L22 - Movement and sensation Flashcards
How to distinguish between posterior and anterior of the brain
Posterior more pointier and has the cerebellum
Anterior more C shaped
How to know the names of the lobes of the brain
They correspond to the names of the bones on the skull that they sit underneath of
Another name for the cerebrum
Cerebral cortex
Valleys
Sulcus pl. sulci in between two gyri
Hills
Gyrus pl. gyri, in between two sulci
What does the central sulcus do?
Separates the frontal and parietal lobes?
What does the parieto-occipital sulcus do?
Separates the parietal and occipital lobes
What does the lateral sulcus do?
Separates the temporal and frontal lobes
What does the transverse fissure do?
Separates the temporal+occipital lobes from the cerebellum
Dural fold at the transverse fissure
Tentorium cerebelli
Function of: parietal lobe
*interpretation of somatosensory info
*sensory info i.e things you touch and feel
Function of: occipital lobe
*interpretation and processicion of visual information
Function of: frontal lobe
*superior portion which is more posterior is in control if motor (somatic efferent)
*emotion, language and personality
Function of: temporal lobe
*has to do with memory, has distinctive structures (when degenerates leads to dementia)
*hearing, group of cells in this lobe
What sits beneath the cerebral cortex?
The corpus callosum, made of white matter (myelinated, plasma mem of oligodendrocytes made of fat)
What sits beneath the corpus callosum?
the Diencephalon, made of the Thalamus and Hypothalamus - regulates hormones
What is the cerebral aqueduct associated with?
Midbrain
What is pons associated with
The 4th ventricle, anterior of the cerebellum
What forms the brainstem
midbrain, pons and medulla oblongata
What forms the brainstem
midbrain, pons and medulla oblongata
What is below the medulla oblongata?
The foramen magnum, separates the brain and spinal cord
Dark layer on the surface of brain (coronal view)
The cerebral cortex made of grey matter (collections of cell bodies)
White layer of brain underneath cerebral cortex
white matter, myelinated axons of the cell bodies
How many types of white matter
3 types
Dark matter inside the brain
deep nuclei, collection of cell bodies, each body has its own unique function
What is unique about white matter?
Made of axons that travel long distances
Commissural tract
Axons from cell bodies on both sides goes from one side of the cerebral cortex to the other, goes in both directions eg. corpus callosum coordinates left and right sides
Projection tracts
Axons of upper motor from cerebrum extend to other parts of the CNS eg the spinal cord lower motor
eg Corticospinal tract that helps to transmit somatic efferent info
Association tract
Long (lobe to lobe) or short (gyrus to gyrus)Wh distance co-ordination or comms between cell bodies on same side of the brain through axons
Gyrus anterior to the central sulcus
Precentral gyrus –> 1º motor cortex - where cell bodies of upper motor neurons reside
Gyrus posterior to the central sulcus
Postcentral gyrus –> 1º somatosensory cortex - where cell bodies are the final destination of sensory info and becomes conscious of the presence
Pathway of somatic efferent (info away from CNS)
*Voluntary movement
*upper motor neurons in 1º mortor cortex –> crosses over in the midbrain –> synapses with lower motor neurons in the ventral horn of the spinal cord
*Effects skeletal muscle
*Neurotrans is ACh
Where are upper motor neurons present?
In the medial and lateral motor cortex, (precentral gyrus cut in the coronal plane), each part correcponds with its own movement of body
What does the medial part of the 1º cortex control
Movement of toes, leg, thigh
Where does the upper motor neuron cross before it synapses with a lower
Axons crosses to opposite site in the midbrain and synapses to lower in the ventral horn
What happens if primary motor cortex is damaged
Cant move specific parts on opposite side of the body depending on where the damage in the brain is
Somatosensory pathway
Input axon (peripheral fibre) from unipolar cell body in the dorsal root ganglion –> central fibre in dorsal horn runs up dorsal column –>synapses with neuron 2 in medulla oblongata –> axon from cell body in medulla oblongata crosses over and synapses with n3 in thalamus –> axon from cell body in thalamus synapses with a somatosensory cortex neuron in post gentral gyrus
Where does the upper motor cortex synapse
At a lower motor neuron in the brainstem or spinal cord
