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Flashcards

MTD

Wannie Chisala Inglês 128 flashcards

Flashcards do conjunto (128)

  1. 1What kind of cells are found in the brain and what is their funcitonGilia = support brain cells provide nutrients and support
    Ependymal = like epethelial cells, line all internal surfaces of brain and ventricles
  2. 2What are the cells of the CNS and what is their function?1) Oligodendrocytes (short branching cells) = act as shwann cells and provide myeline sheath
    2) Microglial cells = immune cells of brain
    3) Astrocytes = provide nutrients and structural support
  3. 3Oligodenrocytes vs shwann cellsShwann cells in the periphery for myeline sheath
    Oligodendrocytes in the CNS for myeline sheath. Wraps around many cells
    Important for regeneration
  4. 4Where are the cell bodies of the motor neurones found and how does this differ to sensory neurones?- Cell bodies of motor neurones in spinal chord
    - Cell bodies of sensory neurones in dorsal root ganglion (can be myelinated and unmyelinated)
  5. 5What is an alpha motor neurone?- Classic
    - Multipolar
    Releases Ach
    Mostley PNS
    Large diameter and thick myelination
  6. 6Where is the ganglion in the sympathetic chain?Paravetebral ganglion
  7. 7What is the protective layer around each fibre?Endoneurium
    Perineurium surrounds each fasicle
    Epineurium around each nerve
  8. 8What is the importance of the axon hillock?Where all electrical information to neuron meets (point of summation)
  9. 9What kind of cells are bipolar?- e.g. in retina
  10. 10What kind of cells are unipolarSensory neuronese
  11. 11What causes multiple sclerosis?Degeneration of myeline (oligodendrocytes) in PNS
  12. 12What 2 factors determine speed of action potential down a nerve1) size of axon (increases with speed)
    2) Myelination
    3) temperature
  13. 13What is the composition of a myelin sheathLower protein than most cells
    more fat content to insulate against ion movement
    has lipids and proteins (myelin basic protein and associated glycoprotein)
    Forms a multilayered membrane
  14. 14What is the nernst equation?Works out membrane potential based on ion concs inside and outside of the cell if membrane was only permeable to that ion
    (MV)
  15. 15What is the membrane potential of NA++ 67mv
  16. 16What is the membrane potential of K+-95 mv
  17. 17What is the membrane potential of Cl-- 65mV
  18. 18What equation calculates total RMPGoldman-Hodgkin-Katz
    GHK equation
    Takes into account different permeabilities for different ions
    2:1 K+:Na+ (non-excitable cells)
    25:1 in excitable cells
  19. 19When are axosomatic synapses useful?Axon synapsing with body of another axon for presynaptic inhibition
  20. 20Describe how action potential is produced?1) In presynaptic neurone, action potential causes endocytosis through influx of calcium
    2) receptors at end cause influx of an ion, produces graded potentials to the hillock
  21. 212) Describe the ions involved in action potential- Na+ open
    - Na+ close, K+ open (+40mV)
    - K+ close
    - Na+ open
  22. 22What is saltatory conductanceAction potential jumps from node to node
  23. 23What is post synaptic densityDarker post syanptic membrane because of higher concs of receptors
  24. 24What are some excitatory neurotransmitters?Ach (on muscarinic metabotropic it is inhibitory)
    Glutamate (main one)
  25. 25What are some inhibitory neurotransmitters?GABA
    GLYSINE
  26. 26Spatial summation- EPSPs from many axons build up to reach action potential
  27. 27Temporal summationESPs from one axon build up to reach action potential
  28. 28What part of the spinal chord do parasympathetic nerves leave?Cranial and sacral region
  29. 29What part of the spinal chord do sympathetic neurones leave?From thoracic and lumbar region
  30. 30True or false, pre-ganglionic neuronal signals can affect a post ganglionic neurone in a different level of the synaptic chain?True
  31. 31What is agnostic action?Action of sympathetic and parasympathetic in one action
    - Erection is sympathetic
    - Ejaculation is parasympathetic
  32. 32True or false, parasympathetic effects are usually system wide effects?False, this is true for sympathetic action
    Parasympathetic usually targets one organ at a time because ganglion is so close to target tissue
    Phasic response, no information on duration of stimulus, More information on rapid changes in stimuli
  33. 33What is the one exception to the ganglion rule?Sympathetic innervatio of adrenal gland with long pre-ganglionic neuron (uses epinephrin)
  34. 34Why are sweat glands also an exceptional case to the rules?Sympathetic innnervation but release Ash and acts on muscarinic receptors
  35. 35Describe the 3 types of M3 receptors and their location?M1 = Neural, slow excitation of ganglia
    M2 = Heart
    M3 = Secretion e.g. in epethelia (CF) and gut
  36. 36Describe the features of smooth muscle- Spindle shaped, smaller than skeletal muscle and form sheets of inter connected cells
    - Single nucleus can divide throughout their lives
    - not striated in appearance
    - slower contraction
  37. 37How does skeletal muscle differ?- Multinucleated cells, unable to divide once differentiated into skeletal muscle
    - striated in appearence due to allignment of sarcomeres
    - somatic control
    - rapid contraction
  38. 38What is the structure of skeletal muscle- External lamina surrounds groups of cells allowing them to function as a single unit (collagen rich)
    - Grooves in external lamina are called caveoli
    - Sarcolemma is the specialized plasma membrane
    - Cytoplasm has tightly packed contractile protein filaments
    - Penicular Lucent Zone contains normal cell machinery
  39. 39What is the role of caveoli?- Increase SA of cell membrane and allow Ca2+ to concentrate in grooves
  40. 40Describe action potentials in smooth muscleSpread via gap junctions (signals communicated by Ca2+ waves)
  41. 41What are the 2 organisations of smooth muscle?1) Unitary = few cells recieve nervous input, actions spread via action potential
    2) Multiunit = each cell receives nervous input, cells electrically isolated and act independently, no gap junctions.
  42. 42Describe contraction of the multiunit?- No spontaneous contractions (phasic)
    - Contractions specifically controlled by ANS input
    - no gap junctions
    - Characterised by fast contractions
    - e.g. in eyes
  43. 43What are dense bodies and focal densities?Structures that attach to actin to provide stability during contraction (on actin)
    Where actin interacts with membrane = dense bodies
  44. 44What is the name of the movement that allows contractionADP + Pi
  45. 45How is smooth muscle contraction different to skeletal muscle contraction- Ca2+ comes from both intracellular and extracellular stores (caveoli and SR)
  46. 46Calmodulin vs TroponinIn skeletal muscle and Heart muscle = Troponin
    Smooth muscle = calmodulin
    both activate MLCK (myosin light chain kinase)
  47. 47What initiates relaxaitonMyosin phosphotase removes phosphate put on myosin by MLCK
    - Reduction in ATP hydrolyisis
  48. 48What kind of sugar is fructose?6-carbon ketose
  49. 49How are D and L sugars defined?Via the asymmetric carbon furthest from the aldehyde or keto group
  50. 50What is glucaronic acid?Present in many mucus secretions = glucose with carboxyl group
  51. 51What is Maltose made of?2 glucose
  52. 52What is lactose made of?Glucose and galactose
    - B 1-4 glycosidic bond
  53. 53What is sucrose made ofGlucose and fructose
  54. 54What kind of bond links monosaccharides?Glycosidic bond via condensation reaction
    Alpha if H on the same side
  55. 55Describe the structure of celluloseB 1-4 GLYCOSIDIC BOND IN D-GLUCOSE
  56. 56Describe the structure of glycogen?alpha 1 -4
    branched because every 6 glycogen is an alpha 1-6 bond
  57. 57What kind of amino acids are involved in o-linked bonds?- Serine and threonine
  58. 58What is the structure of a mucinGlycosylation of proteins alter properties
    Highly O-glycosylated
    They attract and retain water
    Polymerisation with other mucins via disulphide bonds
  59. 59Where is protein synthesis initiated?In the cytosol
  60. 60What type of proteins are synthesised from free ribosomes in the cytosol?- Cytosolic proteins
    - Mitochondrial proteins
    - Nuclear proteins
    - Peroxisomal proteins
  61. 61What targets proteins to ribosomes?SRP = PROTEIN RECOGNITION PARTICLE THAT BINDS TO AN SRP RECEPTOR ON THE RIBOSOME
    = allows ribosome to dock to ER
  62. 62What is the point of entry into the secretory pathway?Via the ER
  63. 63What is the function of the smooth ER- Lipid and lipid membrane biosynthesis
  64. 64What are the functions of the ER?Assembly and folding of all transmembrane proteins
    Processing of proteins to the golgi
    Site of post-translocation modification e.g. n-linked glycosylation (adding sugars)
    Disulphide bond formation (tertiary structure)
    Error checking
  65. 65Describe the structure and function of the Golgi- Proteins enter through the cis face and leave through the trans face
    - Modified in the cisternae
    - Sorts proteins for delivery to other parts of the cell
    - N linked and O-linked glycosylation
    - Oligosaccharide addition/ modificaiton
  66. 66How are vesicles transported in the cell?Via the cytoskeleton on vesicles coated with specialised protteins
    Cytoskeleton has microtubles that aid transport and act as track guides
    Bound to microtubules via motor proteins
  67. 67What are the 3 types of coated vesicles?1) COPI 1, from golgi all around the cell
    2) COPI 2, From ER to golgi
    3) Clathrin = from plasma membrane e.g. endocytosis and from golgi
    - Protein has receptor that allows it to be targeted to the correct place on the membrane that has the correct cargo receptor
  68. 68What is the result of the delta 508 mutation in CFProtein is folded incorrectly and released from chaperone protein
    Results in a deletion of phenylamine
    ER quality control send it to proteosome
    - Biosynthetic arrest
  69. 69Name some vesicle protein and receptor pairs?1) Rab on cytosolic membrane of vesicle binds directly to RAB
    2) V-SNARE proteins bind to T-SNARE receptors on membrane
  70. 70Describe the structure of epethelia?Attached to basal lamina (extracellular matrix)
  71. 71What are the specialised structures that link epethelial cells to each other and basal lamina?- Tight junctions
    - Anchoring junctions
    - Channel forming junctions
  72. 72What is the role of tight juncitons- occluding junctions that seal adjacent cells together and prevent lateral migration of membrane proteins
    - Create cell polarity
    - Allows correct movement of substances
  73. 73What is the role of anchoring junctions?- Provide mechanical stability
    - Anchor cells to the basal lamina or to other cells
    - Allows functioning as a cohesive unit
  74. 74What are the types of anchoring junctions?1) Actin filaments
    cell-cell = adherin junctions, cell to lamina = focal adhesions
    2) Intermediate filaments
    cell to cell = desmososmes, cell to basal lamina = hemidesmososmes
  75. 75Describe the structure and function of the basal lamina- Strong flexible foundation
    - Meshwork formed by interactions between type VI collagen and laminin
  76. 76What is the basement membrane?Basal lamina (type 4 collagen) and reticular lamina (mainly type 3 collagen)
  77. 77What is the role of the basement membrane?-Anchors epethelial cells to connective tissue
    - Mechanical barrier
    - Important in angiogenesis ( making new blood vessels)
  78. 78What are cuboidal epethelial cells used for?Tubes for secretion and transportation
    Found in glands ducts, kidney tubules and covering of overy
  79. 79What type of cells are in the digestive tractSimple collumnar
  80. 80What kind of cells are in the tracheacilliated pseudostratified collumnar
  81. 81What kind of cells are in the bladder?Transitional relaxed = bladder
  82. 82What kind of epithelium is in the skin?Keratinised stratified squamous
  83. 83What is the basal layer?- single layer of mitotically active cells
  84. 84What are some clinical features of CF- salty sweat (greater than 60mm)
    - infertility
    - reduced life expectancy
    - Reduced lung function
    - bowel obstructions
  85. 85What does Enac do in the sweat glandsPumps sodium into the cells, CFTR upregulates Enac to reabsorb NACL
  86. 86What is CF diabetes= Mucus in pancreas stops secretion of insulin
  87. 87What is meconeum ileusbowel obstruction causing failure to pass fecal matter
  88. 88Describe the structure of a virion?- capsid = protein shell
    - nucleocapsid = genome and capsid
    - envelop = lipid bilayer (derived from host cell)
  89. 89What are prions?Infectious proteins
  90. 90What is the coronal plane?Dissects body down centre, from crown of head
  91. 91What are the lines going down the body called?Sagital planes
  92. 92Describe the features of a cervical vetebrae- 7 vertebrae
    - spinous processes are bifurcated
    - has a foramen in each tranverse process
    - 7th cervical vetebrae has a fused spinous process
    (foramen transversarium)
    - made of vertebral body and posterior arch with a vertebral canal
    - smallest
    - body and posterior arch linked by pedicle
  93. 93Describe the thoracic verebrae?- 12 vertebrae
    - Posterior arch made by two lamina
    - Articulate with ribs
    - heart shaped vertebral body
    - Long transverse procces
  94. 94Describe the features of the lumbar vertebrae?- 5 lumbar vetebrae
    - largest
    - thin transverse process
    - has mamary processes on either side of the spinous process
    - oval shaped body
    (neural arch is process and vertabral foramen) everything except body
  95. 95Describe the features of the sternum?- Superior thoracic apeture at top
    - Suprasternal notch at top of menubrum (handle)
    - Sternal angle at T4
    - Sternal body
    - xiphoid process at T9/10
    - 7 TRUE RIBS 1-7
    - 3 FALSE RIBS 8-10
    - 2 FLOATING RIBS 11+12
  96. 96What joins ribs to sternal body and menubrum?- costal cartilege
  97. 97How do ribs articulate with the vertebra?Via demifacets
  98. 98Describe the structure of the ribs?- Head, neck and angle
    on neck there is a tubercle facet
    - costal groove on underside of rib containing veins and arteries
  99. 99How does the trachea split upTrachea
    R/L main bronchi (bifurcate at T4/5)
    Lobar bronchi
    Segmental bronchi
  100. 100How many lobes do the right and left lung have?R = 3 lobes
    L = 2 lobes
  101. 101Where is the mediastinal boundary of the pleura cavity?Back near the spine
  102. 102Describe structure of DNA5" TO 3"
    Phosphodiester bonds
    2nd carbon has no OH = increased stabilty, repels water
    anti-parallel strands
    minor and major grooves
  103. 103What are the types of histones and what are their roles?H2A, H2B, H3 + H4 make the nucleosome = to form chromatin
    H1A used to block ends of chromosomes, regulatory amino acid between nucleosomes
  104. 104When is reverse transcriptase usedRNA Viruses or telomeres
  105. 105What are some uses of RNA other than protein?small RNAs involved in RNA splicing
    LNC RNA involved in control of gene expression
    also small regulatory RNAs do this too
  106. 106How many genes does mitochondria have?13
  107. 107What are transposonsOld, virus like DNA in introns
  108. 108What are the monomers used to make DNA?dATP, dTTP, dGTP, dCTP
    Removal of 2 high energy phosphate groups provides energy
  109. 109What is needed for DNA replication- Primase make RNA primer
    - monomers
  110. 110What are the roles of DNA polymerase?5"to3" polymerase activity
    3"to5" exonuclease activity (remove RNA primer)
    5"to3" exonuclease activity
    DNA Ligase puts together sections of DNA
  111. 111What is the repliosome?All proteins in the transcription complex
  112. 112What is the role of topoisomerases?I = Breaks one strand
    II = Breaks two strands
    = stops tangles
  113. 113What type of RNA polymerase makes mRNAII
    I - rRNA
    III - tRNA and sRNA
  114. 114What is needed for transcripton?- No primer needed
    - TATA box in promoter region 20 bases upstream (2 helical turns(
  115. 115What are the post transcriptional modifications of rna- splicing
    - add cap to 5"
    -Add a poly-A tail to 3"
  116. 116What is the function of the cap protein- unusual methylated G residue
    - stops rna being recognised by degenerative enzymes
    - also acts as a signal to ribosomes
  117. 117What is the role of the poly A tail?added to 3" by enzyme poly a polymerase
    uses ATP to add A
    Stops RNA polymerase
  118. 118What types of RNA are involved in splicing?uRNA (U2+4)
    sn RNA
    use base pairing to find and excise introns
  119. 119What are multigene and super gene families?- Multigene = genes with common origin that still retain common function e.g. Hb and Ig
    - Supergene = genes with common origin that evolved different functions e.g. different receptors
  120. 120How are amino acids added to tRNAsvia aminoacyl-tRNA synthetase
    covalent bonds
    very specific
  121. 121Describe translation initiation?- mRNA binds to small ribosomal subunit
    - AUG is start codon for methionine
    - tRNA recognises this and minds
    - Large ribosomal subunit then binds
  122. 122what is the role of the kozack concensus sequenceincreases amount of transcripton
  123. 123Describe termination?UGA is stop codon
    No t-RNA for stop
    Termination factor cleaves the last amino acid from its t-RNA to release polypeptide
    Generates carboxyl-terminus of protein
  124. 124What is a non synonymous changePoint mutation = missense mutation
    Change at protein level
  125. 125synonymous changepoint mutation = no change at protein level
  126. 126What are the 2 types of chromatin?Euchromatin = active gens
    Heterochromatin = inactive genes (highly dense)
  127. 127How are histones used to target transcription and regulatory machineryAmino terminal tails of each histone protrude from the core
    Also used for disassembly for RNA polymerase
  128. 128How does sperm pro nucleus DNA structure differ?- No chromatin, spermine/dine remplaces it it (small + charges that allow it to pack together)
    - Large loops of DNA attached to annulus ring structure

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FlashCards sobre MTD, criado por Wannie Chisala em 08-01-2017.
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Wannie Chisala
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