Biological Basis Of Behavior Chapter 3 PDF
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University of New Brunswick Saint John
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Summary
This chapter covers the biological foundations of behavior, including nerve tissue, the communication of neurons, the neural impulse, and action potentials. It describes how the nervous system functions and how these processes relate to overall behavior.
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Nerve tissue Glia Cells - Structural Support , Insulation ,...
Nerve tissue Glia Cells - Structural Support , Insulation , makes up 50% brain cells , connected to diseases , Neurons-cells that receive , Integrate and transmit Information Dendrites - receives Information Soma- Axon-transmits away from Soma Communication of neurons Mylein sheath-speeds up transmission Terminal Button-end of axon ; secretes neurotransmitters into synapse Neurotransmitters-Chemical messengers of which interconnect Synapse-point neurons The neural Impulse Hodgkin and Huxley (1952) - giant squid Electrically charged particles (ions) in fluids inside/outside neuron Neuron at rest has negative charge on inside compared to outside 10 Millivolts = resting potential - Action Potential Stimulation causes Cell membrane to open briefly lon channels : flow of sodium (Na + ) Potassium (K + ) Calcium (CA ++) (ci) regulates , , Chloride lon pumps : protien Structures which maintain uneven distribution of ions across the membrane Sodium Channels opens : Na flows into axoplasm (becomes ( + ) inside self-propagation of depolarization: impulse down neural axon Sodium channels close Terminal buttons resting potential restored via potassium channels opening - k" flows outside membrane refectory period Shift in electrical charge travels along neuron: Action potential , All-or-none law Synapse Chemicals as Signal couriers Synaptic cleft presynaptic neuron - Synaptic vesicles release neurotransmitters Postsynaptic neuron - receptor Sites - "Lock-and-key" Posthypnotic Potential Voltage Change at receptor Site - postsynaptic potential (PSP) - Not all-or-none - changes the probability of the postsynaptic neuron firing Positive Voltage Shift-exciatory PSP Negative Voltage shift-inhibitory PSP Neural Networks one neuron receives Signals from thousands of other neurons Requires integration of signals - EPSPs add up threshold, reached - If lPSPs and EPSPs balance , then neurons remains at rest Neural networks - patterns of neural activity - interconnected neurons that fire together or sequentially Synaptic links change Synaptic pruning - dendrites - branch extensions of a neuron that receive information from other neurons neurotransmitters Acetylcholine (Ach)-motor neurons and Voluntary muscles - attention , memory , eg. Alzheimers disease motor neurons and voluntary muscles - Implicated in attention , memory - Specific neurotransmitters work at specific Synapse Lock and key Agnist-mimics neurotransmitters action Antagonist opposes action of neurotransmitters nicotine - a - Interactions between neurotransmitter circuits - Curare Monoamines : Norepinephrine (NE) - CNS and PNS neurons modulates mood , arousal , learning Serotonin (5-HT) critical for sleep wakefulness , Implicated disorders. in aggression eating - , , Dopamine (DA) Important for Voluntary movement - Amino acids GABA (and : glycine transmitters; of the major inhibitory regulates anxiety ; expression of seziures ; modulation of sleep - one. Endorphins encogenous opiates relief and pleasurable "runners high" - pain emotions - - Neuroplasticity brains to the lifespan ability re-organize itself - over Nervous system Central nervous System (CNS) Peripheral nervous System (PNS) - Somatic nervous system Afferent = toward CNS Efferent = away CNS - Automic nervous System (ANS) Sympathetic Parasympathetic Brain Spinal Cord menignes - - Cerebellum Brain function Three subdivisions : major Hindbrain : Medulla/Pons , reticular formation , cerebellum Midbrain Substanti nigrareticularformationserum : Diencephalon : Thalamus ; Hypothalamus (under Limbic System : Amygdala ; Hippocampus (and parts of thalamus/hypothalmus Cerebrum The cortex folded band for function Cerebral Cortex or grey matter is thickly of tissue responsible higher mental - a - fissures connected to the thalamus. ridges (gyri) Valleys (Sulci - or - - The Cerebrum Two Hemisphere , four lobes Cerebral Hemispheres : two specialized halves - separated by Longitudinal Fissure - connected by the corpus colosseum Left hemisphere verbal processing language Speech reading writing - , - , , , Right hemisphere nonverbal processing spatial musical visual recognition - - , , Aphasia impairment production and understanding Including in reading and writing - in language Speech - language Brocas area , wernickes area on left part of brain Split brain research Roger Sperry-1981 Nobel prize sample-Severe callosum cut epilepsy , Corpus consequences - no transfer of sensory information between hemispheres Image field identification to right Visual verbal = Image to left Visual field= manual identification hand identification object in right Verbal = object in left hand = no verbal but picture identification Frontal lobe (ie touch sensory perception and integration through Somatosensory Contex -. Spatial awareness navigation - Visuospatial processing - Math logic language - , , Temporal Lobe Audition language prosody - , , Memory - Emotional processing - object recognition - Smell processing - Facial recognition - occipital lobe - vision : - Processing , Perception , spatial awareness , color recognition , movement detection , pattern recognition - visual attention , focus Endocrine system Another to communicate way Hormone : Chemical messenger secreted into bloodstream and can induce effects far from the site of Secretion Negative Feedback : Once a hormone gets to a certain level , the System sends a message to stop secretion Important Endocrine Glands Pituitary Master gland - Secretes substances that influence other and GH oxytocin all glands and - Thyroid controls metabolic rate - - T4. Tz , Calcitonin Adrenal Controls salt and carb metabolism - - Cortisol , aldosterone, epinephrine , norepinephrine Pancreas Secretes insulin and to control metabolism glucagon Sugar - Gonads - Secrete Sex hormones testosterone , estrogen , progesterone Genes and Behavior The field of behavioral genetics study of the influence of factors traits genetic behavioural - on · chromosomes - strands of DNA carrying genetic information Humans 23 pairs (exept gametes - Genes Each ChromosomeCarries 1000s of genes (also paired - - Genes are dominant or recessive , can be either homozygous or heterozygous , Genotype/phenotype and polygenic inheritance ↑ Homozygous geOPP (Male or female Look the same phenotype Research Methods Family studies - does it run in the family ? Twin Studies - Compare resemblance of identical (monozygotic) and frater a Adoption studies Modern Approaches to the nature vs. Nature Debate & Molecular Genetics : The study of the biochemical bases of genetic inheritance project (2003) Genetic mapping : Locating specific genes (Human Genome Behavioural Genetics - The in-eractionist model " Rose (1995) "We inherit dispositions , not destinies. Richard - - Evolutionary psychology terms of Behavior in adaptive significance Based on Darwins ideas of natural selection - reproductive success is key Adaptions-behavioral as well as physical - Flight-or-fight - Taste preferences Parental investment and mating -