L1 Flashcards
what is the CNS responsible for
it is the integrating and communication centre
what is the PNS responsible for
it is the system linking all parts of the body to the CNS via nerves
what are the 2 major PNS nerves
the peripheral (limbs) and cranial (face) nerves
what are the major subdivisions of the CNS
the brain and the spinal coard
the brain in a major subdivision of the CNS. this can be further broken down into
the forebrain, brainstem and the cerebellum
what makes up the forebrain
the cerebral hemposhairs (cerebrum) and the diencephalon
what makes up the brain stem
the midbrain, pons and medulla
what makes up the hindbrain
the pons and the medulla
what is the approx weight of the brain
1.5Kg
the cerebrum makes up what % of the brain’s total volume
83%
why does the cerebellum contain 50% of the brain’s neurons
it is a very procice structure
what is another name for superior in the brain
dorsal
what is another name for anterior in the brain
rostral
what is another name for posterior in the brain
caudal
what is another name for inferior in the brain
ventral
if you were to cut the brain in the middle of the 2 hemispheres (cut the corpus callosum) what would that section be called
midsagittal
what is another name for a horizontal section
transverse (separates top and bottom)
what is another name for a sagittal section
longitudinal (between the eyes)
what is another name for a vertical section
caronal (separates front and back)
nerve tissue consists of 2 cell types, what are these
neurons (nerve cells) and support cells (glia)
describe neurons
they are highly specialised, excitable cells which have a high metabolic rate.
they provide rapid and specific communication between regions of the body
what are the 4 types of glia in the CNS
astrocytes
oligodendrocytes
microglia
ependymal cells
what are some functions of astrocytes
offer structural support and regional metabolism
what are some functions of oligodendrocytes
structural support and insulation
these are the schwann cells of the CNS
what is the role of microglia
immune function
what is the role of ependymal cells
to line the ventricles
what is gray matter in the CNS
Nucleus
what is gray matter in the PNS
ganglion
what is white matter
axons
what gives white matter its white colour
the lipid material in myelin sheaths
in the brain where in gray matter located and why?
it is located on the outside of the cerebrum (the cortex)
you should think that the 2 hemispheres are circles and gray matter is the outline of the circle therefore there is gray matter on the inside of the brain
where in the brain is white matter
in the middle of the gray matter
where is gray matter located in the spinal cord
on the inside (the butterfly)
why do we have gray matter on the outside of the cerebrum but not on the outside of the spinal cord
because the brain is folded. the folding allows for more nerve cells to be crammed into the brain so that we can think, understand language/speech and have fine movement
what are the external features of the brain
the dura mater, gyri, sulci and fissure
what is a fissure
they separate large regions of the brain
what are the 5 lobes of the brain
frontal parietal occipital temporal insula
where is the insula located
it is buried deep within the lateral sulcus and forms part of its floor
what is the insula hidden by
it is covered by portions of the frontal, parietal and temporal lobes
when are you able to see the insula
when you open up the lateral sulcus
what is the transverse fissure
it separates the cerebrum from the cerebellum
what is the parieto-occipital sulcus
it separates the parietal and the occipital lobes
when is the parieto-occipital sulcus visible
you can only see this from the medial surface of the brain (in a sagittal section)
what makes up the diencephalon
the thalamus, hypothalamus and the pineal gland
what is the width of the spinal cord
the same as your thumb
what is the foramen magnum
the hole in the base of your skull
where does the spinal cord extend from and to
the foramen magnum to the first or second lumbar vertebra
how long is the spinal cord
about 42 cm
how many pairs of spinal nerves are there
31
there are 2 enlargements in the spinal cord. what are they called
the cervical and lumbar enlargements
there are 2 enlargements in the spinal cord. why do we have these
because there are more motor neurons in these areas so that you are able to innovate your limbs
what is the end of the spinal cord called
conus medullaris or the medullary cone
what is the filum terminale
it extends from the conus medullaris to the posterior surface of the spinal cord
this counts as a miningel layer
what is the cauda equina
it is the pony tail
the collection of nerve roots at the inferior end of the vertebral canal
why do we have a cauda equina
because after birth the vertebral column grows faster than the spinal cord
where is the median fissure located
anterior or ventrally
where is the median sulcus located
posterior ot dorsally
what is the central canal
the centre of the spinal cord
what kind of information do the dorsal roots carry
afferent
what kind of information do the ventral roots carry
efferent
what kind of information do the spinal nerves carry
it is mixed
both afferent and efferent
what is another name for the spinal nerves
peripheral nerves
what is paralysis
loss of motor function
what is sensory loss called
paraesthesias
the severity of the spinal cord injury depends on what
the level of the spine the injury occurs at
at what levels would an injury to the spin cause high tetraplegia
C1 - C4
what is tetraplegia
can’t move upper and lower limb
what happens if the injury to the spin is at C5 - C8
low tetraplegia
may have some movement of the upper limb
paraplegia is the result of in injury to what levels of the spine
thoracic, lumbar or sacral
spinal cord injuries can either be……
complete or incomplete
what would be the result if you were to damage the ventral part of the spine on your right side
motor loss (paralisis) on your right side
what would be the result if you were to damage the dorsal part of the spine on your left side
sensory loss (paresthesias) on your left side
what is the dura mater
it is the outermost layer of the miningies
it is a thick layer f connective tissue (fibroblasts and collagen) that surrounds the brain
it is very tough because of the collagen (makes it hard to stretch) and therefore is the main protective and supporting layer
what are the 2 layers of the dura mater called
the periosteal and meningeal layer
what is a venis sines
it is a space between the the periosteal and meningeal layer
they are large veins which sit on the outside of the vain
name one venis sines
the superior sagittal sinus
what is the falx cerebri
it is a partition (structure which divides) which subdivides the cranial cavity to limit excessive movement of the brain within the cranium
where is the falx cerebri located
in the longitudinal fissure
can also be called he median sagittal plane
what is the longitudinal fissure
the deep groove that separates the two cerebral hemispheres of the vertebrate brain
what are the names of the 3 dural folds
falx cerebri, tentorium cerebelli and the falx cerebelli
where is the tentorium cerebelli located
it separates the cerebellum and the cerebrum
in the horizontal plane
where is the falx cerebelli located
it runs along the vermis of the cerebellum
it separates the 2 cerebellar hemispheres
where does the falx cerebri attach anteriorly
the crista galli
where does the falx cerebri attach posteriorly
the upper surface of the tentorium cerebelli in the midline
what is the subdural space
it is the space between the dura mater and the arachnoid mater
it is very narrow (smaller than the arachnoid space) and contains a film of fluid
what could the subdural space be enlarged by
bleading (subdural haemorrhage)
