amnion: meaning, definition, pronunciation and examples
Low frequency / Very technicalTechnical / Scientific / Medical
Quick answer
What does “amnion” mean?
The innermost membrane that encloses the embryo of a mammal, bird, or reptile, containing the amniotic fluid.
Audio
Pronunciation
Definition
Meaning and Definition
The innermost membrane that encloses the embryo of a mammal, bird, or reptile, containing the amniotic fluid.
In a biological or medical context, it refers specifically to this embryonic membrane. The term is also used in botany for the membrane covering a fern sporangium.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning, usage, or spelling. Pronunciation differs slightly (see IPA).
Connotations
Purely technical/medical in both varieties.
Frequency
Extremely rare in general discourse in both varieties, confined to specialist fields.
Grammar
How to Use “amnion” in a Sentence
The N is formedThe N surroundsN rupturewithin the NVocabulary
Collocations
Examples
Examples of “amnion” in a Sentence
adjective
British English
- amnionic fluid
- amnionic cells
American English
- amniotic fluid
- amniotic cells
Usage
Meaning in Context
Business
Virtually never used.
Academic
Used in biology, medicine, veterinary science, and embryology papers and textbooks.
Everyday
Extremely rare; only in discussions of pregnancy complications or detailed biology.
Technical
The primary domain of use. Precise anatomical reference in medical/surgical contexts, developmental biology.
Vocabulary
Synonyms of “amnion”
Strong
Neutral
Weak
Vocabulary
Antonyms of “amnion”
Watch out
Common Mistakes When Using “amnion”
- Confusing 'amnion' with 'ammonia' or 'ammonium'.
- Using 'amnion' to refer to the entire amniotic sac (which includes the chorion).
- Misspelling as 'amniom' or 'ammnion'.
FAQ
Frequently Asked Questions
Not exactly. The amniotic sac is comprised of two membranes: the inner amnion and the outer chorion. 'Amnion' refers specifically to the inner layer.
The standard plural in scientific English is 'amnia', though 'amnions' is also accepted.
It is a defining characteristic of amniotes, a group that includes reptiles, birds, and mammals. Fish and amphibians do not have an amnion.
It is crucial for understanding fetal development, diagnosing prenatal conditions (like oligohydramnios), and performing procedures like amniocentesis, which samples amniotic fluid from within the amnion.
The innermost membrane that encloses the embryo of a mammal, bird, or reptile, containing the amniotic fluid.
Amnion is usually technical / scientific / medical in register.
Amnion: in British English it is pronounced /ˈæm.ni.ən/, and in American English it is pronounced /ˈæm.ni.ɑːn/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “None”
Learning
Memory Aids
Mnemonic
Think: 'AMN' for 'AMNiotic' and 'ION' for 'inner ON' — the inner membrane.
Conceptual Metaphor
A protective bubble, a biological life-support sac.
Practice
Quiz
What is the primary function of the amnion?