Mamm. pays cells (1)

  1. 4 major types of tissue
    • epithelial
    • connective 
    • muscle
    • nervous
  2. what is the epithelial tissue?
    characteristics = 1 or more layers of densely arranged cells with very little ECM

    • Functions
    • 1. conversand protects body
    • 2. lines body cavities
    • 3. movement substances, glandular activity (secretory)

    Where found = skin, lining got respiratory tract, digestive tract, glands of body
  3. what is connective tissue?
    characteristics = few cells surrounded by lots   of ECM 

    • Functions =
    • anchor
    • supports body functions
    • structure
    • transport
    • metabollic support

    where its found = bone, tendon, blood, fat

    ECM = made of fibres in a protein and polysaccharide matrix, secreted and organized by the cells in the ECM (fibroblast)

    Except for blood cells, all connective tissue cells (fibroblasts) secrete ECM molecules like collagen to give support and structure

    If the ECM is calcified
    = makes teeth or bone

    • Specialized forms of ECM
    • tendons
    • cartillage

    • general connective tissue = loose or dense

    • the cells sit in a matrix made of:
    • glycoproteins
    • fibrous proteins 
    • glycosaminoglycans
  4. what is muscle tissue?
    characteristics = long fibrelike cells

    • Functions
    • can contract and generate force

    • Where its found:
    • heart
    • skeletal muscle
    • surrounding hollow organs like bladder and uterus

    • 3 types of muscle cells:
    • 1. skeletal
    • 2. cardiac
    • 3. smooth
  5. what is nervous tissue
    Characteristics = cell specialized for sending nerve impulses

    • Function
    • initiate and transmit electrical impulses

    • Where is it found?
    • brain
    • spinal cord
    • nerves
  6. homeostasis
    body adjusts variable to maintain a "set point" in an acceptable or normal range

    • Examples=
    • temperature regulation
    • regulation of blood CO2 levels
    • regulation of blood glucose levels
  7. homeostasis functioning in glucose metabolism

    • body will make an adjustment to slow glucose uptake and keep more in the blood stream
    • more glucose = released by liver
  8. what are the basic components of homeostatic mechanisms?
    sensor - detects and reacts to any changes from normal set point

    intergrating or control - information is analysed and if needed, a specific action is initiated

    effector mechanism - brings about the change to return to the set point

    feedback - process of information about a variable constantly flowing back from the sensor to the investigator
  9. negative feed back control systems
    • are inhibitory
    • act to reset physiological variables
    • are responsible for maintaining homeostasis
  10. positive feedback controlling systems
    • are stimulatory
    • amplify or reinforce the change that is occurring
    • tend to produce destabilizing effects and disrupt homeostasis 
    • bring specific body functions to swift completion
  11. levels of control (3 types)
    • 1. Intracellular control
    • operates within cells
    • genes or enzymes often regulate cell process

    • 2. Intrinsic control (autoregulation)
    • regulation within tissues or organs
    • may involve chemical signals 
    • ex. growth factors in ovaries

    • 3. Extrinsic control
    • regulation from organ to organ
    • may involve nerve signals
    • may involve endocrine organs (hormones / glands)
  12. connective tissues: structures and types
    Image Upload 1
  13. what are some dense connective tissue?
    • tendons
    • ligaments

    main cell type: fibroblast
  14. adipose connective tissue
    • cell types:
    • white = single droplet lipid
    • brown = multiple droplet lipid

    where found = depends on age and sex
  15. blood connective tissue
    • plasma matrix
    • free blood cells

    where? = in blood and lymph vessels
  16. supporting connective tissue
    • Cartillage
    • light an flexible

    found in = trachea, ear, spine, nose

    • Bone
    • calcified
    • rigid
  17. supporting connective tissue map
    Image Upload 2
  18. mobile connective tissue
    • blood cells:
    • red blood cells = transport O2 and CO2
    • white blood cells = fight invaders

    macrophages = fight invaders
  19. fixed connective tissue
    • macrophages = fught invaders
    • adipocytes = store energy in fat
    • fibroblasts = most common connective tissue
    •                    synthesize the matrix
  20. muscle tissues
    • contractile = force  and movement
    • signal conduction
    • 3 types = cardiac, smooth, skeletal
  21. skeletal muscle components
    • nucleus
    • muscle fibre (cell)
    • striations
  22. cardiac muscle components
    • striations
    • muscle fiber
    • intercalated disks
    • nucleus
  23. smooth muscle components
    • muscle fiber 
    • nucleus
  24. nervous tissue
    • neurons send signals
    • excitable
    • electrical
    • chemical

    glial cell support
  25. characteristics of 4 tissue types
    Image Upload 3
  26. how do cell gain functional anatomy?
    by cell differentiation
  27. how does cell differentiation occur?
    by the control of gene expression
  28. cell maturation by differentiation
    • as cells mature, they differentiate
    • embryo cells (blastocyst) are not yet differentiated = totipotent
    • totipotent cells = can form any cell type in the org. of the embryo
    • In adults, the stem cells = pluripotent cells 
    • pluripotent cells = true embryonic cells since they've gone through growth

  29. where in the body you can find adult stem cells?
    • in the gut
    • bone marrow
  30. promise of stem cells (2 reasons)
    1. undifferentiated cells = give rise to all cell types

    • 2.highly proliferative = self renewing 
    •                                   large quantities can be produced for medical reasons like repairing damaged tissue
  31. why is stem cell therapy being developed?
    • to treat diseases and injuries
    • ex.spinal cord injury, CVD, Alzheimer's
  32. how do we isolate stem cells?
    by therapeutic cloning
  33. what is the danger of this method? what is an advantage?
    • cells could not be reprogrammed easily
    • DNA could have mutation
  34. spinal cord restauration suing stem cell therapy in rats
    • Dr. Douglas Kerr used a rat model to show that stem cell therapy is a viable treatment to restore function to damaged nerve cells
    • ESC were injected into rat spinal cord fluid who model nerve disease
    • stem cells did not regard but restored the environment to prevent further damage
  35. functional anatomy of cells
    • all eukaryotic cells have 4 major structures:
    • 1. plasma membrane
    • 2. cytoplasm
    • 3. nucleus
    • 4. organelles
  36. cell membrane structure
    • plasma membrane = encloses the cell
    • organelle membranes = sacs and canals made of the same material as plasma membrane that encloses organelles such as the ER and the Golgi
    • lipid bilayer of phospholipids
  37. how do membranes function?
    • control transport in and out of cell urinary system
    • ex. water channels
    • allow secretive receptivity and signalling via transmembrane receptor endocrine
    • surface glycoproteins - immune system
    • anchor for cytoskeleton or ECM = imp. fr movement and tissue structure
    • cell signalling provides sites for binding and catalysis of enzymes
    • provides a passageway across the membrane for certain molecules like gap junctions
    • cell to cell communication
  38. surface glycoproteins and immune survaillance
    • self markers (MHC)
    • identifying cells for the immune 

    • self tolerance
    • ability for our immune system to attack foreign cells but spare our own 

    • non self markers
    • molecules on the surface of foreign cell or particles act as flags to the immune system
  39. functions of proteins in cell membranes
    ex. unrinary system

    structure = protein channel

    • function 
    • controlled transport of water soluble molecules
    • ex. Na and K
    • specificity
    • can open or close gated channels
  40. what happens in dehydration or increase salt concentration?
    initial response = release of ADH

    ADH acts on the distal tubule of the kidneys to increase water permeability by inserting aquaporin channels into cell membranes

    water moves out of the distal tubes of the kidneys by osmosis through these channels thus ↓ osmolarity

    overall affect is an ↑ water reabsorption by the kidney and a ↓ in urine flow
  41. endocrine system
    structure = membrane receptor

    • function = when bound by a ligand triggers intracellular signalling cascade that will alter intracellular activities
    • ex. FSH receptor 

    • 1. first messenger = an extracellular chemical messenger
    • 2. binding of an extracellular messenger to receptor activates a G protein, the alpha subunit of which shuttles to and activates adenylyl cyclase
    • 3. cycle AMP (the 2nd messenger) will activate PKA, which will phosphorylate a particular protein
    • 4. phosphorylation changes the shape and function of proteins
    • 5. there will be a cellular response
  42. functions of proteins in cell membranes in cell adhesion
    structure = intergral membrane proteins

    • functions:
    • binds other integral proteins to form cell-cell concentrations
    • binds ECM to give structure to tissues
  43. what are integrins?
    • an example of structural adhesion proteins
    • join cell to cell or cell to ECM
    • heterodimer made of alpha and beta units
    • integral proteins
    • involved in wound healing, angiogenesis, embryo attachment, cancer invasion
  44. what integrin is involved in embryo attachment?
    integrin alpha6
  45. what is the cytoplasm?
    gel like substance of cells that includes many organelles suspended in water materials fluid called cytosol
  46. what are the 2 groups of organelles?
    • 1. membranous organelles
    • specialized sacs or canals made of cell membrane
    • ex. Golgi, ER, plasma membrane, lysosome, proteosome

    • 2. Non membranous organelles
    • made of microscopic filaments or other non membranous materials
    • ex. cytoskeleton, ribosomes, cilia, flagella, nucleolus (imp. for formation of ribososmes)
  47. endoplasmic reticulum
    • structure 
    • made of canals with membranous walls present through out the cytoplasm
    • extend from the nucleus to the plasma membrane 

    • Functions
    • proteins move through canals
    • make proteins
    • transport proteins

  48. 2 types of endoplasmic  reticulum
    • Rough
    • ribosomes are found on the outside of the membrane walls
    • ribosomes make proteins
    • functions in cell synthesis and intracellular transportation
    • transports porteins to the Golgi

    • Smooth
    • does not have ribosomes on membrane walls
    • makes certain lipids and carbs
    • makes membrane for use through out the cell
    • removes Ca++ from cells interior for muscle contraction and hormone production
  49. how does the ER work?
    • ribosomes on the Er make proteins
    • these proteins move through the canals of the ER
    • they're then folded and assembled into macromolecular groups

    proteins = designed for cell export and cell membrane (RER)

    the proteins then go to the Golgi complex to be modified
  50. what are ribosomes?
    • protein factories
    • many are attached to the RER and are just in the cytoplasm
    • ribosome = non membranous structure made of 2 pieces
    • a large subunit + a small subunit
    • each subunit is composed of RNA (ribosomal RNA)
    • free ribosomes make proteins for domestic use
    • attached ribosomes make proteins for export
    • working ribosomes form groups know as polyribosomes

  51. Golgi
    • Structure
    • membranous organelle consisting of cristernae stacked on one another  and located near the nucleus

    • Function
    • processes and packages protein molecules from the endoplasmic reticulum
    • proteins are modified by enzymes in the Golgi
    • processed proteins leave in a vehicle
    • contents may be secreted outside of the cell
  52. Routes of protein transport for export (ER → Golgi → plasma membrane)
  53. proteins are made on the ribosomes of the ER
    • they travel through the ER
    • leave the ER in vesicle that fuse with the Golgi
    • proteins are modified in the Golgi
    • vesicle fuses with Plasma Membrane for the release of the protein outside the cell
  54. organelle lysosomes
    • Structure
    • made of microscopic sacs that have "pinched off" from the Golgi apparatus

    • Functions
    • cell digestive/recycling system performed by enzymes
    • breaks down proteins, food particles,foreign particles (neutrophils) like bacteria, old organelle
    • Amino acids = recycled
  55. how is Tay-Sachs caused?
    its caused by a failure to produce enzyme needed to break down lipids-ganglioside (FA derivative found in all cell membranes)
  56. proteosome protein destroying unit
    • break down protein molecules 1 at a time by tagging each one with a  chain of ubiquitin molecules and unfolding it as it enters the proteasome, the breaking apart peptide bonds
    • short peptide chains exit the other end of the proteasome

    in Parkinsons disease, the proteasome system fails and improperly folded proteins kill nerve cells in the brain that regulate muscle tension

  57. mitochondria
    • Structure
    • composed of inner and outer membranes separated by fluid (matrix)

    • Function
    • powerhouse of the cell
    • catalyses seri A of oxidation reactions that provide 95% of cells energy supply
    • each mitochondrion has 1 DNA molecule, allowing it to produce its own enzymes and replicate itself

    • you can get mitochondrial diseases from the mother ONLY
    • ex. Parkinson, Alzeihmers and Diabetes inheritance

    muscle cells have a lot of mitochondria
  58. Nucleus
    • Structure
    • nuclear envelop made of 2 membranes each with the same molecular structure as plasma membrane
    • sourrounding nucleoplasm
    • nuclear enveloppe has holes called NUCLEAR PORES
    • this allows protein like transcription factors in and out of the nucleus
    • majority of cells has 1 nucleus
    • multinucleate cells = often associated with cancerous cells

    • Nucleus contains DNA which appear as the following:
    • 1. heterochromatin (genes off) = silent genes, tightly compacted
    • 2. euchromatin (genes on)= active sites of gene expression/transcription
    • 3. gene transcription = determines phenotype
  59. cytoskeleton
    • Structure
    • internal supporting framework made up of rigid, rodlike pieces

    • Functions
    • provides support
    • allows movement of cells and of proteins and organelles within the cell

    the cytoskeleton at mitosis and meiosis serves critical functions in chromatin movement and mechanisms
  60. cytoskeleton - micrcofilaments
    • smallest cell filament = microfilaments
    • made of thin, twisted strands
    • that lie parallel to long axis of cell

    microfilaments can slide past each other, causing shortening of the cell muscular contraction
  61. mechanism behind a contraction
    • the myosin heads bend with a strong force e when the bind the actin filaments
    • this pulls the thin filaments past them
    • each head releases and then pulls again
    • the pulling by the myosin heads and the sliding of the actin filaments is the essential movement of muscle contraction

    this is known as SLIDING FILAMENT MODEL
  62. cytoskeleton - intermediate filaments and microtubules
    • Intermediate filaments
    • are twisted protein strands slightly thicker than microfilaments
    • they form much of the supporting framework in many types of cells
    • ex. prtective layer of skin

    • Microtubules
    • are tiny
    • hollow tubes that are the thickest of the cell fibres
    • they are made of protein subunits arranged in spiral fashion

    Function = move things around in the cell

  63. centrosomes
    • an area of the cytoplasm near the nucleus that coordinates the binding and breaking of microtubules in the cell
    • plays an important role in cell division
  64. cytoskeleton - cell extensions
    • cytoskeletons form projections that extend the plasma membrane outward to form tiny, finger like processes
    • ex. microvilli formed from microfilaments
    • cilia and flagella formed by microtubules
  65. cytoskeleton- microvilli, cilia and flagella
    • Microvilli
    • found in epithelial cells that line the intestine and other areas of absorption
    • helps ↑ surface area

    • Cilia and flagella
    • cilia = shorter and more numerous than flagella
    • flagella = only found on human sperm cells

  66. cell connections (gap junctions)
    gap junctions hold cells together to form tissues

    3 categories:

    1. gap junctions = create communication bridges

    • 2. tight junctions = prevent movement of materials between cells
    • cells partly fuse
    • ex. intestinal tract
    • regulate when cels enter and exit

    • 3. anchoring junctions = cells attach to each other or to the ECM
    • ex. belt desmosome or spot desmosome
  67. desmosome
    skin cells are held together this way
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Mamm. pays cells (1)