Week 8 List structure PDF

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Week 8 Structure List -

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Neuron (nerve cells) are structural units of nervous system - Large, highly specialized cells that conduct impulses - Special characteristics - Extreme longevity (lasts a person’s lifetime) - Amitotic, with few exceptions - High metabolic rate: requires continuous supply of oxygen and glucose - All have cell body and one or more processes - Cell body (perikaryon or soma) - Biosynthetic center of neuron - Synthesizes proteins, membranes, chemicals - Rough ER (chromatophilic substance, or Nissl bodies) - Contains spherical nucleus with nucleolus - In most, plasma membrane is part of receptive region that receives input info from other neurons - Nucleus - connection of cell bodies happens by nuclei - Nucleolus - center of nuclei of all neurons, synthesizes rRNA - Mitochondria - ATP production - Chromatophilic substance (nissl bodies / rough ER) - protein synthesis, found in cytoplasm of motor neurons (called nissl bodies) - Nissl bodies - holes around / surrounding rough ER Structure of a Motor Neuron

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Dendrites - receptive regions, Convey incoming messages toward cell body as graded

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potentials (short distance signals) Axon - vary for length of cell - Axolemma - nerve impulses transmit along this, is the neuron central membrane - Axon hillock - cone-shaped area, outside plasma membrane of axon, divides cell body from axon - Myelin - a whitish, protein-lipid substance - Function of myelin - Protect and electrically insulate axon - Increase speed of nerve impulse transmission - Myelinated fibers - segmented sheath surrounds most long or largediameter axons - Non-myelinated fibers - do not contain sheath, conduct impulses more slowly - Myelin sheaths - each cell can wrap up to 60 axons at once - Myelination in PNS - Formed by Schwann cells - Wraps around axon in jelly roll fashion - One cell forms one segment of myelin sheath - PNS - Schwann cells (neurolemmocyte) - formed by myelin sheaths - Nodes of Ranvier (neurofibril node) - gap between schwann cells (myelin sheath gaps), sites where axon collaterals can emerge - Saltatory conduction - neurotransmitters speed up in areas of myelin sheaths - CNS - Oligodendrocytes - their processes form myelin sheaths in CNS, not whole cells - Terminal branches (telodendria) - can have up to 10,000, where branches end, smaller extensions of axon collaterals - Axon terminal (synaptic knob / terminal bouton) - distal endings, where nerve impulses get transported to - Vesicle - hold neurotransmitters - Neurotransmitters - released in the axon terminal, chemicals that stimulate other neurons

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Brain

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Cerebrum (“the noodles” of the brain) - Cerebral hemispheres - form superior part of the brain, account for 83% of brain mass

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Frontal lobe - thinking, memory, behavior, and movement - Precentral gyrus (Primary motor cortex) - in front of

central sulcus Parietal lobe - language and touch - Postcentral gyrus (Primary somatosensory cortex) behind central sulcus - Occipital lobe - responsible for vision / sight - Temporal lobe - hearing, learning, and feelings - Insula - deep part of the brain, non-visible Brainstem - breathing, heart rate, and temperature - Similar in structure to spinal cord but contains nuclei embedded in white matter - Controls automatic behaviors necessary for survival - Midbrain - Pons - Medulla oblongata - continues into spinal cord -

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Diencephalon - part of hypothalamus (control center), center above brain stem Cerebellum - helps with posture, coordination, and balance - Right and left hemispheres - connected by vermis - Cerebellar hemispheres - Anterior lobe - bottom of the ❤ cerebellum - Posterior lobe - where brain stem articulates / comes out - Arbor vitae - “tree of life”, is myelinated and has white matter - Vermis - separates the right and left hemispheres of cerebellum

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Fissures / sulci

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Gyri - ridges - Precentral gyrus - motor cortex - Postcentral gyrus - somatosensory cortex - Cortex of the brain has gray matter (axons and somas) Sulci - shallow grooves - White matter Fissures - deep grooves Central sulcus - separates frontal and parietal lobes - Separates precentral gyrus of frontal lobe and postcentral gyrus of parietal lobe Lateral sulcus - outlines temporal lobes (b/w temporal and parietal lobes), like a little thumb line Longitudinal fissure - splits the cerebrum in half into left and right (separates 2 hemispheres) - If pull this fissure open, can see corpus callosum Transverse fissure - separates cerebrum and cerebellum Parieto-occipital sulcus - separates occipital and parietal lobes...