Ch. 6 Interactions Between Cells and the Extracellular Environment Flashcards
What does the extracellular environment include?
Everything located outside the cell
Cells receive ____ from and release ____ into the extracellular environments.
Nourishment; wastes
How do cells communicate with each other using the extracellular environment?
By secreting chemical regulators into the extracellular environment
How to cells exchange things?
Inside cell –> extracellular
Does diffusion work better over a limited space? Why?
Yes b/c the exchange into extracellular environment occurs faster
What is the extracellular environment in endothelial cells?
The blood running by
True/False: Capillary beds are in close proximity to most cells in the body.
True
__% of our water is within cells in the intracellular compartment; intracellular fluid (ICF).
67% (2/3)
__% of our water is in the extracellular compartment (extracellular fluid, ECF).
33% (1/3)
__% of ECF is in blood plasma.
20%
__% of ECF makes up tissue fluid (or interstitial fluid).
80%
Interstitial fluid
aka tissue fluid
Connects the intracellular compartment with the blood plasma
What does extracellular matrix contain?
Protein fibers (structural support) of collagen and elastin, and ground substance (glycoproteins and proteoglycans)
Foundation to build cells upon; flexible
Protein fibers provide ____ ____.
Structural support
Integrins
Glycoproteins that extend from the cell cytoskeleton and bind to the extracellular matrix; linking cells to the matrix
Selective; different integrins recognize different extracellular matrix
What 3 things to integrins do?
Impart a polarity to cells
Affect adhesion and motility
Affect proliferation
Why is proliferation important? How can it go wrong?
Important: only need once cell covering basement membrane –> proliferation
Tumors are opposite: adding unnecessary cells to cover basement membrane
The plasma membrane is ____ ____.
Selectively permeable
Selectively Permeable plasma membrane
Allows some molecules to cross but not others
What is the plasma membrane generally not permeable to?
Proteins, nucleic acids, or other large molecules
What is the plasma membrane generally permeable to?
Ions, nutrients, and wastes
Non-carrier mediated membrane transport
- Simple diffusion of lipid-soluble molecules
- Simple diffusion of ions through nonspecific channels
- Simple diffusion of water = osmosis
Carrier-mediated membrane transport
- Facilitated diffusion
2. Active transport
Passive Transport
Molecules move from higher to lower concentration w/o using metabolic energy
- -moves down concentration gradient
- -equalize concentration