Intracranial lymph vessels from the brain and meninges follow the courses of the arteries and veins and empty into the deep cervical glands. The superficial glands receive afferent vessels from all anterior superficial parts of the scalp and face including the external ear. Swelling of these glands may result from infection of any of the parts drained. Efferents of these glands drain into either superficial or deep cervical glands, which explains why a deep cervical swelling may result from superficial infection. The deep parotid lymph glands receive afferent vessels from the external meatus, tympanum, soft palate, and posterior nares.
Efferent vessels drain into the super deep cervical glands.
Infections of the external ear are not so likely to cause lymphatic swelling because there is usually free drainage. Infections of the nasopharynx and posterior nares cause glandular enlargement and these structures are nearly always involved in suppurative otitis media. The deep part of the parotid gland is lodged in a definite space behind the ramis of the lower jaw. This space is increased in size when the head is extended, and when the inferior maxilla is moved forward, as in protruding the chin. This explains why pain is caused by all movements which tend to decrease the space of this gland, such as chewing, swallowing, etc.