THE SALIVARY GLANDS

Cattle produce an enormous volume of saliva—perhaps as much as 100 L a day—which contributes to the fer­mentation medium within the forechambers of the stomach, where it helps to buffer the fatty acids that are produced.

Although the parotid gland is almost continuously active, it is smaller than might be expected. It lies ventral to the ear along the caudal border of the masseter, where it partly covers the parotid lymph node. A spurt in its growth is coordinated with the initiation of rumi­nant digestion by the calf. The duct was encountered in the description of the face (Figure 25-2/70).

The mandibular gland is considerably larger. It pro­duces a mixed secretion but only when the animal is actually feeding or remasticating; the flow is most copious when the fodder is dry. The gland extends in an arc on the inner aspect of the lower jaw. Its palpable ventral end projects below the mandible and often almost meets its fellow in the midline; its dorsal end is within the atlantal fossa. The duct runs below the oral mucosa to open by the sublingual caruncle (Figure 25-13/2).

The sublingual gland has the usual two divisions. The polystomatic part lies in the mouth floor, lateral to the tongue, and drains through many small openings beside the frenulum. It is overlapped by the more compact rostral part, whose single duct opens close by or together with that of the mandibular gland.

Many minor salivary glands are scattered below the labial, buccal, palatine, and lingual mucosae; those in the cheeks are particularly well developed. In the aggre­gate, these lesser glands must contribute a considerable volume of secretion.