Biol 224 Theme 2&3

The flashcards below were created by user jaz584 on FreezingBlue Flashcards.

  1. Tissue
    • -stable association of differentiated cells
    • -humans have over 200 types
  2. Organ
    -body structure that integrates different tissues and carries out a specific function
  3. Desmosomes
    • -adhering junctions that "spot-rivet" cells in random places
    • -anchor cells together in tissues
    • -can stretch a lot
    • -used in cell to cell communication
  4. Tight Junctions
    • -also known as occluding junctions
    • -form a tight waterproof junction between cells
    • -major proteins claudins and occludins 
    • -anchor the actin portion of the cytoskeleton together
    • -can have tight or leaky junctions
  5. Blood-Brain Barrier
    • -separation of circulating blood from the brain extracellular fluid
    • -made up of tight junctions around the capillaries that do not exist in normal circulation
    • -allow diffusion of small hydrophobic molecules only
  6. Gap Junctions
    • -communicating junctions made up of connexons 
    • -directly connects the cytoplasm of the cells
    • -similar to plasmodesmata in plants
    • -highly expressed in the heart to allow rapid transport of electrical signals to allow the heart to beat in a paced interval
  7. Membrane Nanotubes
    • -aka cytonemes 
    • -long, thin tubes that connect animal cells over long distances(100um)
    • -transfer of nucleic acid between cells
    • -can carry vesicles and organelles 
    • -can also spread toxins (HIV, prions etc)
  8. Extracellular Matrix
    • -provides essential structural support
    • -made up of polysaccharide gels and elastic proteins
    • -fill any and all spaces between cells
  9. Collagen and Elastic Glycoproteins
    -can be calcified to form shells, bones and spicules
  10. Plasma
    • -make up about 55% of total blood volume
    • -mostly water, but contains dissolved proteins and clotting factors
  11. Serum
    • -the component of blood that is neither a blood cell nor a clotting factor
    • -it is the plasma with the fibrinogens(clotting factors) removed
  12. Movement of Water
    • -fluid moves easily in and out of cells, osmosis
    • -swollen and shrunken cells are more vulnerable 
    • -hypertonic=more solute than compared(water will flow in)
    • -hypotonic=less solute than compared(water will flow out)
  13. Homeostasis
    • -process where the body's internal environment is kept stable
    • -37°C
    • -pH 7.365
    • -blood glucose 5mmol/L
    • -concentration of water vs electrolytes 
    • -blood pressure 120/80 mm Hg
  14. Homeostatic Regulation
    • -mainly by secretion of hormones
    • -by Hypothalamus, pituitary, pancreas, thyroid and parathyroid, adrenals
  15. Regulation of Blood Glucose
    • -insulin secreted by β cells of pancreas 
    • -when glucose levels are high, it is converted to glycogen
  16. Glucagon
    • -secreted by the α-cells of the pancreas and signals glycogenlysis , the conversion of non carbohydrate carbon sources to glucose(gluconeogenesis)
    • -prevents hypoglycaemia
  17. Regulators
    -maintain parameters at a constant level over wide ambient environmental changes
  18. Conformers
    • -allow the environment to determine parameters
    • -endothermic animals(warm blooded)
    • -ectothermic animals(cold blooded)
  19. Avoiders
    -change their location in the environment
  20. Endotherm
    • -organism that produces internal heat
    • -warm blooded animals
  21. Ectotherm
    • -rely on environmental sources of heat
    • -cold blooded animals
  22. Homeotherm
    • -organism that maintains a stable internal temp regardless of external influence 
    • -often higher temp than immediate environment
  23. Poikilotherm
    • -organism who's internal temp varies widely depending on the environment 
    • -lots of fish and reptiles
  24. Homeostatic Control Mechanisms
    • -four interdependent components
    • -set point=normal value for variable
    • -sensor/receptor=monitors the variable
    • -integrator=compares signal to set point
    • -effector=compensates for any deviations from set point
  25. Negative Feedback
    • -upon signal reception, change occurs to depress the deviation
    • -signal says decrease in body temp, response to increase temp (shivering)
  26. Positive Feedback
    • -accelerate or enhance output from stimulus
    • -push levels out of normal range into a supra physiological response
    • -oxytocin release during childbirth to enhance contractions
  27. Feedforward Regulation
    • -learned behaviour to prepare for a change before it occurs
    • -speeds up response and therefor minimizes deviations from the set point
    • -ex. horse trained to get ready for a race, Pavlov's dogs
Card Set:
Biol 224 Theme 2&3
2013-10-04 06:03:20
Biol 224

Theme 2&3
Show Answers: