Tongue

Question 1

what do most muscles of the tongue attach to?

Answer 1

Most muscles serve to attach one bone, usually via a tendon, to another

Question 2

which muscles of the tongue do not attach to bones?

Answer 2

the ocular muscles, the scapulothoracic joint, the diaphragm and perineum

Question 3

what are the intrinsic muscles of the tongue attached to?

Answer 3

other structures in the tongue

Question 4

how are the intrinsic muscles of the tongue named?

Answer 4

by the direction in which they travel:

superior longitudinal, inferior longitudinal, transverse and vertical muscles of the tongue

Question 5

what are the extrinsic muscles of the tongue?

Answer 5

Genioglossus
Hyoglossus
Styloglossus
Palatoglossus

Question 6

function of genioglossus?

Answer 6

Inferior fibres protrude the tongue,
middle fibres depress the tongue,
superior fibres draw the tip back and down

Question 7

function of hyoglossus?

Answer 7

Depresses and retracts the tongue

Question 8

function of styloglossus?

Answer 8

Retracts and elevates the tongue

Question 9

function of palatoglossus?

Answer 9

Elevates the posterior aspect of the tongue

Question 10

innervation of muscles of the tongue?

Answer 10

All of the intrinsic and extrinsic muscles are innervated by the hypoglossal nerve (CN XII)

Question 11

which nerve innervates palatoglossus?

Answer 11

vagal innervation (CN X)

Question 12

what is the tongue attached anteroinferiorly by?

Answer 12

frenulum

a piece of CT lying in midline

Question 13

how is frenulum formed?

Answer 13

sculpting apoptosis (like fingers)

Question 14

what happens if frenulum fails to form by sculpting apoptosis?

Answer 14

result in excess frenulum ‘tongue-tied’

managed by surgery

Question 15

In the anterior ⅔, general sensation is supplied by?

Answer 15

the trigeminal nerve (V)

Specifically the lingual nerve, a branch of the mandibular nerve (CN V3)

Question 16

taste in the anterior 2/3 is supplied by?

Answer 16

the facial nerve (VII) - chorda tympani

Question 17

where does the chorda tympani travel?

Answer 17

In the petrous part of the temporal bone, the facial nerve gives off three branches (incl. chorda tympani)
This travels through the middle ear, and continues on to the tongue

Question 18

innervation to posterior ⅓ of the tongue?

Answer 18

Both touch and taste are supplied by the glossopharyngeal nerve (IX)

Question 19

blood supply to the tongue?

Answer 19

The lingual artery (branch of the external carotid) does most of the supply
a branch from the facial artery (tonsillar artery), can provide some collateral circulation

Question 20

drainage to the tongue?

Answer 20

lingual vein

Question 21

what is the first branchial arch supplied by?

Answer 21

the trigeminal nerve (V)

Question 22

what is the second branchial arch supplied by?

Answer 22

the facial nerve (VII)

Question 23

what is the 3rd branchial arch supplied by?

Answer 23

glossopharyngeal nerve (IX)

Question 24

what is the fourth and sixth branchial arch supplied by?

Answer 24

vagus nerve (X)

Question 25

when the tongue is developing, what does it start as?

Answer 25

as a two longitudinal bulbous ridges, with contribution from the first four branchial arches

Question 26

what happens to the 2 longitudinal bulbous ridges of the developing tongue?

Answer 26

These ridges join, giving rise to the longitudinal line (median sulcus) down the centre of the tongue

Question 27

what is contribution from the 2nd branchial arch grown over by?

Answer 27

The contribution from the second branchial arch is grown over by that of the third arch, but the nerve supply remains
(therefore, the majority of the tongue’s innervation is by CN V (first) and CN IX (third)) - as 2nd is grown over

Question 28

towards the back of the tongue, what is present?

Answer 28

there is a transverse line near the root of the tongue.

This is called sulcus terminalis

Question 29

what is present in the centre of the sulcus terminalis?

Answer 29

in the centre of sulcus terminalis, where it meets the median sulcus, there is a pit

Question 30

what forms over the median sulcus pit?

Answer 30

This is the now-closed top of a deep pit, the foramen cecum (blind window), at the end of which lies the thyroid gland

Question 31

what happens to the thyroid gland during development?

Answer 31

thyroid descends from the tongue down into the neck

Question 32

what does the pit of the median sulcus become?

Answer 32

thyroglossal duct

Question 33

what happens if on the descend of thyroid, the pit of median sulcus (thyroglossal duct) doesn’t close behind the thyroid gland?

Answer 33

midline thyroglossal cysts or fistulae may remain