Definition

Noun: 1. A soft, membrane-covered gap between the cranial bones of an infant or fetus: A fontanel is a space in a baby's skull where the bones have not yet fused together. These spaces are covered by a tough membrane and allow for the skull to be flexible during birth and for rapid brain growth in the first years of life.

Examples of Usage

• Noun:
  • The doctor gently palpated the baby's anterior fontanel to check for dehydration.
  • You can sometimes see a slight pulse in the soft spot of a newborn's head, which is the fontanel.
  • The posterior fontanel is smaller and usually closes within a few months after birth.

Advanced Usage

• "Bulging fontanel": A medical sign where the soft spot appears tense and raised above the level of the skull bones, which can indicate increased pressure inside the skull.
  • A bulging fontanel is a serious symptom that requires immediate medical attention.
• "Sunken fontanel": A medical sign where the soft spot appears depressed, which can be a sign of dehydration.
  • A sunken fontanel in an infant may suggest the baby is not getting enough fluids.

Variants and Related Words

• Fontanelle (noun): An alternative spelling of "fontanel," more commonly used in British English.
  • The midwife noted the size of the baby's fontanelle.
• Soft spot (noun, informal): A common, non-medical term for a fontanel.
  • Be careful when you wash the baby's hair over the soft spot.

Synonyms

• Cranial gap (noun, technical): A descriptive synonym emphasizing the anatomical location and nature of the opening.
• Soft spot (noun, informal): The most common layperson's synonym.

Related Phrases

• Anterior fontanel: The larger, diamond-shaped soft spot at the front of a baby's head. It is the most prominent and usually closes between 12 to 18 months of age.
• Posterior fontanel: The smaller, triangular soft spot at the back of a baby's head. It typically closes by the time a baby is 2 to 3 months old.

Noun

1. any membranous gap between the bones of the cranium in an infant or fetus