HD2 Anatomy2: Embryology Part 1 Flashcards
From which layer is the neural tube derived?
Endoderm
Mesoderm
Ectoderm
From which layer is the neural tube derived?
Endoderm
Mesoderm
Ectoderm
How is the neural tube formed? [1]
The neural tube is formed by an infolding of the ectoderm during embryonic folding.
Neurulation:
How does the notochord form into the neural plate? [1]
The notochord induces the overlying ectoderm to thicken and differentiate into neuroectoderm and form the neural plate.
Neurulation:
How does the neural plate turn into the neural tube? [2]
The neural plate folds dorsally to give rise to the neural groove which then becomes the neural tube
Neurulation:
What is the name for each end of the neural tube? [1]
Anterior / Posterior neuropores
Which structes do the Anterior / Posterior neuropores connect? [2]
The anterior and posterior neuropores connect the lumen of the neural tube with the amniotic cavity.
When does the anterior neuropore close? [1]
When does the posterior neuropore close? [1]
The anterior neuropore closes days 25-6.
The posterior neuropore closes days 27-8.
The rostral/cephalic part of the neural tube becomes the adult []
The caudal part of the neural tube becomes the adult []
The rostral/cephalic part of the neural tube becomes the adult brain.
The caudal part of the neural tube becomes the adult spinal cord.
The lumen of the neural tube goes on to form which structure of the adult CNS? [1]
Acceptable responses: ventricles, ventricular system
The neural crest cells migrate extensively to generate a number of differentiated cell types:
Cranial neural crest cells differentiate into a variety of cells, such as? [4]
Cranial neural crest cells differentiate into a variety of cells, such as bones of neurocranium, meninges, connective tissue and several components of cranial nerves
The trunk region neural crest cells differentiate into two major pathways.
What are they?
1) Pigment producing melanocytes that travel through the dermis into the ectoderm to colonize skin and hair follicles.
2) Migrate to each sclerotome (differentiated mesoderm) to form the dorsal root ganglia, sympathetic neurons, parasympathetic nerves, adrenomedullary cells, and Schwann cells of the gut, abdomen and pelvis.
What is the most common cause of neural tube defects? [1]
Spina Bifida
Explain the thre different types of spina bifida [3]
Spina Bifida Cystica:
- Myelomeningocele: herniated sac containing both CSF and nerves and parts of the spinal cord
- Meningocele: sac containing CSF and meninges only
Spina Bifida Occulta (‘Occulta’ means hidden): which one or more vertebrae have malformed. It rarely causes serious sequelae. Can present with a small tuft of hair or dimple or birth mark
Label A-C of the different types of spina bifida
Describe the physipathology of encephalocoele [1]
encephalocoele:
- herniation of meninges and brain tissue outside the cranium usually, but not always, in the midline.
