Four Tissue Types

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Lecture 02Cells and Tissues
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• Basic functional unit of life is the _______
• All are derived from pre-existing ________
• Bound by selectively permeable membrane
• Include various organelles
• Membrane bound organelles
• Non-membrane bound organelles

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Cell Membranes

• Semipermeable or selectively permeable
• What does this mean and why is it important?
• Fluid mosaic model of membrane organization
• Major components include lipids and proteins
• Phospholipids
• Cholesterol
• Proteins
• Attached Carbohydrate
• How are these compounds arranged and how does
  this account for semipermeable nature of membrane?

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• Movement of Substances in and out of cells
• Passive no energy required substances move
  from greater to lesser concentration
• No carrier required lipid soluble substances
• Carrier or special pore required polar or water
  soluble substances
• Active energy required from lesser to greater
  concentration
• Carrier involved
• Endocytosis and Exocytosis

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• 1. Movement of fat soluble substances across a
  cell membrane from greater to lesser
  concentration occurs by __________________
•  
• 2. Movement of glucose across a cell membrane
  from an area of greater to lesser concentation
  occurs by ____________________ transport.
•  
• 3. Proteins which attach either to the inner or
  outer surface of a cell membrane are
  _______________ proteins.
•  
• 4. An integral or transmembrane protein which
  allows passage of certain molecules through the
  membrane may be referred to as a
  ____________________.

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Cell Organelles

• Cytoplasm
• Organelles
• Nonmembranous contact with cytoplasm
• Membranous organelles surrounded by one or two
  lipid bilayer membranes

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• Membrane bound Cell organelles
• Nucleus
• Endoplasmic reticulum
• Vesicles
• Golgi apparatus
• Lysosomes
• peroxisomes
• Mitochondria

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Nucleus

• Large organelle with double membrane nuclear
  envelope
• Contains 46 human chromosomes
• outer membrane continuous with rough ER
• perforated by nuclear pores
• Nucleolus
• site of ribosome assembly

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• Non-membrane bound organelles
• Ribosomes
• Cytoskeleton
• microvilli
• Flagella/cilia

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• Cytoskeleton
• Lattice of protein fibers extending through
  cytoplasm
• Functions
• Movement
• support
• Cell shape
• Anchoring/movement of organelles, cell parts
• Anchoring cells together
• Constantly rearranged

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• Cytoskeletonal Filaments
• Microfilaments
• thinnest filaments (actin)
• Muscle contraction support microvilli
• Intermediate filaments
• several different proteins
• anchor organelles
• Thick filaments
• In muscle contain myosin interact with thin
  filaments
• Microtubules
• large cylindrical structures (composed of
  tubulin)
• flagella, cilia centrosomes

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Cilia and Flagella

• Function
• Movement
• adapted to move things out of areas like the
  respiratory tract
• Composition
• Both same basic structure cilia shorter
• Cilia oars
• Flagella - whip
• 92 arrangement of microtubules responsible for
  causing movement

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Cilia on Airway Epithelium
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• a. Nucleus
  f. Endoplasmic
  reticulum
• b. Mitochondria
  g. plasma membrane
• c. Ribosomes
  h. nucleolus
• d. Golgi apparatus
  i. cilia
• e. Microvilli
  j. cytoskeleton 
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• ____ 5. a series of folded membranes extending
  from the nuclear membrane - parts are site of
  protein synthesis 
• ____ 6. non-membrane bound organelles, involved
  in protein synthesis 
• ____ 7. series of membrane bound sacs, protein
  modification 
• ____ 8. a double membrane enclosed structure -
  involved in cellular energy transformations 
• ____ 9. membrane extensions which increase
  membrane surface area 
• ____ 10. a fluid mosaic structure involving
  primarily phospholipids and proteins acting as a
  barrier surrounding the a cell 
• ____ 11. darkly staining region within the
  nucleus 
• ____ 12. extensions from the cell membrane
  associated with oar-like movements - important
  for example in the trachea 
• ____ 13. a network of proteins - involved in
  anchoring within cells, cells to each other,
  motility

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• Intercellular Attachment
• Tight Junction impermeable barrier as plasma
  membrane of adjacent cells join together found
  in intestine, kidneys
• Gap junction passageways between adjacent cells
  form to allow ions, nutrients, etc. to pass
  between cells muscle cells
• Desmosomes cell membranes do not join but cells
  are held together by intercellular filaments

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• Cell Division
• Two cell types
• Somatic arise from mitotic divisions
• Sex cells arise from meiotic division
• Frequency of cell division varies with tissue
• Important
• during development
• In certain tissues through life
• Loss in control ? cancer
• Number of chromosomes in daughter cells

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• Cell Division and The Cell Cycle in Somatic Cells
• Interphase
• Normal cell processes
• Preparation for division (if necessary)
• Several phases G1, S, G2
• Duplication of organelles and nuclear material
• Several checkpoints
• Length of time varies
• Mitosis
• Division of nuclear material
• Continuous process with named phases
• Cytokinesis cell division

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• Cell cycle controls Important in controlling
  cell division - Result of specific proteins
• Act at certain points in cell cycle
• 1. G1 favorable conditions?
• 2. G2 trigger for beginning of mitosis
• 3. M exit mitosis/cytokinesis enter G1

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• Cancer
• 1/3 human population affected during lifetime
• Failure of checkpoint controls due to mutation
  of checkpoint protein
• Causes
• mutagens
• Viral infection
• P53 produces critical check point protein
  mutation loss of control cancer

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• Cell Resources
• Text chapter 2
• Cellsalive.com
• Genetic science learning center University of
  Utah (type Genetic science learning center
  into Google it is usually the first site to
  come up)

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Four Tissue Types

• Tissue group of similarly specialized cells
  performing a similar function.
• Epithelial
• Muscle
• Connective
• Nervous

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• Histology
• How we examine tissues
• Teased, smeared or squashed samples, scraped we
  are looking at whole cells
• Thin sections very thin sections of the tissue
  are made using a microtome after tissue has been
  either frozen or embedded in some sort of solid
  substance like wax or plastic
• Staining In either case stains are used so
  enhance contrast in the specimen

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• Epithelial Tissue
• Functions protection, absorption, secretion
• Cover all virtually all body surfaces, in and out
• Lack vascular supply
• Classified based on shape and stacking of cells
• Generally supported on a basement membrane (
  connective tissue)

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• Glands Epithelial Cells involved in secretion
• 2 types
• Exocrine glands connected to the surface by
  tubes (ducts)
• cells that secrete---sweat, ear wax, saliva,
  digestive enzymes onto free surface of epithelial
  layer
• Endocrine glands secretion released to
  bloodstream, not to surface
• hormones regulate body processes

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Structural Classification of Exocrine Glands

• Unicellular are single-celled glands
• goblet cells
• Multicellular glands
• branched (compound) or unbranched (simple)
• tubular or acinar (flask-like) shape

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• Functional Classification of Exocrine Glands
• Merocrine vacuoles transport
• Apocrine part of cell pinches off
• holocrine cell lyses, becomes secretion

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• Connective Tissue
• Most abundant tissue in body
• Not on free surfaces
• Cells separated in a matrix (ground substance
  fibers)
• Good nerve blood supply (except cartilage
  tendons)
• Classified based on matrix components,
  arrangement and type of protein fibers

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• Connective Tissue Cell Types
• -Blast type cells divide produce matrix
  (fibroblasts, chondroblasts, osteoblasts)
• -Cyte type cells mature cell that can not
  divide or produce matrix (chondrocytes
  osteocytes)
• Others
• Immune Cells
• Adipocytes (fat cells) store fat
• Plasma cells
• Mast cells produce histamine that dilate small BV
• Various stem cells
• Mesenchyme

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• Connective Tissue Ground Substance
• Supports the cells and fibers
• Helps determine the consistency of the matrix
• fluid, gel or solid
• Contains many large molecules
• hyaluronic acid is thick, viscous and slippery
• condroitin sulfate is jellylike substance
  providing support
• adhesion proteins (fibronectin) binds collagen
  fibers to ground substance

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• Connective Tissue Fibers
• Collagen (25 of protein in your body)
• Resist pulling forces
• in tendons and ligaments
• Rope-like
• Elastin (lungs, blood vessels, ear cartilage)
• Stretch and recoil to 150 of length
• Reticular (spleen and lymph nodes)
• Network of fibers - support

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• Defective Collagen and Elastin
• Ostoegenesis imperfecta
• mutations in the type I collagen gene
• Ehlers-Danlos Syndrome
• mutations in type I collagen other collagen
  types (III and V)
• arthritic (joint) disease.
• mutation in the elastin gene
• supravalvular aortic stenosis (SVAS isolated
  form)
• narrowing of arteries and disrupted architecture
  of the aorta due to defective elastin
• Marfan syndrome
• Mutations in the fibrillin gene
• Scurvy
• Ascorbic (vitamin C) deficiency ? defective
  formation of collagen

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• Connective Tissue Proper Dense Connective
• Dense regular
• Ligaments bone to bone
• Tendons muscle to bone
• Aponeurosis broad, ribbon-like tendons
• Elastic tissue high proportion of elastic fibers
  walls of blood vessels
• Dense Irregular Connective
• Mesh-like arrangement of fibers
• Dermis of skin
• Covering of bone periosteum
• Capsule covering internal organs

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• Connective Tissue Proper Loose Connective
• Aeolar connective
• Open framework lacks organized structure
• Deep to dermis, epithel. lining of digestive,
  resp, urin, elsewhere
• Adipose
• Converted from aeolar on demand
• Padding, insulation, energy storage
• Cells (adipocytes) largely oil droplets

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• Fluid Connective Tissue
• Blood
• Formed elements
• plasma
• Lymph
• Interstitial fluid
• Lymphocytes others
• Further discussion with circulatory system

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• Support Connective Tissue Cartilage
• avascular
• Matrix
• proteoglycan - complex of proteins chondroitin
  sulfate
• Chondrocytes in lacunae
• Surrounded by pericondrium

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• Cartilage
• Three types - How do they differ and where are
  they found? ( see pages 71, 72)
• Hyaline cartilage
• Elastic cartilage
• fibrocartilage

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• Bone Osseous Tissue
• Highly vascular repairs
• Metabolic high nutrient and oxygen requirement
• Dynamic osteoblasts build while osteocytes
  break down hormonal regulation
• Collagen fibers coated with inorganic salts
• Develops through process of ossification
  conversion of fetal hyaline cartilage skeleton
• Two basic types
• Compact bone
• Spongy bone

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Musclefurther discussion in later sections

• Specialized cells containing myosin and actin
  (protein) fibers which produce contractions or
  movement
• Types
• Smooth involuntary lack striations
• ----Two types with striations-----------
• Skeletal voluntary muscle have cross
  striations and responsible for body movement
• Cardiac only found in heart branched cells
  bound end to end by intercalated discs

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Nervous Tissue

• Involved in sensing and conducting and analysis
  of information
• Two cell classes
• Neurons which conduct impulses
• Neuroglia which support neurons by providing
  support, protection and nourishment
• Further Discussion with nervous system

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• Membranes involve epithelia connective tissue
• Mucous Membranes (sing. mucosa)
• Line body passages to body surface, glandular
  cells produce mucous
• Maintain moist surface
• Serous Membranes
• Lines internal body cavities, produce watery
  transudate
• Cutaneous membranes
• Waterproof and dry, covers body surface
• Synovial membrane

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• Connective tissue Layers
• Superficial fascia subcutaneous layer
  hypodermis
• Beneath the dermis
• Deep fascia
• Dense connective tissue
• Covers groups of muscles of similar function
• Subserous fascia
• deep to deep fascia
• separates from serous membrane of body cavities

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Oklahoma Laws

• Violators can be fined, arrested or jailed for
  making ugly faces at a dog.
• Females are forbidden from doing their own hair
  without being licensed by the state.
• Dogs must have a permit signed by the mayor in
  order to congregate in groups of three or more on
  private property.
• Oklahoma will not tolerate anyone taking a bite
  out of another's hamburger.
• It is against the law to read a comic book while
  operating a motor vehicle.
• Whaling is illegal.
• It is illegal to have the hind legs of farm
  animals in your boots.
• Residents are taxed for the furniture in their
  homes, and any other personal belongings.
  (Repealed)
• Cars must be tethered outside of public
  buildings. (Repealed)
• Anyone arrested for soliciting a hooker must have
  their name and picture shown on television.
• Tattoos are banned.
• It is illegal to wear your boots to bed.
• Fish may not be contained in fishbowls while on a
  public bus.
• Tissues are not to be found in the back of one's
  car.