Central Nervous System Flashcards
what are the two parts of the nervous system
- central nervous system
- Peripheral nervous system
What are the parts of the central nervous system
- Brain
- Spinal Cord
what are the three different forms of protection of the central nervous system
- Bone
- Mengines
- Cerebrospinal fluid (CSF)
what bone protects the brain
the skull
what bone protects the spinal cord
the vertebrae
what is cerebrospinal fluid
It is a watery fluid containing glucose proteins, urea and salts
what are the three functions of cerebrospinal fluid
- Protects - Acts as a shock absorber
- Supports - brain floats in it
- Transports - carries nutrients and waste across the body
what is meninges
Are three layers of connective tissue that cover both the brain and spinal cord
what are the three layers of the meninges (bottom to top)
- Pia mater
- Arachnoid mater
- Dura mater
what is pia mater
Is a very thin, delicate, inner membrane that follows the contours of gyri and sulci. It contains many blood vessels closer to the surface of the brain and spinal cord.
what is arachnoid mater
The middle meningeal layer attaches to the dura mata. It consists of “web-like” fibres and provides a cushioning effect.
where are the subarachnoid and sub dural spaces located?
found between the arachnoid and dura mater
what do the sub-arachnoid and dub dural spaces consist of
cerebrospinal fluid
what is dura mater
Is a thick, tough, durable layer attached to the skull. It is not close fitting in the vertebral column, as it is with the bone of the skull
describe the protection of the spinal cord
Protected by three meningeal layers. Dura mater not like in the skull is not attached to the bones. Instead the epidural space containing fat, blood vessels and connective tissue serves as padding and allows the cord to bend.
what does the spinal cord consist of
- grey matter
- white matter
what is grey matter
Grey matter composes of nerve cell bodies and unmyelinated fibres
what is white matter
White matter composes of myelinated nerve fibres
what letter is grey matter resemble in the spinal cord
the letter H
where is the central canal located in the spinal cord
located in the cross bar of the H (grey matter zone)
what does the central canal consist of
cerebrospinal fluid
how are white matter myelinated fibres arranged
Arranged in bundles called tracts
what is the difference between myelinated and unmyelinated nerve fibres
myelinated nerve fibres are covered in bundles of tissue to enable faster nerve transmission.
what are the different tracts of white matter myelinated fibres
- ascending tracts
- descending tracts
what are ascending tracts
They are sensory axons that carry impulses towards the brain
what are descending tracts
They are motor axons that carry impulses away from the brain
What are the three types of tracts that occur in white matter?
- Tracts that connect various areas of the cortex within the same hemisphere.
- Tracts that carry impulses between the left and right hemispheres.
- Tracts that connect the cortex to other parts of the brain or spinal cord.