Homeostasis Flashcards
Explain circulation
moves fluids and gases; blood vessel and intercellular spaces moves fluids and gases (entire circ system once/min rest)
Explain diffusion
fluid into interstitial space/into and out of the cell; ions/molecules move from high to low conc gradient
What is transport?
movement of ions through channels into cells; pumping ions/molecules against a conc gradient
Explain homeostasis
regulation of blood gases/ion conc and water/blood pressure/hormones
What is negative feedback?
Stimuli that initiate a stop to responses
ex) exercise/CO2 conc (increasing RR to expel from the body and bring back to normal)
What is positive feedback?
Responses to the system that amplify over time.
ex) blood clotting/pregnancy
Lipid bilayer can also be called…
Semipermeable membrane
Passive Transports..
Diffusion/Facilitated diffusion/osmosis
Active transports
Pumps/cotransports
What factors alter diffusion rate?
- Membrane permeability
- Conc difference
- Electrical potential
- Pressure
Where is Na+ found more abundantly?
extracellular fluid
Where is K+ found most abundantly?
Intracellular fluid
Where is Ca++ found most abundantly?
Extracellular fluid
Where is Mg++ found most abundantly?
Intracellular fluid
Where is Cl- found most abundantly?
extracellular fluid
What determines simple ion diffusion?
- conc diff/gradient
- electrical diff
- and channel being open (permeability)
Types of diffusion..
- simple
- channel protein
- facilitated
Explain simple diffusion with channels..
channels are voltage gated or chemical gated. Conformational change in the channel also it to open
What two channels are responsible for action potential of neurons?
Na+ and K+
Explain depolarization.
Na+ influx into the cell, this makes it less negative (+35 mV). When this happens slow activation K+ channels open up to release K+ to make cell more negative.
Explain ROC: Receptor-operated channels
ligand binds to the receptor on the channel and opens it.
ex) acetycholine nicotinic receptor/ seritonin type 3 receptor
