Chapter 13, Problem 4CTE

Medical practice is paying more attention to the autonomic system in considering disease states. Why would autonomic tone be important in considering cardiovascular disease?

Watch this animation (http://openstaxcollege.org/l/bloodflow1) to see how blood flows to the brain and passes through the circle ofWillis before being distributed through the cerebrum. The circle of Willis is a specialized arrangement of arteries that ensure constant perfusion of the cerebrum even in the event of a blockage of one of the arteries in the circle. The animation shows the normal direction of flow through the circle of Willis to the middle cerebral artery. Where would the blood come from if there were a blockage just posterior to the middle cerebral artery on the left?

Which of these physiological changes would not be considered part of the sympathetic fight-or-flight response? increased heart rate increased sweating dilated pupils increased stomach motility

Watch this video (http://openstaxcollege.org/l/nervsystem1) to learn more about the nervous system. As described in this video, the nervous system has a way to deal with threats and stress that is separate from the conscious control of the somatic nervous system. The system comes from a time when threats were about survival, but in the modern age, these responses become part of stress and anxiety. This video describes how the autonomic system is only part of the response to threats, or stressors. What other organ system gets involved, and what part of the brain coordinates the two systems for the entire response, including epinephrine (adrenaline) and cortisol?

Which type of fiber could be considered the longest? preganglionic parasympathetic preganglionic sympathetic postganglionic parasympathetic postganglionic sympathetic

Visit this site (http://openstaxcollege.org/l/neurolab) to see a virtual neurophysiology lab, and to observe electrophysiological processes in the nervous system, where scientists directly measure the electrical signals produced by neurons. Often, the action potentials occur so rapidly that watching a screen to see them occur is not helpful. A speaker is powered by the signals recorded from a neuron and it pops each time the neuron fires an action potential. These action potentials are firing so fast that it sounds like static on the radio. Electrophysiologists can recognize the patterns within that static to understand what is happening. Why is the leech model used for measuring the electrical activity of neurons instead of using humans?

Watch this video (http://openstaxcollege.org/l/lumbarpuncture) that describes the procedure known as the lumbar puncture, a medical procedure used to sample the CSF. Because of the anatomy of the CNS, it is a relative safe location to insert a needle. Why is the lumbar puncture performed in the lower lumbar area of the vertebral column?

In the propagation of a nerve impulse: a. the refractory period begins as the K+ channel opens, allowing K+ ions to flow outward along their concentrationgradient. b. Na+ ions flow out of the axon with their concentration gradient. c. positive charges lower the membrane potential to its lowestaction potential. d. gated K+ channels open at the same time as the activationgate of Na+ channels closes. e. the depolarizing stimulus lowers the membrane potential toopen the Na+ gates.

50% of the population has which body habitus? a. Hypersthenic b. Hyposthenic c. Asthenic d. Sthenic