What is the shape and location of the submandibular duct?

The submandibular duct, also known as Wharton's duct, is indeed accurately described as walnut-shaped due to its unique anatomical configuration. This duct arises from the submandibular gland, which is situated beneath the jaw, specifically posterior to the submandibular gland itself. It extends anteriorly and medially, traveling along the floor of the mouth and eventually opening into the oral cavity at the sublingual caruncle, located near the midline under the tongue.

Understanding the location is crucial, as the submandibular duct's position plays an important role in its function in salivary flow. This anatomical detail helps in clinical evaluations and procedures involving submandibular salivary flow, such as managing salivary stones or during oral surgery. The other options do not accurately reflect the anatomical characteristics of the submandibular duct, as they misrepresent its shape or location.