Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
37 Cards in this Set
- Front
- Back
|
What are the three layers of the neural tube in an embryo?
|
Ectoderm, mesoderm, endoderm
|
|
|
The ectoderm gives rise to what structures?
|
The CNS, peripheral nervous system, epidermis and enamel of the teeth
|
|
|
The mesoderm gives rise to what structures?
|
Muscle, cartilage, bone, dermis of the skin, connective tissue, blood and lymph
|
|
|
The endoderm gives rise to what structures?
|
Epithelial lining of the GI tract, respiratory tract, liver, pancreas and other organs
|
|
|
The neuroectoderm progresses to what three layers of cells?
|
Ependymal, mantal and marginal
|
|
|
The ependymal layer forms what?
|
The innermost layer, lines the ventricles of the brain and spinal cord
|
|
|
The mantal layer forms what?
|
Intermediate layer, forms the gray matter
|
|
|
The marginal layer forms what?
|
Outermost layer, forms the white matter
|
|
|
The neural crest differentiates into what?
|
Autonomic ganglia, sensory ganglia of the cranial nerves, dorsal root ganglia, Schwann cells
|
|
|
Somites give rise to what structures?
|
The axial skeleton (vertebrae and ribs) and axial musculature
|
|
|
How many somites are there?
|
42 to 44
|
|
|
What is the sulcans limitans?
|
The lateral groove on both sides of the neural tube that divides it into upper and lower halves
|
|
|
Where is the alar plate in the spinal cord? What is its function?
|
Dorsal half; contains sensory neurons
|
|
|
Where is the basal plate in the spinal cord? What is its function?
|
Ventral half; contains motor neurons
|
|
|
When does myelination begin in the spinal cord and in what direction?
|
About 4 months, from cervical to sacral
|
|
|
When does myelination begin to occur in the cerebral cortex and in what direction?
|
At birth, first in the motor and sensory cortices then association areas and lastly in the prefrontal cortex
|
|
|
When are corticospinal fibers completely myelinated?
|
Age 2
|
|
|
What is spina bifida?
|
A malformation in the closing of the neural tube and associated somite structures
|
|
|
What is myelodysplasia?
|
Defective development of any part of the spinal cord
|
|
|
What does the term myelo- denote?
|
A relationshp to marrow, the spinal cord or myelin
|
|
|
What three stuctures constitute the meninges?
|
Dura mater, pia mater and arachnoid
|
|
|
What does the term -cele denote?
|
A relationship to a cavity
|
|
|
What is spina bifida occulta?
|
A defect of the vertebral arch
|
|
|
What is one sign of spina bifida occulta?
|
A tuft of hair over the affected area
|
|
|
Are the spinal cord and nerves involved in spina bifida occulta?
|
No
|
|
|
What is the incidence of spina bifida occulta in the general population?
|
As high as 10%
|
|
|
What is a meningiocele?
|
A condition where the coverings of the spinal cord (meninges) protrude into a sac
|
|
|
Does a meningiocele involve sensory or motor deficits?
|
Not usually
|
|
|
What is a myelomeningocele?
|
A protrusion of the spinal cord and its meninges through a defect in the vertebral canal
|
|
|
Are sensory and motor deficits seen with a myelomeningocele?
|
Yes
|
|
|
A myelomeningocele causes disruption of what tracts in the spinal cord?
|
Ascending and descending
|
|
|
What is myeloschesis (myelocele)?
|
A developmental anomaly characterized by a cleft spinal cord, caused by a failure of the neural plate to close
|
|
|
What is a syringomyelocele?
|
A developmental anomaly characterized by a lack of development of the central part of the spinal cord
|
|
|
What is a syringomyelocele filled with?
|
Fluid
|
|
|
What is myelodysplasia?
|
Defective development of any part of the spinal cord
|
|
|
What is the incidence of neural tube defects? What portion of those are anencephaly?
|
1 in 1000 births, 1/2 are anencephaly
|
|
|
What supplement reduces the risk of neural tube defects?
|
Folic acid
|
