Meaning & use
hypotonic
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Meanings
adjectivenot comparablebiologychemistry
Describing a solution that holds a lower concentration of dissolved particles than another solution, so water tends to move into the more concentrated side.
Grammar: Usually describes a solution or fluid: a hypotonic solution, and is rarely graded.
Patterns
- hypotonic to something
- hypotonic solution
Red blood cells swell and may burst when placed in a hypotonic solution.
The fluid outside the cell was hypotonic to the cell contents, so water rushed in.
Pure water is strongly hypotonic compared with the salty inside of a cell.
adjectivenot comparablemedical
Describing a muscle that has weaker tension than normal, feeling floppy and soft to the touch.
Grammar: Used about muscles, limbs or babies: hypotonic muscles.
Patterns
- hypotonic muscles
- a hypotonic infant
The doctor noted that the baby's muscles were hypotonic and arranged further tests.
A hypotonic child may have trouble sitting upright without support.
Therapy can help hypotonic patients build strength gradually.
Common combinations
- hypotonic solution
- The students placed the onion cells in a hypotonic solution and watched them swell.
- hypotonic to
- The sample was hypotonic to the blood plasma.
- hypotonic infant
- A hypotonic infant often feels limp when lifted.
- hypotonic muscle
- A hypotonic muscle lacks the firmness of a healthy one.
- hypotonic saline
- Nurses avoid giving hypotonic saline in some conditions.
Synonyms and how they differ
- low-tone
- Low-tone is a plain-language description for muscles only and is much less formal than the clinical hypotonic.
- flaccid
- Flaccid describes something limp in general, including muscles or plant tissue, but it does not carry the solute-concentration meaning that hypotonic has in science.
- dilute
- Dilute describes a weak, watered-down solution in everyday terms, whereas hypotonic specifically compares two solutions across a membrane.
Opposites
Word family
- hypotonia noun
- the condition of low muscle tone
- hypertonic adjective
- holding a higher concentration of solutes than another solution
- isotonic adjective
- having equal concentration to another solution
- tonicity noun
- the effective concentration of a solution relative to another
Commonly confused: hypotonic or hypertonic?
hypotonic vs hypertonic
Hypertonic means the opposite: more dissolved particles than the comparison solution, so water leaves the cell. Remember hypo- means under and hyper- means over.
Practice
When a plant cell sits in pure water, which is ___ compared with the cell's contents, water moves into the cell.
Choose one answer.
Pure water has fewer dissolved particles than the cell, so it is hypotonic and water moves in. A hypertonic liquid would pull water out instead.
Make it your own
Write a sentence using “hypotonic”, then check it and compare it with the examples above.