Chapter 11 Answers 1 Give a general function of the nervous system The nervous system functions in fast communication and control by transmitting electrical and chemical signals that cause rapid and specific responses 2 List the two divisions of the nervous system name the organs of each Central Nervous System CNS brain and spinal cord Peripheral Nervous System PNS cranial nerves and spinal nerves 3 Differentiate between cranial nerves and spinal nerves Cranial nerves extend to and from the brain spinal nerves extend to and from the spinal cord 4 List the two divisions of the peripheral nervous system Describe direction of impulse transmission in each Which is afferent Efferent Sensory afferent division transmits impulses toward the CNS Motor efferent division transmits impulses away from the CNS to effectors 5 List the two divisions of the motor nervous system and name the effector s of each Which is voluntary Which is involuntary Somatic Nervous System skeletal muscles voluntary Autonomic Nervous System cardiac muscle smooth muscle glands involuntary 6 List and describe three overlapping functions of the nervous system Sensory input sensory receptors gather information Integration processing and interpretation of sensory input Motor output activation of effectors producing a response 7 Describe the function of sensory receptors Detect stimuli and convert them into electrical impulses to be transmitted to the CNS 8 List two types of cells that are located in the nervous system Which conducts impulses Which provides support Which type of cell is more plentiful Neurons conduct impulses Neuroglia provide support more plentiful than neurons 9 List neuroglial cells that are located in the central nervous system and give their general functions list neuroglial cells that are located in the peripheral nervous system and give their general functions CNS Astrocytes support Microglial cells defense Ependymal cells line cavities Oligodendrocytes form myelin PNS Satellite cells support Schwann cells form myelin 10 Describe special characteristics of neurons Long lived mostly amitotic high metabolic rate conduct impulses 11 Name the neuronal structure in which the nucleus is located Cell body 12 Describe the general components of the cell body Nucleus nucleolus cytoplasm rough ER Nissl bodies axon hillock 13 Give the name for the rough endoplasmic reticulum of a neuron lab term Cone shaped region of the cell body where the axon originates site of action Nissl bodies or chromatophilic substance 14 Define axon hillock potential initiation 15 Differentiate between nuclei and ganglia Nuclei clusters of neuron cell bodies in the CNS Ganglia clusters of neuron cell bodies in the PNS 16 Describe neuronal composition of CNS of PNS CNS neuron cell bodies nuclei and processes tracts PNS mainly neuron processes nerves and ganglia 17 Differentiate between tracts and nerves Tracts bundles of processes in the CNS Nerves bundles of processes in the PNS 18 Differentiate between dendrites and axons Which is more plentiful Dendrites receptive input regions short branched more plentiful Axons conduct impulses away from the cell body 19 Give the general function of myelin Insulates axons increases speed of impulse transmission 20 Name the type of neuroglial cell that forms the myelin sheath in the CNS 21 Name the type of neuroglial cell that forms the myelin sheath in the PNS Oligodendrocytes Schwann cells myelin sheath 22 Describe the formation of the myelin sheath Schwann cells or oligodendrocytes wrap around the axon in layers creating the 23 Differentiate between myelinated and nonmyelinated fibers Myelinated covered with myelin sheath fast conduction Nonmyelinated lack sheath slower conduction 24 Define node of Ranvier myelin sheath gap Gaps between adjacent Schwann cells where axon is exposed site of ion exchange 25 Describe two factors that the rate of action potential conduction depend on Axon diameter larger faster Degree of myelination more faster 26 Describe the exact location of the myelin in the myelin sheath Surrounds the axon produced by wrapping of glial cell membranes 27 Describe the formation of the myelin sheath Define neurilemma Formed by glial cell wrapping neurilemma is the outermost layer of Schwann cell containing its nucleus 28 Describe impulse transmission along an unmyelinated axon This type of impulse transmission is called conduction Continuous conduction 29 Describe impulse transmission along a myelinated axon This type of impulse transmission is called conduction Describe the location of the nodes of Ranvier Saltatory conduction nodes are between Schwann cells where the axon is 30 Which type of impulse conduction named in 28 29 above is faster exposed Saltatory conduction 31 Differentiate between A fibers B fibers and C fibers In which fiber are impulses transmitted most rapidly In which fibers are impulses transmitted most slowly A fibers large diameter thick myelin fastest 150 m s B fibers intermediate diameter lightly myelinated moderate speed C fibers small diameter unmyelinated slowest 1 m s 32 Differentiate between unipolar bipolar and multipolar neurons neuron structure Which is rare Unipolar one process sensory neurons Bipolar one axon and one dendrite rare found in retina and olfactory mucosa Multipolar one axon many dendrites most common 33 Differentiate between sensory motor and interneurons neuron function Sensory afferent carry impulses to CNS Motor efferent carry impulses from CNS to effectors Interneurons connect sensory and motor neurons function in integration 34 Give the structural classification of sensory neurons motor neurons and 35 Name the most plentiful type of neuron based on structure name the most interneurons Sensory unipolar Motor multipolar Interneurons multipolar plentiful type of neuron based on function Structure multipolar Function interneurons 99 of neurons Chapter 11 Answers previous content 36 Identify where all interneurons are located Entirely within the CNS 37 Review ion channels chemically gated ion channels voltage gated ion channels Ion channels allow ion movement across membranes Chemically gated channels open with neurotransmitter binding Voltage gated channels open in response to membrane potential changes 38 Explain in general what causes the resting membrane potential to change Opening of voltage gated or chemically gated ion channels that allow ion diffusion 39 Differentiate between graded and action potentials Graded local vary