Biology 4 Eukaryotic cell; Nervous sys.txt

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Biology 4 Eukaryotic cell; Nervous sys.txt
2013-09-09 18:25:15
Biology Eukaryotic cell Nervous sys

Biology 4 Eukaryotic cell; Nervous sys.txt
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    • author "me"
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    • fileName "Biology 4 Eukaryotic cell; Nervous sys"
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    • Def necleolus
    • Region within the nucleus where rRNA is transcribed and Ribosomes assemble
  1. Def endocytosis, and types
    • Endocytosis: 1 method for cellular uptake of extracellular material
    • 1. Phagocytosis: eating, typically receptor mediated, few cells have capability
    • 2. Pinocytosis: drinking, more common, non-selective/specific uptake
  2. Def exocytosis
    Exocytosis: opposite of endocytosis
  3. Describe the ER structure, location, and functions
    • Structure: membrane bound organelle that is contiguous in regions with nuclear and cellular membrane
    • Location: rough ER close to nucleus, SER is distal to the nucleus
    • Fxn: RER to make all proteins which do not act in cytosol; SER make lipids, cholesterol, and steroids, minor detox
  4. Describe Golgi apparatus
    Golgi: membrane bound organelle which functions in organising and shipping protein received from rough ER
  5. What is a lysosome
    Intracellular vessicle which contains low pH and hydrolitic enzymes for macromolecular degradation. Used for both extra a and intracellular molecular degradation
  6. What is a peroxisome
    • It is a cytosolic vessicle
    • Can self replicate
    • Involved in production and degradation of hydrogen peroxide
  7. Def cytoskeleton
    Network of filaments involved in cellular structure and motility
  8. What are the two main components of the cytoskeleton
    • Microtubules - rigid, hollow tubes made of aloha and beta tubulin
    • Microfilaments - single filaments composed of actin
  9. Describe a microtubule structure and some functions
    • Individual filaments are composed of beta and alpha tubulin. 13 filaments align along side one another and form a tube.
    • Fxn: in flagella and cilia, in mitotic spindle
  10. Describe microfilament structure and some functions
    • Filament composed of action
    • Fxn: squeeze membrane during phagocytosis and cytokinesis, provide contractile force in muscle contraction.
  11. Describe an axoneme and function
    Axoneme: structure in cilia and flagella composed if 9 pairs of microtubules surrounding 2 individual microtubules in the center. Outer pairs of microtubules are connected with dynein protein. 9+2 arrangement (20 microtubules total)
  12. Def centrosome
    Major MTOC in which the negative end of the microtubel begins and the positive end grows outward from during mieosis/mitosis
  13. Name three types of cell junctions and describe them
    • 1. Tight Junction - water tight seal forming a barrier between cells (not the strongest junction)
    • 2. Desmosome - like spot welds between cells, hold them together, but no barrier
    • 3. Gap - tiny tunnels to allow ions and small molecules to move between cells
  14. Define the apical and basolateral surface of cells
    • Apical: surface facing lumen side of a cavity
    • Basolateral: surface facing the base, or opposite of apical
  15. Describe a mitochondria and how they are special
    • Role is to AcT as power house for cell - location of Krebs cycle
    • Has own circular DNA coding for own RNA and ribosomes, self replicating
    • No histones or nucleosomes
    • Maternally passed
  16. Describe the structure of a mitochondria
    • 2 phospholipid bilayers
    • Inner membrane forms cristae and is the location for electron transport chain
    • Space between outer membrane and inner membrane is called inter membrane space
  17. Describe the role of the ECM and location/derivation
    • To provide structural support, determine shape and motility, and affect cell growth.
    • Surrounds cells
    • Created by cell itself or fibroblasts
  18. What are the three types of intercellular signalling molecules and what system of signalling does each belong to
    • 1. Neurotransmitter - nervous system
    • 2. Local mediator - paracrine system
    • 3. Hormone - endocrine system
  19. Compare neuronal communication to hormonal
    • Neuronal - fast, specific/direct, and short distance
    • Hormonal - slow, indirect/specific, long distance
  20. Def interstitial fluid
    Fluid between cells
  21. What are the components of the nervous system, and what is its job
    • Brain, spinal cord, nerves, glia, special sense organs
    • Fxn: allow rapid communication across the body for muscle and glandular activation/inactivation
  22. Def neuron and unique qualities
    • Cell specialized in communication via electricity and chemicals
    • Do not divide
    • All energy from glucose
    • Do not need insulin for glucose uptake
  23. Define axon hillock
    Structure at the base of axon which hold the threshold limit
  24. What is the path of a signal through a neuron
    Signal - dendrite - axon hillock - axon terminal/ synapse
  25. Define resting potential and how it is made
    • Electrical gradient across the inside and outside of a cell membrane
    • Sodium potassium pump, pumps out 3 sodium and 2 potassium in at a rate equivalent to spontaneous diffusion to maintain an equilibrium and potential
  26. What are voltage gated channels work. How do they work
    • Integral membrane proteins which change confirmation in response to voltage flux and allow ions into the cell
    • Positive feedback/cascade
  27. Define depolarization
    Polarity reversal when voltage gated sodium channels open
  28. How are VG potassium channels different VG Na channels
    • Have a higher threshold for opening
    • Open later than na channels and in response to depolarization
    • Cause repolarization
  29. Describe the steps of an action potential
    • 1. Membrane at creating potential, sodium and potassium VGC are closed
    • 2. Sodium Chanel opens - depolarization
    • 3. Potassium channels open as sodium channels close
    • 4. Sodium channels close and open potassium channels cause repolarization and hyperpolarization
    • 5. Potassium channels close and membrane equillibrates through sodium potassium pump and passive diffussion
  30. Define syanpse,give two types and list differences
    • Synapse: neuronal structure which propagates nerve impulses from one neuron to the next
    • Electrical - uncommon, bidirectional, fast
    • Chemical - common, unidirectional, slower, helps prevent fatigue
  31. How do synapses and neurotransmitters work together
    • 1. Over 50 different NT
    • 2. 1 NT per synapse - will typically excite or inhibit
    • 3. A single synapse cannot change between excitory and inhibitory
    • 4. Some NT can excite or inhibit based on post synaptic receptor ie. Acetylcholine excites in smooth muscle, but inhibits in cardiac
  32. What kind of receptors do NT bind
    • Ion channels
    • Secondary messengera
  33. White vs grey matter
    White matter has myelin
  34. Define saltatory conduction
    Electrical signal jumping between nodes of ranvier as it propagates through an axon
  35. What are the 3 possible functions of a neuron
    • 1. Sensory ( afferent) - receive and transmit signals
    • 2. Interneuron - transfer signals between neurons (most common)
    • 3. Motor (efferent) - carry a signals to effectors (glands or muscle)
  36. Describe CNS components and overall fxn
    • Brain and spinal cord
    • Fxn: integrate signals between sensory and motor
  37. List components of the peripheral nervous system, fnx, and common neurotransmitter
    • Somatic - voluntary, external stimulus, skeletal muscle only (acetylcholine)
    • Autonomic systems - involuntary (hypothalamus), internal stimulus, 2 parts
    • sympathetic - fight/flight (epinephrine/norepinephrine)
    • parasympathetic - rest/digest (acetylcholine)
  38. List the structures of the 2 main structures of the CNS, their constituent structures and overall fxn of each main structure
    • Lower brain: medulla, hypothalamus, thalamus, and cerebellum - unconscious stuff, pain and pleasure, neccessary for life
    • Higher brain: cerbrum/cerebral cortex - stores memory and processes thoughts
  39. What function do sensory receptors provide?
    Transduction of physical stimuli to electoral signal
  40. List the structure as light travels through in the eye
    Cornea - anterior cavity - lense (which is tensioned by the ciliary muscles) - vitreous humor - Retina - rods and cones (cones = color)

    Iris: colored portion which gives shape to pupil
  41. Name the three regions of the ear and structure that seperates them
    Outer ear - tympanal membrane - middle ear - 3 bones ( maleus, incus, stapes) - inner ear -cochlea - organ of corti - hair cells
  42. Where are semicircular canals located and what is their function
    Inner ear, function in balance and spacial orientation