2.9 Study Guide Flashcards
What forms the neural plate?
longitudinal thickening of ectoderm
What happens after day 24 during embryonic development?
- more folds forming
- ½ million neurons per minute
When does brain formation begin?
day 28
What is spina bifida with myelomeningocele almost always associated with?
Arnold Chiari Type II
In addition to motor problems, what other problems may present with cerebral palsy?
- sensation
- cognition
- language
Arnold Chiari malformation may compress this nerve
CN VIII
microcephaly
- small head
- developmental issues
- treat the symptoms
dentate ligaments
- go through arachnoid mater to dura mater
- stabilize spinal cord
functions of astrocytes
- cell signaling
- helps form blood brain barrier
- remove NT from synaptic clefts
- clean up debris
- regulation connect neurons and capillaries
pseudounipolar neurons
- 2 axons
- no true dendrites
- bring info from the body into the spinal cord
EPSP
- NT binds to postsynaptic membrane receptor that opens
- positive ions (Na+ and Ca2+) flow in
- membrane depolarized
**summation of EPSPs can fire an AP
IPSP
- NT binds to postsynaptic membrane receptor
- negative ion channels open (Cl-)
- membrane hyperpolarized
**inhibits AP when summated
local potentials
- EPSP and IPSP summated to see if an AP will fire
type of receptor: direct activation, fast
ionotropic
type of receptor: indirect activation, slower, affects gene expression and metabolism
metabotropic
ACh in PNS (fast and slow effects)
- fast: muscle
- slow: HR and other autonomic functions
ACh in CNS (slow)
neuromodulation involved in control of movement and selection of attention
primarily inhibits in the brainstem and spinal cord
glycine
principle fast excitatory NT of CNS
glutamate
primarily acts at interneurons within spinal cord as an inhibitor
GABA
acts on pleasure and reward centers
dopamine
affects mood and perception of pain
serotonin
strongly implicated as a neuromodulator in pathophysiology of pain syndromes that involve perception of normally innocuous stimuli as painful
substance P
how to see lesions in white matter
MRI
CNS demyelination
multiple sclerosis
PNS demyelination
Guillain-Barré
Why is MS hard to diagnose?
usu manifests with one sign that may completely resolve
What does lead mimic during neurotransmission?
mimics Ca, Mg, Fe, Cu
How does lead affect neurotransmission?
irreversibly connects so the other ions can’t
What therapy is used for lead poisoning?
chelation therapy
- can remove lead from the body
- not successful in children
What are the axon types?
Ia Ib II A-beta A-delta C fibers
first step in fast pain pathway
initial, immediate sharp sensation that indicates location of the injury
In the fast pain pathway, which laminae are the cell bodies of the second order neurons found?
I, II, V of dorsal horn
Where do most neurons end in the thalamus?
VPL
What results from a lesion in the VPL of the thalamus?
- interrupts pathway to cortex
- inability to localize painful stimuli despite feeling affective (emotional) aspects of pain
example of slow pain
if you break a bone in your hand, it feels like your whole hand hurts
nerve fiber type in slow pain pathway
small, unmyelinated C fiber
lamina I
marginal layer
lamina II
substantia gelatinosa
NT for slow pain pathway
substance P
divergent pathway
slow pain
In the anterior spinothalamic tract, which is the only tract perceived as pain?
spinolimbic
Where is the reticular formation?
brainstem
Where do axons go from the reticular formation?
project to midline and intralaminar nuclei of the nucleus
spinolimbic pathway: small or large receptive fields?
large
VPL
ventral posterolateral nucleus
How are fast and slow pain transmitted from the face?
sensory portion of the trigeminal nerve joints with the fast or slow pain pathway
steps of fast pain from the face
- 1˚ fibers enter pons
- travel down into medulla and upper cervical cord in descending tract of trigeminal nerve
- synapse in spinal nucleus of trigeminal nerve
- 2˚ fibers cross and ascend to VPL of thalamus
- 3˚ fibers project to cerebral cortex
steps of slow pain from the face
trigeinoreticulolimbic pathway
- 1˚ fibers are C-fibers in trigeminal nerve
- synapse in reticular formation
- neurons project to intralaminar nuclei to the cerebral cortex
What neuronal subtype is the primary somatosensory neuron?
pseudounipolar
ANS: mechanoreceptors for pressure
- aortic baroreceptors
- carotid sinuses
- lungs
ANS: mechanoreceptors for stretch
distention in veins, bladder, or intestines
ANS: chemoreceptors in carotid and aortic bodies
respond to oxygen
ANS: chemoreceptors in medulla
responds to hydrogen ions and carbon dioxide
ANS: chemoreceptors in hypothalamus
responds to blood glucose levels and concentration of electrolytes
ANS: nociceptive responses found in
- viscera
- walls of arteries
visceral nociceptors are responsive to
chemical irritation
controls pituitary
hypothalamus
