Week 2 - The Functional Localisation of the Brain Flashcards
What are the three main divisions of the brain?
Forebrain, midbrain, hindbrain
What is the primary function of the cerebral cortex?
Covers the brain’s surface and comprises gray matter where neuron cell bodies are located
What structural feature of the cerebral cortex accommodates the high number of neurons?
Highly folded forming gyri and sulci
How many layers does the neocortex have?
6 layers (I to VI)
What are the three main types of neurons found in the cerebral cortex?
- Granular (stellate) * Pyramidal * Fusiform/multiform cells
What is the role of granular cells in the cortex?
Function mainly as interneurons transmitting signals short distances
Where are pyramidal cells primarily located?
Layers III and V of the cortex
What do pyramidal cells project to?
- Other regions of the brain * Spinal cord * Thalamus * Brainstem
What are association fibers responsible for?
Interconnect areas of the cortex within one hemisphere
What is the largest commissural fiber in the brain?
Corpus callosum
What is the function of projection fibers?
Travel to and from the cortex, connecting to the thalamus and descending to the spinal cord
What are Brodmann’s areas?
Numbered cortical areas that share similar cryoarchitecture and correlate with different functions
Where is the primary motor area located?
Precentral gyrus of the frontal lobes
What does the motor homunculus represent?
The size of body parts correlating to the size of neuron pools supplying the musculature
What is the function of the supplementary motor area?
Contains motor maps for posture and sends efferents to innervate limbs and trunk musculature
What is the role of the premotor area?
Integrates and interprets motor information and helps plan voluntary movements
What is the primary somatosensory cortex responsible for?
Processes sensory information from the contralateral peripheral receptors
The internal capsule is divided into which three parts?
- Anterior limb * Posterior limb * Genu
True or False: The cortex consists mainly of primary cortical areas.
False
Fill in the blank: The _______ connects the anterior temporal lobes and olfactory bulbs.
Anterior commissure
What is the primary sensory area of the parietal lobe responsible for?
It is responsible for processing sensory information from the body and creating a sensory map known as the sensory homunculus.
What are the two nuclei of the thalamus involved in sensory processing?
- Ventral posterolateral (VPL) nucleus
- Ventral posteromedial (VPM) nucleus
What is tactile agnosia?
A deficit in the ability to combine touch, pressure, and proprioceptive input to interpret the significance of sensory information.
What is the primary visual cortex and where is it located?
It consists of an area of cortex on either side of the calcarine sulcus on the medial side of the occipital lobe.
What is visual agnosia?
A deficit in the ability to recognize objects in the opposite visual field despite intact vision.
Where is the primary auditory area located?
Deep within the lateral sulcus on the superior surface of the superior temporal gyri (Heschl’s convolutions) of the temporal lobes.
What is the function of Wernicke’s area?
It is critical for the understanding of language and allows us to interpret and assign meaning to symbols.
What is Broca’s area responsible for?
It is dedicated to the production of language, including spoken, written, and sign language.
What type of aphasia is associated with damage to Broca’s area?
Expressive or productive aphasia.
What are the characteristics of Wernicke’s aphasia?
- Fluent speech
- Intact syntax and grammar
- Inability to understand language
- Content of speech is flawed
What is conduction aphasia?
A condition where damage to the arcuate fasciculus leads to an inability to repeat words despite intact comprehension and expression.
Fill in the blank: The arcuate fasciculus connects _______ and _______.
[Wernicke’s area], [Broca’s area]
True or False: Damage to Wernicke’s area does not affect the fluency of speech.
True
What is astereognosis?
The inability to recognize an object placed in the hand.
What type of organization does the primary auditory cortex exhibit?
Tonotopic arrangement.
What results from a lesion in the auditory association area?
Word deafness or acoustic verbal agnosia.
What is the significance of the sensory homunculus?
It represents the size of cortical representation of body parts correlated to tactile sensation.
What happens to patients with damage to Broca’s area?
They exhibit sparse, halting language and have difficulty with syntax and grammar.
Where do fibres from the retina project to in the thalamus?
Lateral geniculate nucleus.
