6465039
Descripción
Fichas por Madeline Luedke, actualizado hace más de 1 año
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Creado por Madeline Luedke
hace alrededor de 8 años
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| Pregunta | Respuesta |
| Two kinds of cells in nervous system | 1. neurons 2. glial cells |
| Neurons | nerve cells, specialized for reception, conduction, and transmission of electrochemical signals |
| Glial cells | support, protect, and insulate • outnumber neurons 10:1 |
| Four types of neurons | 1. unipolar 2. bipolar 3. multipolar 4. multipolar interneuron |
| sensory neurons | • sensitive to the environment • convert incoming physical stimuli to an electrical signal, then send it to CNS |
| interneurons | nerve cells within the CNS (go in between) |
| Motor neurons | transmit outgoing signals from CNS to muscles, to make behavioral response |
| 3 common features of neurons | 1. dendrites: branches, detectors 2. soma: cell body with nucleus 3. axon: path from soma to the terminal buttons |
| extracellular fluid | • salty bath that surrounds neurons take in oxygen, nutrients and drugs elimate waste |
| Terminal buttons | small buttons next to cell "neighbors" • contain synaptic vesicles: packets of neurotransmitters "water balloons" |
| What is myelin made out of | coiled glial cell layer |
| Four classes of glial cells | 1. schwan cells 2. oligodendrocytes 3. astrocytes 4. microglia |
| schwan cells (glial cell) | insulates peripheral nerves: muscles, organs, glands |
| oligodendrocytes | insulates central nervous system |
| astrocytes | largest glia, star-shaped, many functions |
| microglia | involved in response to injury or disease |
| nodes/ranvier | breaks in insulation to allow access to outside chemicals to replenish signal strength |
| Saltatory Conduction | electricity travels fast then stop to replenish • salta means to leap |
| Cell body (soma) | • metabolic care of neuron • synthesizes proteins • contains chromosomes/genes |
| Transcription factors | turn on appropriate genes to make proteins |
| Axoplasmic transport | new proteins travel where needed inside microtubles which takes them there and back |
| Resting membrane electrical potential | -70mV |
| polarized | carries a charge at rest |
| Sodium | (Na+) • lives outside • pushing inward • 50mV b/c it's less crowded inside • 70mV b/c it's attracted to negative • 120mV inward |
| Chloride | (Cl-) • balanced • 70mV inward b/c it's crowded outside • -70mV inward b/c like repels like |
| Potassium | (K+) • 90mV outward b/c it's crowded inside • repels by positive outside • made inside |
| Negatively charged proteins | (A-) • can't move outside |
| Factors contributing to even distribution | 1. random motion (diffusion) 2. electrostatic pressure |
| Factors contributing to uneven distribution | 1. only certain ions can fit through pores called ion channels (passive, takes no energy) 2. sodium-potassium pumps (active, takes energy) |
| Sodium-potassium/maintenance pump | 3 NA+ out and 2 K+ back in |
| Threshold for firing | -50mV • become less negative: depolarized |
| 3 stimulations that open an ion channel | depolarization: closer to threshold, open Na+ channels, excitatory hyperpolarization: further from threshold, open Cl- /K+ channels, inhibitory |
| What local potentials have in common | 1. Graded reaction (loud/insistent vote) 2. rest after stimulation 3. activity decays rapidly 4. summation/integration |
| local vs action potential | 1. grade v all or nothing 2. decremental (diminishes over distance) v non-decremental 3. spatial (frequency) and temporal (multiple neurons) summation v intensity of stimulus coded by rate of firing 4. produced by opening of ligand-gated channels v opening of voltage-gated channels |
| what are the 3 phases of action potential | 1. rising 2. re-polarization 3. hyper-polarization |
| The steps of action potential | 1. Na+ channel opens (-70mV to -50mV) 2. K+ channel opens to slow down depolarization 3. At 1ms Na+ channels close to begin repolarizing 4. K+ doors close late causing hyperpolarization |
| Absolute Refractory Period | impossible to initiate another action potential (1-2ms after) |
| Relative Refractory Period | harder to initiate another action potential (varies, only with extra stimulation) |
| Refractory Periods | • post-action potential • for cell to rest • limits rate of firing • prevents backward movement of AP |
| Summary | 1. neuron membranes have resting potential (charge) 2. incoming signals (ESPS & ISPS) at a neuron's receptor areas can locally change the charge 3. These incoming PSPs are transmitted passively to place at border between axon hillock & axon 4. That area summates/integrates PSPs and decides AP or nah 5. If yes, Na+ channels open and the signal jumps down axon (saltatory conduction) toward terminal buttons |
| Medial | towards the middle |
| Lateral | towards sides |
| Dorsal | • towards back • top of head |
| posterior | • towards feet • back of head |
| Ventral | • towards belly/front • bottom of head |
| Anterior | • toward head/up • front of head/face |
| Horizontal plane | • cut top and bottom in half A _____________ B |
| Sagittal Plane | • cut right and left side of brain | A | B | |
| Coronal Plane | • cut front and back of brain • garage door hitting you |
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