Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Unit 2: Biological Basis for Behavior Neurons: • Sensory neurons - afferent • Motor neurons - efferent • Interneurons • Mirror neurons – frontal lobe only The Neuron: the basic building block (cell) of the nervous system. • Neurons are composed of the following parts: – – – – – – – – – Axon Soma/Cell Body Dendrite Myelin sheath Terminal Branches Terminal Buttons Synapse Post synaptic Dendrite Glial cells All or None Law: Like firing a gun • Neuron will fire or it won’t – there is no between – Squeezing a trigger hard or soft? – Turning on a light switch slow or fast? • Neurotransmitters can be excitatory or inhibitory: Molecules that mimic neurotransmitters • Mimics can also excite or inhibit – Agonists excite • Black widow spider bite (ACh) – Antagonists inhibit • Butolin (ACh) • Heroin (endorphins) – Why do different people experiences “highs” differently? \ Acetylcholine (ACh) • • • • Released by motor neurons Regulation of attention, arousal, and memory Enables muscle action, memory and learning Lack/death of ACh creating neurons = Alzheimer’s Dopamine (DA) • Control of voluntary movement • Cocaine and amphetamines elevate activity at DA synapses • “reward pathway” • Too little = Parkinson’s • Too much = Schizophrenic disorders, addictive disorders – Dopamine hypothesis Norepinephrine (NE) • Alertness, mood, and arousal • Cocaine and amphetamines elevate activity at NE synapses • Too little = depression Serotonin • Mood, hunger, sleep, and arousal • Prozac and antidepressant drugs affect serotonin circuits – SSRI • Too little = depressive disorders GABA or gamma-aminobutryic acid • Inhibitory transmitter • Regulates anxiety, sleep/arousal • Too little = insomnia, anxiety disorders, seizures Glutamate • Widely distributed excitatory transmitter • Learning and memory • Too much = migraines or seizures – Why do people avoid MSG? Endorphins • • • • Resembles opiates in structure and effects Roles in pain relief and response to stress Regulation of eating behavior “Runner’s High” Monoamines • 3 neurotransmitters – Dopamine, norepinephrine, serotonin GABA and Glutamate • Consist of amino acids – GABA - produces only inhibitory postsynaptic potentials (PSP) – Glutamate – widely distributed in the brain, only has excitatory effects MAOI’s • Monoamine Oxidase Inhibitor • Antidepressants used to treat depression, anxiety, etc SSRI Antidepressants • Selective Serotonin Re-uptake Inhibitor • Anti depressant drugs (and some other illegal drugs like cocaine) – block the reuptake of neurotransmitters, keeping in the synapse longer, – intensifying their activity. – For some depressed people that elevates their mood. Nerves • Are long bundles of neurons that send and return messages to and from the body from the spinal column. Neural Networks • Neurons can communicate with hundred or thousands of other neurons simultaneously. • Neural networks can be built of visual, sensory, cognitive, emotional information drawn from throughout the brain and body. In other words… The brain processes the sensory info and decides what to do Sensory information enters the body through receptor cells Motor nerves receive commands from the brain and react The Nervous System • • • • Central Nervous System Peripheral Nervous System Somatic Nervous System Autonomic Nervous System – Sympathetic/Parasympathetic Nervous System The Central Nervous System • Brain and spinal cord – Memory tip: Brain and spinal cord are located in the center of the body CNS • 40 billion neurons • Each having 10,000 contacts with other neurons • 400 trillion synapses • One grain of sand size speck of your brain contains 100,000 neurons CNS – The Spine • Reflexes – automatic responses to stimuli • Pain example – Sensory of heat from flame travels to spine, interneuron in spinal cord, respond by activating motor neurons leading to the muscles in your arm The Peripheral Nervous System • Sensory and motor neurons that connect the CNS to the rest of the body – Everything else outside the brain and spinal cord – Memory tip: Fingers and toes lie in the outermost areas of the body from the center, or the periphery of the body The Somatic Nervous System • Part of the peripheral that controls skeletal muscles – Memory tip: Volunteer work is done by choice, so the body’s voluntary actions are controlled by this nervous system The Autonomic Nervous System • Part of peripheral that controls glands and the muscles of internal organs (like the heart) – Sympathetic division of nervous system arouses – Parasympathetic division of nervous system calms • Purpose to bring you back to homeostasis The Autonomic Nervous System: An Opponent-Process • They work in opposition to one another – What’s another opponent process we’ve talked about in the past few days? (Think neural impulse…) The Endocrine System • If nerves are the speedy highway of communication – hormones are snail mail • Endocrine system – slow chemical communication, set of glands that secrete hormones into the bloodstream – Hormones: chemical messengers travel through bloodstream and affect other tissues – Endocrine = inside (pancreas, testes, ovaries, bloodstream) – Exocrine = outside (salivary glands, tear glands, sweat glands) Hormones • Chemical messengers (snail mail) • Influence hunger, sex, aggression, etc – Some are chemically identical to neurotransmitters (like norepinephrine) What’s the difference between a neurotransmitter and a hormone? • They are the same! • The only difference is based on where they’re manufactured – Neurotransmitters are in neurons – Hormones are in glands and based in the bloodstream The Endocrine System: Adrenal Glands • Autonomic nervous system gets its orders from the adrenal glands – Located on top of the kidneys – Releases norepinephrine and epinephrine • Called noradrenalin and adrenalin during flight-or-flight response The Master Gland: The Pituitary Gland • Pea sized located in the core of the brain – It is controlled by the hypothalamus – releases hormones that promote growth as well as generally managing the rest of the endocrine system • The master gland – For instance – the pituitary gland tells the sex glands to release sex hormones to have… sex Important glands and hormones they secrete • Anterior pituitary gland – Secretes growth hormone • Too little produces dwarfism, too much produces gigantism • Posterior pituitary gland – Secretes vasopressin and oxytocin • Constricts blood vessels and raises blood pressure • Oxytocin in women sparks labor during pregnancy • Thyroid gland – Releases thyroxin and triiodothyronine • Increases metabolic rate, growth, and maturation • Parathyroids – Releases parathyroid hormone • Increases blood calcium and decreasing potassium • Pancreas – Secretes insulin • Regulates the level of sugar in the bloodstream • Why do diabetics see the a doctor called an endocrinologist? • Ovaries – Secrete estrogen • Promotes ovulation and female sexual characteristics • Testes – Release androgens (testosterone is one type of androgen) • Produces sperm production and male sexual characteristics