Lectures 2 & 4 - Neuro Flashcards
What is the difference between the CNS and the PNS?
CNS: The brain and spinal chord; that which is encased in bone.
PNS: Anything outside of the brain and spinal chord; that which is not encased in bone.
How does the neuraxis change in humans compared to quadrupeds?
The neuraxis is essentially vertical in humans but is rotated anteriorly at the rostral end.
What are the three layers of meninges, from outside to inside?
Dura mater, arachnoid mater, pia mater.
What is between the arachnoid mater and the pia mater?
The subarachnoid space
What is contained within the subarachnoid space?
CSF, arachnoid trabeculae, and blood vessels.
What are the two layers of dura mater, from outer to inner?
Periosteal and meningeal
What is the name of the structure in the brain into which CSF and venous blood drain?
Sinuses, including the superior sagittal sinus.
How does venous blood drain from the subarachnoid space?
Through arachnoid villi.
Where does CSF come from and how is it produced?
It is primarily produced by ependymal cells (modified endothelium) of the choroid plexus in the ventricles.
How many ventricles are there?
Two lateral, third, and fourth
What is the relationship between the ventricles and the subarachnoid space? What does this relationship allow the CSF to do?
The ventricles are continuous with the subarachnoid space, thus allowing the CSF to communicate from the ventricles to the subarachnoid space.
What happens if the CSF does not return to circulation?
Hydrocephalus: Oedema, causing increased intracranial pressure.
How can hydrocephalus be resolved?
A catheter draining CSF from the ventricles into the peritoneal cavity.
What type of blood fills a subdural and epidural hematoma?
Subdural: venous blood
Epidural: arterial blood
What is a pathological difference between an epidural and a subdural hematoma?
An epidural hematoma will peel the dura off of the skull.
What are the two cellular components of the nervous system?
Glia and neurons.
How is information conveyed by the nervous system?
Electrically receives, integrates, and outputs electrical information along the processes of excitable cells called neurons.
Transmission within a single neuron is electrical. What type of transmission occurs between neurons (most often)?
Chemical transmission via neurotransmitters.
Where does transmission between neurons take place?
At synapses.
What are the two types of insulating glia in the nervous system? In which part of the nervous system is each, respectively?
Oligodendrocytes in the CNS, Schwann cells in the PNS.
Why are tracts in the CNS system called ‘white matter’?
The oligodendrocytes insulate the axons of neurons with lipid bilayer.
Why are axons insulated?
To increase speed of transmission without increasing the size of the axon.