Anjali Pillai PSYC 111 Biology Behavior and Mind Chapter 2 Notes The Biology of Mind Everything psychological is simultaneously biological Everything you do is biological Biological perspective concerned with the links between biology and behavior Includes psychologists working in neuroscience behavior genetics and evolutionary psychology These researchers may call themselves behavioral neuroscientists neuropsychologists behavior geneticists physiological psychologists or biopsychologists o Brain mind Plato Heart mind Aristotle o Franz Gall phrenology study of bumps on skull person s mental abilities and traits Localization of function revealed but not accurate at all o Biological perspective interplay b w biology and mind and behavior Studies discovered o Cells neurons and synapses and neurotransmitters localization of function in brain and systems integrate info in mind to produce our experiences brain is adaptive and wired by experience o Cells organs organ sys individual family culture community biopsychosocial Neural Communication Neurons Neuron a nerve cell the basic building block of the nervous system 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 Action potential a neural impulse a brief electrical charge that travels down an axon Threshold the level of stimulation required to trigger a neural impulse o Neurons cell body dendrites axon and terminal branches axons speak dend listen MS degeneration of myelin sheath lack of communication to muscles o Stimulated by signals fires an impulse action potential Gen electricity ions exchanged Outside pos inside neg resting potential Axons surface is selectively permeable Pos into axon depolarization refractory pd pos back outside Most signals excitatory some inhibitory need to surpass threshold How Neurons Communicate Synapse 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 cleft The Nervous System Neurotransmitters chemical messengers that cross the synaptic gaps between neurons When released by the sending neuron neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron thereby influencing whether that neuron will generate a neural impulse Reuptake a neurotransmitter s reabsorption by the sending neuron o Meeting point synapse and gap or cleft rel chemical messengers NT and bind to receptors Reuptake absorbs excess How Neurotransmitters Influence Us Endorphins morphine within natural opiatelike neurotransmitters linked to pain control and to pleasure o Particular pathway only 1 or 2 NT and may affect behavior and emotion interact Ach learning and memory motor neurons brain and spinal cord to body tissues and skeletal muscles contraction no ACh paralyzed Brain has opiate receptors endorphins o How Drugs and Other Chemicals Alter Neurotransmission More morphine body may stop producing naturally and withdrawal too Agonist mimic effects and antagonists block NT function Opiate drugs or botulin blocks ACh Nervous system the body s speedy electrochemical communication network consisting of all the nerve cells of the peripheral and CNS CNS the brain and spinal cord PNS sensory and motor neurons that connect the CNS to rest of body Nerves bundled axons that form neural cables connecting the CNS w muscles glands and sense organs i e optic nerve single cable of million axons Sensory neurons carry incoming info from sensory receptors to brain and spinal cord Motor neurons carry outgoing info from brain and spinal cord to the muscles and glands Interneurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs The Peripheral Nervous System Somatic nervous system the division of the peripheral nervous system that controls the body s skeletal muscles Also called the skeletal nervous system Autonomic nervous system the part of the peripheral nervous system that controls the glands and the muscles of the internal organs i e heart Its sympathetic division arouse its parasympathetic division calms Sympathetic nervous system the division of the autonomic nervous system that arouses the body mobilizing its energy in stressful situations Parasympathetic nervous system the division of the autonomic nervous system that calms the body conserving its energy o Sympathetic accelerate heartbeat raise bp slow digestion raise blood sugar perspire o Parasympathetic opposite effects The Central Nervous System Reflex a simple automatic response to a sensory stimulus i e knee jerk o Work groups neural networks fast connection ways to strengthen networks o Spinal cord two way info highway connecting PNS and brain Up sensory neurons down motor neurons govern reflexes Single sensory neuron and single motor neuron via interneuron o Pain reflex neural activity jerks away then feels pain The Endocrine System Endocrine system the body s slow chemical communication system a set of glands that secrete hormones into the bloodstream Hormones chemical messengers that are manufactured by the endocrine glands travel through the bloodstream and affect other tissues Adrenal glands a pair of endocrine glands that sit just above kidneys and secrete hormones epinephrine and norephinephrine that help arouse the body in times of stress Pituitary gland the most influential gland under the influence of the hypothalamus the pituitary regulates growth and controls other endocrine glands Hormones slower and travel in blood affect brain influence interest in sex food aggression o Act on receptors and last longer Epinephrine inc heart rate blood sugar energy and norepi lasts a while Pituitary gland pea sized in brain next to hypothalamus o Growth hormone and oxytocin pair bonding cohesion and social trust o Also influence release of hormones by other glands i e sex glands o Brain to pituitary to glands to hormones to body and brain The Brain Brain enables mind seeing hearing feeling smelling thinking remembering speaking etc o Brain self reflects and analyzes brain o Brain body mind integrated whole The Tools of Discover Having
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