ANATOMY- cortex and subcortical fibres Flashcards
what is cerebral cortex made up of?
grey matter
What does the cerebral cortex make up?
the outermost layer of the cerebrum
function of cerebral cortex?
memory, learning, reasoning, problem solving, emotions, consciousness and functions related to your senses
what does the white matter make up?
the inner portion of the brain
Below the cortex are axons, which are insulated by myelin- this is white matter
role of white matter?
connects various parts of the cortex to one another and also to other parts of the CNS
what is the white matter made up of?
Made up of mostly myelinated axons (nerve fibres) and their supporting cells (glial cells)
what are the 3 types of fibres in the white matter?
-Association fibres
-Commissural fibres
-Projection fibres
role of association fibres?
-type of white matter tract that connect cortical sites lying in the same hemisphere
role of commissural fibres?
-connect one hemisphere to the other, usually connecting areas with similar function
role of projection fibres?
-connect hemispheres to deeper structures including thalamus, corpus striatum, brain stem and spinal cord
what is the limbic system?
a collection of structures in the brain involved in olfactory, memory, emotions and behavioural responses
what structures are involved in the limbic system?
-Amygdala
-Hippocampus
-Fornix
-The mamillary bodies
-Cingulate gyrus
-Parahippocampal gyrus
role of hippocampus?
involved in memory
what is the hippocampus made up of?
-Dentate gyrus (where info comes in to the hippocampus)
-Subiculum (where info leaves the hippocampus)
-Hippocampus Proper (where info leaves the hippocampus)
Where does info enter the hippocampus?
Dentate gyrus
where does info leave the hippocampus?
-Subiculum
-Hippocampus proper
What white matter tract connects the hippocampus to the septal area + mamillary bodies?
fornix
what white matter tract connects the amygdala to the septal area + hypothalamus dorsally?
striae terminalis
Describe the Papez circuit?
Hippocampus (proper hippocampus + subiculum) –Fornix–> Mammillary bodies –Mammillo Thalamic Tract-> Anterior Nucleus of Thalamus —-> Cingulate gyrus —> Parahypocampal gyrus—>BACK TO HIPPOCAMPUS (dentate)
how is circuit of papez involved in decision making?
Info can travel from the cingulate gyrus to the pre frontal cortex which is in charge of decision making so that your memories influence your descicions
Hippocampus (proper hippocampus + subiculum) –Fornix–> Mammillary bodies –Mammillo Thalamic Tract-> Anterior Nucleus of Thalamus —-> Cingulate gyrus —> Parahypocampal gyrus—>BACK TO HIPPOCAMPUS (dentate)
explain how smell signals are transmitted to the brain
smell > olfactory epithelial cells in the nose> olfactory nerve in the nose > through cribiform plate > olfactory bulb activated > olfactory tract activated > travels down the lateral olfactort striae to the parahyppocampal gyrus and the amygdala
-parahyppocampal gyrus is in the temporal lobe and is involved in the memory of smells
-amygdala is involved in emotions of the smells
