The temporomandibular joint and neural control of chewing, mastication and swallowing

Question 1

Lowest part of costal margin 10th rib

Answer 1

L3

xiphersternum - T9
inferior angle of the scapula - T8
suprasternalnotoch - T2/3
angle of Louis - T4

Question 2

trachea runs how far

Answer 2

C6-T5

Question 3

does exercise dilate or constrict lungs

Answer 3

dilate due to sympathetic

Question 4

ant, lat and post borders of the larynx

Answer 4

Anteriorly- infrahyoid muscles

Laterally- thyroid gland

Posteriorly -oesophagus

Question 5

Identify and describe the subdivisions of the laryngeal cavity.

Answer 5

Supraglottis – From the inferior surface of the epiglottis to the vestibular
folds (false vocal cords).

Glottis – Contains vocal cords and 1cm below them. (The opening between
the vocal cords is known as rima glottidis, the size of which is altered by the
muscles of phonation.)

Subglottis – From inferior border of the glottis to the inferior border of the
cricoid cartilage.

Question 6

the extrinsic muscles or the larynx do what

Answer 6

Extrinsic-elevate or depress the larynx during swallowing

comprised of
the suprahyoid and infrahyoid groups, and the
stylopharyngeus (a muscle of the pharynx).

The supra- and infrahyoid muscle groups attach to
the hyoid bone. This, in turn, is bound to the larynx by
strong ligaments; allowing the whole of the larynx to be
moved as one unit.

As a general rule, the suprahyoid muscles and the
stylopharyngeus elevate the larynx, whilst the
infrahyoid muscles depress the larynx.

Question 7

the intrinsic muscles of the larynx do what

Answer 7

Intrinsic- move the individual components of the larynx, for breathing and
phonation

control shape of rima glottis
All internal muscles are innervated by the inferior laryngeal nerve (branch of
the recurrent laryngeal)

Except cricothyroid, which is innervated by the superior laryngeal nerve

Cricothyroid

Stretches and tenses the vocal ligaments, for forceful speech

Helps alter tone of voice (‘singer’s muscle’)

Attachments: cricoid cartilage to thyroid cartilage.

Thyroarytenoid

Relaxes the vocal ligament, for a soft voice

Attachments: thyroid cartilage to arytenoid cartilage.

Posterior cricoarytenoid

Abducts vocal folds, widens the rima glottidis.

Attachments: cricoid cartilage to arytenoid cartilage.

Lateral cricoarytenoid

Adductors of the vocal folds,narrows the rima glottides

(alters speech tone and volume)

Attachments: Cricoid cartilage to arytenoid cartilage

Transverse and Oblique Arytenoids

Adduct the arytenoid cartilages, closing the posterior portion of rima glottides, narrowing the
laryngeal inlet.

Attachments: From one arytenoid cartilage to the opposite

Question 8

nerve supply of the larynx

Answer 8

The larynx receives both motor and sensory innervation via branches
of the vagus nerve:

Recurrent laryngeal nerve – provides sensory innervation to the
infraglottis, and motor innervation to all the internal muscles of
larynx (except the cricothyroid).

Superior laryngeal nerve – the internal branch provides sensory
innervation to the supraglottis, and the external branch provides
motor innervation to the cricothyroid muscle.

Question 9

muscles of the pharynx and nerve supply

Answer 9

Main three muscles

Superior, middle &
inferior constrictors

Sensory: Glossopharyngeal
nerve (CN9)

Motor: Vagus (CN10)

Gag reflex

Question 10

Which Extrinsic muscle of the tongue is not supplied by the hypoglossal nerve?

Answer 10

palatoglossus - vagus nerve

Genioglossus.
Hyoglossus.
Styloglossus.
Palatoglossus. 
4 extrinsic muscles

Question 11

hypoglossal nerve does the motor function of the tongue

but what nerves do the sensory innervation to the tongue

Answer 11

lingual nerve ( CNV3) front 2/3 - gnarl sensory

chorda tympani ( CN7) special sensory to middle part

glossopharyngeal nerve does general and special sensory of the posterior 1/3

chorda tympani travels with facial nerve and comes through middle ear

internal laryngeal nerve (CN10) also does a bit of the posterio medial tongue

Question 12

hypoglossal nerve does the motor function of the tongue

but what nerves do the sensory innervation to the tongue

Answer 12

lingual nerve ( CNV3) front 1/3 - gnarl sensory

chorda tympani ( CN7) special sensory to middle part

glossopharyngeal nerve does general and special sensory of the posterior 2/3

internal laryngeal nerve (CN10) also does a bit of the posterio medial tongue

Question 13

muscles of mastication

Answer 13

masseter
temporalis
medial pterygoid
lateral pterygoid

Question 14

pharyngeal arches and their cranial nerves

Answer 14

1- trgemnail 
2- facial
3- glosso
4- vagus 
The tongue is innervated by five cranial nerves based on its embryological origin from the pharyngeal arches, namely: Vagus, Hypoglossal, Glossopharyngeal, Facial and Trigeminal.

Question 15

temporalis

Answer 15

Elevates mandible in closing jaws

Retract mandible – posterior, more horizontal fibres

Question 16

medial pterygoid

Answer 16

Elevates mandible in closing jaws – acting synergistically with masseter

Protrudes mandible – a contribution

Produces chewing/grinding movements – alternate unilateral action.

Question 17

lateral pterygoid

Answer 17

Protracts/Protrudes mandible – acting bilaterally
Depresses chin – acting bilaterally
Swings jaw toward contralateral side – acting unilaterally
Produces larger lateral chewing/grinding movements – alternate unilateral contraction

Question 18

all of the muscles of mastication supplied by what nerve

Answer 18

mandibular devision of the trigeminal

The muscles of mastication develop from the mesoderm of the embryonic first pharyngeal arch.

Question 19

TMJ is a Modified Hinge type of Synovial Joint.

Formed by:

Answer 19

Mandibular fossa and
Articular tubercle of temporal bone, and
Head of mandible

ligaments include - sphenomandibular ligament
lateral ligament
stylomandibualr ligament

Question 20

3 phases of swallowing

Answer 20

Voluntary Oral phase – Cerebral cortex control - V, (VII), IX, X & XII

Involuntary Pharyngeal phase, rapid – sensory receptors and swallowing centre in the medulla oblongata – triggers a reflex act (V, IX, X & XII). Respiration is momentarily stopped.

Involuntary Oesophageal phase – X, IX and sympathetic fibres – Peristaltic movement.

Involves coordinated function of muscles in the mouth, pharynx, larynx and oesophagus.

Question 21

what nerves involved in swallowing

Answer 21

CN 4,7,9,10

Frontal gyrus
Precentral gyrus

Question 22

what included in the common integration area

Answer 22

Common integration area:
Integrates sensory information (about food size, temperature and texture) from:
The mouth
Pharynx
Larynx

Sends orders to the swallowing reflex muscles including:
Muscles of mastication.
Intrinsic muscles of the tongue
Muscles involved in closing the larynx and moving epiglottis.

Question 23

deglutination reflex
Sensory receptors in the oropharynx send signal to the deglutition (swallowing) centre in the brain stem.

Initiates motor activity mediated via the

Answer 23

V, IX, X and XII cranial nerves.

Effects muscle contraction:
elevates soft palate to close nasopharynx.
Moves the epiglottis, and elevates and closes off the larynx.
Initiates peristalsis of the pharynx and oesophagus.

Respiration is momentarily stopped during the pharyngeal phas

Question 24

when is respiration momentarily stopped during swallowing

Answer 24

pharyngeal phase

Question 25

pathway of the gag reflex

Answer 25

glossopharyngeal nerve tactiel sensation of posterior 2/3

this goes to brainstem - sensory nucleus of trig menial nerve

Question 26

pathway of the gag reflex

Answer 26

glossopharyngeal nerve tactiel sensation of posterior 2/3
this goes to brainstem - sensory nucleus of trig menial nerve - nucleus ambiguous of vagus and hypoglossal nucleus - through fibres and then to muscles of soft palate and pharynx and upper part of oesophagus and stylopharyngeus - CN9

Question 27

Pseudobulbar palsy, also known as involuntary emotional expression disorder, is a condition that affects your ability to control of the muscles in your face (including your jaw). The muscles in your mouth (i.e. your tongue) and your throat can also be affected. It can have a big impact on your everyday life.

Answer 27

Bulbar palsy is a set of conditions that can occur due to damage to the lower cranial nerves. Clinical features of bulbar palsy range from difficulty swallowing and a lack of a gag reflex to inability to articulate words and excessive drooling. Bulbar palsy is most commonly caused by a brainstem stroke or tumor.

`bulbar - LMN
pseudo- UMN

Question 28

aspiration can cause pneumonia - what is the most common place does this occur in the lungs

Answer 28

right lower lobe

Question 29

what can you use to tract food down the throat

Answer 29

barium

Question 30

if person has difficulty swallowing , hoarse voice and vertigo with rapid onset

Answer 30

stroke of post cerebellar artery - laterally medulla or Wallenberg syndrome

Question 31

45 yr old sliding mass in through on right side of neck and weight loss

Answer 31

supra glottis tumour - CT head and neck

Question 32

hiatus hernia

Answer 32

stomach pushed through diaphragm