Where is sonic hedgehog gene produced?
base of limbs in zone of polarizing activity
What does sonic hedgehog gene do?
- Patterning along anterior-posterior axis
- CNS development
What can result from sonic hedgehog mutation?
holoprosencephaly
Where is Wnt-7 gene produced?
apical ectodermal ridge (thickened ectoderm at distal end of each developing limb)
What is the Wnt-7 gene for?
proper organization along dorsal ventral axis
Where is FGF gene produced?
apical ectodermal ridge
What does FGF gene do?
stimulates mitosis of underlying mesoderm (providing for lengthening of limbs)
What do the homeobox genes do?
involved in segmental organization of embryo in craniocaudal direction
What can hox mutations cause?
appendages in wrong locations
Origin: PNS
Neural crest
Origin: CNS
neuroectoderm
Origin: Adenohypophysis
Surface ectoderm (Rathke pouch)
Origin: Muscle
mesoderm
Origin: anal canal above pectinate line
endoderm
Origin: gut tube endothelium
endoderm
Origin: C cells of thyroid
neural crest
Origin: retina and optic nerve
Neuroectoderm
Origin: epithelial linings of oral cavity
surface ectoderm
Origin: bone
mesoderm
Origin: lens of eye
surface ectoderm
Origin: Pia and arachnoid mater
neural crest
Origin: urethra
endoderm (derived from UG sinus)
Origin: connective tissue
mesoderm
Origin: Lymphatics and blood
mesoderm
Origin: bones of skull
neural crest
Origin: anal canal below pectinate line
surface ectoderm
Origin: parotid, sweat, and mammary glands
Surface ectoderm
Origin: melanocytes
neural crest
Origin: chromaffin cells of adrenal medulla
neural crest
Origin: lungs, liver, gallbladder, pancreas, thymus, parathyroid, thyroid follicular cells,e ustacian tube
endoderm
Origin: nucleus pulposus of intervertebral disc
notochord
Origin: spleen
mesoderm
Origin: vagina, kidneys, testes, ovaries
Mesoderm (intermediate)
Origin: Ondontoblasts
neural crest cells
Origin: adrenal cortex
mesoderm
Origin: dermis
mesoderm
Origin: epidermis
surface ectoderm
Origin: sensory organs of ear and olfactory epithelium
surface ectoderm
Origin: aorticopulmonary septum
neural crest
Origin: peritoneum
Mesoderm
Origin: CV structures
mesoderm
Teratogenic effects: ACE inhibitors
renal damage
Teratogenic effects: alkylating agents
absence of digits
multiple anomalies
Teratogenic effects: aminoglycosides
CN VIII toxicity
Teratogenic effects: carbamazepine
Neural tube defects craniofacial defects fingernail hypoplasia developmental delay IUGR
Teratogenic effects: DES
Vaginal clear cell adenocarcinoma
congenital Mullerian anomalies
Teratogenic effects: folate antagonists
neural tube defects
Teratogenic effects: lithium
Ebstein anomaly (atrialized right ventricle)
Teratogenic effects: methimazole
aplasia cutis congenita
Teratogenic effects: phenytoin
fetal hydantoin syndrome (microcephaly, dysmorphic craniofacial features, hypoplastic nails and distal phalanges, cardiac defects, IUGR, intellectual disability)
Teratogenic effects: tetracyclines
discolored teeth
Teratogenic effects: thalidomide
limb defects (phocomelia, micromelia)
Teratogenic effects: valproate
inhibition of maternal folate absorption (neural tube defects)
Teratogenic effects: warfarin
Bone deformities
Fetal hemorrhage
Abortion
Ophthalmologic abnormalities
Teratogenic effects: cocaine
abnormal fetal growth
fetal addiction
placental abruption
Teratogenic effects: smoking
- Low birth weight
- Preterm labor
- Placental problems
- IUGR
- ADHD
Teratogenic effects: Iodine
congenital goiter (due to EXCESS) hypothyroidism (cretinism due to LACK)
Teratogenic effects: maternal diabetes
- Caudal regression syndrome (anal atresia to sirenomelia)
- Congenital heart defects
- Neural tube defects
Teratogenic effects: vitamin A excess
- Spontaneous abortions
- Birth defects (cleft palate, heart abnormalities)
Teratogenic effects: x-rays
Microcephaly
Intellectual disability
Smooth philtrum, thin upper lip, small palpebral fissures, hypertelorism
FAS
Number of umbilical arteries
2
Number of umbilical veins
1
What are the umbilical arteries and veins derived from?
allantois
When is the allantois formed?
3rd week (extends from yolk sac into UG sinus)
What does the allantois become?
urachus (duct between fetal bladder and yolk sac)
What are long-term consequencesof urachal cyst?
infection
adenocarcinoma
What is the omphalo-mesenteric duct?
vitelline duct
When does the vitelline duct obliterate?
7th week
Is a Meckel diverticulum true or false?
true
Where do branchial clefts (grooves) arise from?
ectoderm
Where do branchial arches arise from?
mesoderm (muscles, arteries) neural crest (bones, cartilage)
Where do branchial pouches arise from?
endoderm
What does 1st branchial cleft form?
external auditory meatus
What is a persistent cervical sinus (2nd-4th branchial cleft)?
branchial cleft cyst (lateral neck)
Which branchial arch forms:
Mandible
Malleus, incus
sphenoMandibular ligament
1st
Which branchial arch forms: Thryoid cartilage Cricoid cartilage Arytenoids Corniculate cartilage Cuneiform cartilage
4th-6th
Which branchial arch forms: Stapes Styloid process Lesser horn of hyoid Stylohyoid ligament
2nd
Which branchial arch forms the greater horn of the hyoid?
3rd
Which branchial arch forms muscles of mastication?
1st
Which branchial arch forms stylopharyngeus?
3rd
Which branchial arch forms muscles of facial expression and stapedius?
2nd
Which branchial arch forms all intrinsic muscles of larynx except cricothyroid?
6th
Which branchial arch forms most pharyngeal constrictors, cricothyroid, and levator veli palatini?
4th
What nerves innervate 1st branchial arch?
V2 and V3
What nerves innervate 2nd branchial arch?
CN VII
What nerve innervates 3rd branchial arch?
CN IX
What nerve innervates 4th branchial arch?
Superior laryngeal branch of X
What nerve innervates 6th branchial arch?
Recurrent laryngeal branch of X
What is Treacher Collins?
1st arch neural crest fails to migrate
What is congenital pharyngo-cutaneous fistula?
persistence of cleft and pouch (2nd) so get fistula between tonsilar area and lateral neck
What arches for posterior 1/3 of tongue?
3 and 4
What is the mnemonic for branchial arch derivatives?
When at the golden arches, children CHEW (1), SMILE (2) then swallow STYLishly (3) or simply SWALLOW (4) then SPEAK (6)
What does 1st branchial pouch become?
Endoderm-lined structures of ear
What does 2nd branchial pouch become?
epithelial lining of palatine tonsil
What does 3rd branchial pouch become?
- Dorsal wings (inferior parathyroids)
- Ventral wings (thalamus)
What does the 4th branchial pouch become?
-Dorsal winges (superior parathyroids)
Male gubernaculum remnant
anchors testes within scrotum
Female gubernaculum remnant
ovarian ligament + round ligament of uterus
Processus vaginalis male remnant
TUnica vaginalis
Processus vaginalis female remnant
obliterated