Osmosis

Osmosis

Movement of water across a semipermeable membrane from an area of low solute concentration to high solute concentration.

Semipermeable Membrane

A barrier that allows water to pass through but blocks many solutes.

Transmembrane proteins that form water channels, allowing water to move through the cell membrane.

Intracellular Fluid

Fluid inside the cell, which may contain more non-diffusible solutes compared to outside.

Interstitial Fluid

Fluid outside the cell that surrounds and bathes it.

Non-diffusible Solutes

Solutes that cannot cross the membrane freely, such as proteins and ions.

Osmotic Pressure

The force that draws water into an area with higher solute concentration.

lower ; solute

Water moves from the area with — solute concentration to the area with — solute concentration to balance the concentration.

cell volume ; equal

Water enters the cell, increasing — until solute concentrations are — inside and outside.

Hydrostatic Pressure

The pressure caused by the rising height of water on the solution side as water enters due to osmosis.

hydrostatic pressure = osmotic pressure

Movement stops when — ; this is the equilibrium point.

centimeters of water ; millimeters of mercury

Units of Osmotic Pressure: Measured in — (cm H₂O) or — (mm Hg), depending on the fluid column height or converted equivalent.

into ; bacl

Osmotic pressure pulls water — the solution; hydrostatic pressure pushes — as water accumulates, eventually balancing out.

Osmotic Pressure

The force that pulls water across a membrane toward the area with more solutes. It helps control whether water enters or leaves the cell.

cell volume

Role of Osmotic Pressure : Maintains — by regulating water movement — if water enters, the cell swells; if water leaves, the cell shrinks.

Isotonic (Isosmotic) Solution

A solution with the same solute concentration as the cell; no net water movement happens.

in and out equally ; no change

Water Movement in Isotonic Conditions : Water moves — , so there is — in cell size or volume.

no swelling or shrinking

What happens when Osmotic Pressure is Equal on Both Sides : Water is balanced, so the cell stays the same — — occurs.

0.9% Sodium Chloride (NaCl) Solution

A solution with 0.9 grams of NaCl per 100 mL of water, which is isotonic to mammalian red blood cells.

same osmotic pressure

Isotonic Effect of 0.9% NaCl: It has the — as red blood cells, so water doesn’t enter or leave the cells excessively — cell shape and volume stay normal.

normal saline

Another name for 0.9% NaCl solution, used in medical settings because it's safe for cells.

Normal Saline

Used to moisten tissues (like open wounds) without damaging cells because it doesn’t cause swelling or shrinking.

isotonic

Why Normal Saline is Safe for Cells: Because it is —, so it does not disrupt water balance in cells — avoids bursting or shrinking.

isotonic solution

A solution with the same solute concentration as inside the cell; water moves in and out equally; the cell stays the same.

hypertonic solution

A solution with more solutes outside the cell; water moves out of the cell, causing it to shrink.

hypotonic solution

A solution with fewer solutes outside the cell; water moves into the cell, causing it to swell or burst.

crenation

The shrinking of a cell due to water loss in a hypertonic environment.

Hemolysis

The bursting of a red blood cell due to water intake in a hypotonic solution.

out ; higher ; outside

Water Movement in Hypertonic Solution: Water moves — of the cell to balance the — solute concentration —

into ; solutes

Water Movement in Hypotonic Solution: Water moves — the cell because there are more — inside.