PSYC 460 1st EditionExam # 1 Study Guide Chapter: 1 – 4Chapter 1 – Major issuesI. Definition of Biological Psychology- The study of the physiological, evolutionary and developmental mechanisms of behavior and experience. A. The different kinds of biological explanations of behavior- Physiological: relates a behavior to the activity of the brain and other organs- Ontogenetic: describes the development of a structure or behavior- Evolutionary: reconstructs evolutionary history of a behavior or structure- Functional: describes why a structure or behavior evolved as it did. II. Genetics and BehaviorA. The basics of Mendelian genetics, sex-linked and sex-limited genes, genetic changes- Autosomal genes: all other genes except for sex-linked genes- Sex-linked genes: genes that are located on the sex chromosome; referred to X-linked genes- Sex-limited genes: are genes that are present in both sexes (on autosomal chromosomes) but activated by hormones and so mainly have an effect on one sexB. Heredity and the environment – monozygotic vs dizygotic twins, adoption studies, and measures of heritability- Monozygotic: from one egg- Dizygotic: (fraternal) from two eggsi. Evolutionary Psychology1. Refers to a change in the frequency of various genes in a population over generations2. It also focuses upon the functional and evolutionary explanations of how behaviors are evolved- Altruistic behavior: a behavior that benefits someone other than the actorChapter 2 – Nerve cells and nerve impulsesI. Anatomy of neurons and glia - the structure of an animal cell The nucleus: a structure that contains the chromosomes The mitochondrion: structure that performs metabolic activities and provides energy that the cells requires  Ribosomes: sites at which the cell synthesizes new protein molecules Endoplasmic reticulum: network of thin tubes that transport newly synthesized proteinsto their locationII. The structure of a neuron, variations among neurons - Motor neuron has its soma in the spinal cord and receives excitation from other neuronsand conducts impulses along its axon to a muscle- Sensory neuron is specialized at one end to be highly sensitive to a particular type of stimulation (touch, light, sound, etc.)- Dendrites are branching fibers with a surface lined with synaptic receptors responsible for bringing information into the neuron - Cell body/soma: contains the nucleus, mitochondria, ribosomes, and other structures found in other cells- Axon: thin fiber of a neuron responsible for transmitting nerve impulses toward other neurons, organs, or muscles- Presynaptic terminals refer to the end points of an axon where the release of chemicals occurs for communication with other neurons- Afferent axon: refers to bringing information into a structure- Efferent axon: refers to carrying information away from a structure- Interneurons or intrinsic neurons are those whose dendrites and axons are completely contained within a single structureIII. The different kinds of glia- Microglia remove waste material and other microorganisms that could prove harmful to the neuron- Oligodendrocytes (in the brain & spinal cord) and Schwann cells (in the periphery of the body) build the myelin sheath that surrounds and insulates certain vertebrate axons- Astrocytes help synchronize the activity of the axon by wrapping around the presynaptic terminal and taking up chemicals released by the axon- Radial glia guide the migration of neurons and the growth of their axons and dendrites during embryonic developmentIV. The blood-brain barrier – the basics of why we need it and how it works- The immune system destroys damaged or infected cells throughout the body because neurons in the brain generally do not regenerate, it is vitally important for the blood brain barrier to block incoming viruses, bacteria, or other harmful material from entering- Active transport is the protein-mediated process that expends energy to pump chemicals from the blood into the brain- The blood-brain barrier is essential to health, but can pose a difficulty in allowing chemicals such as chemotherapy for brain cancer to pass the barrierV. Nourishment in vertebrate neurons- Vertebrate neurons depend almost entirely on glucose: a sugar that is one of the few nutrients that can pass through the blood-brain barrier- The body needs a vitamin, thiamine, to use glucose. Prolonged thiamine deficiency leadsto death of neurons as seen in Korsakoff’s syndrome, a result of chronic alcoholism that is marked by severe memory impairmentVI. All aspects of the nerve impulse- Resting potentialo At rest, the membrane maintains an electrical polarization or a difference in the electrical charge of two locationso The resting potential of a neuron refers to the state of the neuron prior to the sending of a nerve impulseo -70 millivoltso The sodium-potassium pump is a protein complex that actively pumps three sodium ions out of the cells while drawing two potassium ions into the cell- Action potentialo An action potential is a rapid depolarization of the neurono Hyperpolarization refers to increasing the polarization or the difference betweenthe electrical charge of two placeso Depolarization refers to decreasing the polarization towards zeroo The threshold of excitement refers to a level above which any stimulation produces a massive depolarization- The relevant gradients, the chemicals involved (sodium and potassium is all that’s mentioned at this point), the forces acting on those ions, - The all-or-none law o The all-or-none law states that the amplitude and velocity of an action potential are independent of the intensity of the stimulus that initiated ito If a neuron receives a signal of sufficient strength, it fires. If the signal is too weak, it does not fireo It is a propagated response – once triggered, fires to end without decreasing in sizeo Although an action potential is all-or-none, neurons convey info about stimulus strength by varying the rate at which they fire action potentials.- The refractory periodo After an action potential, a neuron has a refractory period during which time the neuron resists the production of another action potentialo The absolute refractory period is the first part of the period in which the membrane cannot produce an action potentialo The relative refractory period is the second part in which it takes a stronger thanusual stimulus to trigger an action potential- Propagation of the action potential, the