**8. Minor salivary glands**

Minor salivary glands are present within the wall of the oral cavity and oropharynx, and have short ducts [48]. They are named on the basis of their location:


The minor salivary glands are present in all three forms, that is, serous, mucous, and seromucous, which are the contributors of serous and mucous secretions through secretary ducts to saliva. Secretary units exist in a variety of forms (i.e., acinar, tubuloacinar, or tubular). Mucous tubules surrounded by the serous acini frequently develop serous demilunes; however striated ducts (the small ducts) are not its characteristics. The epithelium present in it is the simply squamous to low-cuboidal in shape. Later in the oral cavity, it is changed into stratified squamous form. Glands in the cheeks lie in the middle, dorsal, and ventral rows. The glands of the labial regions are assemblage as superior (nasolabial glands), commissural labial (under the skin along the mouth angle), and inferior labial glands which are connected to the commissural labial glands [15].

The composition of the submandibular gland varies in terms of saliva secretion among different species. The mandibular salivary gland is responsible for the production of a major portion of saliva. These are situated in the ventral and caudal part of the angle of the mandible and are irregularly triangular in shape. The gland has three angles, two surfaces, and three borders. The lateral surface is covered partly by the ventral part of the parotid gland. The medial surface is related to retrophyrangeal lymph node, the pharynx, larynx, and the lingual artery. The mandibular salivary gland is cream-colored or pale yellow, weighing from 5 g to 11 g. It is tubule-alveolar in composition. A thin connective tissue capsule covers the gland and the gland is derived into lobes and lobules by connective tissue septa emerging from the capsule. These connective tissue septa contain ducts, blood vessels, lymphatic, and nerves. The mixed alveoli (seromucous) are more abundantly present in the parenchyma than the other two forms. The duct system of the gland consists of intercalated, striated, and excretory duct forms [49].

Like other ruminants, goats are known to process saliva that acts mainly as a bicarbonate phosphate buffer, which aids in rumination and maintaining electrolyte and water balance, thus the saliva has a role in producing alkaline activity and evenness of the food contents within the sac of rumen and reticulum [50]. After suckling, the milk is overstepped by the reticulo-rumen through the esophageal groove into the true stomach (abomasums) in goat kids. The rumen remains very small in kids due to consuming liquid contents only until and unless the animal receives the fibrous diet. The juvenile animal relies on milk to neutralize the acidic environment in the stomach.
