anatomy of tongue Flashcards
1
Q
tongue
A
- massive structure that occupies floor of mouth
- extends from tip back to extreme portion of oropharynx (hyoid bone)
- composed entirely of muscle internally
- covered in membrane and taste organs
- split in half by median fibrous septum
2
Q
general functions
A
- position food for mastication
- propel bolgus backward for deglutition
- oral clearing
- taste platform
- shape oral cavity for most vowels and consonants
3
Q
superior surface
A
- dorsum
- surface within oral cavity is oral surface (2/3)
- surface is oropharynx is pharyngeal surface (1/3)
4
Q
interior surface
A
-ventral
basic subdivisions
-tip, blade and root
-tip, anterior body, posterior body, base
5
Q
dorsal surface
A
- tongue surface divided in half by median suture
- terminates in a pit/depression called foramen cecum - terminal sulcus arises on both sides of foramen cecum
- divides oral and pharyngeal surface posterior and anterior surfaces are quite different
- differentiated embryologically
6
Q
mucuous membrance
A
- clearly different from skin
- inferior surface has a thin membrane to most of oral tract
- membrane on pharyngeal surface is thicker by movable
- anterior dorsal membrane is thin and closely attached to underlying muscles
- membrane consists of deep layer called corium
- extends throughout musculature of tongue
- dense, elastic connective tissue that forms part of a skeleton for tongue
7
Q
anterior dorsal surface
A
-covered by lingual papillae
-tiny growths from tongue epidermis that give surface a rough shape
4 types of papillae
-10 vallate papillae just anterior to terminal sulcus
-largest papillae that contain taste buds at their periphery
-fungiform papillae are found at sides and tip
-covered in secondary papillae with liberal distribution of taste buds
-filliform papillae are most common
-form lines or rows that parallel the vallate papillae
-simple papillae cover the entire membranous surface as well as the surface of other papillae
8
Q
papillae give surface a rough appearance
A
- taste receptors are chemoreceptors (sweet,salty,sour,bitter and umami)
- some distribution of sweet receptors towards front, bitter towards back
- but actually distributed across tongue
9
Q
3 cranial nerves convey taste info
A
-CN VII - anterior tongue and palate
-CN IX - posterior tongue
CN X - epiglottis taste buds
-nerves project to solitary tract nucleus in brainstem
10
Q
posterior surface
A
- corresponds to posterior 1/3 of tongue or pharyngeal tongue
- smoother in appearance than anterior surface
- somewhat nodular because it contains numerous mucuous glands
- relatively minor taste function compared to anterior tongue due to fewer taste buds
- sensory innervation of posterior is different from anterior - glossopharyngeal nerve - CN IX
11
Q
ventral surface
A
- prominent central band of tissue joins inferior tongue to mandible - lingual frenulum
- may have a stability function
- inferior surface of tongue has rich vascular supply
- lateral to frenulum are sublingual folds
- proximal to these folds are sublingual and submandibular salivary gland ducts
- lingual tonsils lie below pharyngeal surface
12
Q
unique set of muscles
A
- complex arrangements allow wide range of shape and position modifications (protean quality)
- alternation of tongue shape relative to oral cavity allow for most of the subtle alterations in acoustic patterns
- all muscles are paired
13
Q
can be differentially affected by neural pathologies
A
-indicated by uncontrolled deviatons to one side
14
Q
intrinsic
A
- superior longitudinal
- inferior longitudinal
- transverse
- vertical
15
Q
superior longitudinal
A
- runs along upper length of tongue
- origin: fibrous tissue near epiglottis, hyoid and median septum
- insertion: runs forward and fans laterally to insert in tip and sides
- action:
- bilateral contraction elevates and curves tip
- unilateral contraction pulls tongue to side of contraction
16
Q
transverse
A
- from median septum to side of tongue
- some fibers continue into palatopharyngeus
- pulls edges towards midline narrowing tongue
17
Q
vertical
A
- runs perpendicular to transverse
- intertwines or interdigitates with transverse
- course from base of tongue into membranous cover
- flattens tongue
18
Q
inferior longitudinal
A
- runs from hyoid tip to below verticalis and transversus, mostly along sides of tongue
- pulls tongue downwards
- assists in retracting tongue when co-contracted with superior longitudinal
- unilateral contraction pulls tongue to ipsilateral side
19
Q
extrinsic muscles ____ while intrinsic muscles ___
A
- move tongue from one position to another
- provide elaborate shaping
20
Q
extrinsic muscles
A
- genioglossus
- hyoglossus
- styloglossus
- chondroglossus
- palatoglossus
21
Q
genioglossus
A
- prime mover: largest muscle providing most of the mobility of the tongue
- bulk of lower medial tongue
- arises from symphysis of inner mandible at mental spine
- fans outward and upward to front, dorsum and back of tongue along with hyoid body
- not extreme tip
22
Q
genioglossus actions
A
- composed of anterior and posterior muscle fiber groups
- contraction of entire muscle pulls tongue downwards (concave shape)
- anterior fiber contraction retracts tongue
- posterior fiber contraction pulls tongue forward either to contact the palate or upper teeth, or push tongue out of mouth
23
Q
hyoglossus
A
- arises from greater cornu of hyoid
- runs upward and laterally to genioglossus to insert in sides of tongue
- thin quadrilateral muscle sheet
- pulls sides of tongue downwards and backwards or can pull hyoid upwards
24
Q
chondroglossus
A
- arises from hyoid (lesser cornu) and sometimes considered part of hyoglossus
- interdigitates with intrinsics
- pulls tongue downwards
25
Q
styloglossus
A
- small muscle arising from anterolateral margin of styloid process (temporal bone)
- courses forwards and downwards to insert within inferior sides of tongue
- one part interdigitates w/hyoglossus
- one part w/inferior longitudinal
- pulls tongue up and back
- assists in forming central groove
- antagonist of genioglossus
26
Q
palatoglossus
A
- forms anterior faucial pillar (palatoglossal arch)
- courses from anterior surface of soft palate through faucial pillar to insert on posterolateral tongue body
- contraction:
- lowers soft palate if tongue is stabilized
- raises sides of tone to form groove if palate stabilized
27
Q
course of hypoglossal nerve CN XII
A
- exits medial medulla through multiple rootlets
- exits cranium through hypoglossal canal
- joined by superior fibers from ansa cervicalis
- passes close to genioglossus surface and proceeds to innervate target m’s
- exclusively contralateral innervation
28
Q
articulatory parameters
A
- shaping and positioning of tongue is difficult to predict solely form course of muscles
- tongue is not a bone controlled by joint rotations
- deformable muscular hydrostat
- elephant trunk
- control of tongue is remarkable accomplishment
29
Q
lingual articulatory parameters
A
- tongue moves forward and back
- body is pulled up or down
- tip is extended or approximates palate or is flattened
- tongue body is made concave or convex
- tongue is grooved or curled
- tip - body motions can be independent or temporarily overlapping
30
Q
tongue motion
A
- can bunch, protrude, retract, wag, curl at tip, form a midline groove, and explore oral cavity
- multiple degrees of freedom
31
Q
body of tongue motion
A
- anterior - posterior
- inferior - superior
- convex - concave
32
Q
tongue tip motion
A
-tip flexion - extension
33
Q
tongue blade motion
A
- grooving
- flattening - compacting
34
Q
brains movement goal
A
- may not be the same as the way we try to categorize them
- goal may be to reshape tongue to achieve particular acoustic goal
- still associating tongue movements with a particular phonetic categories is an important exercise
35
Q
tongue tumors
A
- certain tumors benign but many malignant
- any growths or tissue changes ontongue need to be investigated
- carcinoma refers to a cancerous tumor
- squamous cell carcinoma
- tongue cancer most common males 50-70
- incidence increasing in women
36
Q
tongue cancer risk factors
A
- chronic irritation:
- smoking, sepsis, spices, alcohol
- precancerous lesions:
- shyphillis, glossitis, dental ulcers and papilloma
- poor oral hygiene and malnutrition
- betel chewing
37
Q
risk factors for laryngeal carcinomas
A
- tongue cancer
- most common for lesions is anterior 2/3 and side of tongue
- posterior lesions in midline
38
Q
neurological impairments
A
- two categories
- UMN vs LMN
39
Q
bilateral vs unilateral impairments
A
- tongue always deviates to weak or inactive side
- if lesion is in CNS tongue will deviate to contralateral side
- if lesion affects hypoglossal nerve or neuromuscular junction tongue will deviate to ipsilateral side
40
Q
lisping
A
- developmental speech pattern in which /s,z/ characteristically distorted
- interdental lisp - th instead of s
- tongue tip between teeth
- lateral lisp
- /s,z/ produced with escaping air over side of tongue
- adds characteristic noise and fricative signal may not be introduced
- palatal lisp
- attempt to make fricative by contracting palate instead of forming anterior groove
41
Q
typically evident lisps
A
- early development
- genetically mediateed
- may develop when anterior baby teeth lost
42
Q
articulation therapy
A
- needed in most cases
- variable success rate depending on age of intervention
- be aware that tongue thrust is a different condition
- immature swallow pattern that is not suppressed
- will cause potentially significant dental problems and could result in interdental lisp
43
Q
treatments
A
- radiotherapy
- tumors on posterior or inoperable cases
- surgery
- lesion at tip of tongue or 2/3 anterior
44
Q
prognosis
A
- LN negative with tumors in ant. 2/3 50% 5 year survival
- patient with posterior 1/3 tongue and negative LN 20-25% 5 year survival
45
Q
ankyloglossia
A
- tongue tie
- congenital due to short frenulum linguae
- not common cause of speech defect but can compromise consonants
- movements impaired
- frenulum divided transversely then closed vertically
46
Q
hairy tongue
A
- defective clearing of dying filiform papillae
- black hairy tongue appearance
- poor oral hygiene, tooth loss, tobacco, compromised immune system
- resolved by improve oral hygiene, tongue scraper
47
Q
aglossia
A
missing tongue
48
Q
bifid tongue
A
-split in middle
