Neurons
-Send and receive electrical and chemical signals
-Excitable
Neuroglia/glial cells
-Support and protect neurons
-May be involved in signal transduction
Neuron characteristics
-High metabolic rate
-Extreme longevity
-Nonmitotic
Unipolar neuron
-Very long axon that's fused to dendrites
-Uncommon in humans
Bipolar neuron
-One dendrite and one axon
Multipolar neuron
-Most common
-One axon and multiple dendrites
,Sensory/afferent neuron
Sends impulse from sensory receptors to the central nervous system
Motor/efferent neuron
Sends impulse from the CNS to muscles or glands
Interneuron
Helps sensory and motor neurons communicate
What type of cells are most likely to be involved in brain tumors?
Glial cells
Characteristics of glial cells
-In both CNS and PNS
-Mitotic
-Protect and nourish neurons
-Much more abundant than neurons
-Smaller than neurons
Astrocytes
-Maintain BBB
-Generate scaffolding for CNS
-Repair damaged neural tissue
-Cell development
-Regulates interstitial environment
Which neural cells develop first and what cells develop them?
-Glial cells
-Astrocytes
Choroid plexus
Branching network of mostly ependymal cells that produces cerebrospinal fluid in brain ventricles
Ependymal cells
-Ciliated cuboidal epithelial cells lining the brain ventricles and the central canal of the spinal cord
-Produce cerebral spinal fluid (CSF) and make up the choroid plexus
-Share characteristics with stem cells
Microglial cells
-Small and motile
-Use phagocytosis to remove cell waste
Oligodendrocytes
, -Only located in the CNS
-Wrap around axons and produce myelin
-Only glial cells that can synapse with neurons
What are oligodendrocytes called when they form synapses with neurons?
Progenitor cells
Satellite cells
-Aka amphicytes
-Located in the PNS
-Surround ganglia
-Regulate environment surrounding the neuron
Schwann cells/neurolemmocytes
-ONLY found in PNS
-Form myelin sheaths
-Secrete neurotrophic factors
Layers of brain protection
-Cranial bones
-Cranial meninges
-Cerebrospinal fluid
Cranial meninges
-Dura mater
-Arachnoid
-Pia mater
Dura mater
-Two fibrous layers
-Vascular, contains fluid
Arachnoid
-Made of epithelium
-Cerebrospinal fluid is located underneath in the subarachnoid space