Nervous system Flashcards
What is the CNS?
Central Nervous System
Brain plus spinal cord
What is the PNS?
Peripheral Nervous System
All the other nerves
What is the PNS split into?
Somatic: Voluntary
Autonomic: Involuntary
What is cranial nerve 1 (CNI)?
Olfactory nerve
What is cranial nerve 5 (CNV)?
Trigeminal nerve (face)
What is cranial nerve 10 (CNX)?
Vagus nerve (a parasympathetic nerve)
What is saltatory conduction?
It occurs along a myelinated axon where the electrical impulse jumps from node to node
What is the difference between PNS myelination and CNS myelination?
PNS myelination: Several Schwann cells support a single axon
CNS myelination: A single oligodendrocyte supports several axons
What are glial cells?
Support cells of the CNS
Name the four types of glial cells and state their function
Astrocytes: Controls the local environment of the neurones
Oligodendrocytes: Produce myelin, but also involved with neuronal guidance
Microglia: The brain’s macrophages
Ependymal cells (not true glia): Line the ventricles
Describe the phases of how information is transmitted over a synapse
An action potential in the presynaptic neurone causes an influx of calcium ions
The influx triggers the exocytosis of the neurotransmitter () into the synaptic cleft
These neurotransmitters can bind to receptors on the postsynaptic neurone, creating an action potential
What is the function of the thalamus?
What are the three meninges layers?
Dura mater (tough one)
Arachnoid
Pia
What is the function of the choroid plexus?
It creates cerebral spinal fluid (CSF)
What circular vessel supplies the brain with blood?
The circle of Willis
What can and cannot pass from the blood into the cerebral spinal fluid (CSF)?
Can pass into the CSF:
Water
Salts
Cannot pass into the CSF:
Proteins
Most small molecules
How is the blood-brain barrier achieved in the brain capillaries?
Tight junctions between the endothelial cells
Pericytes
Which meninges layer splits to form the venous sinus?
Dura mater
What is the role of cerebral spinal fluid?
Physical protection: Stops the brain from crashing into the skull
Chemical protection: Provides a regulated extracellular environment
Some CNS hormone distribution
