OCB03-2004 Divisions & general organisation of the brain & spinal cord Flashcards
What is a CNS neuron?
A neutron that is entirely contained within the brain and/or spinal cord
What is a PNS neuron?
If any part of the neurone has projections outside of the brain/ spinal cord
Why is grey matter grey?
Presence of cell bodies
Why is white matter white?
Due to myelin sheath and glial cells
What is the arrangement of grey and white matter in the spinal cord and brain?
The brain has grey matter on the outside and white matter on the inside
The spinal cord has white matter on the outside and grey matter on the inside
What is grey matter concerned with?
processing and cognition
What are the anatomical compartments of the ANS?
Forebrain
Midbrain
Hindbrain
Spinal Cord
What is the hindbrain divided into?
Pons
Cerebellum
Medulla
how many pairs of spinal nerves are there?
31
Where do spinal nerves exit through?
the intervertebral foramen between two vertebrae
Where does the first spinal nerve emerge from?
Between the occipital bone and atlas
what NS are spinal nerves part of?
PNS
Which vertebrae does the spinal cord end at?
L1/L2
Where do the other spinal nerves travel through after the spinal cord ends?
The lumbar cistern, which is the subarachnoid space in the lower lumbar spinal cord
What is the part of the spinal cord after L1/L2 known as?
Cauda equina
What is the caudal equine full of?
Spinal nerves and CSF
What do nerves enter and leave the spinal cord as?
Rootlets
What is the outer part of the cerebrum known as?
Cerebral cortex
What are the ridges of the cerebrum known as?
Gyri, sulci and fissures
How long is the central canal?
It runs the length of the spinal cord
What ventricles of the brain does the cerebral aqueduct connect?
3rd and 4th ventricle
What is CSF inside the ventricles made by?
Choroid plexus
What is CSF reabsorbed by?
Back into the venous bloodstream
What occurs if the CSF is not reabsorbed back into the venous bloodstream?
Hydrocephalus
What occurs during hydrocephalus?
As the CSF builds up, it pushes the cortex outwards, the cortex pushes against the skull plates
The skull plates are ye to fuse in babies so the head grows larger
How is hydrocephalus treated?
A stent is placed to remove excess CSF
What are the 3 layers of the CNS meninges from inner to outer?
Pia mater
Arachnoid mater
Dura Mater
What is the function of the subarachnoid space?
The CSF leaves the ventricles of the brain and exits into this space
Where is the subarachnoid space?
Between the Pia mater and arachnid mater
What is the Pia mater?
The innermost meningeal layer that allows entry of blood vessels into the CNS
What is the arachnoid mater?
Middle meningeal layer
Forms to upper limit of the subarachnoid space
What is the dura mater?
Outer meningeal layer
Closely attached to the periosteum of the cranium
When the CSF is reabsorbed by venous blood, where does it go?
From the sub arachnoid space into the superior sagittal sinus
What is the superior sagittal sinus full of?
Deoxygenated blood bacteria from the heart
What are the arachnoid specialisations that project into the sub arachnoid space called?
Arachnoid granulation
