homeostasis Flashcards
what is Homeostasis
various physiological adaptations to living everywhere.
what are endogenous changes?
these are self-imposed ways of maintaining homeostasis.
what are sensors
receptors that allow the body to detect change
what are effectors?
these are muscles or glands or anything that can create a change.
what is the response?
this is the outcome of the detection ie sweating, shivering etc.
what are conformers?
these are invertebrates that do not maintain homeostasis, and as the environment changes the inside also changes to match.
what are regulators?
these are vertebrates that maintain homeostasis, they have a carrying capacity and cannot handle too hight of something or too low of something, ie cannot handle super low temperatures nor can they handle super high temperatures
what is a physiological adjustment
change occuring almost instantly or over a few minutes/hours to adjust.
what is acclimatization?
environmental change over weeks or months, but reversible.
what is an evolutionary change?
very slow and changes habits and traits, this is not reversible.
what maintains homeostasis?
the cellular membrane
what is the membrane made of and how does it maintain homeostasis?
a hydrophobic tail made of fatty acid chains and hydrophilic head made of phosphate, amines and a glycerol backbone. the reason for homeostasis is the selective permeability and it is fluid.
what is a saturated fatty acid?
no double bonds in the tail and they favour tight packing and make a stiff membrane they are saturated with hydrogen
what is an unsaturated fat
some double bonds producing kinks that make it more fluid and less tight packing
what is the fluid mosaic model?
proteins embedded in the membrane that allow for transport, receptors, enzymes and other anchors
what is the purpose of a plasma membrane
this is critical for homeostasis and it prevents ions, prevents macromolecules from entering cells, allows for gas exchange
what is passive transport?
this is simple diffusion that is good for small molecules that go down the concentration gradient to make it equal on both sides.
what is facilitated diffusion?
this is for molecules too big to get across passively, it is guided through proteins via the channels basically with a tube
what is osmosis?
this moves exclusively water out of a molecule, this water will be filled with solute and will move the water so both sides have the same concentration of solute, this is through aquaporins
what is active transportation?
this is when there is nutrients higher on the outside and waste is higher on the inside.
what is primary active transport?
this is the transport of molecules that uses ATP directly. they use 2 types of mechanisms
antiporters: moving ions in opposite directions
symporters: moving ions in the same direction
this also uses Na K ATPase (the pump breaks ATP and uses the phosphate to open and close)
what is secondary active transport?
this uses ATP indirectly that moves ions indirectly, by:
1. proteins are pumped across the membrane by primary active transport
2. this creates a gradient of proteins making it more positive outside and negative inside
3. protons come back and trade places within the cell.
what does hypotonic mean?
lots of water outside the cell flows in and the concentration of solute goes down, when this happen too much the cell becomes cytolysed
what does hypertonic mean?
theres a lot of water flowing out of the cell and the cell becomes plasmolysed
