General Flashcards
Describe the anatomical encephalic distribution
- telencephalon
- diencephalon
- mesencephalon
- rhomboencephalon
What composes the telencephalon ?
- neocortex
- hippocampus
- lateral ventricles
What composes the Diencephalon ?
- subcortical nuclei
- subcortical structures
- third ventricle
What composes the Mesencephalon ?
- Cerebellar peduncle
- Brainstem
What composes the Rhomboencephalon ?
- Cerebellum
- Pons
- Medulla
Define Meninges
Meninges are the membranous cover of the whole CNS (encephalon and spinal cord). Its function is the mechanical and immunological protection as it provides a network for vascularisation. It is composed of dura matter, arachnoid matter and pia matter.
Define dura matter
Dura matter is the closest membrane to the skull. This loosely arranged membrane can be divided into 4 areas :
- flax cerebri
- flax cerebelli
- tantorium cerebelli
- diaphragma (covers the Stella trucica)
Define arachnoid matter
With practically no vascularisation, this layer is found under the dura matter. In the subdural space, small projections of the arachnoid can be found connecting to dura and therefore allowing the transition of CSF. In the subarachnoid space CSF can be found working as a cushion for the encephalon, protecting it against mechanical damage.
Define pia matter
Like the dura, this layer is highly vascularized. It is primarily involved in the nutrition of the underneath tissues, holding the form of gyri and sulci.
What is the function of the ventricles ?
Their function is the production of CSF for protection against mechanical damage/ intracranial pressure and immunological harm. The CSF is produced in the choroid process of each ventricle.
List the cerebral lobes and the main subcortical structures
Cerebral lobes :
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe
- insular lobe
Subcortical structures :
- midbrain
- brainstem
- cerebellum
- spinal cord
Define sulcus
A fissure (depression) in the surface of the brain
Define gyrus
A ridge on the cerebral cortex
Describe the anatomy of the frontal lobe
Delimitation :
Immediately in front of the central sulcus, where the pre-central gyrus lies.
Sulci :
- central sulcus
- pre-central sulcus
- superior frontal sulcus
- inferior frontal sulcus
Gyri :
- pre-central gyrus
- middle frontal gyrus
- pars pars orbitalis
- pars triangularis
- pars opercularis
Describe the anatomy of the parietal lobe
Delimitation :
Behind central sulcus and above lateral cerebral fissure, ending at the parieto-occipital fissure and divided into superior and inferior parietal lobules by the intra parietal sulcus.
Sulci :
- post-central sulcus
- intra parietal sulcus
- lateral cerebral fissure
- parieto-occipital sulcus
Gyri :
- post central gyrus
- precuneus
Describe the anatomy of the temporal lobe
Delimitation :
Beneath the lateral cerebral fissure, being divided into 3 gury running parallel to the central cerebral fissure.
Sulci :
- superior temporal sulcus
- inferior temporal sulcus
Gyri :
- superior temporal gyrus
- auditory gyri
- middle temporal gyrus
- inferior temporal gyrus
Describe the anatomy of the occipital lobe
Delimitation :
Marked by the parietal occipital fissure on the medial surface.
Sulci :
- parieto occipital sulcus
- superior occipital sulcus (as a continuation of the intra-parietal sulcus)
- collateral sulcus (as a continuation of the inferior temporal sulcus)
- calcarine sulcus
Gyri :
- superior occipital gyrus
- middle occipital gyrus
- inferior occipital gyrus
- cuneus
Describe the anatomy of the insular lobe
Delimitation :
Deep underneath the Sylvanian fissure, under the temporal, frontal and parietal lobules.
Sulci :
- short insular sulcus
Gyri :
- anterior insular lobule
- posterior insular lobule
What is the function of the insular lobe ?
The insular lobe is involved in different stage of sensory processing. It seems to be the neural substract for addictive urges, implicating a role in behavioral modulation, mediating compulsion as an interoceptive conditioned response.
What is laterality ?
The existence of a dominant and non-dominant hemispheres.
Where is the dominant hemisphere located ?
Right hemisphere is dominant in left-handed persons
Left hemisphere is dominant in right-handed persons
What are the specificities of the dominant hemisphere ?
- presents the most developed M1 in terms of connexions complexity
- usually contains the communication centers
- presents higher activation in processes involving planning and strategy
What are the specificities of the non-dominant hemisphere
- most complex connections between temporal pole and parietal lobe
- presents higher activation in processes involving abstraction and perception
What did Penfield design in 1957
The homunculus cerebri, representing the body in the primary motor and somatosensory cortex.
