bananas's version from 2015-07-13 18:04

Germ Layers ***

Question Answer
NeurulationWeek 3: Mesoderm forms notocord that induces Ectoderm to form neural tube and neural crest
Neural crest derivatives in the PNSANS, DRG, Sensory nerves, Schwann cells, CN's
Neural crest derivatives in the EarOssicles: Malleus Incus and Stapes
Neural crest derivatives in the EyeAnterior chamber: cornea, sclera, ciliary muscles and iris pigment
Neural crest derivatives in the MouthOdontoblasts (dentin of the teeth)
Neural crest derivatives in the ThyroidParafollicular cells (C cells): Secrete calcitonin
Neural crest derivatives in the HeartSpiral septum!!
Neural crest derivatives in the GIEnteric nervous system and celiac ganglia
Neural crest derivatives in the Adrenal glandChromaffin cells of Adrenal Medulla
Neural crest derivatives in the SkinMelanocytes
What is derived from Neurectoderm?Neural tube >>
CNS: Oligodendrocytes, Astrocytes, Ependymal cells
Eyes: Optic nerve and Retina
Pineal gland
Posterior PItuitary
What is derived from Surface ectoderm?Eyes: Lenses
Nose: Olfactory epithelium
Ears: Inner ear
Mouth: Oral epithelium
Anterior pituitary
Glands! Salivary, Sweat and Mammary glands
Distal anal canal
What is derived from Endoderm?GI tract: esophagus to pectinate line
Liver, GB, Pancreas
Parathyroid gland
Thyroid follicular cells
Lower 2/3 vajayjay
Bladder epithelium
What is derived from Mesoderm?Muscle, Connective tissue, Bone
Blood vessels
Upper vajayjay and Gonads
Kidneys: Glomerulus, Bowman's capsule, PT, Loop of henle, DCT
Adrenal cortex

Germ cell

Question Answer
Neural Crest Cell derivative Autonomic NS
Neural Crest Cell derivative Schwann cells
Neural Crest Cell derivative Dorsal root ganglia
Neural Crest Cell derivative Sensory nerves
Neural Crest Cell derivative Cranial nerves
Neural Crest Cell derivative Malleus, Incus, Stapes
Neural Crest Cell derivative Cornea
Neural Crest Cell derivative Sclera
Neural Crest Cell derivative Ciliary muscle
Neural Crest Cell derivative Iris pigment cells
Neural Crest Cell derivative Odontoblasts
Neural Crest Cell derivative Parafollicular C cells of thyroid
Neural Crest Cell derivative Aorticopulmonary septum
Neural Crest Cell derivative Enteric nervous system
Neural Crest Cell derivative Chromaffin cells of adrenal medulla
Neural Crest Cell derivative Melanocytes
Neuroectoderm derivative CNS neurons
Neuroectoderm derivative Oligodendrocytes
Neuroectoderm derivative Astrocytes
Neuroectoderm derivative Ependymal cells
Neuroectoderm derivative Optic nerve
Neuroectoderm derivative Retina
Neuroectoderm derivative Pineal Gland
Neuroectoderm derivative Posterior pituitary
Surface ectoderm derivative Eye lens
Surface ectoderm derivative Olfactory epithelium
Surface ectoderm derivative Inner ear (minus ossicles)
Surface ectoderm derivative Anterior pituitary
Surface ectoderm derivative Oral epithelium
Surface ectoderm derivative Salivary glands
Surface ectoderm derivative Epidermis
Surface ectoderm derivative Sweat glands
Surface ectoderm derivative Mammary glands
Surface ectoderm derivative Anal canal distal to pectinate line
Endoderm derivativeGI tract (esophagus to pectinate line)
Endoderm derivativeLiver
Endoderm derivativeGallbladder
Endoderm derivativePancreas
Endoderm derivativeThymus
Endoderm derivativeLungs
Endoderm derivativeParathyroid glands
Endoderm derivativeFollicular cells of thyroid
Endoderm derivativeLower 2/3 of vagina
Endoderm derivativeBladder/urethral epithelium
Mesoderm derivativeUpper 1/3 of vagina
Mesoderm derivativeBone
Mesoderm derivativeMuscle
Mesoderm derivativeBone marrow
Mesoderm derivativeBlood cells
Mesoderm derivativeHeart
Mesoderm derivativeBlood vessels
Mesoderm derivativeLypmhatics
Mesoderm derivativeDermis of skin
Mesoderm derivativeKidneys, adrenal cortex
Mesoderm derivativeGonads

Arches and pouches and clefts, OH MY

Question Answer
1st cleftExternal auditory Meatus
3rd and 4th cleftTemporary cervical sinus
What can form with a persistent 3rd and 4th cleft?Branchial neck cyst
Features of a Branchial neck cystLateral neck. Fixed cyst.
Features of a Thyroglossal duct cystMidline, moves with swallowing


Question Answer
1st arch cartilageMeckels cartilage, Mandible, Malleus+incus, Mandibular ligament [M's]
1st arch musclesMuscles of Mastication (Masseter, Medial pterygoid), Mylohyoid
Tensor Tympani, Tensor veli palatini, Tongue (anterior 2/3)
1st arch nerves CNV2 and V3 (Maxillary and Mandibular)
Failure of the 1st arch cartilage to formTreacher Collins syndrome
Disease of the 2nd arch congenital pharynocutaneous fistula
2nd arch cartilage[S for Second]
- Stapes
- Styloid
- leSSer horn of hyoid
- Stylohyoid ligament
2nd arch musclesMuscles of facial expression (Smile!)
poSterior belly of digastric
Nerves of 2nd arch CNVII (facial expression) [Seven]
Cartilage of 3rd arch greater horn of hyoid
3rd arch muscle stylopharnygeus
4th-6th arch cartilagescartilages: thyroid, cricoid, cuneiform
Nerves of 4th arch CNX (superior laryngeal) swallow
Nerves of 6th arch CNX (recurrent laryngeal) speak


Question Answer
1st pouch derivativesMiddle ear, cavity, eustachian tube, Mastoid air cell
2nd pouch epithelial lining of palatine tonsils
3rd pouchinferior parathyroids and thymus
4th pouch superior parathyroids
Branchial archesmesoderm
branchial cleftsectoderm
branchial pouches endoderm
Failure of the 3rd and 4th pouches to formDiGeorge syndrome:
- No thymus, no T cells (Recurrent infections)
- Cardiac anomalies (Persistant truncus arteriosus, ToF)
- No parathyroid (Hypocalcemia)


Question Answer
1st aortic arch Maxillary artery
2nd arch Stapedial artery
3rd arch Common carotid and
4th archLeft: aortic arch Right: subclavian artery
6th arch Proximal part of pulmonary arteries and l. ductus arteriosus

Brain development

Question Answer
The forebrain is derived fromProsencephalon (Telencephalon + Diencephalon)
The midbrain is derived fromMesencephalon
The hindbrain is derived fromRhombencephalon (Myelencephalon and Metencephalon)
Which adult structures are derived from the Telencephalon?Cerebral hemispheres, Basal ganglia, Hippocampus and Amygdala
Cerebral hemispheres are derived fromTelencephalon
Basal ganglia is derived fromTelencephalon
Hippocampus is derived fromTelencephalon
Amygdala is derived fromTelencephalon
Which adult structures are derived from the Diencephalon?Thalamus, Hypothalamus, Optic nerves + tracts
Thalamus is derived fromDiencephalon
Hypothalamus is derived fromDiencephalon
Optic nerves are derived fromDiencephalon
Which adult structures are derived from the Metencephalon?Pons and Cerebellum
Cerebellum is derived fromMetencephalon
Pons is derived fromMetencephalon
Which adult structure is derived from the Myelencephalon?Medulla
Medulla is derived fromMyelencephalon

Congenital Defects

Question Answer
Elevated maternal AFPNeural tube defect
Anterior abdominal wall defect
Decreased maternal AFPDown's syndrome (confirm with amniocentesis)
Trisomy 18
Chiari IHerniation of cerebellar tonsils (up high) can cause syringomyelia (down low)
Chiari IILumbosacral myelomeningocele (down low) causes herniation at foramen magnum (up high)
SyringomyeliaCape like loss of pain and temperature sensation.
Can have hand muscle weakness and atrophy.
Syringomyelia is caused byChiari I malformation or trauma
Dandy-Walker SyndromeEnlarged posterior fossa >> Cerebellar vermis fails to develop >> Dilation of the 4th ventricle
Dandy-Walker Syndrome is associated withHydrocephalus, Spina bifida
Decreased Estriol levelsPlacental insufficiency
Increased hCG levelsMultiple gestations
Down's syndrome
Decreased hCG levelsEctopic/failing pregnancy
Edward Syndrome (Trisomy 18)
Patau Syndrome (Trisomy 13)
AnencephalyNeural tube defect from amniotic fluid destroying the brain (polyhydramnios)
HoloprosencephalyHemispheres of the brain fail to develop
Holoprosencephaly can be caused bySonic hedgehog
Fetal alcohol syndrome
Patau syndrome
Low AFP, low estriol, low hCGTrisomy 18 (Edward's)
Low AFP, low estriol, High HCG, HIgh inhibinTrisomy 21 (Down's)
PolyhydramniosCan't swallow fluid: Esophageal/duodenal Atresia
Maternal DM
Fetal anemia
OligohydramniosCan't pee: Bilateral renal agenesis
Posterior urethral valves (boys)
Potter sequencePulmonary hypoplasia
Twisted face/skin
Extremity defects
Renal failure
Pee out the belly buttonPatent Urachus
Poo out the belly buttonPatent Vitilline duct


Question Answer
ACE inhibitorsrenal malformations
Fluoroquinolonescartilage damage
Tetracyclinesdiscolored teeth
Cyclophosphamideear/facial anomalies, limb hypoplasia, absence of digits
Methotrexateneural tube defects (folate metabolism), abortion
Carbamazepineneural tube defects (folate metabolism)
Valproic acidneural tube defects (folate metabolism)
Phenytoinfetal hydantioin syndrome (cleft lip, facial/limb abnormalitis, dvlpmtl delay)
LithiumEbstein anomaly - tricuspid valve is displaced downward into RV
StatinsCNS and limb abnormalities
Warfarinfacial/limb/CNS anomalies, spontaneous abortion
IsotretinoinSpontaneous abortion, parathyroid/brain/heart defects; disruption of neural crest cell migration; defective homeobox gene expression
Diethylstilbestrol (DES)clear cell vaginal adenocarcinoma later in life
Thalidomide [Inhibits TNF-α]limb deformity, severe hypoplasia of arms/legs
Alcoholcleft lip/palate, intellectual disability, microcephaly, holoprosencephaly, distinct facial features
Cocaine, tobaccoNot exactly teratogenic, but interfere w blood flow to the fetus; restrictive of growth