Step 1: Embryology Ii

Front 1

What are branchial clefts derived from?

Branchial arches?

Branchial pouches?

Mnemonic to remember this?

Back 1

derived from ectoderm.

mesoderm (muscles, arteries) and neural crests (bones, cartilage)

endoderm.

CAP covers outside from inside
Clefts = ectoderm
Arches = mesoderm
Pouches = endoderm.

Front 2

Branchial arch innervation, and list an associated artery(s) if they exist:
- 1?
- 2?
- 3?
- 4 and 6?

These CN are the only ones with both ____ and ____ (except ___, which only has ____)

Back 2

V2,V3 - maxially artery (branch of external carotid ~ remnant of 1st aortic arch)
VII - stapedial artery, hyoid artery (2nd aortic arch)
IX
X

Both sensory and motor, except V2 which is only motor.

think of the arches in terms of actions chewing, facial expression, stylopharyngeus, swallowing & speaking.

Front 3

Given the following cartilage groups, give me the branchial arch they're derived from:
- thyroid, cricoid, arythenoids, corniculate, cuneiform
- greater horn of hyoid
- Stapes, Styloid process, lesser horn of hyoid, Stylohyoid ligament [Reichert's cartilage]
- Mandible, Malleus, incus, sphenoMandibular ligament [Meckel's cartilage]

Back 3

- 4-6
- 3
- 2
- 1

Front 4

Given the following muscle groups, give me the branchial arch they're derived from, and the innervation (bonus points for other info):
- muscles of mastication (temporalis, Masseter, later and Medial pterygoids), Mylohyoid, anterior belly of digastric, tensor tympani, tensor veli palatini, anterior 2/3 of tongue
- most pharyngeal constrictors; cricothyroid, levator veli palatini
- muscles of facial expression; Stapedius, Stylohyoid, posterior belly of digastric
- all intrinsic muscles of larynx except cricothyroid
- stylopharyngeus

Back 4

- Arch #1 (V2, V3)
- Arch #4 (superior laryngeal branch of X - swallowing)
- Arch #2 (VII)
- Arch #6 (recurrent laryngeal branch of X - speaking)
- Arch #3 (IX)

Front 5

Pt presents with mandibular hypoplasia, and facial abnormalities.
Likely what happened to which pharyngeal arch?
- name of syndrome (meh, dunno if that's important)

Back 5

failure of neural crest cells to migrate to 1st arch.
- Treacher Collins syndrome

Front 6

Baby presents with fistula between tonsillar area, with a cleft in the lateral neck. Problem with which pharyngeal arch? what happened?
- name of defect? (meh on importance of knowing these, see once you do some questions)

Back 6

Arch #3; persistence of cleft and pouch
- congenital pharyngocutaneous fistula.

Front 7

Which pharyngeal arches form the tongue? which portions to which arches?

Walk through the sensory and taste innervation of the tongue.

Motor?

Muscles of the tonuge are dervied from what?

Back 7

Arch 1 = anterior 2/3 of tongue
Arch 3 and 4 = posterior 1/3... this explains the innervation!

Anterior 2/3 of sensation is V3, posterior 1/3 is IX, and back bit is X

Anterior 2/3 of taste is VII, with posterior 1/3 XI and back bit X.

Motor to whole tongue is XII.

occipital myotomes.

Front 8

Baby is born with persistent cervical sinus... could be caused by what related to branchial arches/clefts?

Back 8

branchial cleft cyst w/i lateral neck.

Front 9

What develops into the external auditory meatus?

Back 9

1st branchial cleft.

Front 10

What does the 1st branchial cleft develop into?

2 through 4th?

Back 10

external auditory meatus

temporary cervical sinuses, which are obliterated by proliferation of 2nd arch mesenchyme.

Front 11

What branchial pouch forms:
- endoderm-lined structures of ear: middle ear cavity, eustachian tube, mastoid air cells.
- epithelial lining of palatine tonsil
- superior parathyroids
- inferior parathyroids
- thymus

Where do 3rd pouch structures end up geographically compared to 4th pouch structures?

Back 11

- 1st
- 2nd
- 4th dorsal wings
- 3rd dorsal wings
- 3rd ventral wings

Below the 4th pouch structures.

Front 12

T cell deficiency due to thymic aplasia and hypocalcemia (failure of thyroids to develop)...
- which syndrome
- failure of which branchial structures?
- assoicated with which genetic defect?

Back 12

DiGeorge
- 3rd and 4th pouches
- 22q11.2

Front 13

MEN 2A is a mutation in germline ____, that affects which population of cells?
- which 3 areas are commonly asked about that are affected by this?

Back 13

Ret, that affects neural crest cells.
- adrenal medulla (pheo)
- parathyroid (tumor): 3rd/4th pouch
- Parafollicular cells (medullary thyroid carcinoma): 4th/5th pharyngeal pouch

Front 14

Given the following parts of the ear, give me what they're from, branchially speaking. If it's a mus, give me the innervation too.
- Eustachian tube, middle ear cavity, mastoid air cells
- tympanic membrane
- malleus/incus
- tensor tympani
- stapes
- external auditory meatus
- stapedius

Back 14

- 1st branchial pouch
- 1st branchial membrane
- 1st arch
- 1st arch (V3)
- 2nd arch
- 1st cleft
- 2nd arch (VII)

Front 15

What is the foramen cecum?

Back 15

normal remnant of the thyroglossal duct which normally disappears but may persist nonpathogenically as pyramidal lobe of thyroid.

Front 16

Failure of fusion of the maxillary and medial nasal processes -->

Back 16

cleft lip

Front 17

Failure of fusion of the lateral palatine processes, the nasal septum, and/or the median palatine process --> ?

Back 17

cleft palate

Front 18

What is the diaphragm derived from? (mnemonic?)

Back 18

Several Parts Build Diaphragm
- Septum transversum --> central tendon
- Pleuroperitoneal folds
- Body wall
- dorsal mesentery of esophagus --> crura

Front 19

What can herniation of abdominal contents into thorax b/c of incomplete diaphragm development cause?

Back 19

hypoplasia of thoracic organs due to space compression, scaphoid abdomen, cyanosis.

Front 20

What GI abnormality is associated with Trisomy 21?

Back 20

duodenal atresia - failure to recanalize

Front 21

Foregut forms what section of adult GI tract?

Midgut?
Hindgut?

Back 21

pharynx to duodenum

duodenum to transverse colon

distal transverse colon to rectum