7 - Organization and Function of the Cerebrum

What are the three types of white matter tracts and briefly describe their connections

Commissural fibres - between hemispheres (corpus callosum and anterior commissure)
Association fibres - within hemisphere, between lobes
Projection fibres - from brain to spinal cord

List the 4 main structures in the basal nuclei

Caudate (head + tail)
Lentiform nucleus (bean shaped)
Substantia nigra of midbrain (releases dopamine which starts/stops movement)
Striatum (connects caudate and putamen)

Describe the pathway in the brain when habitual movement in being planned

Primary motor cortex (I want to move) -> basal nuclei (blueprint of movement)-> thalamus (removes extraneous movement) -> primary motor cortex (here's how to move)

Describe symptoms of patients with Huntington's Chorea and what causes it

Increased movement (chorea=dance)
Too many motor instructions are being sent from the basal nuclei

Describe the three functions of the limbic system

Flight and fight response
Storing long term memory
Emotions + smell

What is the function of the hippocampus

Converts short term memory into long term memory (who what when why)

What is the function of the fornix?

Connects hippocampus to mammillary bodies

What is the function of the mammillary bodies?

Converts emotions to memory, connects smell and emotion

What is the function of the amygdala?

Acts as threat detection, illicits a flight or fight response to perceived threat

What is the function of the entorhinal cortex?

Controls input and output of hippocampus and determines locality with memories (where)

What is the function of the thalamus in conjunction with the hippocampus?

Filters out important memories between the prefrontal cortex and the hippocampus

What is declarative memory? Where is long term and short term declarative memory stored?

Cognitive memory (facts and information)
Short term memory- hippocampus, thalamus, amygdala
Long term memory- sensory cortexes (somatosensory, visual)

What is white and gray matter composed of?

White matter - axons (myelinated)
Gray matter - cell bodies/somas

How is white and gray matter organized in the brain?

Grey matter on cortex, white matter on the interior

How is white and gray matter organized in the spinal cord? Describe significant structure

White matter on the exterior, grey matter on the interior
Contains and anterior and posterior horn

What are the two primary fissure in the brain? What part of the brain does it divide?

Lateral fissure
Divides frontal and temporal lobe
Longitudinal fissure
Divides left and right hemisphere

What is the primary sulcus in the brain? What part of the brain does it divide?

Central sulcus
Divides frontal lobe and parietal lobe
Contains 1 motor cortex anterior to it and 1 sensory cortex posterior to it

Name of hills on brain

Gyri

Name of grooves on brain

Sulci

Where is motor function usually located in the cerebrum?

Anterior

Where is sensory function usually located in the cerebrum?

Posterior

What is the function of the frontal lobe?

Motor function, planning motor function, primarily intellectual function, intellect, personality and ethics

What is the function of the temporal lobe?

Processing auditory information, and contains limbic system, responsible for memory, emotions, and flight/fight response

What is the function of the parietal lobe?

Processes combined sensory information from temporal/occipital/special senses to develop sense of environment

What is the function of the occipital lobe?

Processes visual information

Which lobe is the frontal eye field located in? What is its function?

Frontal lobe, combines vision from both eyes into one vision

What lobe is the primary motor cortex located in? What is it's function?

Frontal lobe, maps out motor function in body

What lobe is the primary sensory cortex located in? What is it's function?

Parietal lobe, maps out sensory function in body

What lobe is the Wernicke's area located in? What is it's function?

Temporal lobe, contains "dictionary", make meaning in words

What lobe is the Broca's area located in? What is it's function?

Frontal lobe, allows making of spoken words, speech

What is the significance of the homunculus?

Majority of sensory and motor neurons control upper limbs and face, compared to the trunk and lower limbs

What important regions does the middle cerebral artery supply in the brain? (1)

Sensory and motor neurons for upper limbs and face

What important regions does the posterior cerebral artery supply in the brain? (2)

Occipital and Temporal lobe

What important regions does the anterior cerebral artery supply in the brain? (3)

Sensory and motor neurons for trunk and lower limbs
Frontal lobe
Broca and Wernicke's

What structure connects the left and right hemispheres of the brain?

Corpus callosum and anterior commissure

What is the primary function of left hemisphere of brain?

Logic and language

Describe the three "layers" of gray-white matter from superficial to deep in the brain?

Superficial gray matter
White matter tracts
Deep Nuclei

What two systems are part of the deep nuclei?

Basal nuclei and limbic system

Describe the main functions of the basal nuclei (4)

Starts and stops motor movements (as well as cognitive process)
Eliminates unnecessary movements
Controls subconscious movements
Initiates habitual movements very quickly

Describe symptoms of patients with Parkinson's and what causes it

Loss of control for movement
Substantia nigra of midbrain unable to release dopamine, unable to send movement signals back to basal nuclei

What is non declarative memory? Where is habitual and novel motor movements stored?

Motor memory
Novel memory - cerebellum (visual, balance, position)
Habitual memory - basal nuclei

Which structure in the brain controls whether to use the habitual or novel motor movement pathway?

Thalamus

What is anterograde amnesia? What part of the brain controls anterograde amnesia?

Unable to form new long term memories
Caused by damage to hippocampus

What is retrograde amnesia? Why does someone with anterograde amnesia will not necessarily receive retrograde amnesia as well?

Unable to recall former long term memories
Recalling is controlled by various systems in the brain that are different from anterograde amnesia (hippocampus)

What is the primary function of the right hemisphere of brain?

Creative and abstract