embryologic derivatives

Question 1

surface ectoderm

Answer 1

• adenohyphosis (from Rathke pouch)
• lens of eye
• epi linings of oral cavity
• sensory organs of ear and olfactory epi
• epidermis
• anal canal below pectinate line
• parotid, sweat and mammary glands (superficial glands)

**think superficial structures

Question 2

Neuroectoderm

Answer 2

• brain: neurohypophysis (post pituitary), CNS neurons, oligodendrocytes, astrocytes, ependymal cells, pineal gland)
• retina and optic nerve
• spinal cord

**think CNS

• notochord induces overlying ectoderm to become neuroectoderm (neural plate–> neural tube)

Question 3

Neural Crest

Answer 3

• PNS (dorsal root ganglia, celiac ganglion, CN, Schwann cells, ANS) + pia annd arachnoid
• melanocytes
• chromaffin cells of adrenal medulla
• parafollicular cells (C cells) of thyroid (**this is why mutation in RET causes pheo and medullary thyroid carcinoma)
• odontoblasts (*think Crest toothpaste)
• aorticopulmonary septum/spiral septum

**think PNS

Question 4

mesoderm

Answer 4

• muscle, bone, CT, serous linings of body cavity (peritoneum)
• cardiovascular structures
• blood
• lymphatics
• spleen, kidneys, adrenal cortex
• testes, ovaries, vagina

Question 5

endoderm

Answer 5

• gut tube epithelium (including anal canal above pectinate line)
• urethra
• all the other organs (lungs, liver, gallbladder, pancreas, eustachian tube, thymus, parathyroid, thyroid follicular cells)

Question 6

embryonic structure

1. truncus arteriosus
2. bulbis cordis
3. primitive atria
4. primitive ventricle

Answer 6

gives rise to…

1. ascending aorta and pulmonary trunk (= spiral septum – NCC origin)
2. smooth parts of L and R ventricles (outflow tracts)
3. trabeculated part of L and R atria (muscular portion)
4. trabeculated part of L and R ventricle (muscular portion)

Question 7

embryonic structure

1. Primitive pulmonary vein
2. Left horn of sinus venosus
3. Right horn of sinus venosus
4. R common cardinal vein and R anterior cardinal vein