HNN Topic 4 - Cerebrum Flashcards
Describe the functions of the parietal lobe
- Postcentral gyrus - primary somatosensory area
- Sensory association areas
- Body orientation
- Motor feedback
- Primary gustatory cortex - taste
Describe the function of Brocca’s area
Motor aspect of speech
Describe the external structure of the cerebrum
- Folded to give sulci (grooves) and gyri (ridges)
- Divided into 2 hemispheres by the longitudinal fissure - runs in median sagittal plane
What would be the effect of damage to Wernicke’s area
Receptive aphasia, extremely poor comprehension of speech
List the major sulci of the cerebrum
- Central sulcus
- Lateral sulcus
- Luneate sulcus
- Calcarine sulcus
Describe the parts of the caudate nucleus
Has an anterior head which is wider, then tapers to a body and posterior tail, with a ‘knee’ (genu) between
What is the function of the insular cortex?
Involved in the emotional response to pain
Describe the functions of the occipital lobe
- Primary visual cortex
- Visual association area - vision
- Visual interpretation
Describe the contents of the internal capsule
- Contains ascending and descending axons, going to and from the cerebral cortex
- Large part is cortiospinal tract - carries motor information from the primary motor cortex to lower motor neurons in the spinal cord
Describe the location of the subthalamic nucleus
Inferior to thalamus, above substantia nigra
Describe the appearance of the substantia nigra
Dark appearance due to neuromelanin
Describe the function of the globus pallidus
Inhibiting muscular activity and reducing muscle tone
Describe the internal structure of the cerebrum
- Grey matter - surface of cerebral hemispheres (cortex)
- White matter - deeper parts of brain
List the nuclei of the basal ganglia
- Caudate nucleus
- Lentiform nucleus - globus pallidus + putamen
- Substantia nigra
- Subthalamic nucleus
What is the function of the grey matter structures of the cerebrum?
Processing and cognition
Describe the structures of the internal capsule
- V shaped
- 3 parts -
- Bend in V = genu
- Anterior limb
- Posterior limb
Describe the location and function of the corpus callosum
- Wide, thick white matter nerve tract
- Spans part of longitudinal fissure, connecting the cerebral hemispheres
- Forms part of walls of lateral ventricles
Describe the function of the putamen
Reinforcement and coordination of learned motor skills
Describe the general function of the basal ganglia
Initiate and maintain appropriate motor output
List the lobes of the cerebum
- Frontal
- Parietal
- Temporal
- Occipital
What would be the effect of damage to Brocca’s area?
Expressive aphasia, non-fluent, slow speech
List the major gyri of the cerebrum and their functional significance
- Precentral gyrus - primary motor cortex
- Postcentral gyrus - primary somatosensory cortex
- Superior temporal gyrus - inferior to lateral sulcus, primary auditory cortex
What is the function of the white matter structures of the cerebrum?
Connect the grey matter areas
Describe the gross structure of the cerebrum
- Largest part of the brain
- 2 cerebral hemispheres - L + R, separated by the falx cerebri of the dura mater
- Separated from cerebellum by tentorium cerebelli
Describe the position of the central sulcus
Separates the frontal and parietal lobes
List the major white matter bundles of the cerebrum
Internal capsule, corpus callosum
Describe the functions of the temporal lobe
- Primary auditory area - hearing
- Auditory association area - hearing
- Wernicke’s area - speech comprehension
- Learning and memory (retrieval)
- Emotions
Describe the location of Brocca’s area
- Inferior frontal gyrus (pars opercularis and pars triangularis)
- Most commonly in L hemisphere (dominant in 90%)
Describe the location of the caudate nucleus
Forms the lateral wall of the lateral ventricles, separated from putamen by white matter fibres (internal capsule)
Describe the position of the lateral sulcus
Separates frontal/parietal lobes from the temporal lobe
Where are the luneate and calcarine sulci found?
In the occipital lobe, calcarine sulcus marks the position of the primary visual cortex
Describe the dorsal and ventral striatum
Dorsal striatum = caudate nucleus + putamen
Ventral striatum = olfactory tubercle + nucleus accumbens
Describe the function of the caudate nucleus
Sub-control of voluntary movement
Describe the location of the internal capsule
Separates the caudate nucleus and thalamus from the putamen and globus pallidus (Lentiform nucleus)
Describe the structure of the corpus callosum
4 parts - splenium (posterior), body, genu and rostrum (anterior)
Describe the parts of the globus pallidus
Internal and external segments
Describe the location of Wernicke’s area
Usually in posterior area of superior temporal gyrus, most commonly in L hemisphere
Describe the function of Wernicke’s area
Sensory language area - lexical processing
Describe the main functions of the frontal lobe
- Precentral gyrus = primary motor area (movement)
- Motor association area - movement
- Primary olfcatory area - smell
- Broca’s area - motor speech production
- Cognitive thought and memory
- Control of voluntary movements
What are the basal ganglia?
Collection of nuclei strongly associated with the cerebellum, brainstem and cerebral cortex
Describe the connections and contents of the corona radiata
- White matter sheet that continues ventrally as the internal capsule
- Sheet of ascending and descending axons to and from the cerebral cortex
- Fibres radiate out from cortex and come together in the brainstem
- Associated w/ corticopontine, corticobulbar and corticospinal tracts
Where is the insular cortex found?
Part of cerebral cortex folded deep within the lateral sulcus, lateral to lentiform nucleus
Why is the cerebrum folded?
To give a larger surface area to volume ratio
