Articulation III Flashcards
The tongue
- primary articulator
- most imporatant
- most active
- modifies shape and size of oral cavity
- changes resonance characteristics
- functions as a valve
- noise generator
Biological function of the tongue:
- taste
- mastication (chewing)
- deglutition (swallowing)
The Tongue:
mucous membrane-
outer covering of the tongue
The tongue:
corium or dermis-
dense felt like network of fibrous connective tissue leverally supplied with elastic fibers…can be traced through the lingual musculature to the fibrous midline septum of the tongue
forms the “skeleton” of the tongue
a layer of connective tissue
just below the epidermis
2 anatomical divisions of the tongue
Body- portion of the tongue beneath the hard palate
root or base- behind the hard palate
4 divisions of the tongue
- tip
- blade
- front
- back
Tip of tongue
nearest to the front of teeth
blade of tongue
just below the upper alveolar ridge (body, dorsum)
front of tongue
beneath the hard palate
back of tongue
beneath the soft palate
tongue is divided into _______ from front to back
longitudinal medial sulcus
Foramen secum
pit at the posterior end of the longitudinal sulcus
sulcus terminalis
“V” shaped groove courses anteriorly and laterally to the margins of the tongue
Divided the tongue into ORAL and PHARYNGEAL portions
Palatine surface of tongue
portion under the soft palate; characterized by projections called papillae
papillae
thickly distributed over entire 2/3 of dorsum of tongue
surface characteristic: roughness
vallate of circumvallate papillae
10, form a “V” shaped row on the dorsum of the tongue just anterior to the foramen cecum and sulcus terminalis
Pharyngeal surface of the tongue=
base/root of the tongue
posterior to the sulcus terminalis
still in the oropharynx
smoother than palatine portion
Lingual Tonsils
made up by lymph glands
make up pharyngeal surface
posterior 1/3
Lingual frenulum
extends from the floor of the mouth at the midline to the underside of the tongue
Deep Structures of the tongue
8 or 9 muscles of the tongue
divided into intrinsic and extrinsic groups
median septum
divides tongue into longitudinal halves therefore the muscles of the tongue are considered PAIRED
individually supplied by motor and sensory nerves and blood vessels
Tongue: Intrinsic Muscles (4)
- Superior Longitudinal
- Inferior longitudinal
- transverse
- vertical
Tongue: Intrinsic:
Superior Longitudinal Muscle
O: sub-mucous fibrous tissue “close to the root”
I: not quiet to the tip…terminate in the fibrous membrane
- thin layer of oblique and longitudinal muscle fibers
- just deep to the mucous membrane of the dorsum of tongue
Tongue: Intrinsic:
Superior Longitudinal Muscle
“substantial” portion of the tongue; confined to median portion of the tongue
muscle tends to shorten
turn the tip upward
oblique fibers assist in turning ht lateral margins upward giving dorsum concave or trough-like appearance
Tongue: Intrinsic:
Inferior Longitudinal Muscle
O: root of the tongue (some from hyoid bone)
I: apex of the tongue
F: shortens the tongue or pulls tip upward
-consists of bundle of muscle fibers on the undersurface of the tongue…somewhat laterally
Tongue: Intrinsic:
Transverse Muscle
O: median fibrous septum
I: sub-mucous fibrous tissue at the lateral margins of the tongue
F: tongue to narrow and become elongated
-fibers= radiate somewhat on the lateral aspect of the tongue…fanlike distribution
Tongue: Intrinsic:
Vertical Muscle
O: mucous membrane of the dorsum of the tongue
I: sides and inferior surface of the tongue
F: flattens the tongue
confined to lateral portion of the tongue
highly developed anteriorly
Extrinsic Tongue Muscles (4)
- Genioglossus
- Styloglossus
- Palatoglossus
- Hyoglossus
Tongue: Extrinsic:
Genioglossus
O: superior mental spine (posterior mental spine of the mandibular symphysis)
I: lower attach to thin aponeurosis to upper part of hyoid bone; others radiate to dorsum of tongue…submucous fibrous tissue on either side of midline…extends from root to tip
forms bulk of tongue tissue
strongest and largest of the extrinsic muscles
flat, triangular
Posterior fibers of genioglossus
draw whole tongue anteriorly to protrude the tip from the mouth
press teeth and alveolar ridges
Contraction of anterior fibers of genioglossus
retraction of tongue
Contraction of entire genioglossus muscle
draws tongue downward (makes a trough)
Tongue: Extrinsic:
Styloglossus
O: anterior and lateral surface of the styloid process and stylomandibular ligament
I: near dorsum of tongue and interdigitate with inferior longitudinal muscle; others overlap and blend with Hyoglossus
-fan-shaped, smallest of the muscles that arise from the styloid process
Tongue: Extrinsic:
Styloglossus (description)
F: draws tongue upward and backward
- true antagonist of the genioglossus muscle
- draws sides upward
- assists intrinsic muscles in making dorsum concave or trough-like
Tongue: Extrinsic:
Palatoglossus Muscle
AKA glossopalatine muscle
O: anterior surface of soft palate
I: sides of tongue
F: lower soft palate or raise back of the tongue to groove dorsum
- muscles of the tongue or the palate
- blend with transverse lingual, Styloglossus and Hyoglossus muscles
- forms palatoglossal arch (anterior faucial pillar)
Tongue: Extrinsic:
Hyoglossus Muscle
Function: Retract and depress the tongue, elevate the hyoid bone
O: upper border of the greater cornu and corpus of the hyoid bone
I: lateral sub-mucous tissue of the posterior half of the tongue
-becomes continuous with the Palatoglossus; others interlace with Styloglossus
-another small bundle…
O: lesser cornu and uniton of the fibers at the corpus and greater horn
I: Intrinsic sides of the tongue…and tip of the tongue (Chontrolossus)
-thin quadrilateral sheet
tongue positions and configurations are mediated by
lingual musculature & lower jaw movement
contractions of the extrinsic and intrinsic muscles
Tongue: Motor Control
Posterior Genioglossus
contracts to move tongue anteriorly (produce high vowels)
Tongue: Motor Control
Ballistic Movement
sudden contractions of single muscles that cease abruptly before the movement ceases
Tongue: Motor Control
Movement of the tongue:
complex pattern of finely graded changes in activity…one or two muscle produce most movement.
others cooperate…stabilize adjacent structures…oppose movement