5. The following is a sequence of steps that describes the flow of information from an external stimulus to a physiological response: Stimulus →→sensor integrator → effector →→ response When you walk into the cold wearing only a T-shirt, you shiver. a) Identify the stimulus, sensor, integrator, effector, and response in this interaction between you and the cold. (please respond in your blue book) Stimulus Sensor Integrator Effector Response b) i) Explain what shivering accomplishes regarding thermoregulation, and ii) illustrate using the temperature vs time axes below (please redraw into your blue book). Time c) In response to a viral infection, your body mounts a fever in response, i) Explain generally why it does so and ii) describe the steps from infection to the rise in your body's temperature that we have discussed in class. I Temperature

7. You stimulate a presynaptic cell and record from the postsynaptic neuron of each pair. For each mutation below, describe the following: i) After the first stimulus, how does the excitatory postsynaptic potential (EPSP) you record from the postsynaptic neuron differ from the EPSP recorded from a wild-type animal? Does it increase, decrease, stay comparatively the same, or fail to be generated at all? ii) After five stimulations of the presynaptic cell in quick succession, how does the EPSP you record from the mutant animal differ from that in the same experiment on a wild-type animal? Explain your reasoning in each case. The mutations are as follows: 7A. Mutation of the voltage-gated Ca2+ channels of the presynaptic terminal. The mutant channels have a lower opening threshold.

What is affected by the electrical signal sent by the third structure? (This will be the fourth structure in the arc.) Where is the cell body of the fourth structure located? What is affected by the electrical signal sent by the fourth structure? (This will be the fifth structure in the arc.) What does the fifth structure do in response to that electrical signal and how does this action protect you? Describe a situation where a reflex arc would be activated that is not described in your lesson. Assume that the reflex arc has five components to it. Please choose a reflex that involves a body part below the neck. (If you have trouble with this, do an internet search for information on reflex arcs.)

Taste buds are sensory receptors for taste located on the tongue. When a person eats a spicy food, receptors on the tongue pick up a stimulus. The stimulus initiates the movement of ions across the membrane. If the threshold level is reached, an action potential is generated and a signal is sent to the brain telling the brain that the food is spicy. The reason that some individuals have a higher tolerance to spicy food than others is due to a difference in the a. duration of the refractory period b. number of Na+/K+ ion exchange pumps c. strength of the stimulus d. threshold level