Chp 53 Introduction to the Respiratory System alveoli: the respiratory sac, the smallest unit of the lungs, where gas exchange occursasthma: disorder characterized by recurrent episodes of bronchospasm (i.e., bronchial muscle spasm leading to narrowed or obstructed airways)atelectasis: collapse of once-expanded alveolibronchial tree: the conducting airways leading into the alveoli; they branch smaller and smaller, appearing much like a treechronic obstructive pulmonary disease (COPD): chronic condition that occurs over time; often the result of chronic bronchitis or repeated and severe asthma attacks; leads to destruction of the respiratory defense mechanisms and physical structurecilia: microscopic, hair-like projections of the epithelial cell membrane lining the upper respiratory tract, which are constantly moving and directing the mucus and any trapped substance toward the throatcommon cold: viral infection of the upper respiratory tract that initiates the release of histamine and prostaglandins and causes an inflammatory responsecough: reflex response to irritation in the respiratory membrane, results in expelling of forced air through the mouthcystic fibrosis: a hereditary disease that results in the accumulation of copious amounts of very thick secretions in the lungs, which will eventually lead to obstruction of the airways and destruction of the lung tissuelarynx: the vocal chords and the epiglottis, which close during swallowing to protect the lower respiratory tract from any foreign particleslower respiratory tract: the bronchi and the alveoli that make up the lungs; the area where gas exchange takes placepneumonia: inflammation of the lungs that can be caused by bacterial or viral invasion of the tissue or by aspiration of foreign substancespneumothorax: air in the pleural space exerting high pressure against the alveolirespiration: the act of breathing to allow the exchange of gases, a basic process for living thingsrespiratory distress syndrome (RDS): disorder found in premature neonates whose lungs have not had time to mature and who are lacking sufficient surfactant to maintain open airways to allow for respirationrespiratory membrane: area through which gas exchange must be made; made up of the capillary endothelium, the capillary basement membrane, the interstitial space, the alveolar basement membrane, the alveolar endothelium, and the surfactant layerseasonal rhinitis: inflammation of the nasal cavity, commonly called hay fever; caused by reaction to a specific antigensinuses: air-filled passages through the skull that open into the nasal passagesinusitis: inflammation of the epithelial lining of the sinus cavitiessneeze: reflex response to irritation to receptors in the nares, results in expelling of forced air through the nosesurfactant: lipoprotein that reduces surface tension in the alveoli, allowing them to stay open to allow gas exchangetrachea: the main conducting airway leading into the lungsupper respiratory tract: the nose, mouth, pharynx, larynx, and tracheathe conducting airways where no gas exchange occursventilation: the movement of gases in and out of the lungs

Chp 54 Drugs that Affect the Upper Respiratory Tract Pg 857antihistamines: drugs that block the release or action of histamine,a chemical released during inflammation that increases secretions and narrows airwaysantitussives: drugs that block the cough reflexdecongestants: drugs that decrease the blood flow to the upper respiratory tract and decrease the overproduction of secretionsexpectorants: drugs that increase productive cough to clear the airwaysmucolytics: drugs that increase or liquefy respiratory secretions to aid the clearing of the airwaysrebound congestion: a process that occurs when the nasal passages become congested as the effect of a decongestant drug wears off; patients tend to use more drug to decrease the congestion, and a vicious circle of congestion, drug, and congestion develops, leading to abuse of the decongestant; also called rhinitis medicamentosarhinitis medicamentosa: reflex reaction to vasoconstriction caused by decongestants; a rebound vasodilation that often leads to prolonged overuse of decongestants; also called rebound congestion

Chp 55 Drugs Acting on the Lower Respiratory Tract Pg 878bronchodilator: medication used to facilitate respirations by dilating the airways; helpful in symptomatic relief or prevention of bronchial asthma and bronchospasm associated with chronic obstructive pulmonary diseaseCheyneStokes respiration: abnormal pattern of breathingcharacterized by apneic periods followed by periods of tachypnea; may reflect delayed blood flow through the brainleukotriene receptor antagonists: drugs that selectively and competitively block or antagonize receptors for the production of leukotrienes D4 and E4, components of slowreacting substance of anaphylaxis (SRSA)mast cell stabilizer: drug that works at the cellular level to inhibit the release of histamine (released from mast cells in response to inflammation or irritation) and the release of slow-reacting substance of anaphylaxis (SRSA)sympathomimetics: drugs that mimic the effects of the sympathetic nervous systemxanthines: naturally occurring substances, including caffeine and theophylline, that have a direct effect on the smooth muscle of the respiratory tract, both in the bronchi and in the blood vessels

Chp 56 Introduction to the Gastrointestinal System Pg 903bile: fluid stored in the gallbladder that contains cholesterol and bile salts; essential for the proper breakdown and absorption of fatschyme: contents of the stomach containing ingested food and secreted enzymes, water, and mucusgallstones: hard crystals formed in the gallbladder when the bile is concentrated.gastrin: substance secreted by the stomach in response to many stimuli; stimulates the release of hydrochloric acid from the parietal cells and pepsin from the chief cells; causes histamine release at histamine-2 receptors to effect the release of acidhistamine-2 (H2) receptors: sites near the parietal cells of the stomach that, when stimulated, cause the release of hydrochloric acid into the lumen of the stomach; also found near cardiac cellshydrochloric acid: acid released by the parietal cells of the stomach in response to gastrin release or parasympathetic stimulation; makes the stomach contents more acidic to aid digestion and breakdown of food productslocal gastrointestinal reflex: reflex response to various stimuli that allows the GI tract local control of its secretions and movements based on the contents or activity of the whole GI systemnerve plexus: network of nerve fibers running through the wall of the GI tract that allows local reflexes and controlpancreatic enzymes: digestive enzymes secreted by the exocrine pancreas, including pancreatin and pancrelipase, which are needed for the proper digestion of fats, proteins, and carbohydratesperistalsis: type of GI movement that moves a food bolus forward; characterized by a progressive wave of muscle contractionsaliva: fluid produced by the salivary glands in the mouth in response to tactile stimuli and cerebral stimulation; contains enzymes to begin digestion, as well as water and mucus to make the food bolus slippery and easier to swallowsegmentation: GI movement characterized by contraction of one segment of the small intestine while the next segment is relaxed; the contracted segment then relaxes, and the relaxed segment contracts; exposes the chyme to a vast surface area to increase absorptionswallowing: complex reflex response to a bolus in the back of the throat; allows passage of the bolus into the esophagus and movement of ingested contents into the GI tractvomiting: complex reflex mediated through the medulla after stimulation of the chemoreceptor trigger zone; protective reflex to remove possibly toxic substances from the stomach

Chp 57 Drugs Affecting Gastrointestinal Secretions Pg 911acid rebound: reflex response of the stomach to lower-than normal acid levels; when acid levels are lowered through the use of antacids, gastrin production and secretion are increased to return the stomach to its normal aciditydigestive enzymes: enzymes produced in the gastrointestinal tract to break down foods into usable nutrientsGI protectant: drug that coats any injured area in the stomach to prevent further injury from acid or pepsinhistamine-2 (H2) antagonist: drug that blocks the H2 receptor sites; used to decrease acid production in the stomach (H2 sites are stimulated to cause the release of acid in response to gastrin or parasympathetic stimulation)peptic ulcer: erosion of the lining of stomach or duodenum; results from imbalance between acid produced and the mucous protection of the GI lining or possibly from infection by Helicobacter pylori bacteriaprostaglandin: any one of numerous tissue hormones that have local effects on various systems and organs of the body, including vasoconstriction, vasodilation, increased or decreased GI activity, and increased or decreased pancreatic enzyme releaseproton pump inhibitor: drug that blocks the H_, K_-ATPase enzyme system on the secretory surface of the gastricparietal cells, thus interfering with the final step of acid production and lowering acid levels in the stomach

Chp 58 Drugs Affecting Gastrointestinal Motility Pg 931 antidiarrheal drug: drug that blocks the stimulation of the gastrointestinal (GI) tract, leading to decreased activity and increased time for absorption of needed nutrients and waterbulk stimulant: agent that increases in bulk, frequently byosmotic pull of fluid into the feces; the increased bulk stretches the GI wall, causing stimulation and increased GI movementcathartic dependence: overuse of laxatives that can lead to the need for strong stimuli to initiate movement in the intestines; local reflexes become resistant to normal stimuli after prolonged use of harsher stimulants, leading to further laxative usechemical stimulant: agent that stimulates the normal GI reflexes by chemically irritating the lining of the GI wall, leading to increased activity in the GI tractconstipation: slower-than-normal evacuation of the large intestine, which can result in increased water absorption from the feces and can lead to impactiondiarrhea: more-frequent-than-normal bowel movements, often characterized as fluid-like and watery because notenough time for absorption is allowed during the passage of food through the intestineslubricant: agent that increases the viscosity of the feces, making it difficult to absorb water from the bolus and easing movement of the bolus through the intestines