PHIS 206 1st EditionLecture 8Outline of Last Lecture I. Cortical Association AreasII. MemoryIII. AmnesiaIV. CerebellumV. Brain Stem: connects cerebellum and cerebrumVI. Reticular FormationOutline of Current Lecture I. AfferenceII. Sensation v. PerceptionIII. Sensory SystemIV. Receptor/Generator PotentialsV. How Receptors WorkVI. Receptor PropertiesVII. Afferent (Delivers to Brain)VIII. Sensory Neuron InputIX. Sense―PainX. PerceptionXI. Autonomic Nervous SystemXII. Somatic Nervous SystemXIII. 2 Neurons―Autonomic Nervous SystemCurrent LectureI. Afference-blood pressure, etc… brain knows it but we don’t-Other type carries information about the outside world: sensory systems have receptors that are specialized to interact with energy and convert it to action potentialsII. Sensation v. Perception-sensations: raw information that comes in; can have some sensations same as othersThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.-perceptions: varies b/w person-to-personIII. Sensory System-has to interact with some energy in the outside environment-sensory receptors interact with certain frequencies (attuned to stimuli)-has to be able to convert energy into some input transducers: converting environmental activities into action potentialsIV. Receptor/Generator Potentials-sensory receptor properties1.) interacts with some form of energy in the environment2.) acts as transducer of energy to action potentials-adequate stimulus: stimuli that receptors are very sensitive toV. How Receptors Work-When stimulated, Na+ channels in membrane opens decrease negativity of membrane potential: receptor potential (those receptors that are not neurons)-Graded stimuli: present weak stimulus, small change in receptor potential but no action potential (have to reach threshold)-Most receptors: frequency of action potential is related to stimulus strength-Frequency coding: when stimulus is strong, more action potentialsEx.) loud sound, more action potentials/unit time-Population coding: increase strength of stimulus, more neurons fireVI. Receptor Properties-adaptation: continue to stimulate, gradually receptors will stop respondingEX.) Fix eyes on object w/o moving head or eyes-receptors respond to the rate of change of stimulus-neurally-mediated receptors: blood pressure up when running and then adapt in a couple of minutes-Over long periods of time, receptors do not work-Exceptions tonic receptors: generate action potentials at the same level when continuously stimulatedVII. Afferent (Delivers to Brain)-visual receptors: optic nerve, see light-Neurons are specialized -Label-lined: coded (nature of stimulus) and (amplitude of stimulus)-referred pain: direct association with label-lined pain afference pathways same (spinal cord + brain); pathways back/forthVIII. Sensory Neuron Input-area from which sensory neuron can be stimulated: receptive fields very large: present 2 stimuli far apart but still not able to tell they are 2 stimuli (ears) very small: close; able to make finer distinctions (fingers)-sensory acuity: ability to discriminate b/w 2 sensory that are close byIX. Sense―Pain-pain receptors: naked nerve neurons ending in a particular location-2 Types:1.) Fast Pain/1st Pain: carried in A. Delta neurons; are mild (can pinpoint)-sensitive to mechanical/chemical2.) Slow Pain/2nd Pain: carried in C. Delta neurons; non-poorly localized pain; continued until stimulated-sensitive to pressure Energy in cells Ex.) breaking leg bone*non-adaptable sensors/ continuous painX. Perception-analgesia system: releases opiums into brain; causes pleasure/pain-endorphins: indigenous morphin-like compoundsXI. Autonomic Nervous System: involuntary activities-blood pressure, lungs, etc…-2 subsections:1.) Sympathetic: “fight or flight” becomes activated2.) Parasympathetic: response to non-physical activity (eating)XII. Somatic Nervous System-makes muscles moveXIII. 2 Neurons―Autonomic Nervous SystemParasympathetic SympatheticLong, ACh Short, AChShort, ACh Long,
View Full Document
Unlocking...