9. Oral cavity & tongue

Question 1

name the boundaries of the oral cavity

Answer 1

• roof: hard and soft palate - floor: muscular diaphragm and tongue - lateral walls: buccinators

Question 2

label

Answer 2

Question 3

why is food maintained in OC when chewing

Answer 3

2 arches are formed in OC by the palatoglossal (anterior) and palatopharyngeal (posterior) muscles - run from soft palate to tongue and pharynx. Their contraction during chewing (CN X) pulls soft palate down towards back of tongue, closing oropharyngeal isthmus.

Question 4

name the 3 pairs of salivary glands and describe the location of their ducts

Answer 4

1. parotid glands: Stensen ducts pierce masseters and buccinators to enter OC near 2nd upper molars
2. submandibular glands: Wharton ducts open into OC at base of lingual frenulum bilaterally
3. sublingual glands: minor ducts open into OC at sublingual fold

Question 5

what is SIALOLITHIASIS, how is it diagnosed

Answer 5

Stone formation (<1cm) in ducts draining salivary glands (esp. submandibular) as a result of dehydration and reduced salivary flow.

Symptoms: significant pain and swelling (+/- infection).

Diagnosis: history, X-ray or sialogram

Question 6

which muscles control the tongue - what is their action

Answer 6

1. 4 paired intrinsic muscles
   - lie entirely within tongue (not attached to bone but blend with extrinsic muscles), running longitudinally, vertically and transversely
   - act to alter shape of tongue
2. 4 extrinsic muscles
   - insert into tongue to change its position and anchor it to surrounding structures
   i. GENIOGLOSSUS: mental symphysis to tongue dorsum
   ii. HYOGLOSSUS: hyoid bone to side of tongue
   iii. STYLOGLOSSUS: styloid process to side of tongue
   iv. PALATOGLOSSUS: palatine aponeurosis to across tongue

Question 7

describe the sensory and motor innervation of the tongue

Answer 7

Motor: all muscles innervated by hypoglossal n. (CN XII) except palatoglossus (vagus n.)

General sensory:

• anterior 2/3: trigeminal n. - lingual n. (branch of Vc)
• posterior 1/3: glossopharyngeal n.

Special sensory (taste):

• anterior 2/3: facial n. - chorda tympani
• posterior 1/3: glossopharyngeal n.

Question 8

what is tonsilitis, what are the symptoms

Answer 8

Infection and inflammation of tonsils, mainly viral but can be bacterial (Strep.)

Symptoms:

• pain
• difficulty swallowing
• cervival lymph nodes
• fever
• bad breath

Question 9

what is Quinsy

Answer 9

PERITONSILLAR ABSCESS: infection of tissues surrounding tonsil. Can follow up from tonsillitis or arise alone.

Symptoms:

• severe through pain
• difficulty opening mouth
• deviated uvula if unilateral
• fever
• bad breath
• drooling