Week 1 - wet room Flashcards
embryologically, which two vesicles of the neural tube give rise to the brainstem?
mesencephalon & rhombencephalon
what are the cavities (of the ventricular system) which lie within the brainstem?
cerebral aqueduct
4th ventricle
what is the name of the groove which separates the pons and medulla?
pontomedullary junction
which nerves emerge from the pontomedullary junction?
CN VI and VII (abducens and facial nerve)
what surface features are found on the medulla?
pyramids
olives (laterally to the pyramids)
inferior cerebellar pedundle
what is the decussation of the pyramids and what part of the brainstem is this present?
medulla
decussation is the crossing over of fibres from the pyramidal tract from one side to the other.
what type of fibres does the pyramids contain?
motor fibres
what is the function of the olives and where are they found?
The medulla - lateral to the pyramids
They are associated with perception of sound
what does the open part of the medulla open into?
the 4th ventricle
what is the middle cerebellar peduncle made up of?
centripetal fibres / incoming fibres
what structure does the cerebral peduncle arise from?
midbrain
- the cerebral peduncle is the whole of the midbrain except from the tectum
what fibres does the cerebral peduncle contain?
sensory and motor
where do fibres which run in the cerebral peduncle go to and come from?
the cerebrum and pons
what connects the 2 cerebral hemispheres?
corpus callosum
what is the function of the cerebellar peduncles?
they connect the cerebellum to the brainstem
what is the function of the cerebral peduncle?
it helps transport nerve impulses from higher parts of the brain to the brain stem to help refine our movements
what are the different parts of the cerebellum?
anterior and posterior lobes
cerebellar tonsil
flucculonodular node
grey and white matter?
if there is changes in intra cranial pressure what part of the brain herniates through the foramen magnum first?
cerebellar tonsil
what change in pressure would cause herniation of the cerebellar tonsil into the foramen magnum?
a sudden drop in intracranial pressure
what is the term for herniation of the cerebellar tonsil into the foramen magnum?
cerebellar coning
what is the name of the fissure which separates the two cerebral hemispheres?
longitudinal fissure
the cerebral hemispheres sit on the base of the anterior and middle cranial fossa’s but what does it sit on in the posterior fossa?
tentorium cerebelli
fold of dura matter
what covers the cerebellum?
tentorium cerebelli
fold of dura matter
what type of nerve fibres are found within the corpus callous?
commissural fibres (connecting bundle)
what is the main function of each part of the cerebrum?
- frontal lobe ?
- parietal lobe ?
- occipital lobe ?
- temporal lobe ?
primary motor cortex
primary sensory cortex
primary visual cortex
primary auditory cortex
at what level does the spinal cord terminate in an adult and child?
adult = L1 child = L2/3
at what vertebral level does the arachnoid and dura matter terminate?
S2
what lies within the spinal canal?
spinal cord
meninges
CSF
central gelatinous substance of spinal cord
what happens to the pia matter inferior to the spinal cord termination?
becomes and extends as a thin filament called the film terminale
at what level would you perform a lumbar puncture and why?
L3/4
your spinal cord terminates at L1 and beyond this until S2 lies the CSF wrapped in arachnoid and dura matter
what is the difference between upper and lower motor neurones?
upper motor neurones travel within the spinal cord
lower motor neurones are the neurones which U.M.N synapse with when it exits the spinal cord
what is the name of the continuation of the spinal nerves after the cord terminates?
cauda equina
is damage to the cauda equina classified as an upper or lower motor neurone lesion?
lower motor neurone lesion
what are the symptoms of an upper motor neurone lesion?
spasticity
increase in muscle tone
complex sensory syndromes
what are the symptoms of a lower motor neurone lesion?
decrease in muscle tone (flaccid paralysis)
global sensory changes
What embryological vesicle give rise to the midbrain of the brainstem?
Mesencephalon
What embryological vesicle gave rise to the hindbrain (pons & medulla) ?
Rhombencephalon
What is the disadvantage of the abducens nerve having the longest course when it leaves the pontomedullary junction?
It leaves it vulnerable to damage due to raised intracranial pressure or other mechanical damage such as intracranial fractures of cerebral artery aneurysms.
This can result in CN VI palsy
Damage to the abducens nerve due to increased intracranial pressure can give a misleading clinical presentation, how?
The clinical presentation of damage to the nerve causes doubles vision and the patient wont be able to abduct the eye.
This is misleading because it makes you think that there is something wrong with the eye and not about intracranial pressure
What part of the brain stem are superior and inferior colliculi located?
Midbrain
where do you find the calcarine sulcus and what does it divide?
In the medial side of the occipital lobe
It divides the visual cortex into 2
What are the different parts of the ending of the spinal cord?
The spinal cord ends at L1
It tapers out in a cone shape called the conus medullaris
After conus medullaris there is still nerves which continue down the spine called the cauda equina
When the spinal cord ends at conus medullaris, the pia matter becomes filament our forming the film terminale
The arachnoid and pia matter end at S2
What ligaments are removed so you can view the spinal cord?
Ligamentum spinosum
What is the procedure called which removes part of the vertebra so you can view the spinal cord?
Laminectomy
What nerves emerge from between the midbrain and pons?
The occulomotor and trochlear nerves
