Salivary glands

Question 1

what controls the salivary glands?

Answer 1

they are organs so they are controlled by the autonomic nervous system.

• sympathetic: “sticky” saliva, fight or flight response, periarterial plexus
• parasympathetic: “runny” saliva, rest and digest

Question 2

which parasympathetic axons control salivation?

Answer 2

• facial nerve (CN VIII)

- glossopharyngeal nerve (CN IX)

Question 3

where does each of the glands secrete their saliva?

Answer 3

• parotid gland: near the 2nd maxillary molars, via parotid papilla
• submandibular gland: drains to the sublingual caruncle
• sublingual gland: drains superior into the mouth via sublingual folds
• other minor salivary glands (1000’s of them), have basal (background n continuous) secretion to keep the mouth moist.

Question 4

state the features of the parotid gland

Answer 4

• anterior and inferior to ears
• largest salivary gland
• produces thick saliva rich in amylase
• 25% of daily saliva
• drains into the parotid duct which goes round the masseter muscle and pieces through the buccinator

Question 5

what is the parotid region

Answer 5

• capsule by the investing layer of deep cervical fascia

- due to strong deep cervical fascia, the gland cannot swell so would cause extreme pain

Question 6

what are the contents of the parotid region

Answer 6

• plexus facial nerves
• retromandibular vein
• external carotid artery

Question 7

describe the innervation of the parotid gland

Answer 7

• nerve fibres originate from CN XI
• they travel to the tympanic branch of the tympanic plexus where they become lesser petrosal nerves.
• then the fibre synapse at the otic ganglion, where they become post-ganglionic axons.
• they travel to the parotid gland via the auricular temporal branch of the mandibular trigeminal nerve.

Question 8

what is the mylohyoid line?

Answer 8

the line which the mylohyoid muscle (muscle of the floor of the mouth) attaches to

Question 9

where is the submandibular fossa?

Answer 9

inferior to the mylohyoid line

Question 10

state the features of the submandibular gland

Answer 10

• mixture of serous (thick) and mucus (thin) saliva
• located in the submandibular triangle and floor of the mouth
• passes behind the free border of the mylohyoid bone
• has two parts; superficial and deep, separated by the mylohyoid muscle which attaches to the hyoid bone
• drains into submandibular papillae via submandibular ducts (caruncle drainage)

Question 11

what is the submandibular traingle

Answer 11

• where the superficial part of the submandibular gland is positioned and can be palpated here
• contains: hypoglossal nerves, facial artery and submandibular lymph nodes

Question 12

describe the anatomical relationship of the lingual nerve and submandibular duct

Answer 12

the lingual nerve passed the submandibular duct inferiority, from lateral to medial, towards the tongue

Question 13

state the features of the sublingual gland

Answer 13

• serous saliva (thicker saliva)
• smallest of the 3 major glands
• almond-shaped
• lies superiorly to the mylohyoid muscle
• drains into the floor of the mouth via sublingual ducts (8-20 sublingual ducts)

Question 14

describe the innervation of the submandibular and sublingual gland

Answer 14

• fibre originates from the facial nerve in the tympanic plexus
• exists the tympanic plexus as chorda tympani, which hitches a ride with the lingual nerve
• eventually reaches the submandibular ganglion
• the post-ganglionic nerve then travels to submandibular and sublingual glands.