Branchial Derivs & embryo Flashcards
Which Branchial pouch?
Ear
1st pouch
Which Branchial pouch?
Tonsils
2nd pouch
Which Branchial pouch?
Inferior parathyroids
3rd - Dorsal pouch
Which Branchial pouch?
Thymus
3rd - Ventral pouch
Which Branchial pouch?
Superior parathyroids
4th pouch
Which Branchial arch?
- CN V2 & V3
- “Chewing” bones & muscles
1st arch
(neural crest fails to migrate –> mandibular hypoplasia, facial abnormalities)
“Chew”
Which Branchial arch?
- CN 7 & Muscles of facial expression
- Stapes, Styloid, Stylohyoid
2nd arch
“Smile”
Which Branchial arch?
- CN 9
- Stylopharyngeus
- Cartilage: Greater Horn of Hyoid
3rd arch
(persistence of cleft & pouch –> fistula between tonsillar area, cleft in lateral neck)
(styloPHARYNGEOUS innervated by glossoPHARYNGEAL nerve)
“Swallow STYLishly”
Which Branchial arch?
- CN X, Superior Laryngeal branch
- Levator veli palatini, pharyngeal constrictors, cricothyroid
4th arch
“simply swallow”
Which Branchial arch?
- CN X, Recurrent Laryngeal branch
- intrinsic muscles of larynx (except cricothyroid
6th arch
“speak”
Think - Elisa’s Dad w/ #6
Which Branchial Cleft?
External Auditory Meatus
1st Cleft
Which Branchial Cleft? Cervical sinuses (which are obliterated eventually)
Clefts 2-4
obliterated by proliferation of 2nd arch mesenchyme
Persistent Cervical Sinus = Branchial cleft cyst w/in lateral neck
Branchial clefts – which embryologic tissue?
Ectoderm
CAP from outside to inside
Branchial arches – which embryologic tissue?
Mesoderm - Muscles & Arteries
&
Neural Crest - Bones & Cartilage
(CAP from outside to inside)
Branchial pouches – which embryologic tissue?
Endoderm
CAP from outside to inside
Which Aortic Arch?
Maxillary Artery
1st arch
Which Aortic Arch?
Stapedial arter & Hyoidal artery
2nd arch
“Second = Stapedial”
Which Aortic Arch?
Common Carotid & proximal part of Internal Carotid
3rd arch
Which Aortic Arch?
Aortic arch on left & proximal right Subclavian artery on right
4th arch
“4th arch = 4 limbs = Systemic”
Which Aortic Arch?
Proximal part of Pulmonary arteries & (on left only) Ductus Arteriosus
6th arch
pulmonary & pulmonary-to-systemic shunt
When does obliteration of Vitelline duct occur?
7th week (failure = Vitelline fistula or Meckel's Diverticulum)
Meckel’s Diverticulum – embryological cause?
Failure of Vitelline duct to close
Umbilical arteries & veins are derived from what embryological structure?
Allantois
Gene for segmental organization of embryo (limbs in right places)
Homeobox (Hox)
Gene where mutation causes holoprosencephaly (forebrain fails to develop)?
Sonic hedgehog gene
patterning along A-P axis
Gene necessary for D-V axis development?
Wnt-7
Gene stimulating for lengthening of limbs?
FGF gene
Dx?
Anterior midline neck mass that moves w/ swallowing
Thyroglossal duct cyst
- Normally disappears & becomes foramen cecum
(Vs. persistent cervical sinus leading to branchial cleft cyst in lateral neck)
Cause of D-transposition of Great Vessels?
Failure of the aorticopulmonary septum to spiral
4 Sx of Tetralogy of Fallot?
- Pulmonary infundibular stenosis (most determinant for prognosis)
- RVH
- Overriding aorta (overrides the VSD)
- VSD
Congenital rubella is ass’d w/ what cardiac defects?
- Septal defects
- PDA
- Pulmonary artery stenosis
Infant of diabetic mother is ass’d w/ what cardiac defect?
Transposition of Great Vessels
