the bronchi. Branches given off from the arch of the aorta--the brachiocephalic
(innominate) and left common carotid arteries--are in close relation to the trachea. The
cervical portion of the trachea is related anteriorly to the sternohyoid and sternothyroid
muscles and to the isthmus of the thyroid gland.
f. Salivary Glands.
(1) The salivary glands consist of three paired glands: the sublingual,
submaxillary, and parotid. They communicate with the mouth and pour their secretions
into its cavities. The combined secretion of all these glands is termed saliva. The
salivary glands consist of tissue found in the mucosa of the cheek, tongue, palate, floor
of the mouth, pharynx, lip and paranasal sinuses. A tumor of a salivary gland may
occur in any of these structures.
(2) The external carotid artery supplies the salivary glands and divides into
its terminal branches: the internal maxillary and superficial temporal. The superficial
temporal and internal maxillary veins unite to form the posterior facial vein.
(3) The sublingual gland lies on the undersurface of the tongue beneath the
mucous membrane of the floor of the mouth at the side of the frenulum linguae, in
communication with the sublingual depression on the inner surface of the mandible. It
is supplied with blood from the submental arteries. Its nerves are derived from the
sympathetic nerves. The many tiny ducts of each gland separately enter into the oral
cavity on the sublingual fold.
(4) The submandibular gland lies partly above and partly below the posterior
half of the base of the mandible and on the mylohyoid and hyoglossus muscles. This
gland is closely associated with the lingual veins and the lingual and hypoglossal
nerves. The external maxillary artery lies on the posterior border of the gland. Its duct
(Wharton's duct) enters the mouth at the frenulum of the tongue.
(5) The parotid gland, the largest of the salivary glands, lies below the
zygomatic arch in front of the mastoid process and behind the ramus of the mandible.
This gland is enclosed in fascia, attached to surrounding muscles, and divided into two
parts--a superficial and a deep portion--by means of the facial nerve. The parotid duct
(Stensen's duct) pierces the buccal pad of fat and the buccinator muscle, finally opening
into the oral cavity opposite the crown of the upper second molar tooth. The superficial
temporal artery and small branches of the external carotid arise in the parotid gland
behind the neck of the mandible.
g. General Structures of the Neck.
(1) The general topography of the organs lying in front of the prevertebral
facial has been described. A layer of deep cervical fascia surrounds the neck like a
collar and is attached to the trapezius and sternocleidomastoideus
(sternocleidomastoid) muscles. In front of the neck, the deep fascial layer is attached to
the lower border of the mandible.