Development of head and neck part 3

Question 1

What arches contribute to tongue?

Answer 1

Anterior 2/3rds of the tongue - 1st and 2ndarch

Posterior 1/3rd of tongue - 3rd arch

Question 2

What is the line that seperates anterior 2/3 of tongue and posterior 1/3?

Answer 2

Sulcus terminalis

Question 3

What is the region on the tongue (in the midpoint) that is the site of development of the thyroid gland?

Answer 3

Foramen caecum

Question 4

CN supply of anterior 2/3 of tongue

Answer 4

General sensation - trigeminal (1st arch)
Taste is from facial nerve

Question 5

CN supply of posterior 1/3 tongue

Answer 5

General sensation and taste from glossopharyngeal nerve

Question 6

Muscles that form the tongue origin

Answer 6

Occipital somites that migrate anteriorly from base of skull
Arise from level of hypoglossal nerve

Question 7

How does the thyroid gland develop?

Answer 7

Thyroid diverticulum grows inferiorly from foramen caecum

Forms thyroglossal duct

At 5th week descends past hyoid bone, thyroid cartilage, anterior to oesophagus and trachea

Question 8

What happens to the thyroglossal duct?

Answer 8

Breaks down at 5th week, if remains can get cysts here that are or are not connected to tongue

Question 9

How can you test for thyroglossal duct cyst connected to tongue?

Answer 9

Pt stick tongue out and if cyst elevates - connected to tongue so thyroglossal duct cyst

Question 10

What can also be found along path of thyroid gland descent?

Answer 10

Ectopic thyroid gland tissue