Test Bank for McCance & Huether’s Pathophysiology: The Biologic Basis for Disease in Adults and Children (9th Edition) by Julia Rogers

Test Bank for McCance & Huether’s Pathophysiology: The Biologic Basis for Disease in Adults and Children (9th Edition) by Julia Rogers 1. What organic compound facilitates transportation across cell membranes by acting as receptors, transport channels for electrolytes, and enzymes to drive active pumps? a. Lipids b. Proteases c. Proteins d. Carbohydrates ANS: C Proteins have several functions, including acting as receptors, transport channelsfor electrolytes, and enzymes to drive active pumps Lipids help act as the “glue” holding cell membranes together. Proteases cause the breakdown of protein. Carbohydrates are involved in cellular protection and lubrication and help produce energy via oxidative phosphorylation. 2. Understanding the various steps of proteolytic cascades may be useful in designing drug therapy for which human diseases? a. Cardiac and vascular disorders b. Autoimmune and malignant disorders c. Gastrointestinal and renal disorders d. Endocrine and gastrointestinal disorders ANS: B Understanding the various steps involved in this process is crucial for designing drug interventions. Dysregulation of proteases features prominently in many human diseases, including cancer, autoimmunity, and neurodegenerative disorders.Cardiac, vascular, gastrointestinal, renal, and endocrine disorders do not involve this process. 3. Which structure prevents water-soluble molecules from entering cells acrossthe plasma membrane? a. Carbohydrate chains b. Glycoprotein channels c. Membrane channel proteins d. Lipid bilayer ANS: D The bilayer’s structure accounts for one of the essential functions of the plasma membrane. It is impermeable to most water-soluble molecules (molecules that dissolve in water) because the water-soluble molecules are insoluble in the oily core region. The bilayer serves as a barrier to the diffusion of water and hydrophilic substances while allowing lipid-soluble molecules, such as oxygen (O2) and carbon dioxide (CO2), to diffuse through it readily. Carbohydrate chains, glycoprotein channels, and membrane channel proteins do not prevent water- soluble molecules from entering cells across the cell membrane. 4. A student asks for an explanation of the absolute refractory period of the action potential. What response by the professor is best? a. A stronger than normal impulse will evoke another response. b. No stimulus is able to evoke another response at this time. c. Multiple stimuli can produce more rapid action potentials. d. The hyperpolarized state means a weaker stimulus produces a response. ANS: B During the absolute refractory state of the action potential, no stimulus is able to evoke another response from the cell. A stronger than normal impulse may generate a response in the relative refractory period. This period of time is not related to the number of stimuli. A hyperpolarized state means a stronger than normal stimulus would be needed to generate a response. 5. Which form of cell communication is used to communicate within the cellitself and with other cells in direct physical contact? a. Protein channel (gap junction) b. Plasma membrane-bound signaling molecules c. Hormone secretion such as neurotransmitters d. Extracellular chemical messengers such as ligands ANS: B Cells communicate in three main ways; they display plasma membrane-bound signaling molecules that affect the cell itself and other cells in direct physical contact with it, they affect receptor proteins inside the target cell, and they form protein channels (gap junctions) that directly coordinate the activities of adjacentcells. Neurotransmitters are released by neurons and cross the synaptic cleft to communicate with the cells they innervate. Ligands are involved in binding processes. 6. Which mode of chemical signaling uses blood to transport communication tocells some distance away? a. Paracrine b. Autocrine c. Neurotransmitter d. Hormonal ANS: D Chemical signaling can be classified into three categories: (1) local-chemical mediator, (2) hormone, and (3) neurotransmitter. Hormones are released by one setof cells and travel through tissues or the bloodstream to another set of cells where they produce a response by those cells. In paracrine signaling, cells secrete local chemical mediators that are quickly absorbed, destroyed, or immobilized. Paracrine signaling requires close membrane-to-membrane contact. Paracrine signaling usually involves different cell types; however, cells also may producesignals that they, themselves, respond to, which is called autocrine signaling. Neurotransmitters are released by neurons and cross the synaptic cleft to communicate with the cells they innervate. 7. Which mode of chemical signaling uses local chemical mediators that are quickly taken up, destroyed, or immobilized? a. Paracrine b. Autocrine c. Neurotransmitter d. Hormone ANS: A In paracrine signaling, cells secrete local chemical mediators that are quickly takenup, destroyed, or immobilized. Autocrine signaling occurs when the target cells produce signals that they themselves respond to. Neurotransmitters are released byneurons and cross the synaptic cleft to communicate with the cells they innervate. Hormones are released by one set of cells and travel through tissues or the bloodstream to another set of cells where they produce a response by those cells.