Basic Anatomy of the CNS Flashcards
What are the clinical manifestations of a dysfunctional cerebellum?
Tremor
Dyssynergia = disturbance of muscular coordination Dysdiadochokinesia = impaired ability to perform rapid, alternating movements
Tests =
Finger to nose
Examine gate
rapid alternating hand movements
How do the ventricles appear on CT and why?
dark = filled with CSF
How do the sulcus appear on CT and why?
dark = contain CSF
Define ectoderm
Outermost layer of the 3 primary germ layers
Skin, CNS
Define mesoderm
Middle layer of the 3 primary germ layers
Muscle, CVS, kidneys, cartilage, bone
Define endoderm
Innermost layer of the 3 primary germ layers
Gut
What is the notochord?
Induces changes in overlying ectoderm = growth factors
= ectoderm starts to bend down, forms neural tube which breaks off
What is the neural tube?
Created from the notochord
Goes onto create your brain and spinal cord
Outline the structures that make up the brainstem
Medulla (bottom) = CNS/resp centres, major motor pathway, medullary pyramids
Pons (middle) = feeding, sleep
Midbrain (top) = eye movement, reflex to sound/vision
What are the medullary pyramids?
Major motor pathway
Carrying motor fibres down to the spinal cord
What are the ventricles of the brain
Hollow spaces filled with CSF
Contain a network of ependymal cells involved in the prod of CSF
What structures make up the CNS?
Cerebral hemispheres
Brainstem and cerebellum
Spinal cord
Oligodendrocytes
Microglia
What structures makes up the PNS?
Dorsal and ventral roots
Spinal nerves
Peripheral nerves
Schwann cells
What are cranial nerves?
Nerves that arise in pairs from the lower surface of the brain one on each side
Specialised spinal nerves
Where is the ventral surface of the brain?
inferior surface
Where is the dorsal surface of the brain?
Superior surface
Outline decussation
Fibres cross from one hemisphere to the other side
= one side of the brain control the other side of the body
Define sulcus
Groove separating adjacent gyri
Define gyrus
Fold in the brain
Maximises volume of the brain
Define fissure
Large split between adjacent large areas of the brain
E.g. Giant sulcus
What is the central sulcus?
Important landmark = where the primary motor and sensory cortex reside
Marks the boundary between the frontal lobe and parietal lobe
Runs uninterrupted from the midline to the temporal lobe
Where is the primary somatosensory cortex found?
In the post-central gyrus
Found posterior to the central sulcus
Where is the primary motor cortex found?
In the pre-central gyrus
Anterior to the central sulcus
Discuss the frontal lobe
Motor cortex
Higher cognition, motor function, speech
Anterior
