-
Gray Matter
- cell bodies, poximal dendrites
- CNS - cortex, nucleus
- PNS - ganglion
-
White Matter
- myelinated axons
- CNS - tract, fasciculus, funiculus, lemniscus, peduncle, commisure
- PNS - nerve fiber, nerve, rami, root
-
soma
- a neuron cell
- metabolic center
- integration of impulses
-
dendrites
- a neuron cell
- one or more per cell
- preferred site of synapse
- spines increase surface area for synaptic contacts
-
axon
- a type of neuron
- one per cell
- axon hillock
- initial segment
- terminals contain vesicles of neurotransmitter
-
pseudounipolar
- sensory neurons
- (e.g. posterior root ganglion)
-
bipolar neurons
visual, olfactory, auditory, vestibular systems
-
multipolar neurons
- motor neurons
- interneurons
- projection neurons
-
astrocytes
- glial cells
- structural support
- protoplasmic = gray matter
- fibrous = white matter
- blood brain barrier - tight junctions
- response to injury - glial scar
- metabolic functions - regulate intracellular environment, neural transmission, produce growth factors, cytokines
- tumor formation = astrocytomas
-
oligodendrocytes
- CNS glial cell
- myelinate CNS axons - one cell does multiple axons
-
microglia
- CNS glial cell
- immune surveillance - not from neuroectoderm
- response to injury
-
ependymal cells
- CNS glial cells
- line the ventricles
-
choroid epithelial cells
- CNS glial cell
- derived from ependyma
- control flow of ions and metabolites
-
meningeal cells
- CNS glial cells
- modified fibroblasts
-
response of neuron to axotomy
- cell swelling
- chromatolysis - eccentric nucleus, loss of nissl bodies
- dendrite retraction
- changes in mRNA and protein synthesis
- formation of retraction bulbs
- Wallerian degeneration (distal stump)
- transneuronal degeneration
- PNS - axon regeneration(stimulated by proliferating Schwann cells)
- CNS - limited axon regeneration
-
Receptors for neurotransmitters:
CNS?
PNS?
- CNS: EPSP, IPSP
- PNS: end plate potentials at neuromuscular junction
-
Neurotransmitter in CNS synapse?
glutamate (75-80%)
-
Neurotransmitter in PNS synapse?
Ach
-
Basic reflex arc
- 1. afferent nerve fiber
- 2. synapse
- 3. efferent nerve fiber
-
Where does the cranial dura get its:
sensory innervation?
blood supply?
- sensory innervation: Trigeminal nerve (CN V)
- blood supply: middle meningeal artery
-
In a T2 weighted image CSF is?
white
-
In a T1 weighted image CSF is?
black
|
|
