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Unformatted text preview: BIOPSYCHOLOGY Ch. 2: Anatomy of the Brain • Blood-Brain Barrier : a mechanism that impedes the passage of many toxic substances from the blood into the brain o a consequence of the special structure of cerebral blood vessels o cells of the blood in brain are tightly packed, thus forming barrier to the passage of many molecules (proteins and other large molecules to be specific) o however, some large molecules are critical for normal brain function (eg glucose) o different parts of the brain have unique blood barrier ex. Sex hormones are rapidly entered in parts of brain involved in sexual behavior • Cells of the Nervous System : 2 fundamentally different types, neurons and glial cells) o NEURONS : cells that are specialized for the reception, conduction, and transmission of electrochemical signals External: • Cell wall : the metabolic center of the neuron; also called the soma • Cell membrane: the semi-permeable membrane that encloses the neuron • Dendrites : the short processes emanating from the cell body, which receive most of the synaptic contacts from other neurons • Axon hillock : cone-shaped region at the junction between the axon and the cell body • Axon : the long, narrow processes that projects from the cell body • Myelin : the fatty insulation around many axons • Nodes of Ranvier : that gaps between sections of myelin • Buttons : the buttonlike endings of the axon branches, which release chemicals into synapses • Synapses : the gaps between adjacent neurons across which chemical signals are transmitted Internal: • Endoplasmic reticulum : a system of folded membranes in the cell body; rough portions (with ribosomes) play a role in the synthesis of proteins; smooth portions (without ribosomes) play a role in the synthesis of fats • Nucleus : the spherical DNA-containing structure of the cell body • Mitochondria : sites of aerobic (oxygen-consuming) energy release • Microtubules : tubules responsible for the rapid transport of material throughout neurons • Cytoplasm : the clear internal fluid of the cell • Ribosomes : internal cellular structures on which proteins are synthesized; they are located on the endoplasmic reticulum • Golgi complex : a system of membranes that packages molecules in vesicles • Synaptic vesicles : spherical membrane packages that stores neurotransmitter molecules ready for release near synapses • Neurotransmitters : molecules that are released from active neurons and influence the activity of other cells Neuron Cell Membrane: • The cell membrane of a neuron is composes of a lipid bilayer : two layers of fat molecules o Embedded are numerous protein molecules that are the basis of many of the cell membrane’s functioning Classes of Neurons: • Multipolar neuron : more than 2 processes emanating from their cell bodies (most neurons) • Unipolar neuron : one process extending from cell body • Bipolar neuron : two processes extending from cell body •...
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- Spring '10
- Psychology, brain damage, neurotransmitter molecules, NT molecules