Neuron and Nervous system. Psychology 101/102.
Neuron and Nervous system. Psychology 101/102. PSY 101
Popular in Intro to Psychology
13392 - PSY 101 - 01
verified elite notetaker
Popular in Psychlogy
verified elite notetaker
This 5 page Class Notes was uploaded by Mary Idenu on Wednesday September 30, 2015. The Class Notes belongs to PSY 101 at Louisiana Tech University taught by in Summer 2015. Since its upload, it has received 43 views. For similar materials see Intro to Psychology in Psychlogy at Louisiana Tech University.
Reviews for Neuron and Nervous system. Psychology 101/102.
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 09/30/15
PSYCHOLOGY 101102 THE NEURON AND THE NERVOUS SYSTEM BIOLOGICAL PSYCHOLOGY Is the scientific study of links between biological and psychological processes Concerned with the links between biology and behavior There are many kinds of biological psychologists including behavioral neuroscientists neuropsychologists behavior geneticists physiological psychologists biopsychologists WHAT ARE NEURONS AND HOW DO THEY TRANSMIT INFORMATION Building blocks or nerve cells Neurons differ but all are variations on the same theme Composed of a cell body and its branching fibers THE NEURON Cell body nucleus with chromosomes Dendrites a neuron s bushy branching extensions that receive messages and conduct impulses toward the cell body Axon the neuron extension that passes messages through its branches to other neurons or to muscles or glands Myelin Sheath a fatty tissue layer segmentally encasing the axons of some neurons enables vastly greater transmission speed as neural impulses hop from one node to the next Glial Cells cells in the nervous system that support nourish and protect neurons they may also play a role in learning thinking and memory MYELIN Insulating layer of fatty material Composed of glial cells Helps efficient transmission of signals to other cells Gaps in myelin sheath are nodes of Ranvier GLIAL CELLS quotglue cells provide nutrients amp ion of insulating myelin guide neural connections mop up ions and neurotransmitters play role in learning and thinking participate in information transmission and memory proportion of glia to neurons increases in complex animals Among other critical roles glial cells increase neural efficiency It is said the Albert Einstein had more glial cells carry incoming messages from sensory receptors to the CNS communicate within the CNS and process information between incoming and outgoing messages carry outgoing messages form the CNS to muscles and glands THE SYNAPSE Junction between one neuron s axon and another s dendritescell body Neurotransmitters cross the synapse Plays a fundamental role in the communication between neurons The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron The tiny gap at this junction is called the synaptic gap or synaptic cleft Neurotransmitters are chemicals that transmit information across the synaptic gap cleft neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron determining whether or not a neural impulse is generated Reuptake a neurotransmitter s reabsorption by the sending neuron THE ACTION POTENTIAL A brief electrical charge that travels down the axon of a neuron Triggered by chemical signals from neighboring neurons or when stimulated by signals from our senses RESTING POTENTIAL o The fluid outside an axon s membrane has mostly positively charged sodium ions o A resting axon s fluid interior has mostly negatively charged potassium ions 0 The axon s surface is very selective about what it allows though its gates selectively permeable DEPOLARIZATION When a neuron fires the security parameters change 1 the first section of the axon opens amp positively charged Na ions flood in through the cell membrane 2 this loss of the insideoutside charge difference causes the next axon channel to open and then the next like a line of falling dominos REFRACTORY PERIOD Resting pause The neuron pumps the positively charged Na ions back outside then it can fire again The time following an action potential Another action potential can t occur during the refractory period After the action potential reaches 40 mv membrane channels return to original state The neuron can now generate another action potential Excitgtorv Vs lnhibitorv Sigm IExcitatory quotacceleratorquot Inhibitory quotbreakquot If excitatory signals exceed the inhibitory signals by a minimum intensity threshold the combined signals trigger an action potential Increasing the level of stimulation above the threshold will NOT increase the neural impulse s intensity Allornone response What happens to neurotransmitters in the synapse Reuptake Neurotransmitters are absorbed back into the presynaptic neuron Enzyme Deactivation Disassembly Neurotransmitters are broken down by enzymes in the synapse Autoreceptors Neurotransmitters bind to autoreceptor sites on the presynaptic neuron Neurotransmitters passively drift out of the synaptic gap TYPES OF NEUROTRANSMITTERS FUNCTIONS MALFUNTIONS 1 Acetylcholine ACh Enables muscle With Alzheimer s ACh action learning and producing neurons memory deteriorate 2 Dopamine Influences High levels linked to movement schizophrenia low levels learning attention linked to Parkinson s disease and emotion 3 Serotonin Affects mood Low levels linked to hunger sleep depression arousal 4 Norepinephrine Helps control Low levels depress mood alertness and arousal 5 Endorphins Boosts mood Artificial opiates cause brain lessens pain to stop producing endorphins THE NERVOUS SYSTEM Connects the central nervous system to the body s organs and muscles 0 arouses amp expends energy 0 accelerate heartbeat 0 raise blood pressure 0 slow digestion 0 raise blood sugar 0 increase perspiration 0 alert amp ready for action 0 conserves energy amp calms you 0 slows heartbeat 0 lowers blood pressure 0 increases digestion 0 lowers blood sugar 0 decreases perspiration The sympathetic and parasympathetic nervous systems work together to keep us in a steady internal state called homeostasis Controls voluntary movements The brain and spinal chord