Study Guide #18, The Respiratory System

Study Guide #18, The Respiratory System 1. What are the 4 main functions of the respiratory system? 1. Provides body with oxygen and removes carbon dioxide 2. It influences sound and speech 3. Makes the sense of smell and taste possible 4. Helps maintain homeostasis through regulation of acid-base balance 2. The respiratory tract is divided into what 2 tracts? Name the parts in each one. 1. Upper- (structures outside thoracic cavity) nasal cavity, nasopharynx, oropharynx, laryngopharynx, larynx 2. Lower- (structures inside thoracic cavity) trachea, bronchi, lungs 3.What are 3 functions of the upper respiratory tract? 1. Warm and humidify inspired air- (conchae in nasal cavity) 2. Responsible for the senses of smell and taste 3. Swallowing food 4. What is the purpose of mucus in the nasal cavity? Dust sticks to mucus keeping it out of the respiratory tract which is swallowed into digestive tract 5.The pharynx (muscular tube-throat) is divided into what 3 regions/define 1. Nasopharynx- posterior nares to soft palate (contains openings for L&R Eustachian (auditory) tubes)- behind nasal cavity 2. Oropharynx- space B/T soft palate & base of tongue (contains tonsils) 3. Laryngopharynx- passes dorsal to the larynx/connects to esophagus 6. What are the 3 functions of the larynx? 1. Prevents food & liquids from entering trachea 2. Acts as a air passageway B/T pharynx and trachea 3. It produces sound 7. What part of the larynx closes over top of the larynx during swallowing to direct food and liquids into the esophagus? epiglottis 8. What two pairs of folds are formed by the mucous membrane lining of the larynx and define? 1. Vestibular folds- (superior)- false vocal cords. No role in speech. They close the glottis during swallowing to keep food/fluid out of airway 2. Vocal cords- (inferior) Produces sound when air passes over them during exhalation 9. The lower respiratory tract starts with the trachea (windpipe) which extends into the bronchial tree. What are 5 parts of the bronchial tree? 1. Primary bronchi- large tubes (one for each lung) have C shaped rings of cartilage to help prevent collapse 2. Secondary bronchi- one for each lobe (3lobes R side/2 lobes on Left) 3. Tertiary bronchi- cartilaginous rings become irregular 4. Bronchioles- rings disappear- lack supportive cartilage 5. Alveoli- (ducts) primary structures for gas exchange 10. Which bronchus is more likely location for aspirated food and small objects to get lodged and why? Right bronchus is slightly wider and more vertical 11. What is the purpose of C rings in the trachea and why are they a C shape? Encircle trachea to reinforce it and keep it from collapsing during inhalation- “C” faces posteriorly- gives esophagus room to expand 12. What are the primary structures for gas exchange? alveoli. What must happen for gas (oxygen and carbon dioxide) to enter or leave a cell? Gas must be dissolved in a liquid for gas exchange to Occur. Surfactant is part of this fluid 13. Alveoli are wrapped up in? capillaries and coated with surfactant. Alveolar cells secrete surfactant-a lipoprotein that disrupts the electrical attraction B/T the water molecules- Surfactant reduces surface tension and this helps prevent alveolar collapse 14. Name 3 differences between the left and right lung? 1. R lung is shorter, broader, and larger than the L lung 2. R lung has 3 lobes (superior, middle, inferior) L has 2 lobes 3. R lung handles 55% of the gas exchange 15. What are the 2 types of pleura in the thoracic cavity and define? 1. Visceral pleura- serous membrane- covers the surface of the lungs extending into the fissures 2. Parietal pleura- serous membrane- lines the entire thoracic cavity 16. What is the space called between the 2 pleura and define? Pleural cavity- only a potential space- 2 membranes are normally separated only by a film of slippery pleural fluid that lubricates and creates pressure gradient that assists in lung inflation 17. What are the 3 types of muscles used during normal inspiration? 1. External intercostal muscles 2. Internal intercostal muscles 3. Diaphragm- main muscle responsible for pulmonary ventilation 18. What is the purpose of accessory muscles? Additional muscles used during times of forced or labored breathing 19. What are the 2 main breathing centers called and where are they located? These 2 centers are located in the medulla oblongata in the brain 1. Inspiratory center- Primary respiratory center 2. Expiratory center- used when forceful exhalation is needed (ex.exercise). Normal exhalation is a passive process 20. What other 2 breathing centers influence breathing rhythm and where are they located? These 2 centers are located in the pons in the brain 1. Apneustic center- increased length and depth of inspiration 2. Pneumotaxic center- normal breathing rhythm and prevents overinflation of the lungs 21. What are 5 factors that influence breathing and describe. 1. Oxygen decreases- peripheral chemoreceptors (carotid and aortic) detect decreased levels of oxygen (O2) and signal medulla to increase the rate and depth of respirations to bring in more oxygen 2. Hydrogen ions (decreased pH)- central chemoreceptors (in brainstem) detect decreased pH levels and signal respiratory centers to increase rate and depth of breathing to blow off excess CO2 & increase pH 3. Stretch receptors- in lungs and chest wall. Detect stretching and signal respiratory center to exhale. Prevents overinflation 4. Pain and emotion- hypothalamus and limbic system send signals in response to emotion- affect rate and depth of respiration 5. Irritants- nerve cells respond to irritants by signaling respiratory muscles to contract- such as coughing and sneezing 22. Intrapleural pressure maintained is slightly less than atmospheric pressure. What happens if the thoracic wall in the chest is punctured? The lung will collapse (pneumothorax). Air from the atmosphere rushes into the pleural cavity (potential space becomes space filled with air). Negative pressure is lost. The lung recoils and collapses. 23. Define the following: 1. Tidal volume- amount of air inhaled & exhaled during quiet breathing 2. Inspiratory reserve volume- air inhaled using maximum effort after normal inspiration 3. Expiratory reserve volume- air exhaled using maximum effort after normal expiration 4. Residual volume- air left even after forced expiration, ensures gas exchange continues B/T breaths 5. Vital capacity- tidal volume + inspiratory and expiratory reserve volumes. Amount of air inhaled/exhaled with deepest possible breath 6. Total lung capacity- vital capacity + residual volume, maximum amount of air that the lungs can contain 24. Gas diffuses from an area of high pressure to an area of low pressure 25. 98.5% of oxygen is transported from the lungs as oxyhemoglobin. 26. Carbon dioxide is transported in plasma and bound to hemoglobin but most of the carbon dioxide is transported in the form of bicarbonate ions.