Chapter 6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 31) A chemical that is secreted by a cell to act on cells in its immediate vicinity is called a(n) ________.

: paracrine Section Title: Cell-to-Cell Communication Learning Outcome: 6.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 38) Many second messenger systems activate ________, enzymes that transfer a phosphate group from ATP to a protein. The phosphorylation of proteins sets off a series of intracellular events that lead to the ultimate cellular response.

: protein kinases Section Title: Signal Pathways Learning Outcome: 6.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 44) Homeostatic regulation usually involves a(n) ________ that is sensitive to a particular stimulus (variable) and a(n) ________ whose activity has an effect on the same stimulus.

: receptor; effector Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 42) An intracellular signal molecule that translates a signal from a neurotransmitter or hormone into an intracellular response is called a ________.

: second messenger Section Title: Signal Pathways Learning Outcome: 6.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 43) The secretion of the hormone insulin in response to changes in blood glucose level is an example of a(n) ________ reflex.

: simple endocrine Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 24) Peripheral cells sensitive to the presence of hormones are called ________.

: targets Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 49) What is the half-life of a signal?

: the time required for a signal to lose half its activity Section Title: Novel Signal Molecules Learning Outcome: 6.7

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 61) A physiological parameter which is regulated in an up-down fashion by signals that are always present but change in intensity is said to be under ________.

: tonic control Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 35) If the concentration of an endocrine ligand decreases, the target cell may insert more receptors into the cell membrane in an attempt to keep its response at a normal level, in a process known as ________.

: up-regulation Section Title: Modulation of Signal Pathways Learning Outcome: 6.1

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 60) Homeostatic control that takes place at the tissue or cell by using paracrine or autocrine signals is called ________. A) local control B) reflex control C) Cannon's law D) down-regulation

: A Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 21) the minimum stimulus to trigger a response

: A Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 15) Usually, cytokine binding activates A) JAK kinase. B) tyrosine kinase. C) intrinsic transducers. D) calmodulin kinase. E) citrulline kinase.

: A Section Title: Signal Pathways Learning Outcome: 6.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 55) One intracellular calcium-binding protein is A) calmodulin. B) calcitonin. C) calcitriol. D) IP3. E) nitric oxide.

: A Section Title: Signal Pathways Learning Outcome: 6.3

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 52) The most important factor determining which type of receptor a signal molecule will bind to is A) the lipid solubility of the ligand. B) the size of the ligand. C) the size of the receptor molecule. D) the location of the receptor molecule.

: A Section Title: Signal Pathways Learning Outcome: 6.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 34) ________ are molecules that bind to the receptor in such a way that they block the normal ligand from binding and turning the receptor on. As a result, the signal pathway remains inactive.

: Antagonists (or Competitive inhibitors) Section Title: Modulation of Signal Pathways Learning Outcome: 6.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 3) The most significant difference between a paracrine and an autocrine is A) the cell that releases it. B) the cell that responds to it. C) the method of transport. D) the route of transport. E) There are no differences—they are the same.

: B Section Title: Cell-to-Cell Communication Learning Outcome: 6.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 22) the organ or gland that performs the change

: B Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 8) Down-regulation may allow a target cell to A) only increase its number of receptors for a ligand. B) only decrease its number of receptors for a ligand. C) only increase its binding affinity for a ligand. D) decrease the receptors' binding affinity and increase its number of receptors.

: B Section Title: Modulation of Signal Pathways Learning Outcome: 6.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 16) What by-product results during the production of nitric oxide? A) arginine B) citrulline C) nitric oxide synthase D) carbon monoxide E) carbon dioxide

: B Section Title: Novel Signal Molecules Learning Outcome: 6.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 5) Why do some normal cells fail to respond to a chemical signal? A) Chemical signals are only delivered to specific cells. B) Some cells lack the necessary receptors. C) Some cells are completely without receptors. D) Some cells are completely without ligands. E) Signal chemicals often break down before reaching a distant target.

: B Section Title: Signal Pathways Learning Outcome: 6.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 11) When adenylyl cyclase is activated, A) calcium ions are released from intracellular stores. B) cAMP is formed. C) cAMP is broken down. D) protein kinases are metabolized. E) steroids are produced.

: B Section Title: Signal Pathways Learning Outcome: 6.4

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 81) Brain cells are able to absorb glucose independent of insulin. What must be missing from brain cells compared to most other cell types? One of the risks of diabetes mellitus is diabetic coma, which results when insufficient glucose is available to the brain. Would you expect diabetic coma to be triggered when insulin is low or high? Explain. (Hint: Think about regulation of the number of glucose transporters in brain cells and how the hyperglycemia present prior to insulin treatment may affect transporters.)

: Brain cells lack the insulin receptors that stimulate glucose uptake, because an insulin-independent mechanism for glucose uptake is present. Brain cells will down-regulate their glucose transporters during periods of hyperglycemia. When insulin levels increase during treatment of type I diabetes, promoting lower concentrations of glucose in the blood, this can trigger diabetic coma because the brain cells have too few glucose transporters for the new, lower levels of blood glucose. Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

Human Physiology: An Integrated Approach, 6e (Silverthorn) Chapter 6 Communication, Integration, and Homeostasis 1) Cells that respond to signals are usually called A) responders. B) receivers. C) targets. D) contacts. E) junctions.

: C Section Title: Cell-to-Cell Communication Learning Outcome: 6.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 17) An integrating center A) is the disturbance or change that sets the pathway in motion. B) is an electrical and/or chemical signal that travels to the effector. C) evaluates incoming signals and compares it with the setpoint. D) is the minimum stimulus that must be achieved to set the reflect response in motion.

: C Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 20) receives information about the regulated variable and initiates a response

: C Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 59) Each of the following is an example of homeostasis except one. Identify the exception. A) Increased pressure in the aorta triggers mechanisms to lower blood pressure. B) A rise in blood calcium levels triggers the release of a hormone that lowers blood calcium levels. C) A rise in estrogen during the menstrual cycle increases the number of progesterone receptors in the uterus. D) Increased blood sugar stimulates the release of a hormone from the pancreas that stimulates the liver to store blood sugar. E) A decrease in body temperature triggers a neural response that initiates physiological changes to increase body temperature.

: C Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 54) When calcium becomes available inside a cell, it comes from A) extracellular fluid only. B) intracellular storage only. C) extracellular fluid and intracellular storage. D) It is always available as a major cytosol cation.

: C Section Title: Signal Pathways Learning Outcome: 6.3

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 53) An ion widely important in intracellular signaling is A) sodium. B) potassium. C) calcium. D) chloride. E) cobalt.

: C Section Title: Signal Pathways Learning Outcome: 6.3

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 76) "Too much of a good thing can hurt you." "It's all good." We've all heard phrases like this, and know that they contain some truth. For example, both life essentials water and sunshine can harm us. Not enough cholesterol in the body is worse than too much. What otherwise poisonous gas has recently been shown to be a signal molecule? What does it do in the body?

: Carbon monoxide is one of the gaseous signal molecules. It activates guanylyl cyclase and cGMP in smooth muscle and neural tissue. Section Title: Novel Signal Molecules Learning Outcome: 6.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 4) Neurotransmitters and neurohormones both A) are released by neurons. B) affect only cells with a specific receptor. C) travel in the blood to their target cell. D) are released by neurons and affect only cells with specific receptors. E) are produced by all cells.

: D Section Title: Cell-to-Cell Communication Learning Outcome: 6.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) Match the term with its description: A. threshold B. effector C. integrating center D. setpoint E. sensory receptor 19) the desired target value for a parameter

: D Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 6) Receptor molecules on the surface of a cell A) determine that cell's response. B) may allow a particular ligand to bind. C) bind to all ligands. D) determine that cell's response and may allow a particular ligand to bind. E) determine that cell's response and bind to all ligands.

: D Section Title: Signal Pathways Learning Outcome: 6.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 10) Lipophilic hormones A) bind to receptors on the surface of the cell. B) function by way of a second messenger system. C) cannot diffuse through the cell membrane. D) bind to receptors inside the cytoplasm or nucleus. E) function by activating cAMP.

: D Section Title: Signal Pathways Learning Outcome: 6.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 9) Inositol triphosphate A) is a water-insoluble messenger molecule. B) binds to the calcium channel of the endoplasmic recticulum. C) is involved in the release of calcium into the cytosol. D) is a second messenger that is involved in the release of calcium into the cytosol. E) uses all of the mechanisms.

: D Section Title: Signal Pathways Learning Outcome: 6.3

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 57) The binding of lipophilic messengers, such as steroid hormones, to their receptors triggers A) adenylyl cyclase activation. B) cyclic nucleotide formation. C) G protein inhibition. D) gene transcription. E) protein kinase activation.

: D Section Title: Signal Pathways Learning Outcome: 6.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 13) Cyclic AMP activates A) a G protein. B) adenylyl cyclase. C) protein hormones. D) protein kinase A. E) hormone receptors.

: D Section Title: Signal Pathways Learning Outcome: 6.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 51) The intracellular effector in chemical signaling is often A) a hormone. B) a membrane receptor molecule. C) ATP. D) a protein kinase. E) cholesterol.

: D Section Title: Signal Pathways Learning Outcome: 6.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 27) ________ can be caused by alterations in receptors or by problems with G protein or second messenger pathways.

: Diseases Section Title: Modulation of Signal Pathways Learning Outcome: 6.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 2) Which is NOT a basic method of cell-to-cell communication? A) cytoplasmic transfer of signals B) contact-dependent signals C) diffused chemical signals D) nerve and blood-transported signals E) mechanical signals

: E Section Title: Cell-to-Cell Communication Learning Outcome: 6.1

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 58) Both insulin and glucagon are peptide hormones that target liver cells. The response of the target cells to each of these two hormones is opposite. This information implies that A) the two hormones bind to different cell surface receptors. B) one hormone binds to a receptor on the cell membrane and the other to an intracellular receptor. C) each of the two hormones uses a different second messenger. D) both hormones interact with receptors at the cell nucleus. E) the two hormones bind to different receptors and use a different second messenger.

: E Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.5

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 18) Which of the following are considered differences between endocrine and neural control systems? A) specificity B) nature of the signal C) speed D) duration of action E) All of the answers are correct.

: E Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 23) continuously monitors its environment for a specific variable

: E Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 56) Signal molecule receptors exhibit A) specificity only. B) competition only. C) saturation only. D) competition and saturation only. E) specificity, competition, and saturation.

: E Section Title: Modulation of Signal Pathways Learning Outcome: 6.5

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 7) Receptor molecules are located A) only in the outer cell membrane. B) only in the cytosol. C) only in the nucleus. D) only on the cell surface. E) in all of these places.

: E Section Title: Signal Pathways Learning Outcome: 6.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 12) Second messenger molecules directly A) change the regulation of ion channels. B) increase intracellular calcium concentration. C) change enzyme activity. D) change regulation of gene expression. E) All of the answers are correct.

: E Section Title: Signal Pathways Learning Outcome: 6.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 14) Diacylglycerol is produced from A) cyclic AMP. B) phospholipase C. C) a G protein. D) protein kinase A. E) phosphatidylinositol bisphosphate.

: E Section Title: Signal Pathways Learning Outcome: 6.4

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 47) Explain the two forms of down-regulation.

: Either the number of receptors decreases or desensitization in which the binding affinity of the receptors for the ligand decreases. In both cases the result is a lessened response of the target cell even though the concentration of the signal molecule remains high. Section Title: Modulation of Signal Pathways Learning Outcome: 6.6

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 39) Explain how epinephrine can cause intestinal blood vessels to constrict and cause skeletal muscle blood vessels to dilate.

: Epinephrine can bind to different isoforms of the adrenergic receptor. Epinephrine binds to the alpha receptor on the intestinal blood vessels and beta receptors on the skeletal muscle blood vessels (see Fig. 6.18). Section Title: Modulation of Signal Pathways Learning Outcome: 6.5

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 37) The ________ link membrane receptors to either ion channels or to membrane enzymes located on the cytoplasmic face of the membrane.

: G proteins Section Title: Signal Pathways Learning Outcome: 6.3

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 74) Nobel Prizes were awarded to the discoverers of G proteins, the G protein-coupled adenylyl cyclase-cAMP system, and nitric oxide. Summarize each of these, and explain the importance of these discoveries to our understanding of signal pathways.

: G proteins are coupled to hundreds of different receptors on cells. These are receptors that bind ligands such as hormones, neurotransmitters, and molecules important in sensory systems. Activated G proteins open ion channels or alter enzyme activity. The G protein-coupled adenylyl cyclase-cAMP system was the first signal transduction pathway discovered, and therefore paved the way for our understanding of signal transduction. cAMP is the second messenger in many signaling systems. Nitric oxide functions as a neurotransmitter, neuromodulator, and paracrine important in cardiovascular regulation. Section Title: Novel Signal Molecules Learning Outcome: 6.4

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 71) Briefly explain the effects of the hormone insulin on glucose transport. What is diabetes mellitus? How are Types I and II different? Why do insulin injections help alleviate one type but not the other?

: Insulin promotes glucose transport into most types of cells. Diabetes mellitus results when insulin regulation of blood glucose concentrations is impaired. In type I, the pancreas fails to produce insulin, whereas in type II insulin levels are normal to high, but target cells fail to respond properly. Insulin injections can successfully treat type I but not type II, because the endogenous insulin production in type II is sufficient but the response is abnormal. Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 36) The nervous system has a role in preserving the "fitness" of the ________.

: Internal Environment Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 65) Describe the signal molecule derivatives of arachidonic acid.

: Leukotrienes are secreted by certain types of white blood cells and play a role in asthma and anaphylaxis. Prostanoids, including prostaglandins and thromboxanes, have a variety of target tissues and effects. Section Title: Novel Signal Molecules Learning Outcome: 6.4

: Level II: Reviewing Concepts (Bloom's Taxonomy: Application) 63) Describe the four classes of membrane receptor molecules.

: Ligand-gated receptors are ion channels, integrins are linked to the cytoskeleton, receptor-enzymes activate intracellular enzymes, G protein-coupled receptors involve activation of G proteins. See Figure 6.3. Section Title: Signal Pathways Learning Outcome: 6.3

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 67) What are NSAIDs, what is their function, and what are some drawbacks to their use?

: Nonsteroidal anti-inflammatory drugs, such as aspirin and ibuprofen, prevent inflammation. They have side effects such as bleeding in the stomach. Section Title: Novel Signal Molecules Learning Outcome: 6.6

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 78) You are part of a research team designing a robot for competition. Your robot needs to be able to respond to painful stimuli like stepping on broken glass. What type of human control system will you model your robot's after and explain your reasons for choosing it.

: One should choose the nervous system and a simple neural reflex because of its ability to rapidly respond and remove the robot from potential harm. The response will be specific for the region in harm and the robot will get a sense of the intensity of pain via a change in the frequency of signaling. Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 77) Receptors in cell signaling are not to be confused with receptors that activate a reflex arc. Explain the difference, using specific examples.

: Receptor molecules are proteins on or in cells that bind to ligands. This binding triggers a response within a cell, to the signaling chemical. For example, this is how a hormone exerts its effect on a target cell. Receptors in a reflex arc are not protein molecules but rather are entire cells, parts of cells, or multicellular structures. These receptors cause a signal to be sent to an integrating center, which may or may not then initiate a response usually involving many cells. For example, a blood pressure receptor detects a decrease in pressure, and sends a neural signal to cardiovascular integrating centers to trigger a vascular response to increase pressure. Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.7

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 70) Compare and contrast hormones, neurotransmitters, and neurohormones.

: See Figure 6.1 and the "Long-Distance Communication May Be Electrical or Chemical" section in the chapter. Section Title: Cell-to-Cell Communication Learning Outcome: 6.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 66) Describe or diagram the basic pattern of a biological signal transduction pathway.

: See Figure 6.4 and the "Membrane Proteins Facilitate Signal Transduction" section in the chapter. Section Title: Signal Pathways Learning Outcome: 6.4

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 82) Asthma is a respiratory disorder characterized by construction of airways and mucus production which makes it very difficult to breathe. The constriction of airways, mucus production and altered gene expression in the cells lining the airways of asthmatics is due to increased release of neurotransmitter acetylcholine. Explain how a single molecule can have such a large and diverse effect in a single cell.

: See Figures 6.5, 6.6 and 6.8; signal amplification. Section Title: Signal Pathways Learning Outcome: 6.4

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 72) Compare and contrast neural and endocrine control.

: See Table 6.2 in the chapter. Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 73) Compare and contrast neural, neuroendocrine, and endocrine reflex pathways.

: See Table 6.3 in the chapter. Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 29) ________ is a process by which an extracellular signal molecule, called the ________, activates a membrane receptor that in turn alters intracellular molecules, called the ________, to create a response.

: Signal transduction, first messenger, second messenger Section Title: Signal Pathways Learning Outcome: 6.3

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 80) Blood glucose levels are kept fairly steady in healthy people through the action of the hormones insulin and glucagon. Insulin decreases blood glucose by promoting glucose uptake by cells, whereas glucagon increases blood glucose by promoting release of glucose from cells. Describe these hormone actions as simple reflex pathways, identifying the stimulus, integrating center, efferent pathway, and response.

: Stimulus: increased blood glucose. Integrating center: endocrine cell (in pancreas). Efferent pathway: insulin secretion. Response: increased cellular uptake of glucose. Feedback: negative. Stimulus: decreased blood glucose. Integrating center: endocrine cell (in pancreas). Efferent pathway: glucagon secretion. Response: release of glucose from cells. Feedback: negative. Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 46) Compare and contrast the four basic methods of cell-to-cell communication.

: The cells can: 1. transfer signal molecules to adjacent cells through gap junctions 2. use contact-dependent signals, which rely on interactions between cell surface molecules on different cells 3. use locally acting chemicals, called paracrines, autocrines, or neuromodulators 4. use long-distance means, which rely on combinations of electrical and chemical signals Section Title: Cell-to-Cell Communication Learning Outcome: 6.1

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 79) The fight-or-flight reaction prepares an animal to respond to a threatening situation, by either fighting or running away. One aspect of this response is changes in blood flow such that the skeletal muscles and heart receive higher blood flow (vessels dilate) while digestive organs receive less (vessels constrict). Which signal molecule(s) is/are involved in this response, and how do they produce these changes in blood vessels? Explain how this example illustrates one or more of the following concepts: multiple ligands for one receptor, multiple receptors for one ligand, agonists and antagonists.

: The signal molecules are norepinephrine and epinephrine. Both of these chemicals bind to the same adrenergic receptors (multiple ligands) and have the same effect on their receptors, so they are agonists. When alpha-adrenergic receptors are activated in digestive organs, blood vessels constrict. When beta-adrenergic receptors are activated in skeletal and cardiac muscles, blood vessels dilate (multiple receptors). Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.7

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 62) Insulin increases glucose transport across the cell membrane of an adipocyte but not across the membrane of a liver cell. How can one hormone have two different effects?

: The two types of cells differ either in the receptors on their cell membranes or in the signal transduction that occurs after binding of insulin. Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.5

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 64) What general action is shared by about half of the medical drugs currently in use?

: These drugs act on membrane receptor proteins. Section Title: Signal Pathways Learning Outcome: 6.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 48) In your own words restate and explain Cannon's four postulates for maintaining homeostasis.

: This is discussed in the "Cannon's Postulates Describe Regulated Variables and Control Systems" section of the chapter. Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.8

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 69) Design a flow chart or concept map to summarize the information in the text under the heading "Cell-to-Cell Communication." This chart should make clear the four basic methods of cell-to-cell communication, and the relevance of and distinction between paracrine, autocrine, neurocrine, and cytokine chemicals.

: This is discussed in the "Cell-to-Cell Communication" section in the chapter. Section Title: Cell-to-Cell Communication Learning Outcome: 6.2

: Level II: Reviewing Concepts (Bloom's Taxonomy: Comprehension) 68) Define tonic control and give a physiological example.

: Tonic control regulates physiological parameters in an up-down fashion. An example is the neural regulation of blood vessel diameter (see Fig. 6.15). Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.6

: Level III: Problem Solving (Bloom's Taxonomy: Synthesis) 75) Food items are occasionally shown to offer protective effects to those who eat them. Garlic, for example, may improve heart health. The pungency of garlic is due to sulfur-containing compounds. Explain how these compounds are good candidates for garlic's heart benefits.

: When sulfur compounds are metabolized, hydrogen sulfide may be produced. This gas has recently been shown to be a signal molecule that relaxes blood vessels. Section Title: Novel Signal Molecules Learning Outcome: 6.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 50) What is an orphan receptor?

: a receptor that has no known ligand Section Title: Novel Signal Molecules Learning Outcome: 6.3

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 32) If the signal molecule acts on the cell that secreted it, the chemical is called a(n) ________.

: autocrine Section Title: Cell-to-Cell Communication Learning Outcome: 6.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 30) A gap junction forms when opposing membrane-spanning proteins called ________ on two adjacent cells unite, creating a protein channel that is capable of opening and closing.

: connexins Section Title: Cell-to-Cell Communication Learning Outcome: 6.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 45) When epinephrine combines with alpha adrenergic receptors on smooth muscle in intestinal blood vessels, the blood vessels ________; however, when epinephrine binds to beta-2 adrenergic receptors on certain skeletal muscle blood vessels, the vessels ________.

: constrict, dilate Section Title: Homeostatic Reflex Pathways Learning Outcome: 6.7

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 28) Lipid signal molecules that act in a paracrine fashion and combine with G-protein coupled receptors include ________ and ________.

: eicosanoids, sphingolipids Section Title: Novel Signal Molecules Learning Outcome: 6.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 26) Before nitric oxide was identified, its action was observed in ________ and it was given the name ________.

: endothelial cells (blood vessel lining), endothelial-derived relaxing factor (EDRF) Section Title: Novel Signal Molecules Learning Outcome: 6.2

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Comprehension) 40) To maintain ________, the body uses a combination of simple diffusion across small distances; wide spread distribution of molecules through the circulatory system and rapid, specific delivery of messages by the nervous system.

: homeostasis Section Title: Cell-to-Cell Communication Learning Outcome: 6.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 41) Most long-distance communication between cells takes place through the ________ and ________ systems with their combination of chemical and electrical signals.

: nervous, endocrine Section Title: Cell-to-Cell Communication Learning Outcome: 6.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 33) All molecules secreted by nerve cells (neuromodulators, neurotransmitters, and neurohormones) are known as ________.

: neurocrines Section Title: Cell-to-Cell Communication Learning Outcome: 6.1

: Level I: Reviewing Facts and Terms (Bloom's Taxonomy: Knowledge) 25) A few gases are known to act as signal molecules, including ________, ________, and ________.

: nitric oxide, carbon monoxide, hydrogen sulfide Section Title: Novel Signal Molecules Learning Outcome: 6.2