The Tongue

Question 1

Describe the different types of lingual papillae found on the tongue, including their location and sensory innervation.

Answer 1

Filiform lingual papillae, most numerous, covering anterior 2/3rd of tongue, no taste buds, velvety texture aids in handling food.
Fungiform lingual papillae, bright red mushroom shaped, most numerous on apex and sides of tongue, contains tastebuds
Circumvallate lingual papillae, large, circular, anterior to sulcus terminalis in a V-shaped row (10-14 in number) contains tastebuds and serous gland of von ebner.
Foliate lingual papillae, found on lateral surface of tongue, vertical mucosal folds, more prominent in children, contain tastebuds.

Question 2

List the extrinsic tongue muscles. Which nerve(s) innervate these muscles?

Answer 2

Extrinsic muscles help to move the tongue and include….
Hyoglossus, Styloglossus and Genioglossus all innervated by hypoglossal nerve (CNXII)
Palatoglossus innervated by the vagus nerve (CNX)

Question 3

List the intrinsic muscles of the tongue, which nerve/s innervate?

Answer 3

Intrinsic muscles change the shape of the tongue and include…
Vertical, flattens and broadens tongue
Transverse, narrows and elongates the tongue
Superior longitudinal, makes the dorsum concave
Inferior longitudinal, makes the dorsum convex
All innervated by the Hypoglossal (CNXII)

Question 4

What is the significance of the foramen caecum on the dorsal surface of the tongue?

Answer 4

V-shaped sulcus where anterior and posterior of tongue meet. Site in the embryo where the epithelium invaginated to form the thyroid gland.

Question 5

What are the parts of the tongue?

Answer 5

Base- posterior 1/3rd, pharyngeal part, attaches to the floor of the mouth
Body- anterior 2/3rds, oral part, mobile
Apex- tip of tongue, mobile

Question 6

Where are the lingual tonsils?

Answer 6

On the base of the tongue

Question 7

What is the sulcus terminalis?

Answer 7

Where the posterior 1/3 and anterior 2/3rds of the tongue join.

Question 8

What are taste buds?

Answer 8

Receptor organs that respond to the special sensation of taste

Question 9

What is the lingual frenum?

Answer 9

Midline mucosal fold between the ventral surface of the tongue and the floor of the mouth

Question 10

Nerve supply to the anterior 2/3rd of the tongue? general and special.

Answer 10

General - Mandibular branch of the trigeminal nerve (V), via lingual nerve
Special (taste) - Facial nerve (VII), via chorda tympani

Question 11

Nerve supply to the posterior 1/3rd of the tongue? general and special.

Answer 11

The most posterior part (near the epiglottis) is supplied by the vagus nerve (CNX). General &Special (taste) - Glossopharyngeal nerve (IX)

Question 12

What is the main arterial supply to the tongue?

Answer 12

Lingual artery, branch of the external carotid artery.

Question 13

Venous drainage of the tongue? Dorsal and Ventral surface.

Answer 13

Dorsal- dorsal lingual vein
Ventral- deep lingual vein
Both drain into internal jugular vein.

Question 14

Outline the lymphatic drainage pattern of the apex of the tongue

Answer 14

Apex of the tongue drains first to submental LN, then into submandibular LN &deep cervical LN

Question 15

Outline the lymphatic drainage pattern of the body of the tongue

Answer 15

Body of the tongue (lateral) drains to submandibular (ipsilateral) LN then to superior deep cervical LN. Body of the tongue (centre) drains to submandibular (bilateral) LN then to superior deep cervical LN

Question 16

Outline the lymphatic drainage pattern of the base of the tongue

Answer 16

Base of tongue (lateral) drains to superior deep cervical LN (ipsilateral)then inferior deep cervical LN
Base of tongue (centre) drains to superior deep cervical (bilateral) then inferior deep cervical LN

Question 17

What is the tongue?

Answer 17

The tongue is a specialised mobile muscular organ.
It is a voluntary, striated skeletal muscle. It is multifunctional and its muscles and special keratinized mucosal covering help in articulation/speech, mastication/chewing, deglutition/swallowing, taste and oral cleaning.
The tongue has two symmetrical halves divided by the median septum; this line is the median lingual sulcus.
The tongue has four pairs of intrinsic muscles that change the shape of the tongue and four pairs of extrinsic muscles that act to move the tongue

Question 18

Styloglossus muscle, origin, insertion &action

Answer 18

Origin, styloid process of the temporal bone
Insertion, lateral aspect of the tongue
Action, elevates the tongue- important in early stage of swallowing

Question 19

Hyoglossus muscle- origin, insertion &action

Answer 19

Origin, hyoid bone
Insertion, lateral aspect of the tongue
Action, depresses the tongue

Question 20

Genioglossus- origin, insertion and action

Answer 20

Origin- superior genial tubercles of the mandible
Insertion- dorsum, from base to apex
Action- protrusion

Question 21

Palatoglossus- origin, insertion and action

Answer 21

Origin- median palatine raphe
Insertion- lateral surface of the tongue
Action- elevates the base of the tongue, helps separate oral cavity from pharynx