Nervous System Flashcards
What do the meninges envelop?
Brain
Spinal cord
In the CNS, which cells are responsible for myelination?
Oligodendrocytes
How do anti-pyretic drugs work?
Inhibit cycle-oxygenate enzyme
Also reduce level of prostaglandins in hypothalamus
What are the layers of the meninges from outer to inner most layer?
Dura mater
Arachnoid
Pia mater
Which is darker, grey or white matter?
Grey matter
What makes up grey matter?
Cell bodies, dendrites, axon terminals
What makes up white matter?
Glial cell, myelinated axons
What makes up Nissl bodies/substance?
Aggregations of RER
What is the function of the cell body?
Maintenance of the axon etc
What can cause multiple sclerosis?
Loss of myelination (by oligodendrocytes) in the CNS
How many axons can 1 Schwann cell myelinate?
Only 1
How many axons can 1 oligodendrocyte myelinate?
Many- up to 250
What makes a neurone pre-ganglionic?
When it’s cell body is in the CNS
What makes a neurone post ganglionic?
When it’s cell body is in the PNS
What does the afferent division of the PNS do?
Send info TO the CNS via sensory/afferent neurones
List the glial cells found in the CNS
Oligodendrocytes, astrocytes, microglia, ependymal cells
List the glial cells of the PNS and what they do
Schwann cells, satellite cells. Schwann form myelin sheath, satellite cells offer physical support amongst other roles
What is the role of ependymal cells, what are they and where are they found?
Ciliated cuboidal epithelial cells, Line central canal and form a physical barrier, produce cerebrospinal fluid
What are astrocytes and what do they do?
Most abundant neuroglia, wrap around capillaries, form blood brain barrier (BBB), control chemical environment within CNS
What do microglial cells do?
They are macrophages so act as the immune cells of CNS
Why is myelination so important?
Allows depolarisation to ‘jump’ between nodes of ranvier, means it doesn’t have to occur along the whole length of the axon which would be a lot slower.
What does myelin consist of?
Layers of plasma membrane wrapped around the axon TF high density of lipids present
How would you stain nerve axons without losing lipids in myelin?
Use osmium tetroxide–> preserves lipids
Which is the fight or flight response done by- para or sympathetic?
Sympathetic