NR 324 Critical Care Exam 1 Study Guide

NR 324 Critical Care Exam 1 Study GuideCritical Care Exam 1 Guide Respiratory anatomy and physiology  Upper airway o Consists of the nasal cavity and the pharynx. o Purpose - to warm, to filter, and to humidify atmospheric air. o The upper airway is also responsible for the sneeze reflex.  Lower airway o The lower airway consists of: (1) larynx; (2) trachea; (3) right and left main stem bronchi; (4) bronchioles (5) alveoli. The epiglottis is another structure and its purpose is to cover the larynx during swallowing. The trachea also warms and humidifies air just like the upper airway and it also contains cilia to propel mucus and other foreign particles upward. The trachea extends to the angle of Louis or sternal angle. The trachea then branches to right and left main stem bronchi. This area is known as the carina. The bronchi further branch out into bronchioles. Attached to bronchioles are the air sacs known as the alveoli where gas exchange takes place.  oxygenation vs ventilation o Oxygenation- How much oxygen our body absorbs - gas exchange in cap alveolar membrane o Ventilation-action of breathing in out- respiration (chest move up and down) o Need oxygenation and ventilation for proper gas exchange  Ventilation (action of breathing in and out) o Breathing is both voluntary and involuntary. o Involves inspiration, or inhalation (movement of air into the lungs)- active o expiration, or exhalation (movement of air out of the lungs) - passive o Breathing is controlled by the resp centers located in the pons and the medulla of the brain stem. o Breathing is regulated by chemoreceptors, These chemoreceptors sense increased levels of carbon dioxide, low levels of oxygen or high levels of hydrogen ions. When these levels change, the respiratory center is stimulated to send messages down to the spinal cord to the phrenic nerve which innervates the diaphragm to contract producing inspiration. Expiration is a passive process. Under normal circumstances, when individuals hold their