Parotid gland (dave's notes) Flashcards
What is the function and general shape of the parotid gland?
The parotid is a serous salivary gland with scattered mutinous acini. It has an irregular shape.
Where is the parotid found?
The parotid fills a gap between mastoid process, ramus and styloid process.
Describe the poles and surfaces of the parotid. What is the coating of the parotid?
Upper and lower poles, lateral, anterior and deep surfaces. Surrounded by tough parotid sheath - investing layer of the deep fascia
Describe the shape and location of upper pole of the parotid
A small concave surface adhering to the external acoustic meatus near the TMJ capsule
Describe the shape and location of the lower pole of the parotid
Rounded, lying below and behind the angle of the mandible. Indented by SCM, overlaps the posterior belly of digastric.
Describe the surface of and location of the lateral surface of the parotid
Subcutaneous and almost flat
What is the shape of the anterior surface of the parotid?
U shaped
What are the relations of the anterior surface of the parotid?
The anterior surface is U shaped clasping the ramus of the mandible. Masseter lies on the outer surface and the medial pterygoid is on the inner surface.
What surface of the parotid is nearest the medial pterygoid and submandibular gland? What prevents direct contact between the parotid and these structures?
The anterior surface. Stylomandibular ligament.
What is formed when the anterior surface and the lateral surface of the parotid meet?
The anterior border
What is found deep to the anterior border of the parotid?
The parotid duct and the five branches of the facial nerve. The terminal branches of the external carotid are deeper still.
What are the relations of the deep/posteromeidal surface of the parotid
Indented by the surrounding structures; lies against the styloid process and its muscles
List the muscles of the styloid process
Stylohyoid, styloglossus, stylopharyngeus and ligaments, stylohyoid, stylomandibular (ligament)
What structures does the styloid process separate the parotid gland from?
The internal jugular vein and internal carotid artery
What is found embedded in the parotid gland?
Superficial to deep: facial nerve, retromandibular vein, external carotid artery
Describe the course of the facial nerve through the parotid gland
Enters deep but emerges superficial BEHIND the ANTERIOR border
Describe the course of the retromandibular vein through the parotid gland
Runs immediately deep to the facial nerve
What are the deepest large structures found within the parotid gland?
The terminal branches of of the external carotid artery
Give the the length and course of the parotid duct
5cm long, passes forwards across masseter, turns around the anterior border to pierce buccinator.
Where does the parotid duct open?
On the mucous membrane of the cheek opposite to the 2nd upper molar. Protected by a flap.
What is the blood supply to the parotid gland? Venous drainage?
External carotid, retromandibular vein.
Where does parotid lymph drain to?
External carotid artery nodes to deep cervical nodes.
What type of nerve supply does the parotid gland receive?
Secretomotor and sympathetic fibres
Via what nerve is the secretomotor supply to the parotid gland?
ISN ??? to glossopharyngeal nerve (tympanic branch) -> to tympanic plexus otic ganglion; hitch-hikes via at the auriculotemporal nerve.
How do sympathetic fibres reach the parotid gland?
From the superior cervical ganglion via the external carotid artery and middle meningeal arteries
Describe the structure of the parotid gland
Predominantly serous acini
Many ducts
Fat cells
How does the parotid gland develop?
From a groove in the cheek becoming a tunnel with a blind ending.
