neuroanat - first five lectures Flashcards
what three sections is the brain made of ?
the forebrain, brainstem and the cerebellum
what does the forebrain consist of ?
the cerebrum ( cerebral hemispheres ) and Diencephalon
what does the brainstem consist of ?
the midbrain, pons and medulla
what does the hindbrain consist of ?
pons and medulla - hindbrain is part of midbrain
how much does the brain weigh ?
the brain weigh 1.5kgs
what does grey matter consist of ?
nucleas of neurons are in the CNS and the ganglion of the neurons are in the PNS - both are grey matter q
what does white matter consist of?
axons - lipid material in myelin sheaths
hill tops in the brain are also called
gyri
valleys in the brain are also called
sucli
what structure seperates large regions of the brain
Fissure
where is the insula located
it is buried deep within the lateral sulcus
what makes up the insula
it is formed by portions of the temporal, parietal and frontal lobes.
which structure seperates the cerebellum from the cerebrum ?
the transverse fissure
which structure seperates the parietal and occiptal sulcus ?
the parieto-occipital sulcus
what is the location of the spinal cord ?
it extends from the foramen magnum to the first/second lumbar vertebra
what is the width of the spinal cord ?
around thumb width
what is the length of the spinal cord ?
it is around 42cm long
how many spinal nerves does the spinal cord contain ?
the spinal cord contains around 31 pairs of spinal nerves
what is the function of the spinal cord
it provides a two way street of information to and from the brain.
name the two enlargements of the spinal cord ? and theyre significance ?
conus medullaris and filum terminale
these are the places from where nerves serving the upper and lower limbs originate
what is the cauda equina ?
a collection of nerve roots at the inferior end of the vertebral coloumn - occurs after birth as the vertebral coloumn grows faster then the spinal cord.
which sections eg transverse.lumbar.cervical of the spinal cord have more grey matter ?
the cervical and lumbar have more grey matter then the thoracic.
what are two common injuries to the spinal cord ?
paralysis - loss of motor function and paresthesias - sensory loss
which sex - male/female contributes to 80% spinal injuries ?
male
spinal cord injury : high tetraplegia - what level does this occur at ?
c1=c4
spinal cord injury : low tetraplegia - what level does this occur at ?
c5- c8
injuries of spinal cord ( excluding cervical level ) = ?
paraplagia
spinal injuries can be complete or imcomplete or both ?
both
what are the meninges ?
membranes outside the brain and spinal cord
what is the function of the meninges ?
the protection of the brain and spinal cord
` what are the three layers of the meninges ?
duramater … arachnoid mater … piamater
describe large subarachnoid space
it the the space inbetween the arachnoid and pia mater , which contains cerebrospinal fluid.
describe the dura mater
thick layer of CONNECTIVE tissue surrounding the brain- mostly collagen fibres - very tough
what are the two layers of dura mater ? and what do these form ?
periostal and meningeal 2 layers of the dura mater and they form the dural venous sinuses
what are meningeal layer folds ?
these are fold that extend in to form flat partition
what are the three meningeal layer foldings ?
the flax cerebri , tentorium cerebelli and falx cerebelli
what does the flax cerebri subdivide ?
it divides the two cerebral hemispheres( not completely) and lies in the median sagittal plane - hence longitidunial fissure
what does falx cerebri attach to anteriorly and posteriorly ?
anteriorly it attaches to crista galli - a bony structure and posteriorly it attaches to the tentorium cerebelli
what does the tentorium cerebelli seperate ?
it seperates the cerebrum from the cerebellum
what is the subdural space ?
it is the space inbetween meningeal dura mater and arachnoid mater - it is very narrow and only contains a thin film of fluid within it.
what is a subdural haemorrhage ?
as thye subdural space has blood vessels within it - trauma to the brain may cause the blood vessels to bleed
what comes after a subdural haemorrhage ?
subdural haematoma
describe the arachnoid mater
it is a delicate transparent membrane, which does not dip into sulci and follows the brain.
its is also connected to the pia mater layer via fine strands of connective tissue called arachnoid trabecula.
what connects the pia mater layer to the arachnoid mater
arachnoid trabecula
describe the subarachnoid space ?
it is the space below the arachnoid mater and is filled with cushion of the brain, it is also much wider then the subdural space
what is a subarachnoid haemorhage ?
as the subarachnoid space contains blood vessels, which are poorly protected and can be punctured causing the haemorhage
what are arachnoid villi ?
knob/finger like projections of the arachnoid mater, which protude into the venous sinuses.