The Cerebral Hemispheres Flashcards
What is the name of the small dips in the surface of the cerebrum?
Sulci
What is the name of the larger dips on the surface of the cerebrum?
Fissure
What is the name of the cavity in each ventricle?
Lateral ventricle
What is the name of the large dip down the centre of the cerebrum
Medial longitudinal fissure
What is the faux cerebri?
The fold of the dura as it dips into the median longitudinal fissure
What is the innermost meninge of the brain?
Pia matter
What dip separates the temporal lobe form the frontal lobe laterally?
Lateral sulcus
What dip continues from the lateral sulcus over the superior part of the cerebrum to join the other lateral sulcus and separate the parietal and frontal lobes coronally?
Central sulcus
What is the area just anterior of the central sulcus not he surface of the cerebrum?
Precentral gyrus
What is the area just posterior to the central sulcus on the surface of the cerebrum?
Postcentral gyrus
What dip can be seen when the brain is cross-sectioned in the midline separating the parietal and occipital lobes?
Pareto-occipital sulcus
What is the c-shaped structure or bridge in the centre of the brain?
Corpus collosum
What is the dip that runs around and in line with the corpus colloum in the midline orientation?
Cingulate sulcus
What is the insula?
The insula, part of the temporal lobe - can only be seen on resection of the frontal and parietal lobes
What are the sections of the frontal lobe?
superior, inferior, inferior frontal gyri
What are the sections of the parietal lobe?
Superior, inferior parietal lobule
What are the sections of the temporal lobe?
Superior, middle, inferior temporal gyri
What Brodmann’s Areas?
52 sections of the cortex divided on th e basis of histology that are used to describe locations on the cortex
In basic terms what is the motor area of the brain?
Anterior part of cerebrum
On basic terms what is the sensory part of the cerebrum?
Posterior part of cerebrum
Which areas of the brain receive the initial sensory information?
Primary sensory areas
Where is the primary motor cortex? What is its latin name?
In the precentral gyrus
Motor homunculus
Each part of the body represented somatotrophically
What are areas 44 and 45 found anterior to the pre central gyrus?
The inferior frontal gyrus or Broca’s Area
What are the primary sensory areas of the parietal lobe?
1,2,3 - receive the sensations from the body somatotrophically
Sensory homunculus
What is hemisensory neglect?
Neglect of actions and senses one one side of the body due to insult to the primary sensory are of the parietal lobe
What are the primary auditory association areas?
Areas 41 and 42.
What is a feature of the primary auditory association areas in the dominant hemisphere?
Wernicke’s Area is present. This deals with understanding of the spoken word
What is the main function of the occipital lobe?
The visual cortex - processing of visual images
What is the function of the limbic “lobe”
A functional area of the cerebral hemisphere in the medial plane. Primarily responsible for memory and emotional aspects of behaviour
What makes up the limbic area?
Cingulate gyrus, hippocampus, parahippocampal gyrus, amygalda
What is the main motor speech area?
Broca’s area
What is aphasia?
Problem with speech due to damage to one or more speech areas of the brain
What are the two kinds of aphasia?
Broca’s aphasia
Wernicke’s aphasia
What are the features of Broca’s aphasia?
Understanding of speech, able to say key words but misses small words so context often lost. Often due to damage of the frontal lobe and frequently presents with weakness of one side of the body
What are the features of Wernicke’s aphasia?
Fluent speech but with meaningless words. No understanding of speech. Often due to damage of the temporal lobe, rarely presents with paralysis
What are the three types of myelinated axon fibres in the white matter?
Commisural, association, projection
What are the commisural fibres?
Fibres which connect the two hemispheres of the cerebrum (corpus callosum)
What are the association fibres?
Fibres which connect areas of the hemispheres
What are the projection fibres?
Fibres which run between the cortex and other subcortical centres either taking motor fibres away from the cortex or sensory fibres towards the cortex
What is the internal capsule?
A group of projection fibres passing to nd from a real of the cortex via a narrow area between the thalamus and caudate nucleus
What is the clinical significance of the internal capsule?
It derives blood supply from the middle cerebral artery and is frequently affected in stroke
What is the basal ganglia?
They are subcortical nuclei (collections of neuronal cell bodies in the grey matter) deep within each cerebral hemisphere
What three structures make up the basal ganglia?
Caudate nucleus, putamen, globus pallidus
What relation does the substantia nigra have to the basal ganglia?
As it is in the midbrain, it is not anatomically part of it but functionally it is part of the ganglia
Describe the anatomy of the basal ganglia
Caudate is most superior and has a tail, putamen is the most lateral part and is attached to the global pallidus
Describe the functions of the basal ganglia
The caudate nucleus and putamen are the input regions that receive input from the motor cortex, premotor cortex and thalamus
They are then connected to the output regions - global pallidus and substantia negra
Global pallid us then projects to the thalamus, which sends fibres to the motor area of the cortex
What is the major function of the basal ganglia?
To regulate initiation and and termination of movements
What is another name for the basal ganglia?
The extrapyramidal system
What are some pathologies of the basal ganglia?
Parkinson’s, chorea, athetosis
