Definition

1. Noun:
   • The plural form of sternum: In anatomy, "sterna" is the plural of "sternum," referring to the long flat bone located in the center of the chest, to which the ribs are attached.
   • A genus of birds: In taxonomy, "Sterna" (capitalized) is a genus of seabirds in the subfamily Sterninae, commonly known as terns.

Usage Examples

• Noun (Anatomy):

  • The rib cages of birds and humans both contain sterna. (The chest bones of birds and humans both contain breastbones.)
  • The surgeon examined the patient's fractured sterna. (The surgeon examined the patient's fractured breastbones.)

• Noun (Taxonomy):

  • The genus Sterna includes the common tern. (The bird genus Sterna includes the common tern.)
  • We observed several Sterna diving for fish. (We observed several terns diving for fish.)

Advanced Usage

• In technical/medical writing: The plural "sterna" is standard in anatomical descriptions involving multiple subjects or comparative anatomy.

  • The study compared the sterna of various avian species. (The study compared the breastbones of various bird species.)

• In zoological context: When capitalized, "Sterna" is always treated as a singular proper noun (the genus name) but takes a plural verb when referring to multiple birds of this genus as a group.

  • Sterna are found in coastal regions worldwide. (Terns are found in coastal regions worldwide.)

Variants and Related Words

• Sternum (n): The singular form; the breastbone.

  • The sternum protects the heart. (The breastbone protects the heart.)

• Sternal (adj): Relating to the sternum.

  • The sternal region was sore after the surgery. (The area of the breastbone was sore after the surgery.)

Synonyms

• Breastbone(s): A common synonym for sternum/sterna in an anatomical context.
• Terns: The common name for birds of the genus .

Notes on Different Meanings

• The meaning is entirely dependent on context. In a medical or biological text, "sterna" likely refers to anatomical bones. In an ornithological text, "Sterna" (capitalized) refers to the bird genus. The uncapitalized form is almost exclusively the anatomical plural.

Noun

1. a genus of Sterninae