3. Histology of the NS Flashcards
Central nervous system (CNS)
brain and spinal cord
Peripheral nervous system (PNS)
everything outside the CNS
Somatic nervous system
voluntary functions
Autonomic nervous system
involuntary functions
Sympathetic system
Fight or flight
Increase heart rate and blood flow
Diverts blood to skeletal muscle
Mobilisation of glycogen and fat
Neurotransmitter is noradrenalin
Parasympathetic system
Conservation and restoration of energy
Decrease heart rate and blood flow
Digestion and absorption of nutrients
Excretion of waste
Neurotransmitter is acetylcholine (Ach)
Cell body
large central nucleus large aggregations of rER called Nissl substance
Dendrites
Highly branched processes
End in sensory receptors
Sites of info input into the cell
Axons
Single, long processes
End in small swellings called terminal boutons
Site of info output
Bipolar neuron
Unipolar neuron
Multipolar neuron
Myelin
insulation
speeds up conduction
What is myelin called in the PNS
Schwann cells
What is myelin called in the CNS
Oligodendrocytes
white matter of the brain
myelinated
grey matter of the brain
non-myelinated
Nodes of Ranvier
gaps between Schwann cells
NMJ
Also called a Motor End Plate
Specialised type of synapse between nerve cells and skeletal muscle
One axon terminates in many end plates
Astrocytes
structural scaffolding
Microglia
immune cells (specialised macrophages)
Alzheimer’s disease
extracellular deposition of a protein called amyloid
senile plaques
aggregations of abnormal neurones
loss of synapses between neurones
Myasthenia Gravis
autoimmune disease
body makes antibodies to the acetylcholine receptors
muscle weakness, drooping head and eyelids
Multiple Sclerosis
immune system attacks the myelin of the CNS
loss of coordination, paralysis,
loss of sensation
