Exam 1 Review Topics Lesson 1 Listed below are some of the key topics discussed in class This is not meant to be a comprehensive review of lessons 1 4 for that you should go over your notes You are ultimately responsible for all of the information that was presented in class What is the difference between the afferent division and the efferent division of the nervous system Which involves the sensory pathway Which involves the motor pathway What are their components Afferent Division of the Nervous System involves o Receptors detects the stimuli o Sensory neurons relays the information down their axons Specialized cells that monitor specific conditions in the body or external environment When stimulated a receptor passes information to the CNS In the form of action potentials along the axon of a sensory neuron o Sensory pathways Deliver somatic and visceral sensory information to their final destinations inside the CNS using Nerves axon bundles in the PNS Nuclei cell bodies located in the CNS Tracts axon bundles in the CNS Efferent Division of the Nervous System involves o Nuclei contains the cell bodies of motor neurons o Motor tracts and nerves carries commands to effectors muscles and glands o Somatic Motor Portion of the Efferent Division Controls peripheral effectors o Somatic Motor Commands Travel from motor centers in the brain along somatic motor pathways of Motor nuclei Nerves axons in the PNS peripheral nervous system Tracts axons in the CNS central nervous system o Somatic Nervous System SNS Motor neurons and pathways that control skeletal muscles What are the 6 general senses What are the 5 special senses Why is receptor specificity important to the detection of a specific stimulus What does that have to do with labeled lines in the nervous system General Senses o Describe our sensitivity to Temperature Pain Touch Pressure Vibration o Olfaction smell o Vision sight o Gustation taste o Equilibrium balance o Hearing Special Sensory Receptors tissues o Receptor specificity Proprioception monitors the position and movements of skeletal muscles and joints Special Senses provided by special sensory receptors o located in sense organs such as the eye or ear are protected by surrounding Each receptor has a characteristic sensitivity your hands do not smell nor taste your eyes do not hear etc Interpretation of Sensory information o Arriving stimulus reaches cortical neurons via labeled line link between receptor and cortical neuron Each labeled line carries info about one modality form such as Physical force such as pressure Dissolved chemical Sound Light What is the difference between sensation and perception If a receptor has a large receptive field is it easier or harder to localize the stimulus What if the receptor has a small receptive field Sensation The arriving information from these senses o Taste hearing equilibrium and vision provided by specialized receptor cells Perception Conscious awareness of a sensation Receptive field o Area is monitored by a single receptor cell o The larger the receptive field the more difficult it is to localize a stimulus o Easier to localize a stimulus if there is a small receptive field What is adaptation and how are tonic and phasic receptors involved What is the difference between central adaptation and peripheral adaptation Adaptation o Reduction in sensitivity of a constant stimulus o Your nervous system quickly adapts to stimuli that are painless and constant Ex New smells rings earrings o Tonic receptors Show little peripheral adaptation Are always active Are slow adapting receptors Ex Pain receptors nociceptors remind you of an injury long after the initial damage has occurred o Phasic receptors Are normally inactive Become active for a short time whenever a change occurs Are fast adapting receptors Provide information about the intensity and rate of change of a stimulus Ex Thermoreceptors detect rapid changes in temp o Central Adaptation o Peripheral Adapation spinal cord brain afferent and efferent aspects of the nervous system What are the four types of general sensory receptors What is the difference between the pain information sent by type A fibers and type C fibers General Sensory Receptors o Are divided into four types by the nature of the stimulus that excites them o 1 Nociceptors pain Are common In the superficial portions of the skin In joint capsules Within the periostea of bones Around the walls of blood vessels Analgesia inability to feel pain Hyperalgesia increased sensitivity to pain May be sensitive to Temperature extremes Mechanical damage Dissolved chemicals chemicals released by injured cells Are free nerve endings with large receptive fields Branching tips of dendrites Not protected by accessory structures Can be stimulated by many different stimuli Two types of axons Type A large myelinated and Type C small unmyelinated fibers o Myelinated Type A fibers Carry sensations of fast pain or prickling pain such as that caused by an injection or a deep cut Sensations reach the CNS quickly and often trigger somatic reflexes Relayed to the primary sensory cortex and receive conscious attention o Unmyelinated Type C fibers Carry sensations of slow pain or burning and aching pain Cause a generalized activation of the reticular formation and thalamus You become aware of the pain but only have a general idea of the area affected o 2 Thermoreceptors temperature Also called temperature receptors Are free nerve endings located in The dermis Skeletal muscles The liver The hypothalamus Temperature sensations Conducted along the same pathways that carry pain sensations Sent to o The reticular formation o The thalamus o The primary sensory cortex to a lesser extent o 3 Mechanoreceptors physical distortion Sensitive to stimuli that distort their plasma membranes Contain mechanically gated ion channels whose gates open or close in response to Stretching Compression Twisting Other distortions of the membrane o 4 Chemoreceptors chemical concentration Details of chemoreceptors are two points down How many different classes of mechanoreceptors are there Of the tactile receptors how many types are there Can you name the different types of stimuli that each type detects Three Classes of Mechanoreceptors o 1 Tactile receptors Provide the sensations of touch pressure and vibration Touch sensations provide information about shape or texture Pressure sensations indicate degree of mechanical distortion Vibration sensations indicate
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