APHY 101 final ivy tech 100% SOLUTION

APHY 101 final ivy tech 100% SOLUTION Every neuron has a. many axons. b. a cell body. c. myelin. d. a neurilemma. - ANSWER b Which of the following neuroglia are not part of the CNS? a. Ependymal cells b. Astrocytes c. Satellite cells d. Microglia - ANSWER c Neurons that conduct impulses from the CNS to muscles or glands are a. sensory neurons. b. interneurons. c. motor neurons. d. unipolar neurons. - ANSWER c Myelin is composed largely of carbohydrates. True False - ANSWER false A stimulus great enough to change the membrane potential and propagate an action potential is said to have reached _________. a. recruitment b. threshold c. summation d. tetanus - ANSWER b Nodes of Ranvier lie between neurons. True False - ANSWER false Action potentials are related to impulses conducted along an axon in that a. many impulses are required to cause one action potential. b. active transport of Na+ and K+ are required for impulse conduction but not for an action potential. c. impulses are stronger responses than are action potentials. d. propagation of a series of action potentials along a nerve cell fiber constitutes an impulse. - ANSWER d The neurotransmitter that controls skeletal muscle contraction is a. beta endorphin. b. nitric oxide. c. acetylcholine. d. GABA. - ANSWER c The most rapid conduction of an impulse along an axon occurs on a fiber that is a. thick and myelinated. b. thick and unmyelinated. c. thin and myelinated. d. thin and unmyelinated. - ANSWER a A myelinated nerve fiber is ______, whereas an unmyelinated nerve fiber is ______. a. gray, and composing the gray matter of the brain and spinal cord; white, and composing the white matter of the brain and spinal cord b. white, and composing the gray matter of the brain and spinal cord; gray, and composing the white matter of the brain and spinal cord c. white, and composing the white matter of the brain and spinal cord; gray, and composing the gray matter of the brain and spinal cord d. white, and composing the gray matter of the brain and spinal cord; red, and composing the white matter of the brain and spinal cord - ANSWER c The two types of cells of the nervous system are a. axons and dendrites. b. neurons and neuroglia. c. motor neurons and sensory neurons. d. Schwann cells and microglia. - ANSWER b What is the correct sequence of events along an axon that follows a membrane reaching threshold potential? 1. The membrane depolarizes. 2. Sodium channels open and sodium ions diffuse inward. 3. The membrane repolarizes. 4. Potassium channels open and potassium ions diffuse outward. a. 3, 2, 4, 1 b. 2, 1, 4, 3 c. 1, 2, 4, 3 d. 4, 1, 3, 2 - ANSWER b During the absolute refractory period, a stimulus of high intensity may trigger a nerve impulse. True False - ANSWER False Which lobe of your brain are you using when you answer this question? a. Frontal b. Parietal c. Temporal d. Occipital - ANSWER a Symptoms of concussion include all except a. disturbed sleep. b. decreased sensitivity to light and sound. c. memory lapse. d. balance problems.