Which lymph nodes are located beneath the jaw?

The submandibular nodes are located beneath the jaw and play a crucial role in the lymphatic drainage of the oral cavity, salivary glands, and parts of the throat. These nodes are positioned in the submandibular triangle, which is the area bounded by the mandible and the muscle structures of the neck. The presence and condition of the submandibular nodes can be vital indicators of various conditions, including infections or malignancies in the regions they drain.

The other options refer to different groups of lymph nodes in the neck. The preoticular nodes are not a recognized group; parotid nodes are associated with the parotid gland and are located around that gland; and posterior cervical nodes are found along the posterior side of the neck, draining different areas. Hence, identifying the correct location of the submandibular nodes is essential for a thorough HEENT assessment.