Question

what structure is highlighted?

a. optic disc
b. facial n. (cn vii)
c. von ebners glands
d. vallate papilla
e. taste bud

Explanation:

Analyze the histological image

The histological section shows a large, dome-shaped mucosal projection on the surface of the tongue, surrounded by a deep circular furrow or trench. This characteristic structure is a vallate (circumvallate) papilla. The green highlighted region covers the entire body of this papilla, including its epithelial lining and connective tissue core.

Identify surrounding structures

Deep to the furrow surrounding the papilla, serous salivary glands (von Ebner's glands) are visible in the submucosa, which empty their secretions into the trench. Along the lateral walls of the papilla facing the trench, pale oval structures representing taste buds can be found. Since the entire dome-shaped projection is highlighted in green, the highlighted structure is the vallate papilla.

Evaluate the options

• A. Optic disc: Incorrect. This is a structure of the eye, not present in this oral cavity section.
• B. Facial n. (CN VII): Incorrect. While CN VII carries taste sensation from the anterior two-thirds of the tongue, this is a histological slide of a epithelial surface structure, not a nerve bundle.
• C. von Ebner's glands: Incorrect. These are the serous glands located deeper in the tissue beneath the trench, not the highlighted surface projection.
• D. Vallate papilla: Correct. The highlighted green region represents the entire vallate papilla.
• E. Taste bud: Incorrect. Taste buds are microscopic structures embedded within the lateral epithelium of the papilla, not the entire large highlighted structure itself.

Answer:

• (A) Optic disc
• (B) Facial n. (CN VII)
• (C) von Ebner's glands
• (D) Vallate papilla (Correct answer)
• (E) Taste bud