tongue, pharynx, oesophagus, stomach Flashcards
what 6 things occur ingroups of 3
3 extrinsic tongue muscles 3 sets of intrinsic tongue muscles 3 nerves supply the tongue 3 regions of the pharynx 3 circular muscles of the pharynx 3 longitudinal muscles of the pharynx
what can be seen in the midline and below the central incisors and what do they do
- 2 spikes of bone = superior genial spines
- attach largest muscles of the tongue (right and left genioglossus muscles)
- there are 4 but lower ones are covered by the above muscle
- the hyoid bone can also be seen (U shaped, free-floating) which provides attachment for many muscles ie the hyoglossus of tongue
what two sets of muscles does the tongue contain
3 sets of:
extrinsic (originate outside the tongue, act to move it around)
intrinsic (confined entirely to the tongue, act to change its shape)
why are the extrinsic muscle names easy to remember
ALL combine the origin of the muscle
with “glossus” (from greek for tongue)
list the 3 extrinsic muscle of the tongue
1) STYLOGLOSSUS
2) HYOGLOSSUS
3) GENIOGLOSSUS
where does the styloglossus originate and what does it do
styloid process of temporal bone
lifts tongue up and back (as styloid process of temporal bone is fixed below external ear canal)
where does the hyloglossus originate and what does it do
hyoid bone
pulls tongue down (hyoid bone is mobile but muscles attaching to its inferior surface hold it in place so it cant be pulled upwards)
where does the genioglossus originate and what does it do
superior genial tubercles of mandible
protrudes the tongue (bc its attached anteriorly so pushes the tongue forwards when the Genioglossus contracts it)
what do intrinsic muscles occur as
sets of muscle fibres which intertwine together (cannot be dissected apart)
what are the 3 intrinsic muscle fibres
- horizontal
- vertical
- longitudinal
where are horizontal fibres and what do they do
stick out from coronal section/ midline in both directions
make tongue
1) narrower
2) longer
3) thicker vertically / thinner laterally
as they pull the sides of the tongue inwards when contract
why does the tongue get thicker in a vertical direction when it becomes narrower
certain volume of fluid in tongue
has to be accomodated for
where are vertical fibres and what do they do
mixed together with horizontal fibres in the core of the tongue make tongue 1) vertically thinner 2) thicker laterally 3) longer by drawing its dorsal surface down
where are longitudinal fibres and what do they do
2 sub groups (superior + inferior) run along length of tongue as they run along length they get shorter and ... Curve tip of tongue up (superior group) or down (inferior group)
which nerve supplies motor supply to all muscles of the tongue
cranial nerve XII
= hypoglossal nerve (true hypoglossal nerve fibres arise in hypoglossal nucleus in the brain and are ALL motor fibres. ALL they do is supply the muscles of the tongue)
