Definition

1. Adjective:
   • (Of a solution) Having a lower osmotic pressure than a comparison solution: A hypotonic solution has a lower concentration of solutes compared to another solution, typically the fluid inside a cell. When a cell is placed in a hypotonic solution, water tends to move into the cell.
   • (Of living tissue) Lacking normal tone or tension: This describes muscles or other tissues that are flaccid, weak, or have reduced firmness and strength.

Usage Examples

• Adjective (Solution):
  • Distilled water is a hypotonic solution compared to human blood plasma.
  • Plant cells become turgid when placed in a hypotonic environment.
• Adjective (Tissue):
  • After the nerve injury, the patient exhibited hypotonic muscles in the affected limb.
  • The doctor noted the infant's hypotonic posture during the examination.

Advanced Usage

• In a biological/medical context: The term is often used comparatively. A solution is described as hypotonic another fluid (e.g., "The IV fluid was hypotonic to the patient's serum.").
• In physiology: Hypotonic can describe a state of reduced muscle tone, which is a clinical sign in various neurological or muscular disorders.

Variants and Related Words

• Hypotonicity (n): The state or condition of being hypotonic.
  • The hypotonicity of the solution caused the red blood cells to swell.
• Hypotonia (n): A medical term specifically for diminished muscle tone.
  • The baby was diagnosed with benign congenital hypotonia.
• Antonym: Hypertonic (adj): Having a higher osmotic pressure (for solutions) or increased tone (for tissues).

Synonyms

• For solutions: Dilute (in a comparative sense), hypoosmotic.
• For tissues: Flaccid, atonic, lax, low-toned.

Related Phrases/Idioms

This term is primarily technical and scientific; it is not commonly used in idiomatic expressions or phrasal verbs.

Adjective

1. (of a solution) having a lower osmotic pressure than a comparison solution
2. (of living tissue) lacking normal tone or tension