Lecture 33 - Anatomy of the Nervous System Flashcards
What are the 3 nervous systems
- Central nervous system
- Peripheral nervous system
- Enteric nervous system
The CNS contains the
brain
spinal cord
The PNS contains the
peripheral nerves (cranial & spinal)
Neuromuscular junction
What embryonic layer makes the nervous system
ectoderm
what embryonic layer makes the notochord
mesoderm
What does the notochord become
nucleus pulposus of intervertebral disc
what does the alar plate give rise to?
dorsal horn (sensory)
what does the basal plate give rise to?
ventral horn (motor)
where is the subarachnoid space located in relation to the layers of the dura
between the dura mater and arachnoid mater
what is found in the subarachnoid space
CSF
what is the cerebellomedullary cistern and what is its clinical significance?
space at C1 where the SAS is expanded and spinal taps are performed
where is the CSF produced?
choroid plexus
summarize primary neuralation
- ectoderm thickens to make the neural plate
- neural groove appears
- folds generate the neural tube and neural crest cells
summarize secondary neuralation
- caudal neuropore closes
- solid tube of ectodermal cells develop cavities - producing a hollow tube that connects with the central canal
- sacral/caudal cord segments develop here
What are the 3 zones of the early spinal cord (outermost to innermost)
- marginal layer
- mantle layer
- ventricular zone
the dorsal median sulcus deals with _____ inputs
sensory
the ventral median fissure deals with ____ inputs
motor
Describe the locations of the lateral horn
T1-L4/5 (sympathetic)
S1-3 (parasympathetic)
What do neural crest cells produce
sympathetic postganglionic neurons
adrenal medulla
melanoblasts
Schwann cells
What is Spina Bifida
failure of fusion of the vertebral arch
Spina Bifida Occulta
bone missing
Spina Bifida Aperta
meninges protrude (meningocele)
meninges + spinal cord (meningomyelocele)
dura mater
very tough
fused to the skull and C1 periosteum
covers optic nerve
arachnoid mater
fused to dura mater
delicate trabecular projections to pia mater
“buffer zone”
pia mater
closely apposed to CNS
adjacent to glia limitans
thickens bilaterally to form denticulate ligaments to suspend spinal cord
What is the blood-brain barrier
a barrier between the plasma in CNS vessel and ECF made of endothelial tight junctions, pericytes, and astrocytic endfeet
what two locations can be used to sample CSF
- cerebellomedullary cistern
- lumbar cistern
Meningitis
inflammation of meninges
subdural abscess
caused by bacterial infections and can cause separation of dura from skull
Meningiomas develop from
arachnoid cap cells
Describe the ventricular system
2 lateral ventricles
3rd ventricle
4th ventricle
Lateral ventricles
each has choroid plexus
connect via interventricular foramen to 3rd
3rd ventricle
contains extensions of lateral choroid plexi
surrounds interthalamic adhesion
connects to 4th via mesencephalic aqueduct
4th ventricle
lies over pons and medulla
has paired choroid plexi
flows into central canal + SAS
choroid plexus
cluster of villi projecting into the ventricle
CSF producing
Arachnoid villi ____ with increasing CSF pressure and ____ drainage
expand; increase
