Parotid (Salivary) Gland – Anatomy, Innervation & Function – Human Anatomy | Kenhub


What’s your favorite type of food? I have a bit of a sweet tooth, so a nice slice
of cake is the ideal treat for me. That soft fluffy sponge, the light airy filling,
and those sweet juicy strawberries. Is your mouth watering yet? Mine it totally is. But how much do you know about the glands
that produce your saliva? Stick around to find out more about one of
them in our short tutorial on the parotid gland. The parotid gland is the largest of the three
major salivary glands and you have two of them, one on each side of your face. It’s pyramidal or kind of triangular in
shape and can be divided into a deep lobe and a superficial lobe, which are separated
by the facial nerve. The parotid gland is enclosed within a product
capsule which is derived from the investing layer of the deep cervical fascia. In terms of location, the parotid gland is
bordered by various structures. It is bordered superiorly by the zygomatic
arch, anteriorly by the masseter muscle, inferiorly by the inferior border of the mandible, and
posteriorly by the external ear and the sternocleidomastoid muscle. The parotid duct, also known as the Stensen
duct, transports saliva into the oral cavity. It arises from the anterior surface of the
parotid gland and runs across the anterior surface of the masseter muscle before piercing
the buccinator muscle. The duct opens into the oral cavity near the
upper second molar tooth. You should have gotten a clue about the function
of the parotid gland from the start of our tutorial and when we talked about the parotid
duct. Any ideas? Well, the function of the parotid gland is
pretty simple. It produces saliva. Specifically, it produces a serous saliva
which is watery and rich in enzymes. This saliva is then secreted via the parotid
duct into the oral cavity where it lubricates and assists in the breakdown of carbohydrates. It also functions as an antimicrobial agent
in the mouth. Next, we’re going to talk about some associated
structures of the parotid gland. The structures we’re going to talk about
and their relationship with the parotid gland is of great clinical significance particularly
during parotid gland surgery. The first structure we’re going to talk about
is the facial nerve, which as I said earlier, divides the parotid gland into deep and superficial
lobes. The facial nerve gives rise to five terminal
branches within the parotid gland which go in to innervate the muscles of facial expression. The external carotid artery enters or passes
deep to the parotid gland. As it ascends superiorly, the external carotid
artery gives rise to the posterior auricular artery before dividing into its two terminal
branches – the maxillary artery and the superficial temporal artery. The last structure we’re going to talk about
is the retromandibular vein. This vein is formed within the parotid gland
by the union of the superficial temporal and maxillary veins. It’s time to move on and discuss the blood
supply, innervation, and lymphatic drainage of the parotid gland. The parotid gland receives its arterial supply
from the branches of the external carotid artery, whereas its venous drainage is carried
out by the retromandibular vein. You may have thought that the parotid gland
would be innervated by the facial nerve, but that would be too easy. The parotid receives both sensory and autonomic
innervation. It receives its sensory supply from the auriculotemporal
nerve and the greater auricular nerve. The parasympathetic supply which stimulates
saliva production comes from the glossopharyngeal nerve via the auriculotemporal nerve and it
receives the sympathetic supply from the superior cervical ganglion. Lymph from the parotid gland drains to the
superior deep cervical nodes. Now that we’re experts on the parotid gland,
let’s get clinical. Salivary gland tumors are relatively uncommon,
but the most common site is the parotid gland. These tumors are usually benign whereas tumors
of the other major salivary glands are more likely to be malignant. Risk factors associated with parotid tumors
include radiation exposure, previous Epstein-Barr infection, and smoking. Patients usually present with a painless lump
or swelling in the region of the parotid gland. As the tumor grows, other symptoms may occur
such as difficulty swallowing or opening the mouth. Any suspicious lesions undergo ultrasound
scan with fine needle aspiration cytology to determine management. Management of benign tumors usually involves
observation in older patients and surgical excision in younger patients due to the risk
of tumors becoming malignant. Radiotherapy can also be used in the treatment
of parotid tumors. And that brings us to the end of our short
tutorial on the parotid gland. But don’t let your learning stop here, visit
kenhub.com where you can read interesting articles, test your knowledge with challenging
quizzes, explore our atlas with beautiful anatomical images, or watch more video tutorials
like this one. Yep, you’ll find everything you need to master
anatomy in no time. Go on, click the button. You know you want to.

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