Final answer:
The sublingual and submandibular glands are most responsible for the lack of lubrication in a xerostomic patient due to their significant role in secreting mucous-rich saliva, which provides the necessary lubrication for the oral cavity.
Step-by-step explanation:
In a xerostomic patient, which salivary glands are most likely responsible for the lack of lubrication? The correct answer is D. Sublingual and submandibular glands.The salivary glands in question include the sublingual glands, which are found under the tongue, and the submandibular glands, which reside below the jaw. These glands contribute significantly to the lubrication of the mouth by secreting saliva through their respective ducts into the oral cavity. The parotid glands also play a role in saliva secretion but secrete a watery solution that is less effective in lubrication when compared to the thicker mucous-rich saliva produced by the submandibular and sublingual glands. Therefore, the sublingual and submandibular glands, due to their mucous-secreting cells and contribution to the overall volume and viscosity of saliva, are the ones likely to be most responsible for the lack of lubrication in a xerostomic patient.