aortic arch/branchial arch/pouch party

Question 1

CAP covers outside to inside

Answer 1

Clefts = ectoderm (also called branchial grooves)
Arches = mesoderm (muscles and arteries) and neural crest (bones of skull, cartilage) 
Pouches = endoderm

Question 2

2nd-4th cleft form the TEMPORARY cervical sinuses

Answer 2

which are obliterated by proliferation of 2nd arch mesenchyme

persistant cervical sinus –> branchial cleft cyst within lateral neck

Question 3

Branchial cleft cyst within the lateral neck

Answer 3

• persistant cervical sinus

- should of been obliterated by proliferation of 2nd arch mesenchyme

Question 4

1st cleft develops into?

Answer 4

external auditory meatus

Question 5

6th aortic arch derivatives

Answer 5

-proximal part of pulmonary arteries and (on left only) the ductus arteriosus

side note) the ductus arteriousus turns into the ligamentum arteriosum shortly after birth

Question 6

2nd aortic arch derivative?

Answer 6

Stapedial artery and hyoid artery

Second = Stapedial SSSSSS

Question 7

4th aortic arch derivative?

Answer 7

on left, aortic arch, on the right the proximal part of the right subclavian artery

4th arch (4 limbs) = systemic circulation

Question 8

1st aortic arch derivitive?

Answer 8

part of the maxillary artery (branch of external carotid)
1st arch is maximal

side node the middle menegeal artery is a branch of the maxillary artery

Question 9

3rd aortic arch derivative?

Answer 9

Common carotid
proximal part of the internal Carotid artery

C is the third letter in the alphabet

Question 10

Congenital pharyngeal cutaneous fistula

Answer 10

-persistance of the celft and pouch of the 2nd branchial arch derivatives

leads to fistula between tonsillar area and lateral neck
-found along anterior border of sternocleidomastoid muscle

Question 11

Treacher collins syndrome

Answer 11

1st branchial arch derivative neural crest (facial bones, facial cartilage) fails to migrate

• mandibular hypoplasia
• facial abnormalities

Question 12

5th Branchial arch

Answer 12

makes nothing!

Question 13

4th-6th branchial arch

Answer 13

Cartilage:
thyroid, cricoid, arytenoids, corniculate, cuneiform

Muscles:
4th arch: most pharyngeal constrictors, cricothyroid, levator veli palatini
6th arch: all intrinsic muscles of the larynx except cricothyroid

nerves:
4th arch: CN X (superior laryngeal branch) - simply swallow
6h arch: CN X (recurrent laryngeal branch) speak

Question 14

arches 3 and 4 of the branchial arch form

Answer 14

posterior 1/3 of the tongue

Question 15

1st and 2nd branchial arches form

Answer 15

anterior 2/3 of the tongue

Question 16

1st branchial arch

Answer 16

MMMMMMMM
cartilage:
meckel, mandible, malleus, incus, sphenomandibular ligament

muscles of mastication:
temporalis, Masseter, laterial and Medial pterygoids
-mylohyoid, anterior belly of digastric, tensor tympani, tensor veli palatini

nerves:
V2 and V3 maxillary and submandibular branches chew

Question 17

2nd branchial arch derivative

Answer 17

SSSSSSSSSS
Reichert cartilage:
stapes, styloid process, lessor horn of hyoid, stylohyoid ligament

muslces of facial expression:
stapedius, stylohyoid, platySma, belly of digastric

nerves:
VII smilleee

Question 18

Branchial arch derivative mnemonic

Answer 18

When at a restaurant of golden ARCHES, children tend to CHEW (1) then SMILE (2) then SWALLOW STYlishly (3) or SIMPLY SWALLOW (4) then SPEAK (6)

Question 19

Branchial 3rd arch

Answer 19

cartilage:
greater horn of hyoid

muscles:
stylopharyngeous

nerve: CN IX swallooowww stylisshhly

Question 20

pouch mnemonic
ear, tonsils, bottom to top

remember pouches are derived from endoderm

Answer 20

1 ear
2 tonsils
3 dorsal ( bottom for inferior parathyroids)
3 ventral to thymus
4 top = superior parathyroids

Question 21

4th pouch

Answer 21

dorsal wings-develops into superior parathyroids

missing in digeorge

Question 22

3rd pouch

Answer 22

dorsal wings develop into inferior parathyroids
ventral wings develop into thymus

note the 3rd pouch structures end up below the 4th pouch structures

missing 3rd pouch in digeorge

Question 23

1st pouch

Answer 23

develops into middle ear, cavity, eustachian tube, mastoid air cells
-contributes to endoderm line structures of ear

Question 24

2nd pouch

Answer 24

-develops into epithelial lining of the palatine tonsil

Question 25

MEN 2A

Answer 25

Square
germline RET mutation (neural crest cells) ras
-adrenal medulla pheochromocytoma
-parathyroid tumor (3/4th pharyngeal pouch)
-parafollicular cells medullary thyroid cancer: derived from neural crest cells, assoc with 4th and 5th pharyngeal pouches

Question 26

Digeorge syndrom

Answer 26

• bye bye 3rd and 4th pouch
• results in T-cell def due to no thymus
• hypocalcemia due to no parathyroids
• assoc with cardiac defects like conotruncal anomalies

Question 27

cleft lip

Answer 27

failure of fusion of the maxillary and medial nasal processes (formation of the primary palate)

Question 28

cleft palate

Answer 28

failure of fusion of the two lateral palatine processes or failure of fusion of lateral palatine processes with the nasal septum and/or median palatine process (formation of secondary palate)