NUR 101 Body Structure and Function by NaFkEnF

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									NUR 101 Body Structure and
Function


MODULE C: CELLS AND TISSUES
CELLS

  CELLS
  A.  vary considerably in
      size
  B.   are microscopic
  C.   differ notably in shape
COMPONENTS OF A CELL

    CYTOPLASMA
   A.   Cytoplasm which contains
        specialized organelles and is
        surrounded by a plasma
        membrane
   B.   Organization of cytoplasmic
        substances important to life
COMPONENTS OF A CELL

  PLASMA MEMBRANE
  1. Forms outer boundary of cell
  2. Thin, two-layered membrane of
     phospholipids containing proteins
  3. Is selectively permeable
CYTOPLASM ORGANELLES

 Ribosomes
 Endoplasmic reticulum (ER)
 Golgi apparatus
 Mitochondria
 Lysosomes
 Centrioles
 Cilia
 Flagella
RIBOSOMES

 1. Are very tiny particles found through out
    the cell
 2. Some are attached to a network of
    membranous canals called
    endoplasmic reticulum (ER) ,some are
    free in the cytoplasm
 3. Make enzymes and other protein
    compounds -“protein factories”
ENDOPLASMIC RETICULUM (ER):

 1. Form a network of connecting sacs and
    canals from the nucleus almost to the plasma
    membrane.
 2. Carry proteins and other substances through
    the cytoplasm from one area to another
 3. Are both rough and smooth. The rough ER
    receives and transports newly made proteins
    and smooth ER makes new membrane
GOLGI APPARATUS

 1. Tiny flattened sacs stacked near the nucleus.
 2. Collect vesicles filled with proteins and other
    compounds from the smooth ER
 3. Chemically processes the molecules and
    packages the material in vesicles that move
    from the golgi apparatus to the plasma
    membrane and opens to the outside of the
    cell “chemical processing and packaging
    center”
MITOCHONDRIA

 1. Made of two membranous sacs one inside
    the other
 2. Complex, energy releasing chemical
    reactions occur continuously
 3. Supply most of the power for cellular work
    “power plants”
 4. Enzymes within the walls use oxygen to
    break down glucose and other nutrients to
    release energy required for cellular work
LYSOSOMES

 1. Are membranous walled organelles that in
    the active state look like small sacs.
 2. Contain chemicals (enzymes) that digest food
    compounds “ digestive bags”
 3. Also digest other substances such as
    microbes which protects the cell
 4. Can kill the cell if the digesting enzymes
    escape from the lysosomes sac into the cell
    “suicide bags”
CENTRIOLES

 1. Are two rod-shaped structures
 2. Lie at right angles to each other
    near the nucleus
 3. Participate in cell reproduction
CILIA

 1. Fine almost hair like extensions on
    the exposed or free surfaces of
    some cells
 2. Are capable of moving in unison in
    a wavelike fashion over the surface
    of a cell.
Flagella

 1. Are single projections extending
    from cell surfaces
 2. Are much larger than cilia
 3. “Tails” of sperm cells only example
    of flagella in humans
STRUCTURAL COMPONENTS OF
A CELL
  NUCLEUS
   1. Controls cell because it contains the
      genetic code- instructions for making
      proteins, which in turn determine cell
      structure and function
   2. Component structures include nuclear
      envelop, nucleoplasm, nucleous, and
      chromatin granules
   3. Chromosomes contain DNA
Movement of Substances
Through Cell Membranes
  PASSIVE TRANSPORT
   1. Diffusion
             Osmosis
             Dialysis
   2. Filtration
   ACTIVE TRANSPORT
   1. Ion pumps
   2. Phagocytosis and pinocytosis
Passive Transport Processes

  DIFFUSION
   1. is the process by which substances
      scatter evenly throughout an available
      space without utilizing energy.
   2. movement is from high concentration
      to low concentration
   3. specialized examples diffusion :
      osmosis and dialysis
Passive Transport Processes

  FILTRATION
  1. is the movement of water and solutes
     through a membrane caused by
     hydrostatic pressure
  2. move water and solutes from an area
     with higher hydrostatic pressure to an
     area with lower hydrostatic pressure
  3. is the process responsible for urine
     formation
Active Transport Processes

  ION PUMP
   1. is a protein structure in the cell
      membrane called a carrier
   2. uses energy from ATP (adenosine
      triphosphate) to move ions across cell
      membranes against the concentration
      gradient (lower concentration to higher
      concentration)
   3. is specific to particular ions
Active Transport Processes

  PHAGOCYTOSIS – is the movement of cells
   or other large particles into the cell by trapping
   it in a section of plasma membrane. The
   material then fuses with lysosomes and is
   destroyed
  PINOCYTOSIS- is the movement of fluid and
   dissolved molecules into the cell by trapping
   them in a section of plasma membrane that
   pinches off inside the cell
Movement of Substances
Through Cell Membranes
  TONICITY
    Isotonic is a solution containing an equal
     level of NACL as a living red blood cell
    Hypotonic is a solution containing a lower
     level of NACL than is found in a living red
     blood cell
    Hypertonic is a solution containing a higher
     level of NACL than is found in a living red
     blood cell
DNA STRUCTURE
1. Large molecule shaped like a spiral staircase
2. Sugar (deoxyribose) and phosphate units
   comprise the sides of the molecule
3. base pairs (adenine-thymine or guanine-
   cytosine) compose “steps”
4. Gene is a specific sequence of base pairs
   within a DNA molecules
5. Genes dictate formation of enzymes and
   other proteins by ribosomes thereby indirectly
   determining a cell’s structure and function,
   genes are heredity determinants
GENETIC CODE

 The coded or stored information in each
  gene controls protein and enzyme
  production, enzymes facilitate cellular
  chemical reactions, and cellular chemical
  reactions determine cell structure and
  function and thereby heredity.
 DNA with its genetic code is contained in
  the nucleus of the cell.
Protein synthesis
  The process of transferring genetic information from
   the nucleus into the cytoplasm requires the completion
   of two steps:
  Transcription is the formation of a messenger RNA
   (mRNA) from a particular DNA gene sequence. mRNA
   then passes from the nucleus to the cytoplasm

  Translation is the synthesis of protein by ribosomes
   utilizing the information contained in the mRNA
   molecule to direct choice and sequence of amino acids
   to form a protein strand and molecule
CELL REPRODUCTION
 DNA REPLICATION is a process by which
  each half of a DNA molecule becomes a whole
  molecule identical to the original DNA
  molecule; precedes mitosis
 MITOSIS Is a process in cell division that
  distributes identical chromosomes (DNA
  molecules) to each new cell formed when the
  original cell divides. It enables cells to
  reproduce their own kind, Makes heredity
  possible
CELL REPRODUCTION

 PHASES OF CELL DIVISION (MITOSIS)
  Prophase
  Metaphase
  Anaphase
  Telophase
PROPHASE : First Phase

 1. Chromatin granules become organized
 2. Chromosomes (pair of linked
    chromatids) appear
 3. Centrioles move away from the nucleus
 4. Nuclear envelope disappears, freeing
    genetic material
 5. Spindle fibers appear
METAPHASE : Second Phase

 1. Chromosomes align across center of
    cell
 2. Spindle fibers attach themselves to
    each chromatid
ANAPHASE : Third Phase

 1. Centromeres break apart
 2. Separated chromatids now called
    chromosomes
 3. Chromosomes are pulled to opposite
    ends of cell
 4. Cleavage furrow develops at end of
    anaphase
TELOPHASE : Fourth Phase

 1. Completed cell division
 2. Two Nuclei and nuclear envelopes
    appear
 3. Cytoplasm is divided (cytokinesis)
 4. Two fully functional cells, each having
    identical genetic characteristics are
    formed
TYPES of TISSUE

    EPITHELIAL
    CONNECTIVE
    MUSCLE
    NERVOUS
EPITHELIAL TISSUE

 Types of Epithelial Tissue
 1. Simple squamous
 2. Stratified squamous
 3. Simple columnar
 4. Stratified transitional
 5. Pseudostratified
 6. Simple cuboidal
CONNECTIVE TISSUE

Types of Connective Tissue
1. Areolar
2. Adipose
3. Dense fibrous
4. Bone
5. Cartilage
6. Blood
7. Hemopoietic
MUSCLE TISSUE

 There are three kinds of muscle tissue:
 Skeletal (striated voluntary) – Long threadlike
  cells with multiple nuclei and striations
 Cardiac (striated involuntary) Branching
  interconnected cylinders with faint striations
 Smooth (non- striated involuntary visceral)
  threadlike cells with single nuclei and no
  striations
NERVOUS TISSUE

1. Consists of two kinds of cells : Neurons the
   functional or conducting units and Glia (
   neuroglia) the connecting and supporting
   cells
2. Is characterized by a cell body and two types
   of processes: one axon which transmits a
   nerve impulse away from cell body and one
   or more dendrites which carry impulses
   toward the cell body

								
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