Salivation Flashcards
list the 3 major salivary glands
parotid (largest)
submandibular
sublingual (smallest)
where is the parotid gland
- in posterior aspect of face anterior to external ear
- wrapped around posterior border of ramus of mandible (both superficial AND deep to it)
- lies on deep surface of mandible
what duct does the parotid gland have and where does this open into
- single discrete duct
- runs superficial to masseter muscle
- turns medially to pierce buccinator
- opens into vestibule of mouth
- opposite crown of upper 2nd molar
what is the structure and location of the submandibular gland
- horseshoe shape
- has intra oral (inferior to mucosa of floor of mouth) ad extra oral (palpated below lateral aspect of body of mandible and wraps around posterior border of mylohyoid muscle) parts
- wraps around inferior border of mandible
- surrounded by submandibular lymph nodes
what duct does the parotid gland have and where does this open into
- single discrete duct that runs anteromedially to open at sub-lingual papillae (projection in floor of mouth behind lower incisor)
- there are right and left papillae which receive ducts of the right and left submandibular glands respectively
where is the sublingual gland located
- between lateral surface of tongue and inner surface of mandible
- inferior to mucosa covering floor of mouth
what ducts does the sublingual gland have
- a SERIES of (15-20) DUCTULES which open along the length of the sub-lingual folds (in floor of mouth, seen if lift tongue up - pulled up by submandibular duct and mucosa covering them raised)
which other salivary glands do we have and where are these
- tiny accessory salivary glands
- embedded in mucosa of tongue, palate and lips
- supplied by entirely different set of nerves
how many cranial nerves are on each side of the head and neck and which types of fibres do they carry
12 (I-XII)
- some sensory and others motor
- most carry a mixture of the two (provide much of motor + sensory supply to innervation of head and neck region)
how do the cranial nerves emerge from the brain
leave skull through specific foramina / fissures
I (olfactory nerve) = most superiorly
- progressively more inferiorly
- XII (hyperglossal nerve) = most inferiorly
which cranial nerve is the only one to leave the head and neck region
- vagus nerve
- innervates structures in chest and abdomen
- latin vagrantis = wanderer
in contrast where do the spinal nerves emerge
- from spinal cord
- leave through spaces between vertebrae of the spinal column
which nerves stimulate secretion and which cranial nerves do the ones supplying the major salivary glands run in
- SECRETOMOTOR FIBRES
run in… - VII - facial nerve
- IX - glossopharyngeal nerve
why is the trigeminal nerve V also important despite not itself providing secretor motor fibres to salivary glands
- branches of it carry some of facial glossopharyngeal nerve fibres to their target glands
which system are nerve fibres causing salivary glands to secrete part of and what does this mean for secretion of the salivary glands
- parasympathetic nervous system (division of the autonomic nervous system - part of nervous system controlling functions we do not have voluntary control over)
- means we don’t have direct conscious control over it
what functions are parasympathetic nerve fibres associated with
- ‘rest-and-digest’
sympathetic division = ‘fight-and-flight’ - antagonistic
how are secretomotors innervated
- cranial nerves VII and IX provide motor innervation that stimulates salivation
what are swellings on nerves carrying autonomic nerve fibres called and where are they found
- autonomic ganglia
- where autonomic nerve fibres join other autonomic nerve fibres
- nerves inside these are structurally different to sensory nerve fibres
how are ganglia formed
- pre-ganglionic fibres (coming into ganglion) stop in the ganglion by making synapses (functional connections) with the cell bodies of the post-ganglionic nerve fibres (leaving)
why is the ganglion present
accomodates all cell bodies of the post ganglionic fibres (cell bodies = thicker than nerve fibres that come from them so take up a lot of space)