Thursday, September 15, 2016

Ch. 3 | cells & tissues

cell parts:

organelle: membrane-bound structure w/in a cell that carries out specific functions
cytoplasm: area btwn plasma membrane & nucleus; contains organelles & cytosol (fluid inside cell)
nucleus: houses genetic material
  1. controls cellular structure
  2. directs cellular activities
  3. produces ribosomes in nucleoli
plasma membrane: cell's gatekeeper; semi-permeable lipid bilayer
  1. barrier separating inside & outside of cell
  2. controls flow of substances into & out of cell
  3. helps identify the cell to other cells 
  4. participates in intercellular signaling
centrosomes: consists of centriole pairs
  1. plays a role in cell division
ribosomes: made of RNA & proteins 
  1. make new proteins
smooth endoplasmic reticulum: doesn't have ribosomes 
  1. synthesizes fatty acids & steriods
  2. inactivates/detoxifies drugs & harmful substances
  3. stores & releases calcium ions  
rough endoplasmic reticulum: contains ribosomes on walls 
  1. make proteins 
golgi complex: array of flat membrane sacs 
  1. modifies/sorts/packages/transport proteins received from rough ER
  2. transfer proteins to their destinations 
mitochondria: folded inner membrane surrounded by smooth outer membrane 
  1. generates ATP/energy 
membranes: transport substances 
2 fluid compartments:
  1. intracellular fluid (inside the cell)
  2. extracellular fluid (outside the cell); different locations = different names:
      -interstitial fluid: btwn cells w/in a tissue
      -plasma: w/in blood vessels
      -lymph: w/in lymphatic vessels
      -cerebrospinal fluid: surrounding brain & spinal cord

concentration: amount of solute dissolved in a given volume of solvent 
concentration gradient: difference in concentration of substance btwn 2 areas 

types of transport: 
  • passive: movement w/o using energy 
  1. diffusion- substances move high-->low concentration (down concentration gradient)
  2. facilitated- diffusion using a channel/pore/carrier
  3. osmosis- diffusion of water 
-hypotonic: solution has lower solute concentration than cytosol = cell swells 
-isotonic: solution has same solute concentration as cytosol = no net movement
-hypertonic: solution has higher solute concentration than cytosol = shrivels up 
  • active: energy is used to move substances across a membrane against concentration gradient 
protein synthesis: complex process in which proteins are made 
1. gene on DNA strand is copied into mRNA (messenger RNA)
2. mRNA is transported out of the nucleus & into ribosomes
3. ribosomes read mRNA so tRNA (transfer RNA) knows which amino acids to bring
4. ribosomes join amino acids together as required by DNA
5. ribosome falls apart & releases newly made protein

cell division functions:
  1. cell renewal
  2. cell repair
  3. cell growth
  4. reproduction
types of cell division:

  • mitosis: somatic cell division
parts of interphase: (resting phase) 

1. G1- growth phase where proteins are synthesized 

2. S- DNA is replicated

3. G2- another growth phase where proteins are made 

  • cytokinesis: cytoplasm division
  • meiosis: gamete cell division 
daughter cell: either of the two identical cells that form when a cell divides

tissues: groups of cells working together to perform a specific function 
2 components found in tissue: 
  1. cells
  2. extracellular matrix (which has 2 components: ground substance & protein fibers)
4 basic types of tissues:
1. epithelial: protection, covers body surfaces, form glands, lines body cavities/hollow organs/ducts
  • epithelial cell shapes & layers:
stratified: protection

Simple squamous- blood vessels, lining of heart (diffusion & filtration) 
Simple cuboidal- ovary linings, eye surfaces (secretion & absorption) 
Simple columnar- lining of digestive tract (absorption) 
Stratified squamous- skin (upper layers), lining of vagina, mouth (protects underlying cells) 
Transitional- lining of urinary bladder (specialized) 
Pseudostratified columnar- lines respiratory passageways

2. connective: binds/protects/supports body & organs
  • Areolar – skin (provides strength/elasticity/support)
  • Adipose – hypodermis/subcutaneous layer (energy reserve/support/protection)

  • Reticular – spleen, lymph nodes (forms framework of organs, binds smooth muscle cells)
  • Bone – bones of the skeletal system (mechanical support, blood cell production)
  • Blood – blood vessels (transport of substances & gases)

3. muscular: generates force for movement, contracts

  • Skeletal muscle – attached to the skeleton (striated, voluntary)
  • Smooth muscle – inside hollow organs (striated, involuntary, intercalated discs)
  • Cardiac muscle – located in the heart (not striated, involuntary)
4. nervous: transmit impulses to coordinate activities, receives stimuli
  • neurons: specialized cells that are sensitive to various stimuli
  • neuroglia: supporting cells that don't generate nerve impulses 
  • Nerve cells – located throughout the body
microscope parts:

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