Cow salivary glands

Cow salivary glands are the accessory organs of its digestive system. Here, I will discuss the anatomy of the cow’s major salivary glands with a hand-drawing diagram and real images.

Quick answer:  Cow salivary glands consist of both the major and minor types, where the major type includes pairs of parotid, mandibular, and sublingual glands.

I will describe the topographic locations of these three major salivary glands, including their other anatomical features. However, you will learn the specific ducts of these glands along their opening sites within the mouth of a cow.  

What are the salivary glands of a cow?

Figure 1 shows three pairs of hand-drawn large organs situated on the side of the face and the adjacent part of the neck. These are the cow’s salivary glands, which are named parotid, mandibular, and sublingual.

Thus, like numerous glands in the stomach and intestine, you will also find these accessory glands in the digestive system. However, there are also a few other accessory glands, like the liver and pancreas, in the cow’s digestive system.

Again, these three pairs of well-defined glands are termed the major salivary glands. Whereas the labial, buccal, lingual, and palatine are the minor salivary glands in the ruminant (Rowen et al., 2000).

Table 1 presents an overview of the cow’s three pairs of major salivary glands –

Salivary glands	Parotid	Mandibular	Sublingual
Shape	Triangular	Elongated	Lobulated (2)Two parts
Color	Reddish brown	Pale yellow	Pale yellow/pink
Location	Ventral to the ear	Ventral to parotid	(Variable)
Surfaces	Lateral and medial	Lateral and medial	Dorsal and ventral
Main duct	Stenson’s duct	Wharton’s duct	Polystomatic ducts Monostomatic duct (1)
Duct opening site	Papillae salivalis	Caruncula sublingualis	(Variable)

However, I will provide details on the location, surfaces, courses of the ducts, and the opening sites of these salivary glands. For a description of any of these salivary glands, you might mention the following –

• Shape and topographic location of the salivary gland,
• Surfaces and borders of the glands, and
• Courses of the main duct of these salivary glands (origin and duct opening sites),

Parotid salivary gland of a cow

Figure 2 shows the cow’s triangular-shaped parotid salivary gland. It also presents the location, direction, surfaces, borders, and topographic relationship of the cow’s parotid salivary gland.

Location: The cow’s salivary gland is located in the space between the ramus of the mandible and the wing of the atlas bone. However, it overlaps the caudal part of the cow’s masseter muscle.

Here, the masseter muscle is part of the masticatory muscles and is described under the cow’s muscular system.

Shape and direction: The shape of the parotid salivary gland is roughly triangular in the cow. Here, the base of the parotid gland is directed dorsally, where the apex is ventrally.

For description, the cow’s parotid salivary gland possesses 2 surfaces, 2 borders, a base, and an apex. Now, I will help you to understand and identify these features from the cow’s parotid gland.

Surfaces of the cow’s parotid salivary gland

Figure 3 presents the external and internal surfaces of the cow’s parotid salivary gland. However, it also presents the relationship of these surfaces with surrounding organs and structures.

External surface: The external or lateral surface of the parotid gland is covered with fascia parotido auricularis muscle along the vertical length. However, the zygomatico auricularis muscle also covers the parotid gland at its base.

Again, the external surface is crossed obliquely by the external jugular vein at its lower parts.

Internal surface: The internal or medial surface is uneven and related to several structures. These structures include –

• Great cornu of the hyoid bone,
• The masseter, digastricus, and occipitohyoideus muscles,
• Tendons of the brachiocephalicus and sternocephalicus muscles (parts of the cow’s neck muscles),
• External carotid artery with its branches,
• Branches of the facial nerve,
• The pharyngeal lymph node and the mandibular salivary gland,

Here, the branches of the cow’s facial nerve pass through the parenchyma of the parotid salivary gland.

Borders, base, and apex of the cow/cattle’s parotid gland

Figure 4 highlights the rostral and caudal borders of the cow/cattle’s parotid salivary gland. However, it also highlights the dorsal base and ventral apex of the parotid salivary gland.

Rostral border: It is closely attached to the masseter muscle and partly covered by the parotid lymph node.

Caudal border: Here, the caudal border of the cow’s parotid gland is concave (Figure 4). However, it attaches to the various surrounding structures.

Base of the gland: It is broad, notched, and encircles the base of the external ear.

Apex of the gland: It is slightly bent and fits into the angle of union of the external jugular vein and external maxillary vein.

Parotid duct/Stenson’s duct course

Figure 5 shows the cow’s parotid/Stenson’s duct that arises from the ventral aspect of the medial surface of the gland. It extends medially along the ventral border of the mandible.

Here, it passes between the masseter muscle in front and the external maxillary vein behind. Now, it passes to the lateral surface at the vascular groove of the cow’s mandible.

However, the duct runs upward and forward between the anterior border of the cow’s masseter muscle and the facial vein. Finally, it pierces the buccinator muscle and opens at the base of the papilla salivalis (Ghosh, 2000).

The papillae salivalis is located on the cheek opposite the level of the cow’s upper second molar tooth. Here, the molar and premolar teeth of the cow are also known as the cheek teeth.

Cow’s mandibular salivary gland

Figure 6 presents the topographic location, extremities, surfaces, and borders of the cow’s mandibular salivary gland.

Here, the mandibular gland is the largest of all the salivary glands of a cow. However, it is long, narrow, curved, and oval.

Location: This salivary gland is located along the medial side of the angle of the mandible.

Extension: It extends from the level of the wing of the atlas to the basihyoid bone. However, the cow’s mandibular salivary gland is partly covered by the parotid salivary gland.

Extremities of the cow’s mandibular gland

Here, Figure 7 presents the caudal and rostral extremities of the cow’s mandibular salivary gland.

Caudal extremity: Here, the caudal extremity of the cow’s mandibular gland is rounded. However, this extremity of the gland is loosely attached to the fossa atlantis of the wing of the cow’s atlas bone.

Rostral extremity: The rostral extremity is larger and more rounded than that of the caudal extremity. It lies at the side of the root of the cow’s tongue underneath the mucous membrane of the floor of the mouth.

Surfaces and borders of the mandibular salivary gland

The cow’s mandibular gland presents 2 surfaces: external and internal, and 2 borders: dorsal and ventral (Figure 8).

External/lateral surface: This surface is covered by the parotid salivary gland, digastricus, and internal pterygoid muscles. However, the tendons of the brachiocephalicus and sternocephalicus muscles also cover this surface of the gland.

Internal/medial surface: It is related to the following organs/structures/muscles –

• Cow’s larynx,
• The straight capitis ventralis major muscle,
• Cow’s carotid artery,
• The vagus and accessory nerves, and
• The sympathetic nerve trunk,

Dorsal border: This border is concave and thin, and the mandibular duct arises from this border.

Ventral border: Here, the ventral/lower border of the cow’s mandibular gland is convex and thick.

Cow’s mandibular duct course (Wharton’s duct)

Figure 9 presents the hand-drawing presentation of the course of the cow’s mandibular duct. However, another name for this duct is Wharton’s duct.

Here, the Wharton’s duct arises from the middle of the concave dorsal border of the gland. It extends forward and crosses the disgastricus and stylohyoideus muscles.

However, it also passes under the hypoglossal nerve and attaches to the internal surface of the sublingual gland. Finally, it runs forward under the mucous membrane of the mouth and opens on the caruncula sublingualis.

However, the caruncula sublingualis is a papilla located on the floor of the mouth at the level and opposite to the last incisor tooth.

Sublingual salivary glands in a cow

Figure 10 presents two separated parts (dorsal and ventral) of the cow’s sublingual salivary gland.

Location: The cow’s sublingual salivary glands are located beneath the mucous membrane of the mouth. They remain between the body of the cow’s tongue and the ramus of the mandible.

Dorsal/superior part of the sublingual salivary gland

Figure 11 highlights the location and relationship of the dorsal/superior sublingual salivary gland of a cow. It also presents the schematic diagram of the duct of the superior sublingual salivary gland.

Here, the dorsal/superior part of the cow’s sublingual salivary gland is also known as the polystomatic sublingual gland. Let’s see the location, extension, color, and relationship of the dorsal sublingual gland of the cow.

Extension: The dorsal part of the cow’s sublingual gland extends from the rostral pillar of the soft palate to the mandibular symphysis.

Appearance and color: This part of the sublingual gland is long, thin, and pale yellow. However, it consists of a fairly large number of glandular lobes (lobulated).

Relationship to other organs: Laterally, it is related to the mylohyoideus muscle; medially, to the styloglossus and palatoglossal muscles.

Ducts: The various glundular lobes of the dorsal part of the cow’s sublingual gland give rise to an equal number of secretory ducts. These are known as the cow’s minor sublingual salivary gland.

They open at the base of the papillae located in a line on either side of the frenum linguae at the floor of the mouth.

Ventral/inferior sublingual salivary gland in a cow

Figure 12 highlights the location, extension, and relationship of the ventral/inferior part of the cow’s sublingual gland. It also shows the duct of this ventral part of the gland along with its opening.

Location and extension: The ventral part of the cow’s sublingual salivary gland is shorter but thicker than the dorsal part. It lies just ventral to the dorsal/superior sublingual gland.

However, this part of the gland is pink and extends from the mandibular symphysis to the level of the last premolar tooth. This part of the cow’s sublingual salivary is also known as the monostomatic salivary gland.

Relationship with other organs: The whole of the ventral part of the cow’s sublingual gland is compressed laterally. Its external surface is related to the mylohyoideus muscle.

However, its internal surface relates to the genioglossus and styloglossus muscles. It also relates to the mandibular duct (Wharton’s duct) and branches of the cow’s lingual nerve.

Borders: Here, the dorsal border of this gland is under the mucous membrane of the floor of the cow’s mouth. However, the ventral border is related to the geniohyoid muscle.

Ducts:  There is only one duct for this ventral part of the cow’s sublingual salivary gland. It either joins with the mandibular duct or opens separately at the base of the caruncula sublingualis. However, the duct opening is so close to the mandibular duct opening.

FAQ’s on the cow’s salivary glands

Conclusion

Cow salivary glands comprise three pairs of well-defined major as well as scattered lobules of minor glands. Here, the cow’s major salivary glands are the parotid, mandibular, and sublingual glands.

However, the parotid gland is triangular, the mandibular gland is elongated, and the sublingual gland is lobulated in the cow. Each of the salivary glands has specific ducts that open into a specific area of the cow’s mouth.

References

• Ghosh, R. K. : Primary veterinary anatomy, 2nd Edn.Current Books International, Kolkata.
• Rao, P. and Singh, A. (2024). Morphological analysis of minor salivary glands of the pig: Gross anatomical studies. The Haryana Veterinarian 63(1): 37-40.
• Rowen D. Frandson, W. Lee Wilke, and A. Dee: Anatomy and physiology of farm animals, 4th edn.Wiley-Blackwell, USA.
• Getty, R. Sission and Grossman’s The anatomy of the domestic animals, 5th Edn. W. B. Saynders and Co., Philadelphia (USA).
• S AL Sadi, Gross study of the salivary glands in cattle, Basrah Journal of Veterinary Research, 12 (1): 65 – 75,
• Nickel, R., Schummer, A. and Seiferle, E.: The anatomy of domestic animals, 1st Edn. Verlag Paul Parey, Berlin.
• Hermanson et al., Miller and Evan’s Anatomy of the Dog, 5th Edn. Elsevier.
• J Kaman, A Doubled Ductus Parotideus in a Cow, Acta Vet. Brno 1986, 55: 3-9  
• Mcleod, W. N.: Bovine anatomy, 2nd Edn. Burgess Publishing Co., Minneapolis.
• Dyce, K. M., W. O. Sack, and CSG Wensing : Textbook of Veterinary Anatomy, Lea & Febiger. Philadelphia

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