They are the smallest units that perform specific functions necessary for the survival and maintenance of the organism.
Intracellular Fluid.
Osmolarity.
It provides foundational knowledge in physiology.
Feedback mechanisms help to maintain homeostasis by responding to changes in the internal environment.
Osmolarity measures the concentration of solute particles in a liter of solution, while osmolality measures the concentration of solute particles in a kilogram of solvent.
A semipermeable membrane.
The movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration.
They work together to maintain stable internal conditions despite external changes.
The main types of membrane transport include passive transport, active transport, and facilitated diffusion.
Secondary active transport relies on the energy from the electrochemical gradient rather than direct ATP hydrolysis.
Intracellular fluid (ICF) and interstitial fluid (ISF).
It drives the movement of substances during passive transport.
A process that uses the energy from the electrochemical gradient created by primary active transport to move substances across a membrane.
Interstitial Fluid.
The sodium-potassium pump (Na+/K+ pump).
They facilitate the movement of specific molecules across the membrane.
1 mol of osmotically active solute particles.
They assist in transporting substances across the cell membrane.
To regulate the movement of molecules in and out of the cell.
The movement of molecules against their concentration gradient, requiring energy.
They allow for the organization and specialization of biological processes within an organism.
Osm/kg H2O.
Because mass is invariant, while water volume can change with temperature.
A process that uses energy, typically from ATP, to move ions or molecules against their concentration gradient.
Common ions include sodium (Na+), potassium (K+), calcium (Ca2+), and chloride (Cl-).
The process by which substances move across a cell membrane.
Plasma and interstitial fluid.
To maintain concentration gradients across membranes.
Passive transport and active transport.
They facilitate the movement of substances across the membrane.
An example is the nephron in the kidney, which is responsible for filtering blood and forming urine.
A protein structure that allows ions to pass through the cell membrane.
1 milliosmole (mOsm).
Polar molecules and ions that cannot easily cross the lipid bilayer.
1 kg.
Cell membranes and organ systems.
Substances that facilitate communication between cells.
They drive the movement of molecules during passive transport.
The process by which a living organism regulates its internal environment to maintain stable, constant conditions.
A process that allows substances to cross membranes with the assistance of special proteins.
The osmolality of a solution relative to plasma.
Two particles (Na+ and Cl-).
They help maintain balance and regulate bodily functions.
Homeostasis refers to the body's ability to maintain a stable internal environment despite external changes.
It is a passive transport mechanism, meaning it does not require energy.
ATP (adenosine triphosphate).
~2 mOsm.
They regulate the flow of ions in and out of cells, influencing electrical signals and cellular activities.
Movement of substances across a membrane without the use of energy.
To transmit signals and regulate physiological processes.
Yes, it can involve either symport (moving substances in the same direction) or antiport (moving substances in opposite directions).
The movement of molecules across the membrane without the use of energy.
Hormones.
Water volume increases, causing osmolarity to fall slightly.
The concentration gradient of solutes.
It helps maintain cell turgor and regulates fluid balance.
It provides the energy needed to transport substances against their concentration gradient.
They can be voltage-gated, ligand-gated, or mechanically gated, depending on the mechanism that opens or closes them.
Passive transport and active transport.
The diffusion of water across a selectively permeable membrane.
Movement of substances against their concentration gradient, requiring energy.
By binding to specific receptors on the target cells.
