General features of Brain, Meninges & Blood supply Flashcards
define the following terminology
- unilateral/bilateral
- afferent/efferent
- ipsilateral/contralateral
- unilateral - 1 hemisphere /bilateral - 2 hemisphere
- afferent - ascending signals/projections(coming into the brain) /efferent - descending signals/projections (going away from the brain)
- ipsilateral - same hemisphere /contralateral - alternate hemisphere
what is the significance of contralateral brain?
it is the alternate hemisphere and controls most of the movements and sensations of the brain but NOT all of them
what is the significance of these fissures?
- median long fissure/longitudinal fissure (falx cerebri within)
- lateral sulcus
- central sulcus
- median long fissure - divides it into 2 hemisphere
- lateral sulcus - divides the frontal and temporal lobe
- central sulcus - divides the frontal and parietal lobe
what is gyri and sulci?
gryi - hills
sulci - valleys
what does the grey and white matter represent?
grey matter - cell bodies
white matter - axons; nerve fibres
in how many ways can the brain be divided?
- anterior/posterior
- dorsal/ventral
- rostral/caudal
- superior/inferior
what does the anterior and posterior part of brain correspond to? (AR-PC)
anterior - rostral
posterior - caudal
what is the function of frontal lobe
- premotor area
- precentral gyrus
- posterior ventrolateral (mainly left)
- involved in motor function, problem solving, spontaneity, memory, language, judgement, personality, impulse control, social and sexual behaviour
- anterior part/ pre-frontal gyrus - higher cognitive functions and. determination of personality
- posterior part - motor and premotor area
- inferior frontal gyrus - broca’s area - imp. for language production and comprehension
- premotor area - general movements, connections to BG and eye movements
- precentral gyrus - somatotopically/ topographically organised movement e.g. homunculus brain
what is the function of parietal lobe
- define the two types and its function
- supra marginal and angular gyrus
- inferior post central sulcus
- somatosensory
- two parietal lobes: dominant and non-dominant
- dominant lobe (left) - perception, interpretation of sensory info and formation of idea of complex and meaningful response
- non-dominant lobe (right): visuospatial functions
- supra marginal and angular gyrus (posterior parietal)- mathematical operations
- Inferior postcentral sulcus - gustatory (sense of taste)
what is the function of occipital lobe and what does the damage result in?
- vision - visual information
- Damage - partial or complete blindness
- Somatotopically arranged
- Cortical blindness
what is the function of temporal lobe and what does it consist of?
- primary auditory cortex, hippocampus, amygdala
- superior temporal gyrus (of left hemisphere): Wernicke’s area - understanding of spoken words
- lateral sulcus (sylvan fissure) - auditory cortex
why is cerebellum called the largest part of the hindbrain?
- 10% of brain volume
- majority of neutrons (3.6x no. in neocortex)
what is the function of cerebellum? and what does the damage to cerebellum result in?
- function - coordination of movement and balance
- damage - DANISH
D - dysdiadocokinesis
A - ataxia
N - nystagmus
I - intention tremor
S - slurred speech
H - hypotonia
what is the function of thalamus and basal ganglia?
- Thalamus – filter, relay, independent nuclei (relay station)
- Basal ganglia – modulator, motor and cognitive pattern generator, ‘chunking’
thalamus and BG are white matter?
True or False
False, they are deep grey matter nuclei
what is the primary characteristic of the following
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe
- cerebellum
- brainstem
- frontal lobe - primary motor cortex and pre-frontal cortex
- parietal lobe - primary somatosensory cortex and association cortex
- temporal lobe - primary auditory cortex, auditory association cortex (WERNICKE’s area), hippocampus and amygdala
- occipital lobe - primary visual cortex and visual association cortex
- cerebellum - motor control of equilibrium, posture and muscle tones and movement coordination
- brainstem - ascending and descending tracts, cranial nerve nuclei and the reticular formation
where are these structures found?
- insula
- opercula (lips)
- insula - forms the floor of lateral sulcus
2. opercula - part of the frontal, parietal and temporal that lies over the insula
what is the corpus callosum and its function?
there are a large bundle of white matter (fibres, tracts running along) that connect the two hemispheres
where can you find the following?
- olfactory tracts
- optic nerves/ optic chiasma
- mammillary bodies
- hypothalamus
- crura cerebri of cerebral peduncles
- olfactory tracts - runs on the inferior surface of the frontal lobe
- optic nerves/ optic chiasma - the optic nerves run backwards and medially converging in the midline to form to form ‘optic chiasma’ and then run backwards and laterally to form optic tracts (nerves-> chiasma -> tracts)
- mammillary bodies - two round eminences behind the optic chiasma
- hypothalamus - behind the optic chiasma up to and including the mammillary bodies
- crura cerebri of cerebral peduncles - two large masses of white matter emerging from the back of mammillary body on each side from cerebral hemisphere. they pass backwards coverage at the midline at the upper border of pons
what are the other names for
- anterior speech area
- posterior speech area
- anterior speech area - Broca’s area
2. posterior speech area - wernickle’s area
name the cranial meninges
- pia
- archanoid
- dura
how many layers does the dura have and name them
the dura has two layers
- outer endosteal layer - lies inferior of skull
- inner meninges layer - completely envelopes the CNS
Mostly the two layers of dura matter is fused
True or False
True
describe dural venous sinuses
- the system of communicating blood filled spaces where the dural fold attaches to the skull
- sinuses connect major cerebral veins to the internal jugular vein to drain out the blood
when is the cranial cavity divided into three areas and what are those areas?
mostly the dural folds are fused together however, at times the inner layer separates from the skull to form dural folds which support the subdivisions of the brain and divide the cranial cavity into three area - right and left hemispheres and the posterior cranial fossa
what is subarchanoid cisterns and what does it consist of?
- the space between arachnoid and pia matter when the arachnoid spans over the gyri is called subarachnoid cisterns
- cisterns -> calcify -> arachnoid granulations
- it consists of CSF
how to identify the following
- foramen of magendie
- foramen of luschka
- foramen of magendie - it is the midline communication b/w the 4th ventricle and subarchanoid space
- foramen of luschka - it is the lateral communication b/w the 4th ventricle and subarchanoid space
name the location of these cisterns
- cerebellomedullary cistern
- pontine cistern
- interpenducular cistern
- cerebellomedullary cistern - lies in the angle formed by the dorsal surface of the medulla and the inferior surface of the cerebellum
- pontine cistern - lies in the ventral surface of the pons
- interpenducular cistern - consists of circle of willis
is the pia matter visible to naked eye? and what is its main role?
- it is indistinguishable with the naked eye
- it is functionally v. imp because it forms a part of the BBB
what are the different types of haemorrhage? define them
- extra dural - the space b/w the skull and dura
- subdural - the space b/w the dura and arachnoid
- subarachnoid - the space b/w the archanoid and pia
- intracerebral