UNIT 5: Tongue + Hypoglossal Nerve Flashcards

(78 cards)

1
Q

what is considered a muscular hydrostat

A

tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a muscular hydrostat

A

a fluid filled incompressible epithelial bag - the muscles serve as the fluid

a constant volume sys

any reduction in volume in one part is associated w an equivalent inc in another part

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the two anatomical divisions of the tongue

A

oral tongue

pharyngeal tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

oral tongue includes

A

anterior 2/3 w/i oral cavity (tongue dorsum aka superior surface)
tip, blade, front, back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

pharyngeal tongue includes

A

posterior 1/3 aka tongue base
w/i oropharynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the general features of the anterior 2/3 of the tongue? midline depression?

A

thick rough, epithelial covering

midline depression = longitudinal sulcus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

4 types of papillae on ant 2/3 of tongue

A

fungiform
filiform
folliate (simple)
vallate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

papillae

A

microscopic projections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

fungiform papillae are …. and contain …

A

mushroom shaped paillae
contain taste buds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

where do you find fungiform papillae

A

scattered over tongue dorsum and sides

predominant on tip of tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

fungiform papillae are innervated by

A

chorda tympani of CN VII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

which type of papillae is most numerous

A

filiform papillae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

describe filiform papillae, do they have taste buds? purpose?

A

very small, sharp pointed projections on tongue dorsum

no taste buds, used to grip food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what type of paillae is highly dev in cats?

A

filiform

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

which papillae accounts for the rough texture of the tongue dorsum?

A

filiform

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how are filiform papillae arranged?

A

in parallel rows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

describe foliate papillae

A

variable in humans

mucosal folds present on the lateral aspects of the tongue, anterior to the palatoglossal arch

aka simple papillae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are foliate papillae covered by

A

epithelium containing taste receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

which are the largest papillae

A

vallate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how are vallate paillae arranged? what shape are they?

A

7-12 arranged in posteriorly pointing arrowhead

cylinder-shape surrounded by a moat w taste buds on the cylinder and in the wall of the moat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what division do the vallate papillae form?

A

division bw anterior 2/3 and posterior 1/3 of tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

vallate papillae are innervated by

A

CN XI (glosso)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

describe the surface of the pharyngeal tongue (post 1/3)

A

smooth, thin, nodular covering due to presence of lingual tonsils in underlying submucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

terminal sulcus is

A

a groove on the pharyngeal tongue that is just posterior to circumvallate papillae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
foramen cecum is a
small pit w/i the terminal sulcus on the pharyngeal tongue - marks the embryological origin of the thyroid gland
26
median and lateral glossoepiglottic folds on the pharyngeal tongue form the
valleculae at junction w epi
27
describe the ventral and inferolateral tongue
thin, smooth mucous membrane
28
lingual frenulum is
a fold of mucosa that attaches underside of tongue to floor of mouth
29
on either side of the lingual frenulum you will see
lingual veins seen thru thin mucosa
30
sublingual papilla is
opening of duct of submandibular salivary gland (L and R on either side of mouth)
31
sublingual folds of mucosa overlie the ______, with openings along the
sublingual salivary glands, w openings along the sublingual fold
32
5 basic taste sensations
salty sweet sour bitter umami
33
current hypothesis of how taste is mapped is
each papilla contains receptors for each taste sensation
34
which areas that send taste signals are innervated by CN IX?
posterior 1/3 tastes from soft palate and lingual surface of epi
35
what CN innervated anterior 2/3 of the tongue?
chorda tympani of CN VII
36
Taste from laryngeal surface of epi and larynx is supplied by
CN X
37
the gustatory nucleus is in
the NTS of the medulla
38
the gustatory cortex is in the
lateral cortex, insula
39
complex tastes also involve participation of the
olfactory nerve CN I
40
so what 4 CNs are involved in taste?
CN IX, CN X, CN VII, CN I
41
all muscles of the tongue are ____, with the two sides partially separated by the _____
bilateral median septum
42
median septum is
a fibrous partition that runs from tongue tip to hyoid bone (doesn't reach surface of the tongue)
43
intrinsic muscles of the tongue are ...... and are responsible for
contained in the hydrostat, arranged at right angles responsible for shape
44
extrinsic muscles of the tongue are .... and are responsible for ....
originate outside the tongue, pass into the tongue thru root responsible for position and shape
45
the 4 intrinsic muscles of the tongue are
superior longitudinal inferior longitudinal transverse vertical
46
superior longitudinal: O, I, A, Inn
O = fibrous tissue near epi and hyoid, and the median septum I = lateral regions of tongue and apex A= shortens tongue; acts on tongue tip - elevating, retracting, turning tip unilaterally Inn = hypoglossal (CN XII)
47
superior longitudinal forms
broad band beneath the dorsal epithelium
48
inferior longitudinal: O, I, A, Inn
O = tongue root and hyoid bone I = tongue tip A= shortens tongue; turns tip down, deviates Inn = CN XII
49
inferior longitudinal occupies...
lower sides of tongue
50
transverse is arranged at
right-angle to the longitudinal fibres
51
transverse: O, I, A, Inn
O = median septum I = fibrous tissues at lateral margins A = narrows and elongates tongue Inn = CN XII
52
vertical is perpendicular to
transverse and longitudinal
53
vertical: O, I, A, Inn
O = inferior and lateral margins of tongue I = dorsal membranous cover A = flattens and widens Inn = CN XII
54
what are the 4 extrinsic muscles of the tongue
genioglossus hyoglossus styloglossus palatoglossus
55
genioglossus: O, I, A, Inn
O = mental spine of mandible I = mucous membrane of tongue dorsum from base to tip; inferior fibres insert into hyoid bone A = protrudes tongue, depresses central portion Inn = CN XII
56
genioglossus is a
large muscle making up bulk of the tongue
57
hyoglossus is a
quadrilateral sheet on side of tongue, lateral to genioglossus
58
hyoglossus: O, I, A, Inn
O = greater cornu and body of hyoid bone I = mucous membrane on lateral margins of tongue A = pulls down sides of tongue Inn = CN XII
59
styloglossus is a
slender muscle, runs inferiorly/anteriorly, passing below superior constrictor of pharynx
60
styloglossus: O, I, A, Inn
O = styloid process of temporal bone, stylomandibular ligament I = posterolateral portion of tongue, interdigitates w hyoglossus A = lifts sides of tongue, pulls tongue backward Inn = CN XII
61
palatoglossus forms the
anterior faucial pillars; marks junction bw oral cavity and pharynx
62
palatoglossus: O, I, A, Inn
O = inferior surface of palatal aponeurosis (palatine bone) I = posterolateral portion of tongue A = elevates and retracts tongue base; depresses soft palate (narrows the oropharyngeal isthmus) Inn = pharyngeal branch of CN X
63
hypoglossal CN XII has how many fibre types
one, GSE
64
how does the hypoglossal nerve dev?
does not dev from a branchial arch, therefore somatic vs visceral i.e. Developing along the neural tube, remember it comes from somites (give rise to skin and muscles of limbs and muscles of the tongue)
65
the hypoglossal nerve supplies ____ extrinsic muscles of the tongue and ____ intrinsic muscles of the tongue
3/4 all
66
describe the intracranial course of the hypoglossal nerve
cell bodies of LMNs are contained in the hypoglossal nucleus in the medulla hypoglossal nerve exits cranium via hypoglossal foramen in the posterior cranial fossa (near foramen magnum)
67
there is _____ innervation of all tongue muscles except _____
bilateral genioglossus (contralateral)
68
hypoglossal nerve extracranial course:
courses medial to CN IX, X, XI runs bw arteries and veins passes lateral to hyoglossus and genioglossus, and then supplies target muscles
69
cortical neurons that drive the genioglossus muscle project only to the ______ hypoglossal nuclei, therefore to test CN XII you can...
contralateral test the action of the genioglossus - if the muscle contracts bilaterally it will protrude the tongue, if innervation is impaired it will deviate laterally on protrusion to the side of weakness
70
the right and left hypoglossal nuclei are located close to the midline of the _____, a nuclear lesion tends to affect ______ nuclei causing ....
medulla both nuclei causing loss of innervation to the tongue
71
6 ways to test CN XII functions
symmtery of tongue at rest symmetry on protrusion range of motion on lateralization range of motion on elevation range of motion on retraction accuracy and speech of diadochokinesis
72
during dev, where does the anterior 2/3 of the tongue arise from
the mounds of tissue at the fusion line bw the mandibular processes of the 1st arch tuberculum impar and lateral lingual swellings
73
during dev, where does the posterior 1/3 of the tongue arise from
a swelling, hypobranchial eminence, at the midline bw the 3rd and 4th arches
74
anterior half of hypobranchial eminence grows forward to
fuse w the anterior tongue at sulcus terminalis
75
posterior half of the hypobranchial eminence becomes the
epiglottis
76
where do the muscles of the tongue arise from
somites - blocks of tissue in the occipital region cells migrate and infiltrate the epithelial covering of the dev tongue formed by the 1st, 3rd, 4th arches nerve associated w somites = CN XII
77
how does the epiglottis form
anterior half of hypobranchial eminence migrates to tongue base transverse depression devs bw anterior and posterior halves of hypobranchial eminence depression deepends w backward migration of posterior half = glossoepiglottic fossa then divided into calleculae by the median glossoepiglottic fold
78
they hypoglossal nerve is purely
a motor nerve