NR 545 Unit 2 Evolve Questions & Answers Graded A

Chapter 15 1. Which structure is part of the central nervous system (CNS)? A. Brain Correct B. Somatic nervous system C. Peripheral nerve pathways D. Cranial nerves The brain is part of the CNS. The peripheral nervous system (PNS) consists of the cranial nerves and the spinal nerves. The PNS can be divided into the somatic nervous system and the autonomic nervous system. 2. Which of the following is an insulating substance for the neuron? A. Schwann sheath B. Myelin Correct C. Neurilemma D. Node of Ranvier Myelin is an insulating substance. The neurilemma is the same as a Schwann sheath; it is the delicate tissue that surrounds each axon. The nodes of Ranvier are interruptions at regular intervals that occur in the myelin. 3. Which neurons transmit impulses from neuron to neuron? A. Unipolar neurons B. Sensory neurons C. Motor neurons D. Interneurons Correct Interneurons, or associational neurons, transmit impulses from neuron to neuron. Motor neurons transmit impulses away from the CNS. Sensory neurons carry impulses from the peripheral sensory receptors to the CNS. Unipolar neurons have one process that branches shortly after leaving the cell body. 4. Which term describes successive, rapid impulses received from a single neuron on the same synapse? A. Temporal summation Correct B. Spatial summation C. Actuation D. Facilitation Temporal summation refers to the effects of successive, rapid impulses received from a single neuron on the same synapse. Spatial summation refers to the combined effect of impulses from a number of neurons on a single synapse at the same time. Facilitation refers to the effects of excitatory postsynaptic potential (EPSP) on the plasma membrane potential. 5. Which of the following is a component of the midbrain? A. Cerebral hemisp