Chapter 3 - Biopsychology Class Notes

CHAPTER 3: Biopsychology Biapsychology: biopsychology explores the biological mechanism that underlie benawor Lastudies gonerics. focusing on now inneriied genes can affect not just the physiclogical, but psychological traits of a person La Studies the structue + function of the nervous system L Studies how ine nervous system interaces mi tue endocrine system Human Genetics: Studying human genetics can help researchers understand tue biological basis underlying the aifferent benauors, thougnis and reactions of humans Theory of Evolution: Charles Darwin explored the concept of inheritance of traits througnout generations in his theory of evolution through natural selection • tue organisms better sulted for their environment will Survive and reproduce, while those that are poorly suited for their environent will die off. Characterishes that affect survival /reproduction: 1. those that help protect aganst predators Theory of Evolution: 2. those that increase access to food •genes + DNA change to heip 3. thase that help offspring stay drive Us survive "It is not the strangest of the species that survives, nor tve most intelligent that survives. It is the one tatis mast adaptabe to change.* - Charles Darwin Genetic Variation the genetic difference between individuals contributes to a species adaption to its environment • begins when an egg (23 chromosomos) is fertilized by a sperm (23 chromosomes) Chromosome: long strand of genetic information known as DNA Deoxyribonucieic Acid: DNA helix shaped molecule made of nucreatide base pairs (sequences of DNA make genes) Gene: sequence of-DNA that controls or partially controis physical characteristics known as traits (eve color. hair color, etc) La gene may havemultiple possible variations or alleres(a specific version of a genes Genotype vs. Phenotype: •genotype refers to the generc makeup of an individual based on the DNA inherited from one's parent phenotype describes an individual's obsenvable characieristics, such as hair color. Syin color, height, and build Dominant vs. Recessive Alleles polygenic traits: inneritable traits controlled by more than one gene however, some traits are controlled by only one gene alleles con be dominant or recessive L dominant = always result in expression of that phenotype (Aa or AA) recessives only physically expressed if the person is homozygous for that Allele (aa) heterozygous: consisting of 2 different alleles (Aa) homozygous • consisting of 2 identical alleles (AAor aa) Punnett Square • Used to predict how genes will interact in the production of offspring • Mutations: sudden, permanent change in gene Gene• Environment Interactions Nature + Nurture work together like complex pieces of a human puzzie, the interaction of our enuironment and genes makes Us the individuals we are Range of reaction- asserts our genes set the boundaries within which me com operate, and our environment interacts with the genes to determine where in that range we fall genetic environmental correlation- view of gene-environment interaction that asserts asserts our genes affect our environment and our environment influences tue expression of our genes epigenetics- study of gene-environment mieractions such as how the same genotype leads to different pronotypes The Neuron • the function of a neuron is aided oy specific aspects of its structure • Semi-permeabe membrane allows smaller molecures or molecules wo electrical charge to pass through, while stopping larger or hignly charged molecues incoming electrical signais from other neurons are received by the dendrites which then send Hesignal down the axon • axons are covered in myelin sheath made of fatty substance that insulates axons + allows the signal to travel down the axon quicker •at the end of the axons are terminal buttons which contain synaphe vessels (storage sites for chemical messengers called neurotransmitters The Synapse • the synapse is the space between the terminal button of one neuron + tue dendrite of another neuron Action Potential 1. Neuro transmitters from nearby neurons attach to receptors on denantes causing the membrane porential to change deporarization - membrane potential becomes less negative making tve neuron more likely to fire (excitation) hyperpolarization- membrane potential becomes more negative making tre neuron less likely to fire (inhilormon) 2. If level of charge reaches excitation an action potential will occur. lon channeis open causing Na+ to rush into the cell and the inside to momentarily become more positive threshold of excitation- level of charge in the membrane that causes the neuron to become active • acton potential - an electrical signal -action potentials act on an all-or-none principle - the incoming signal is either sufficient to reaon the threshold ofexcitation or wis not → during action potential, the electrical charge across tue membrane changes drastically Reuptake • once an action potental has occurred, excess neurotransmitters in the synapse either drift away, are broken down or reals orbed - reuptake involves moving a neurotransmitter from the synapse back into the axon terminal from which it is released • reuptake inuones moung a nuerotransmitter from the synapse back into the axon terminal from which it was released Neurotransmitters Neurotiansmitter: Chemical messenger of the nervous system L different neurons release different types of neurotransmitters that haue many different functions Biological Perspective: view that psychological disorders like depression + scrizophrenia are associated with imbalances in one or more neuromansmitter systems Acetylcholine- muscle action + memory Beta-endorphin- pam + preasure • dopamine. mood, sleep + leaming norepinephrine - heart, intestines + alertness • serotonin- mood + sieep - Gamma-aminobutyric acia (GABA) - brain function+ steep • glutamare- memory + leaming