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All Textbook Solutions for Human Physiology: From Cells to Systems (MindTap Course List)
Define physiology.The nutrient-absorbing intestinal cells have a multitude of finger like projections in contact with the digested food (see Figure 16-20, p. 602). Based on your knowledge of structure— function relationships, explain the functional advantage of this structural feature. (Answers are in Appendix C.)1CYU2CYU3CYUDistinguish among external environment, internal environment, intracellular fluid, extracellular fluid, plasma, and interstitial fluid.2CYU3CYU1CYU2CYUDraw a row diagram showing the relationships among the components of a negative-feedback control system.Which of the following activities is not carried out by every cell in the body? Obtaining O2 and nutrients Performing chemical reactions to acquire energy for the cells use Eliminating wastes Largely controlling exchange of materials between the cell and its external environment Reproducing2REWhich of the following is not a type of connective tissue? a. bone b. blood c. the spinal cord d. tendons e. the tissue that attaches epithelial tissue to underlying structuresThe term tissue can apply either to one of the four primary tissue types or to a particular organs aggregate of cellular and extracellular components. (True or false?)Cells in a multicellular organism have specialized to such an extent that they have little in common with single-celled organisms. (True orfalse?)Cell specializations are usually a modification or elaboration of one of the basic cell functions. (True or fa1se?)The four primary types of tissue are __________________, _________, _________, and __________________.8RE9RE_________ controls are inherent to an organ, whereas _________ controls are regulatory mechanisms initiated outside an organ that alter the activity of the organ.11RECompare physiology and anatomy.2UC3UC4UCWhat factors must be homeostatically maintained, and which body systems contribute to maintaining each of these factors?6UC7UC1ACR1TAHL2TAHLThe hormone insulin enhances the transport of glucose (sugar) from the blood into most body cells. Its secretion is controlled by a negative-feedback system between the concentration of glucose in the blood and the insulin-secreting cells. Therefore, which of the following statements is correct? A decrease in blood glucose concentration stimulates insulin secretion, which in turn further towers blood glucose concentration. An increase in blood glucose concentration stimulates insulin secretion, which in turn lowers blood glucose concentration. A decrease in blood glucose concentration stimulates insulin secretion, which in turn increases blood glucose concentration. An increase in blood glucose concentration stimulates insulin secretion, which in turn further increases blood glucose concentration. None of the preceding is correct.4TAHL5TAHLState the principles of the cell theory.2CYUState the functions of DNA and the different types of RNA.2CYU3CYU1CYUDiscuss the structure and function of a ribosome.3CYU4CYUDescribe the structure and functions of a Golgi complex.2CYU3CYU1CYU2CYU3CYU1CYU2CYU1CYU2CYU3CYU4CYU1CYU2CYU1CYU2CYUList the three types of cytoskeletal elements and state one function of each.Explain how motor proteins transport proteins along a cytoskeletal highway.3CYU4CYU1RE2RE3RE4RE5RE6RE7RE8RE9REUsing the answer code on the right, indicate which form of energy production is being described: 1. takes place in the mitochondrial matrix 2. produces H2O as a by-product 3. results in a rich yield of ATP 4. takes place in the cytosol 5. processes acetyl-CoA 6. takes place in the mitochondrial innermembrane cristae 7. converts glucose into two pyruvate molecules 8. uses molecular oxygen 9. accomplished by the electron transport system and ATP synthase (a) glycolysis (b) citric acid cycle (c) oxidative phosphorylation11RE1UC2UC3UCCompare exocytosis and endocytosis. Define secretion, pinocytosis, receptor-mediated endocytosis, and phagocytosis.5UCCompare lysosomes with peroxisomes.Distinguish among cellular respiration, oxidative phosphorylation, and chemiosmosis.8UC9UCCells expend energy on what three categories of activities?11UC1SQE2SQE3SQECalculate the number of cells in the body of an average 68-kg (150-lb) adult. (This will only be accurate to about 1 part in 10 but should give you an idea how scientists estimate this commonly quoted number.) Assume all cells are spheres 20 m in diameter. The volume of a sphere can be determined by the equation v=4/33. (Hint: We know that about two thirds of the water in the body is intracellular and the density of cells is nearly 1 g/mL. The proportion of the mass made up of water is about 60%.)5SQEApplying Clinical Reasoning Kevin S. and his wife have been trying to have a baby for the past 3 years. On seeking the help of a fertility specialist, Kevin learned that he has a hereditary form of male sterility involving nonmotile sperm. His condition can be traced to defects in the cytoskeletal components of the sperms flagella. As a result of this finding, the physician suspected that Kevin also has a long history of recurrent respiratory tract disease. Kevin confirmed that indeed he has had colds, bronchitis, and influenza more frequently than his friends. Why would the physician suspect that Kevin probably had a history of frequent respiratory disease based on his diagnosis of sterility from nonmotile sperm?The stomach has two types of exocrine secretory cells: chief cells, which secrete an inactive form of the protein-digesting enzyme pepsinogen, and parietal cells, which secrete hydrochloric acid (HCI) that activates pepsinogen. Both cell types have an abundance of mitochondria for ATP production—the chief cells need energy to synthesize pepsinogen, and the parietal cells need energy to transport hydrogen ions (H+) and chloride ions (Cl-) from the blood into the stomach lumen. Only one of these cell types also has an extensive rough ER and abundant Golgi stacks. Would this type be the chief cells or the parietal cells? Why?2TAHL3TAHLWhy do you think a person is able to perform anaerobic exercise (such as lifting and holding a heavy weight) only briefly but can sustain aerobic exercise (such as walking or swimming) for long periods? (Hint: Muscles have limited energy stores.)5TAHLDraw how phospholipid molecules align themselves into a lipid bilayer when in water.2CYU3CYU1CYU2CYU3CYU1CYUDistinguish between passive and active forces that produce movement of substances across the plasma membrane.List the means of unassisted membrane transport.2CYU3CYUDraw a graph comparing simple diffusion down a concentration gradient and carrier-mediated transport.Describe what causes the carrier to change shape to expose binding sites for passengers to opposite sides of the membrane in facilitated diffusion, primary active transport, and secondary active transport.Distinguish between symport and antiport.1CYUDescribe the relative contributions of k+ and Na+ to the resting membrane potential.3CYUThe nonpolar tails of the phospholipid molecules bury themselves in the interior of the plasma membrane. (True or false?)2RE3REAt resting membrane potential, there is a slight excess of (positive/negative) charges on the inside of the membrane, with a corresponding slight excess of (positive! negative) charges on the outside.Using the answer code on the right, indicate which membrane component is responsible for the function in question: 1. channel formation____________________________________ (a) lipid bilayer 2. barrier to passage of water- __________________ (b) proteins soluble substances ____________________________________ (c) carbohydrates 3. receptor sites 4. membrane fluidity 5. recognition of self 6. membrane-bound enzymes 7. structural boundary 8. carriers6RE7RE1UC2UCWhat two properties of a particle influence whether it can permeate the plasma membrane?4UC5UC6UCDescribe the contribution of each of the following to establishing and maintaining membrane potential: (a) the Na+K+ pump, (b) passive movement of K+ across the membrane, (c) passive movement of Na+ across the membrane, and (d) the large intracellular anions.Using the Nernst equation, calculate the equilibrium potential for Ca2 and for C1 from the following sets of data: a. Given [ Ca2+ ]0=1mM,[ Ca2+ ]i=100nM, find Eca2+ b. Given [ Cl- ]0=110mM,[ Cl- ]i=100mM, find EclOne of the important uses of the Nernst equation is in describing the flow of ions across plasma membranes. Ions move under the influence of two forces: the concentration gradient (given in electrical units by the Nernst equation) and the electrical gradient (given by the membrane voltage). This is summarized by Ohms law: Ix=Gx(VmEx) which describes the movement of ion x across the membrane. I is the current in amperes (A); G is the conductance, a measure of the permeability of x, in Siemens (S), which is I/V;Vm is the membrane voltage; and Ex is the equilibrium potential of ion x. Not only does this equation tell how large the current is, but it also tells what direction the current is flowing. By convention, a negative value of the current represents either a positive ion entering the cell or a negative ion leaving the cell. The opposite is true of a positive value of the current. a. Using the following information, calculate the magnitude of Na [ Na+ ]0=145mM,[ Na+ ]i=15mM,Gna+=1nS,Vm=70mV b. Is Na+ entering or leaving the cell? c. Is Na+ moving with or against the concentration gradient? Is it moving with or against the electrical gradient?Using the Goldman-Hodgkin-Katz equation, determine what happens to the resting membrane potential if the ECF K+ concentration doubles to 10 mM.When William H. was helping victims after a devastating earthquake in a region not prepared to swiftly set up adequate temporary shelter, he developed severe diarrhea. He was diagnosed as having cholera, a disease transmitted through unsanitary water supplies contaminated by fecal material from infected indiv iduals. The toxin produced by cholera bacteria causes Cl- channels in the lurninal membranes of the intestinal cells to stay open, thereby increasing the secretion of Cl- from the cells into the intestinal tract lumen. By what mechanisms would Na+ and water be secreted into the lumen in conjunction with Cl- secretion? How does this secretory response account for the severe diarrhea that is characteristic of cholera?Which of the following methods of transport is being used to transfer the substance into the cell in the accompanying graph? a. diffusion down a concentration gradient b. osmosis c. facilitated diffusion d. active transport e. vesicular transport f. It is impossible to tell with the information provided.Assume that a membrane permeable to Na+ but not to Cl- separates two solutions. The concentration of sodium chloride on side 1 is higher than on side 2. Which of the following ionic movements would occur? a. Na+ would move until its concentration gradient is dissipated (until the concentration of Na+ on side 2 is the same as the concentration of Na+ on side 1). b. Cl- would move down its concentration gradient from side 1 to side 2. c. A membrane potential, negative on side 1, would develop. d. A membrane potential, positive on side 1, would develop. e. None of the preceding is correct.A solution may have the same osmolarity as normal body fluids yet it may not be isotonic. Explain why.4TAHL5TAHLName the two types of excitable tissue.2CYUState the factor responsible for triggering gate opening and closing in each of the four types of gated channels.1CYU2CYU3CYUDraw and label an action potential, indicating the ion movements responsible for the rising phase and the falling phase.2CYU3CYU4CYUExplain why synapses operate only in the direction from presynaptic to postsynaptic neurons.2CYU3CYU4CYUDefine target cell.Distinguish among the four types of extracellular chemical messengers with regard to their source and the distance to their target cells.Outline the three general means by which binding of a water soluble extracellular chemical messenger to its matching surface membrane receptor brings about the desired intracellular response.4CYUDistinguish between cytokines and eicosanoids.Discuss the roles of phospholipase A2, cyclooxygenase, and lipooxygenase.3CYU1CYU2CYU3CYU1CYU2CYUConformational changes in channel proteins brought about by voltage changes are responsible for opening and closing Na+ and K+ gates during the generation of an action potential. (True or false?)2RE3RE4RESecond-messenger systems ultimately bring about the desired cell response by inducing a change in the shape and function of particular designated intracellular proteins. (True or false?)Each steroidogenic organ has all the enzymes necessary to produce any steroid hormone. (True or false?)7RE8RE9RE10RE11RE12RE13REA common membrane-bound intermediary between the receptor and the effector protein within the plasma membrane is the __________________.15RE16RE17RE18REDefine the following terms: polarization, depolarization, hyperpolarization, repolarization, resting membrane potential, threshold potential, action potential, refractory period, and allor-none law.2UC3UC4UCCompare the four kinds of gated channels in terms of the factor that opens or closes them.6UC7UC8UC9UCDefine signal transduction.Compare the tyrosine kinase and JAK/STAT pathways.12UC13UCDescribe how arachidonic acid is converted into prostaglandins, thromboxanes, and leukotrienes.15UC16UCExplain how the cascading effect of hormonal pathways amplifies the response.18UCAnswer the following questions regarding conduction of action potentials using the velocities given on p. 100: a. How long would it take for an action potential to travel 0.6 m along the axon of an unmyelinated neuron of the digestive tract? b. How long would it take for an action potential to travel the same distance along the axon of a large myelinated neuron innervating a skeletal muscle? c. Suppose there were two synapses in a 0.6 m nerve tract and the delay at each synapse is 1 msec. How long would it take an action potential and chemical signal to travel the 0.6 m now, for both the myelinated and unmyelinated neurons? d. What if there were five synapses?2SQE3SQE1ACRThe rate at which the Na+K+ pump operates is not constant but is controlled by a combined effect of changes in ICF Na+ concentration and ECF K+ concentration. Do you think the changes in both ICF Na+ and ECF K+ concentration following a series of action potentials in a neuron would accelerate, slow down, or have no effect on the Na+K+ pumps in this cell?Which of the following would occur if a neuron were experimentally stimulated simultaneously at both ends? a. The action potentials would pass in the middle and travel to the opposite ends. b. The action potentials would meet in the middle and then be propagated back to their starting positions. c. The action potentials would stop as they met in the middle. d. The stronger action potential would override the weaker action potential. e. Summation would occur when the action potentials met in the middle, resulting in a larger action potential.3TAHLAssume presynaptic excitatory neuron A terminates on a postsynaptic cell near the axon hillock and presynaptic excitatory neuron B terminates on the same postsynaptic cell on a dendrite located on the side of the cell body opposite the axon hillock. Explain why rapid firing of presynaptic neuron A could bring the postsynaptic neuron to threshold through temporal summation, thus initiating an action potential, whereas firing of presynaptic neuron B at the same frequency and the same magnitude of EPSPs may not bring the postsynaptic neuron to threshold.5TAHLDraw a flow diagram showing the organization of the subdivisions of the human nervous system.2CYU3CYU1CYU2CYU3CYU1CYUOutline the components of the brain from the least specialized, oldest evolutionary level to the newest, most specialized level.3CYU1CYU2CYU3CYU4CYU1CYU2CYU3CYU1CYU2CYU3CYU1CYU2CYU3CYU4CYU1CYU2CYU1CYU2CYU3CYU1CYU2CYU1REIn emergencies when O2 supplies are low, the brain can perform anaerobic metabolism. (True or false?)Stellate cells initially process sensory input to the cortex, whereas pyramidal cells send fibers from the cortex to terminate on efferent motor neurons. (True or false)4RE5RE6RE7RE8RE9RE10RE11RE12RE13REDiscuss the function of each of the following: astrocytes, oligodendrocytes, ependymal cells, in icroglia, cranium, vertebral column, meninges, cerebrospinal fluid, and blood—brain barrier.2UC3UC4UC5UC6UC7UC8UC9UC10UC11UC12UC13UC14UCDistinguish between a monosynaptic and a polysynaptic reflex.Julio D., who had recently retired, was enjoying an afternoon of playing golf when suddenly he experienced a severe headache and dizziness. These symptoms were quickly followed by numbness and partial paralysis on the tipper right side of his body, accompanied by an inability to speak. After being rushed to the emergency room, Julio was diagnosed as having suffered a stroke. Given the observed neurological impairment, what areas of his brain were affected?1TAHL2TAHLThe hormone insulin enhances the carrier-mediated transport of glucose into most of the bodys cells but not into brain cells. The uptake of glucose from the blood by neurons does not depend on insulin. Knowing the brains need for a continuous supply of blood-borne glucose, predict the effect that insulin excess would have on the brain.4TAHLUnder what circumstances might it be inadvisable to administer a clot-dissolving drug to a stroke victim?1CYU2CYU3CYU1CYU2CYU3CYU1CYU2CYU3CYU4CYU1CYU2CYU3CYU4CYU1CYU2CYU3CYU1RE2RE3RE4RE5RE6RE7RE8RE9RE10RE11RE