Ch 3 Frontal lobe affects behavior Biological psychology o Organization of the nervous system o The neuron Communication Drugs o Brain structure and function The nervous system o Function gather and process information Produce responses to stimuli Coordinate the workings of different cells Uses nerve cells or neurons and glia glial cells Sensory Motor Inter o Central and Peripheral nervous system o Central brain and spinal cord o Peripheral autonomic involuntary action and somatic voluntary action Handles input sensory nerves and output motor nerves o Somatic nervous system consists of nerves that are connected to sensory receptors Sense the world Act voluntarily o Autonomic system regulates internal organs and glands Involuntary breathing digestion anything you can t control Sympathetic system mobilizes bodily resources and increases the output of energy during emotion and stress High energy usage Prepares for fight or flight o Pupils open o Pulse quickens o Adrenaline released Parasympathetic system operates during relaxed states conserves energy Conserves energy Prepares for rest o Pupils constrict o Pulse slows o Communication Neurons o Basic unit of the nervous system o Cells that receive and transmit information o Communicate via electrochemical signals o There are many different types of neurons o Excitatory or inhibitory Glia o Support nurture and insulate neurons o Remove debris when neurons die o Formation and maintenance of neural connections o Modify neuronal functioning Otto Loewi o Father of neuroscience o Discovered frog hearts communicated chemically Structure of neurons o Dendrites receive information from other neurons and transmit it toward the cell body o Cell body the part of the neuron that keeps it alive and determines whether or not it will fire o Axon a neuron s extending fiber that conducts impulses away from the cell body and transmits them to other neurons May be relatively short four thousands of an inch or relatively long a few feet Axons may be insulated by a layer of fatty material called the myelin sheath Composed of glial cells Segmented nodes of ranvier Myelination reduces confusing signals from nearby neurons o Speeds things up o Occurs throughout your life o Symptoms of multiple sclerosis o How a neuron fires One neuron stimulates another Stimulation causes a change in electrical potential between the inside and the outside of the neuron Negative on the inside positive on the outside Sudden momentary inflow of Na ions followed by outflow of K ions creates an electrical impulse Action potential brief change in electrical voltage that occurs between the inside and the outside of an axon when a neuron is stimulated and which serves to produce an electrical impulse All or none either happens or it doesn t Hyperpolization refractory period must reset to fire again AP steps Resting potential 70 mv sodium potassium pump keeps Na outside and K inside the cell Depolarization sodium gates open and Na enters Threshhold 55 mv reached with influx of Na Action Potential peak 40 mv Repolarization sodium gates shut potassium gates open Na stops coming in and K leaves Refractory period overreaction 90 Resting state Na K o Pump regains balance 70 Impulse reaches the axon terminal the end of an axon from which the axon releases its message The axon terminal has within it several synaptic vesicles containing a neurotransmitter Neurotransmitter a chemical substance that is released by a transmitting neuron at the synapse and that alters the activity of a receiving neuron Synapse the site where transmission of a nerve impulse from one nerve cell to another occurs includes o The axon terminal o The synaptic cleft the space in between neurons o Receptor sites in the membrane of the receiving cell which are specialized to receive specific messages What happens to the neurotransmitter after action potential o NT released from presynaptic membrane o NT crosses synaptic cleft o Binds to postsynaptic receptors o Excitatory More action potentials Na enters cell o Inhibitory Fewer action potentials K leaves cell Chemical messengers o Neurotransmitters Serotonin Affects neurons involved in sleep appetite sensory perception temperature regulation pain suppression and mood Dopamine Affects neurons involved in voluntary movement learning memory emotion pleasure or reward and possibly response to novelty Related to Parkinson s Acetylcholine Affects neurons involved in increased heart rate and the slowing of intestinal activity during stress and neurons involved in learning memory dreaming waking from sleep and emotions Gaba The major inhibitory neurotransmitter in the brain Glutamate o o The major excitatory neurotransmitter in the brain Neurotransmitters can be problematic if too high or too low Can affect and be affected by behavior Endorphins Chemical substances in the nervous system Similar in structure and action to opiates Involved in pain reduction pleasure memory Levels go way up when under stress May also contribute to attachment falling in love Hormones Endocrine glands produce and release hormones into the bloodstream Melatonin a hormone secreted by the pineal gland that is involved in the regulation of daily biological rhythms Oxytocin a hormone secreted by the pituitary gland that stimulates uterine contractions during childbirth facilitates the ejection of milk during nursing and seems to promote in both sexes attachment and trust in relationships Adrenal hormones hormones that are produced by the adrenal glands and that are involved in emotion and stress Sex hormones hormones that regulate the development and functioning of reproductive organs and that stimulate the development of male and female sexual characteristics include androgens estrogens and progesterone Drugs o Effects of drugs on the brain Disrupt ion flow across membrane Saxitoxin paralyzer Tetrodoxtoxin secretion of a puffer fish Affect amount of neurotransmitter available in the synapse by Disrupting neurotransmitter release o Prevent release Botulinum toxin o Increases release alcohol Disrupting neurotransmitter binding o Block action of neurotransmitter Drugs used to treat schizophrenia o Mimic action of neurotransmitter Heroin and other opiates Nicotine caffeine alcohol Preventing reuptake of neurotransmitter o Amphetamines and cocaine o Some anti depressants SSRIs o Nerve gasses sarin and some insecticides Preventing neurotransmitter from being synthesized or stored in vessicles Black widow