Role and rules for selecting interfixes
An interfix, or connecting vowel, is a special word-building tool that acts as a link between the roots being combined. The interfix -o- is most commonly encountered in medical practice, whereas the vowel -i- is used much less frequently.
Within classical historical norms, the choice of letter depended on the origin of the root:
- For words of Ancient Greek origin, exclusively the letter -o- was used.
- For inherently Latin words, the letter -i- was used. For example, the term auriscalpium (ear-scoop) is assembled from the Latin words auris (ear) and scalpo (to scrape), while vivificatio (revitalization) is formed from vivus (alive) and facio (to make).
However, when creating modern medical terms (neologisms), this strict regularity is no longer observed. In new "learned" words, the universal connecting vowel is -o-, regardless of whether the source components belong to Greek or Latin. For this very reason, modern terms are written as corticovisceralis or nasolacrimalis.
Interfix-free compounding
In a number of cases, roots are connected directly, and the connecting vowel is omitted. This is usually dictated by the phonetic features of the words being combined:
- The first root ends in a vowel. For example, the term element brady- (slow) forms the word bradycardia upon compounding, and brachy- (short) gives the term brachydactylia.
- The second root begins with a vowel. If the word encephalon (brain) is added to the stem rhin- (nose), we get the term rhinencephalon without additional intermediate sounds.
Variability of the source stem
Many nouns and adjectives in Latin and Ancient Greek (first and foremost belonging to the third declension) have different stems in their nominative and genitive case forms.
The basic rule of clinical compounding requires always using the genitive stem as the source base.
- Latin words: the word "cortex" in the nominative case looks like cortex, but in the genitive it becomes cortic-is. Therefore, the stem cortic- is taken for compounding (resulting in the term corticovisceralis). A similar situation is observed with the word paries (wall), which changes to pariet-is in the genitive case and provides the stem for parietographia.
- Greek words: the word "body" (soma) has the form somat-os in the genitive case; consequently, the derivative stem somat- is used in compound terms.
Diversity of term element forms
Term elements can exhibit significant spelling variability. This depends on historical tradition, the position of the root within the term, or translation specifics.
- Case variability. Both nominative and genitive forms of the same word may become established in clinical terminology. The concept of "all" appears as pan- (pandemia) or pant- (pantophobia). The root "large" can appear as mega- (megacolon) and as megal- (megaloblastus).
- Three-variant forms. Individual elements change depending on whether they stand at the beginning or the end of a word. A striking example is the meaning "pertaining to blood." The initial forms are haemo- (haemoglobinum) and haemato- (haematologia), while -aemia (anaemia) is used as the final form.
- Phonetic and graphic features. Differences in spelling are often caused by the degree of latinization of the Greek word. The Greek word cheir (hand) can be transcribed as both cheir and chir. The word koinos (common) yields the Latin variants coenosis and koino-.
This variability is clearly manifested when terms are transferred into Russian. For example, from the source word neuron (nerve), terms with different pronunciations are formed: we say *nevro*logy, but *neuro*surgery. The concept *neur*itis denotes a cell process (axon), while the similar word *neur*itis refers to an inflammatory process in a nerve.
Briefly: answers to topical questions
How do the rules of Greek and Latin word compounding differ in clinical terminology?
In classical norms, the choice of the connecting vowel (interfix) depends on the etymology of the word, but in modern neologisms this distinction is erased.
| Characteristic | Greek words | Latin words |
|---|---|---|
| Interfix (classical norm) | -o- | -i- |
| Interfix (neologisms) | -o- | -o- |
| Source stem | Genitive stem | Genitive stem |
At the same time, interfix-free compounding works the same way: the connecting vowel drops out if the first component ends in a vowel (bradycardia) or the second begins with a vowel (rhinencephalon).
If you are constructing a modern medical term and are unsure about choosing a vowel between two consonants, use "-o-". In new words, it has almost completely replaced the letter "-i-" even for Latin roots.
Class and exam questions
In which cases is the connecting vowel between roots not used at all?
The interfix disappears if the first component of a compound word already ends with a vowel letter, or if the second component starts with one.
Which case form of a word should be used to create a term?
According to the rules of Latin and Ancient Greek grammar, the genitive stem (Genitivus) is used to create complex clinical terms.
Why are terms related to blood spelled differently?
This term element has a three-variant form. The choice depends on its position in the word: haemo- or haemato- are placed at the beginning, and -aemia is used at the end of the term.
What else to study on this topic
- Declensions of nouns and adjectives in Latin
- Principles of latinization of Ancient Greek roots
- Classification of final term elements in clinical medicine
- Historical features of translating ancient medical texts into Russian
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Other topics in the section "Prefixation. Prefixal-suffixal derivatives"
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