Embryology: Development Of Pharynx

Front 1

Pharyngeal or Branchial cleft develop from ?

Back 1

ectoderm

pharyngeal clefts are grooves that demarcate the pharyngeal arches externally

Front 2

Pharyngeal arches develop from ?

Back 2

mesoderm + neural crest

Front 3

Pharyngeal pouches develop from ?

Back 3

endoderm

Front 4

_______ are out-pocketings along the lateral wall of the most cranial part of the gut, extending from the ____ membrane to the commencement of the esophagus.

Back 4

Pharyngeal Pouches; buccopharyngeal

Front 5

Derivatives of Ist Ph.pouch ?

Back 5

Tympanic cavity & auditory tube

Front 6

Derivatives of 2nd Ph.pouch ?

Back 6

Tonsillar fossa

Front 7

Derivatives of 3rd Ph.pouch ?

Back 7

Parathyroid and Thymus

Front 8

Derivatives of 4th Ph.pouch ?

Back 8

Parathyroid and thymus

Front 9

Derivatives of 5th Ph.pouch ?

Back 9

Ultimobranchial body which gives rise to the parafollicular cells.

Front 10

Development of Thyroid Gland

Back 10

Develops as a median endodermal downgrowth (thyroid bud) from the floor of the pharynx.

Front 11

The thyroid bud grows ventrally and caudally and becomes canalised to form ?

Back 11

thyroglossal duct.


Later, it detaches its connection and migrates to the neck.

Front 12

vestigal remnanent of thyroglossal duct?

Back 12

foramen cecum of the tongue (located on floor of pharynx and point of origin of thyrogl.duct)

Front 13

Development of Thyroid Gland:

Cells of thyroid follicles are ____ whereas CT components are derived from invasion of surrounding ______.

Back 13

endodermal; mesoderm

Front 14

1st Pharyngeal Clefts forms what?

Back 14

forms the external acoustic meatus

Front 15

Cleft 2,3, and 4 form what?

What does it persist as?

Back 15

form the cervical sinus which normally regress and disappear

Front 16

Which pharyngeal pouches combine to form same structures?

What do they form?

Back 16

3&4

parathyroid and thymus

Front 17

gives rise to the parafollicular cells

Back 17

Ultimobranchial body; via 5th pharyngeal pouch

Front 18

4th pharygeal arches form?
(identify muscular and skeletal parts)

innervation?

Back 18

- Most laryngeal cartilages
- Pharyngeal and laryngeal muscles
- Vagus, Medullary part of accessory nerve

Front 19

1st pharygeal arches form?
(identify muscular and skeletal parts)

innervation?

Back 19

- Mandible (in part)
Malleus & Incus

- Muscles of mastication,
Digasticus (in part)

- Mandibular division of Trigeminal nerve

Front 20

2nd pharygeal arches form?
(identify muscular and skeletal parts)

innervation?

Back 20

(Hyoid Arch)
- Hyoid apparatus (in part), Stapes
- Muscles of the facial expression, digastricus (in part), Stapedius
- Facial nerve

Front 21

3rd pharygeal arches form?
(identify muscular and skeletal parts)

innervation?

Back 21

Third Arch
- form Hyoid apparatus (REMAINING part)
-Pharyngeal muscles (in part)
- Glosso-pharyngeal nerve