Cell and membrane
Homeostasis, compartments, membrane transport and the membrane potential.
14 pages
Exam priority: high
- Body fluid compartmentsConcept · About two thirds of the body's water is inside cells and one third outside them, between cells…
- Homeostasis and feedback controlConcept · The body measures its variables (temperature, glucose, pressure) and corrects them when they…
- Membrane transport: diffusion, channels and carriersMechanism · Substances cross the cell membrane by dissolving in it, through channels, on carriers, or by…
- Osmosis, osmolarity and tonicityConcept · Water crosses a membrane towards the side with more dissolved particles; that is how cells swell…
- The resting membrane potentialMechanism · The inside of a resting cell is negative compared with the outside, mainly because potassium…
Exam priority: medium
- Cell signaling for physiologyConcept · Hormones and neurotransmitters bind receptors that switch on chains of signals inside the cell
- Diffusion and Fick's lawConcept · Molecules move from where there are more to where there are fewer; Fick's law says how fast
- Ion channels and gatingConcept · Channels are protein pores that open and close to let one specific ion through in microseconds
- Primary and secondary active transportMechanism · Cells spend energy to move substances against their gradient, using ATP pumps or riding on the…
- The Nernst and Goldman equationsMeasurement · Two formulas that work out a cell's voltage from the ion concentrations inside and outside it
- Transport across epithelial sheetsMechanism · Epithelia move salt and water in one direction because their two faces carry different…
For completeness
- Cell movement: ameboid crawling, chemotaxis and ciliary beatingMechanism · White cells crawl by pushing out a front edge and pulling up the back; cilia beat like oars…
- Cell volume regulationRegulation · Cells guard against swelling or shrinking by moving ions and small molecules out or in, and…
- Endocytosis, exocytosis and vesiclesMechanism · Cells wrap particles in little membrane bags to bring them in (endocytosis) or to release their…
A to Z
Educational physiology content; not a diagnostic or treatment guide and no substitute for a health professional's advice. Values are approximate references. No doses are given.
Representative model, for educational purposes only.