms require constant supply of energy which in most instances is obtained from oxidation of high-energy carbon compounds which occurs through several steps. This results in formation of carbon dioxide. Energy released at each stage d harnessed in form of high energy compounds e.g. ATP. Respiration is the process by which O2 is transported to and used by cells and CO2 is produced and eliminated from the body. The primary function of the respiratory system is to obtain oxygen for use by the body’s cells and eliminate carbon dioxide that the cells produce. The term respiration includes two processes – external respiration and internal respiration which refer to three separate but related functions namely: - Ventilation (breathing), Gas exchange and Oxygen utilization. External respiration is the absorption of O2 and removal of CO2 from the body as a whole and internal respiration is the utilization of O2 and production of CO2 by the cells and the gaseous exchanges between the cells and their fluid medium. 1.2 Major Parts of the Respiratory System The respiratory system consists of a gas exchange organ (the lungs) and a pump that ventilates the lungs. The pump consists of the chest wall, respiratory muscles which increase and decrease the size of the thoracic cavity, areas in the brain which control the muscles and tract and nerves that connect the brain to the muscles. 1.3 Divisions of Respiratory System The respiratory system has functional and structural divisions. The respiratory system is divided functionally into the conducting division and the respiratory division. The conducting division includes all of the cavities and structures that transport gases (nasal cavity, pharynx, larynx, trachea, the bronchi, bronchioles) to the respiratory division which has the structures involved in the gas exchange (alveoli) in the lungs between the air and blood. Structurally it is divided into the upper respiratory tract ( and lower respiratory tract( Diagram 1: Parts of the Respiratory System 1.4 Organization of the Respiratory System The respiratory system comprises of lungs and respiratory passages (airways), which work in intimate collaboration with the thoracic cage, respiratory muscles and the pulmonary circulation. It uses highly effective convective systems of ventilation and circulation for long distance transport of O2 and CO2 and uses diffusion exclusively for short distance movements of O2 and CO2. The main components of the respiratory system are: - the air pump, mechanism for oxygen and carbon dioxide carrying, gas exchange surface, circulatory system and regulatory mechanisms. 1. The air pump This is made up of the lungs, airways, thoracic cavity and associated skeletal muscles and the muscles of respiration. The pump is responsible for alveolar ventilation which involves delivery of air to and removal of air from the alveoli spaces. This is achieved via inspiration and expiration mechanisms (mechanics of respiration) 2. Mechanism for carrying O2 and CO2 This is made possible by the red blood cells which contain haemoglobin 3. Surface area for gas exchange The gas exchange barrier consists of the alveoli and pulmonary capillaries. The alveoli provide a large surface area for diffusion of gases. 4. Circulatory system The circulatory system comprises of the systemic circulation and pulmonary circulation which are responsible for transport of gases throughput the body. Blood flow to the lungs is described as pulmonary perfusion. 5. Regulatory mechanisms a. Local regulatory mechanisms These are mechanisms responsible for local regulation of ventilation and perfusion of the lung tissues. This is achieved via local chemoreceptors b. Central regulatory mechanisms 1. The respiratory control centres in the CNS rhythmically stimulate the muscles of inspiration 2. Modify ventilation patterns during exercise, or changes in physical or mental activity 3. This is made possible by central chemoreceptors which sense changes in partial pressures of O2 and CO2 and the pH. These chemoreceptors are part of the feedback loops. 1.5 Functions of the Respiratory System 1. Provide oxygen to the blood stream and remove carbon dioxide 2. Enables sound production or vocalization as expired air passes over the vocal cords 3. Assists in abdominal compression during micturation (urination), defecation and parturition (childbirth) 4. Lung Defence mechanism - protective and reflexive non-breathing air movements e.g. coughing and sneezing to keep the air passageways clean. 5. Temperature regulation – loss of heat dur