L3 Flashcards
describe the pathway of blood drainage in the brain
from fine veins in the brain –> pial venous plexuses (veins in the pia) –> cerebral veins –> dural venous sinuses –> internal jugular vein –> heart
describe the pathway for blood drainage from the scalp
veins in the scalp –> emissary veins –> dural venous sinuses –>intrajugular vein –> heart
where are the venous sinuses located
between the 2 layers of the dura mater
periosteal (top) and meningeal layers
superior and deep structures drain into what sinuses (there’s 5)
superior sagittal sinus
inferior sagittal sinus
straight sinus
transverse sinuses (one on each side of the brain)
sigmoid sinus
where is the superior sagittal sinus located
it lies along the superior margin of the falx cerebri and joins onto the right transverse sinus
what drains CSF into the superior sagittal sinus
arachnoid villi
where is the inferior sagittal sinus located
it lies along the inferior margin of the falx cerebri
where does the inferior sagittal sinus join onto
the straight sinus
where is the straight sinus located
whinin the tentorium cerebelli
towards the back in the midline of the brain
what is the straight sinus protected by
the tentorium cerebelli
what does the straight sinus join onto
it joins the transverse sinus
where are the transverse sinuses located
they run in the horizontal plane
at the back of the brain going from the middle out
what is the sigmoid sinus continuas with
the transverse sinus
what does the sigmoid sinus opens up into
internal jugular vein
what is the confluens
where the sinuses join
inferior structures drain into what sinus
cavernous sinuses
where are the cavernous sinuses located
lateral to the pituitary gland (on either side) and they are linked with venous channels
where do the cavernous sinuses drain
the superior and inferior petrosal sinuses
where are the superior and inferior petrosal sinuses located
they are called petrostal because they run over the petrosal bone which is part of the temporal bone
where does the superior petrosal sinus drain
into the transverse sinus
where does the inferior petrosal sinus drain
the internal jugular vein
the facial skin around the nose and upper lip drain into what veins
the ophthalmic veins
where do the ophthalmic veins drain
the cavernous venous sinus
how could an infection on the face or the scalp lead to meningitis
blood from the scalp is drained into the emissary veins which gets drained into the sinuses. from here the infection could get into the miningies causing meningitis
the facial skin around the nose and upper lip drain into the ophthalmic veins which drain into the cavernous venous sinus
what are the 3 functional areas of the cerebral cortex
motor areas
- voluntary motor functions
sensory areas
- conscious awareness of sensation
association areas
- the integration of information
conscious behaviour involves …….
the entire cortex
everything is talking to each other to create a purposeful response/action
what are the gyri of the frontal lobe
superior frontal gyrus (front to back. superior is the closest to the longitudinal fissure)
middle frontal gyrus
inferior frontal gyrus
precentral gyrus (middle to out)
what are the sulci of the frontal lobe called
superior frontal sulcus
inferior frontal sulcus
central sulcus
what structures are found in the inferior frontal gyrus
orbital (most inferior)
triangular
opercular (most superior)
the triangular and opercular make up broca’s area (on the left side)
what makes up broca’s area
the triangular and opercular
what side of the brain is broca’s area most likely to be on
left
how could you locate broca’s area in the brain
where the triangular and opercular come together they form “lips”.
the lips sit anterior to the lateral sulcus
what is another name for the precentral gyrus
the primary somatic motor cortex
what is the precentral gyrus responsible for
it is the motor homunculus where the area dedicated to the specific region of the body is proportional to the amount of motor control over that region
where to the neurons from the precentral gyrus project to
each pyramidal neuron projects its axon to the spinal cord
what is another name for pyramidal tract
corticospinal tract
the precentral gyrus supplies about how many axons to the corticospinal tract
30%
what muscles in the body have the most precise motor control
face, hands and tongue
what is the premotor cortex responsible
learned motor skills eg learning how to play an instrument
in coordinates and movement and in also involved in planning that movement
the premotor cortex supplies what % of pyramidal tract axons
30%
what is the supplementary motor area involved in
motor control, particularly for speech
where is the cingulate gyrus located
you can see it in the longitudinal fissure. it sits on top of the lateral ventricle
if you damage the supplementary and cingulate motor areas what are the results
loss of desired skilled movements and speech
the prefrontal cortex has extensive connections with what other lobes
parietal, temporal and occipital lobes
what part of the brain is involved with intellect, complex learning abilities, recall and personality
prefrontal cortex
how does the prefrontal cortex mature
it matures slowly and is heavily dependent on +ive and -ive feedback from one social environment (how you grow up)
the prefrontal cortex is closely linked to the emotional part of the brain. what is this part of the brain called
the limbic system
the link between the limbic system and the prefrontal cortex plays a role in intuitive…..
judgment and mood
damage to the prefrontal cortex results in
mental and personality disorders
what are the guri in the parietal lobe
the postcentral gyrus
supramarginal gyrus
the angular gyrus
where is the postcentral gyrus located
behind the central gyrus
where is the supramarginal gyrus located
it sits at the end of the lateral sulcus
where is the angular gyrus located
sits at the end of the superior temporal sulcus
there are 2 “sub-lobes” in the parietal lobe. what are these called
the superior and inferior parietal lobes
what separates the the superior and inferior parietal lobes
the intraparietal sulcus
what is another name for the postcentral gyrus
the primary somatosensory cortex
what is the role of the postcentral gyrus
it is dedicated to the sensations of various body parts. the bigger the representation in the cortex the more sensitive it is
it is also involved in spatial discrimination
occlusion of a branch of the anterior cerebral artery to the primary somatosensory cortex would cause….
contralateral sensory loss greatest in the lower limb
occlusion of a branch of the middle cerebral artery to the primary somatosensory cortex would cause….
contralateral sensory loss most severe to the face and upper lip
what is another name for the superior parietal lobe
somatosensory association cortex
what is the role of the superior parietal lobe
the somatosensory association cortex is involved in integrating different sensory inputs relayed via the primary somatosensory cortex to produce a comprehensive understanding of the…..
position of limbs
location of touch or pain
shape, weight and texture of an object
what happens if you damage the somatosensory association cortex
you won’t be able to recognise objects without looking at them
the gyri forming the walls of the calcarine sulcus form what part of the visual cortex
the primary visual cortex
what runs through the middle of the primary visual cortex
the calcarine sulcus
what is on either side of the primary visual cortex
the association cortex
what does the visual association cortex do
it communicates with the primary visual cortex and interprets visual stimuli (identifies what they are)
where are faces recognised
in the temporal lobe
how do we do our seeing
with cortical neurons
where is the temporal lobe located
inferior to the lateral sulcus
name the gyri of the temporal lobe
superior temporal gyrus
middle temporal gyrus
inferior temporal gyrus
parahippocampal gyrus
what separates the superior and middle temporal gyrus
the superior temporal sulcus
what separates the middle and the inferior temporal gyrus
the inferior temporal sulcus
what structures do you see from the ventral surface of the temporal lobe
parahippocampal gyrus
uncus
rhinal sulcus
inferior temporal gyrus
occipitotemporal sulcus
collateral sulcus
what sits under the parahippocampal gyrus
the hippocampus
what sits anterior to the parahippocampal gyrus
the uncus
what runs lateral to the uncus
rhinal sulcus
what runs lateral to the posterior part of the parahippocampal gyrus
the collateral sulcus
what runs medial to the inferior temporal gyrus
occipitotemporal sulcus
what does amygdala mean
almond (because it looks like a almond)
what structures in the temporal lobe are responsible for emotion
the amygdala and the uncus
what is the role of the hippocampus
learning and memory
what connects the hippocampus to the rest of the brain
The hippocampus is connected to the rest of the brain by a white matter tract. Part of this is called the fimbria
what is medial to the hippocampus
the thalamus
what is the forex
The forex connects the hip to other brain regions (outlet pathway)
where is the septum pellucidum located
on top of the forex
wernicke’s area is also known as the….
auditory association area
what does Wernicke’s area do
it is involved in the perception of sound, it stores memories of sound and is involved in the language process
when are the neurons in the transverse temporal gyri active
this is an auditory area and the neurons are active when you are listening
what is the primary auditory cortex sensitive to
pitch, rhythm and loudness
what is the functions of the insular lobe
emotion, homeostasis, cognition and perception/self awareness
what is another name for Broca’s area
the motor speech area
where is Broca’s area located
it is the opercular and triangular parts of the inferior frontal gyrus
what is Broca’s area responsible for
it generates motor programs for the larynx, tongue, cheeks and lips involved in speech
it then transmits that to the primary motor cortex for action
when does Broca’s area become active
when preparing to speak
which side of the brain is Broca’s area usually located
on the left
damage to Broca’s area results in…..
nonfluent aphasia
what is nonfluent aphasia
slow speech/difficulty choosing words
the entire vocabulary may only consist of 2 or 3 words
where is Wernicke’s area located
the posterior part of the superior temporal gyrus
what does Wernicke’s area do
permits recognition of spoken and written language
it creates a plan for speech
what happens when you damage Wernicke’s area
fluent aphasia
what is fluent aphasia
when speech is normal but excessive and makes little sense
the person has no understanding of the meaning of words and is not able to repeat them if asked to
