Anatomy of the brain Flashcards
In the brain the white mater is on the inside- true to false?
True
What is the shape of the grey mater in the spinal cord?
H shaped
What is in white matter?
Axons and their support cells
What is in grey matter?
Neuron cell bodies
What do association fibres connect?
Cortical sites lying in the same hemisphere
What do commissural fibres connect?
One hemisphere to another, usually areas with similar function
Give an example of a commissural fibre
Corpus collosum
What do projection fibres connect hemispheres to?
deeper structures (inc thalamus, corpus striatum, brainstem and spinal cord)
The anterior and posterior brain is divided by the ——- sulcus
central
The front/parietal lobe is divided from the temporal lobe by the…
Lateral sulcus
Longitudinal fissures separate the — ———-
two hemispheres
Precentral gyrus is the primary —– cortex
MOTOR
Postcentral gyrus is the primary ——- cortex
SOMATOSENSORY
Where is the gustatory area located
Postcentral gyrus
CNIV palsy is often caused by…
Congenital, trauma
CNIII palsy is often caused by…
Compression (aneurysm-posterior communicating artery, herniation)
Inadequate blood flow
CNVI palsy is often caused by…
Microvascular (diabetes)
^ICP
TRUE/FALSE
For some higher functions of the brain one hemisphere is dominant
TRUE
What is dominance high for?
Language
Mechanically behaves like a fluid and a solid
Viscoelastic
The CSF supports the brain- ——- buoyancy
neutral buoyancy
What are the layers of the scalp?
S- Skin C-Connective tissue (contains the named arteries of the scalp) A- Aponeurosis L-Loose connective tissue P-Pericardium
What does the aponeurosis(Tendinous layer) do?
Holds open lacerations and rich tissue supply hence heavy bleeding
What is the pericardium?
The outer membrane of a bone, responsible for bone formation. Thin membranous layer that is found on the surface of all bones.
What is the name of the thinnest part of the skull?
Pterion
What is the shape of the pterion?
H shaped suture
What is the bony structure directly above the middle meningeal artery?
Pterion
What are sutures?
Fibrous joints that help prevent skull fractures from spreading (minimise propagation)
What are the 3 fossa of the skull?
Anterior
Middle
Posterior
What are the meninges?
Protective covering over the brain and the spinal cord
Which layer of the dura lies closest to the skull and vertebrae?
Dura
What is the nerve supply to the DURA?
Afferent fibres of trigeminal (CNV) and upper cervical nerves
What are the two sublayers of the Dura?
Periosteal layer
Meningeal layer
Describe the arachnoid layer of the meninges?
Thin, membrane-like, arachnoid granulations
What do arachnoid granulations do?
Reabsorb CSF
What does the PIA layer of the meninges envelop?
Spinal cord and the brain
What is the name of the tough sheet of dura matter forming a roof over the pituitary fossa which sit in the sella turnica?
Diaphragm sell
What is the name of the tough sheet of dura matter tenting over the cerebellum?
Tentorium cerebellum
Where does the tentorium cerebellum attach?
To the ridges of the petrous temporal bones
What midline structure made of dura matter that attaches to the deep aspect of the skull separates the R + L tentorium cerebelli?
Flax cerebri
What is the cochlea filled with?
Perilymph
What is the chemical composition of perilymph?
High in Na+, low in K
If hearing in completely lost what is the most likely diagnosis?
Stenosis in bones in the ear
All sensory information has to pass through the thalamus, what is the exception?
Smell
What are the two important uncle in sound localisation?
Superior olivary nucleus
Nucleus of lateral leminiscus
What is the name of the organisation that is present in the auditory cortex?
tonotopic
In the auditory cortex where does the low frequency sound end up?
Anterolateral part
In the auditory cortex where does the high frequency sound end up?
Posteromedial part
If Broca’s area is damaged what is the result?
Expressive dysphagia
Where is Broca’s area located?
Frontal lobe
Where is wernickes area located?
Temporal lobe
Wernickes area if damaged will lead to what?
Receptive dysphagia
What does receptive dysphagia look like?
Difficulty comprehending language and words out of order/meaningless
TRUE/FALSE Projection of vestibular information onto cerebral Cortex is unilateral
FALSE- bilateral
Where is the primary vestibular cortex?
Ahh PSYCH! There is no agreed upon region of the brain that is activated exclusively by vestibular stimulation
Which 3 areas have vestibular information converge there?
- Area of parietal cortex (posterior to post central gyrus)
- Infront of the primary auditory cortex
- Posterior insula cortex
Due to the lens how are objects projected onto the retina?
Reversed and upside down
TRUE/FALSE Optic tract always sees the ipsilateral visual fields
FALSE- Optic tract always sees the opposite visual field from both sides
The lower visual field is projected to gyrus…
gyrus superior to the calcimine sulcus
The upper visual field projects to the gyrus…
gyrus inferior to the calcimine sulcus
What is the name of the group of fibres that loop anteriorly round the temporal part of the lateral ventricle before ending below calcarine sulcus
Meyers loop
What part of the brain controls tracking movement?
Visual cortex in response to stimuli
TRUE/FALSE Tracking movement tends to be saccadic?
FALSE- it is a smooth movement
Frontal eye fields are in charge of what types of movement?
Movements of control
Movements of control are independent of moving stimulus. TRUE/FALSE
TRUE
Edinger-Westphal nucleus is a parasympathetic pre ganglionic nucleus. What 2 things does it innervate?
Iris sphincter muscle
Ciliary muscles
What two things does the accommodation reflex require input from?
Oculomotor
Edinger-Westphal nucleus
What two things can go wrong within the cranial cavity/
Herniations
Haemorrhage
What are the two broad categories of herniation
Infratentorial herniation
Supratentorial herniation
What are the two types of infratentorial herniation?
Upward–> Cerebellar up over tentorium cerebelli
Downward–> Cerebellar tonsils herniate into foramen magnum
What is a downward herniation also known as?
Tonsilar herniation
What are the 4 types of supratentorial herniation?
Cingulate
Central
Uncal
Transcalvarial
What two things happen as a result of an uncal herniation?
Compression of the oculomotor nerve (CNIII)
Complete obliteration of supra cellar cistern
What is the name of the area where there is potential for venous spread of infection from superficial to deep veins
Danger triangle
Why is the danger triangle aptly named?
The veins have much thicker walls so will not collapse like other veins but stay open and do not have valves so that bacteria can travel unhindered through ophthalmic veins back to cavernous sinus
Where do cerebral veins drain?
Dural venous sinus
Where do dural venous sinus drain?
Confluence of sinuses
Where is blood directed after the confluence of sinus
Sigmoid sinus
What does the sigmoid sinus drain into at the jugular foramen?
internal jugular vein
Circle of willis is inferior to the midbrain TRUE/FALSE
TRUE
The BBB is a physical barrier that restricts the movement of molecules TRUE/FALSE
FALSE- Not a physical barrier but a series of different transport system facilitating or restricting the movement of molecules
What are the tree layers of the cerebral cortex?
Molecular layer
Purkinje cell layer
Granule cell layer
The molecular layer of the cerebral Cortex contains many cells TRUE/FALSE
FALSE- It contains almost no cells, made of molecules, huge numbers of synapses between cell processes
Granule cell layer contains –% of neurones
50%
