Module 1: Neuroanatomy Flashcards
what are the 4 main subdivisions of the brain?
forebrain, midbrain, hindbrain and cerebellum
what structures make up the forebrain?
cerebrum hemispheres and diencephalon
what structures make up the midbrain?
brainstem and middle of the brain
what structures make up the hindbrain?
pons and medulla of the brainstem
where are 50% of the brain’s neurons found?
cerebellum
what would a lateral view of the brain picture?
the brain from the side, either left or right
what would a coronal view of the brain picture?
a cross section through the brain, often pictures deep
what would a sagittal view of the brain picture?
view from the top down of the brain
what is the midsagittal line?
the line that goes down the middle of the brain; slightly curved
what are neurons?
highly specialised, excitable cells that provide rapid and specific communication between regions of the body
what are glia cells?
cells that give structural support and insulation in the nervous system
what are the 4 types of glia cells?
astrocytes, microglia, ependymal cells and oligodendrocytes
what is grey matter and where is it found in the brain?
collections of cell BODIES found on the outside of the brain
what is white matter and where is it found in the brain?
collections of cell AXONS found on the inside of the brain
what are gyri?
the upper part of folds in the brain
what are sulci?
the lower part of folds in the brain
what is a fissure in the brain?
a deep sulcus in the brain
what are the 5 lobes of the brain?
frontal lobe, parietal lobe, occipital lobe, temporal lobe and the insula
what is the insula?
a lobe deep inside the brain that forms the foundation of other lobes such as the frontal, parietal and temporal lobes
what is the central sulcus?
divides the frontal and parietal lobes
what separates the cerebrum from the cerebellum?
transverse fissure
what separates the temporal lobe and the frontal lobe?
the lateral sulcus
what separates the parietal and occipital lobes?
parietal-occipital sulcus
what is the foramen magnum?
hole in the base of the skull through which the brain connects to the spinal cord
how many spinal nerves are in each of the parts of the spinal cord (31 total)?
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal
what are the names of the 2 enlargements in the spinal cord?
cervical enlargement and lumbar enlargement
why are there enlargements in the spinal cord?
they contain motor neurons responsible for the movement of the upper limbs (cervical) and the lower limbs (lumbar)
what is the conus medullaris/medullary cone?
the end of the spinal cord that sits under the lumbar enlargement
what is the filum terminale ?
extends from the medullary cone to the end of the coccyx as an anchor to allow the spinal cord to stand straight
what is the cauda equina?
a collection of nerve endings at the end of the vertebral canal
why does the cauda equina exist?
because the vertebral column grows faster than the spinal cord, so it is longer than the sc
grey matter in on the inside of the spinal cord T/F
true, white matter is on the outside to protect the grey matter, opposite to the brain
where is the anterior median fissure found in the spinal cord?
at the anterior-middle of the spinal cord
where is the posterior median sulcus found in the spinal cord?
at the posterior-middle of the spinal cord
how does sensory information enter the spinal cord (afferent)?
through the dorsal roots
how does motor information leave the spinal cord?
through the ventral roots
what structures have a MIX of afferent and efferent fibres from the spinal cord?
spinal nerves
what is paralysis?
loss of motor function
what is parathesis?
loss of sensory feeling
what is high tetraplegia and what causes it?
loss of functioning of upper and lower limbs and potentially loss of breathing ability, caused by damage to C1-C4
what is low tetraplegia and what causes it?
some of functioning of upper and lower limbs without the risk of losing breath, caused by damage to C5-C8
what is paraplegia and what causes it?
loss of functioning in legs, caused by damaged to the thoracic, lumbar or sacral spinal cord
damage to the left ventral horn of T1 would cause ??
loss of motor functioning in right leg
what is the purpose of meninges in the brain?
to protect the brain and spinal cord
what is the dura mater?
the first layer of meninges, very tough
what are the 2 layers of the dura mater?
periosteal and meningeal layers
how are venous sinuses formed in the brain?
the separation of the periosteal and meningeal layers of the dura mater
what do the venous sinuses do in the brain?
drain the brain of fluids
which layer of the meninges is repeatedly folded to cause partitions between regions of the brain?
meningeal layer of the dura mater
what 2 regions are separated by the falx cerebri?
two cerebral hemispheres
what 2 regions are separated by the tentorium cerebelli?
the cerebrum and cerebellum
what 2 regions are separated by the falx cerebelli?
the two cerebellar hemispheres
what are the 3 layers of the meninges?
- dura mater
- arachnoid mater
- pia mater
where is there subdural space in the brain?
between the dura mater and arachnoid mater, filled with some fluid
what happens if the subdural space fills with blood?
subdural haemorrhage
how is the arachnoid mater different from the pia mater?
the arachnoid mater doesn’t dip into the sulci like the pia mater does
what do arachnoid trabecula do?
fine strands of connective tissue that connect the arachnoid mater to the pia mater and are in the subarachnoid space
what do arachnoid villi do?
stretch into sinuses to drain the CSF to and from the sinuses around the rest of the brain
what are arachnoid granulations?
collections of arachnoid villi
what are cisterns in the brain?
enlarged subarachnoid spaces that hold CSF around the brain
where in the brain sits the cisterna magnum/cerebellomedullary cistern?
inferior to the cerebellum
where is CSF extracted from in newborns to check for meningitis/infection?
cisterna magnum
where in the brain sits the superior cistern?
superior to the cerebellum
where in the brain sits the interpeduncular cistern?
anterior to the midbrain
where in the brain sits the pontine cistern?
anterior to the pons, smallest cistern in brain
what meninges layer is associated with the perivascular space?
pia mater, the space where pia mater and blood vessels join to supply the brain with blood
what are the layers of the spinal cord meninges starting from the spinal cord out?
spinal cord - subarachnoid space - arachnoid mater - dura mater - epidural space (and pia mater)
why does the spinal cord dura mater only have one layer of dura instead of 2?
because the spinal cord requires greater range of movement than the brain does
where does the main source of protection of the spinal cord come from?
epidural layer (fats and venous plexus)
where is the epidural space the largest in the spinal cord and what is this used for clinically?
L2; to inject epidural anaesthesia to women giving birth
what is the lumbar cistern?
a cistern in the spinal cord where a lumbar puncture can be inserted to extract CSF
what is the function of denticulate ligament in the spinal cord?
a pia mater layer that horizontally supports the spinal cord
what is the function of filum terminale in the spinal cord?
a pia mater layer that vertically supports the spinal cord
what is meningitis?
the inflammation of the pia and arachnoid maters
what are the 4 ventricles called?
2 lateral ones, third and fourth
which ventricles does the inter-ventricular foramen connect?
lateral ventricles to the third ventricle
which ventricle does the cerebral aqueduct connect?
third ventricle to the fourth ventricle
what are the 3 horns that the lateral ventricles have and which lobes are these each near?
anterior - frontal
inferior - temporal
posterior - occipital
what is the choroid plexus and where is it found in the brain?
where CSF is made; found in the ventricles
what are the 3 openings CSF is able to leave the fourth ventricle through called?
- either of the 2 lateral apertures
- median aperture
what is the superior medullary velum?
the roof of the fourth ventricle
what is the main purpose of CSF in the brain?
to decrease the weight of the brain by 97% and prevent the brain from collapsing in on itself
what is the sequence of CSF flow through the brain in
1) produced in the choroid plexus
2) third ventricle
3) fourth ventricle
4) into cisterna magma or to other side of brain or into the central canal (to spinal cord)
5) to the sinuses at the top of the brain
what forms the blood-brain barrier?
tight junctions between the endothelial cells of the cerebral capillaries which allows for only a select few things to get through to the brain
what is hydrocephalus?
enlarged ventricles due to overproduction of CSF in the brain
what are the 2 main arteries that travel up the neck to supply blood to the brain?
- internal carotid artery
- vertebral artery
where does the external carotid artery supply blood to?
the face
does the internal carotid artery supply to the anterior or posterior part of the brain?
anterior