Lecture 1 - Topography Flashcards
What are the 3 main parts to the CNS?
Cerebral hemispheres
Brainstem and cerebellum
Spinal cord
What is the main functions of the cerebral hemispheres?
Higher function
Motor and sensory (conscious)
Emotion
Memory
What is the main function of the brainstem and cerebellum?
Communication via cranial nerves
Cerebellum = motor sequencing and coordination
What are the main functions of the spinal cord?
Ascending sensory and descending motor pathways
Spinal reflex arcs
Control of upper and lower limbs
What makes up grey matter?
Cell bodies and dendrites with rich blood supply
What is grey matter called in the PNS?
Ganglion
What is a ganglion?
What is its equivalent in the CNS?
Collection of cell bodies
Grey matter
What is the general function of grey matter/ganglia?
Where computation/processing occurs
What makes up white matter?
Mainly myelinated (+some non myelinated) axons with NO cell bodies
What is the function of white matter?
Act as pathways which connects areas of grey matter together
What is the equivalent of white matter in the PNS?
A nerve/root
How many segments make up the spinal cord?
31 segments
What does each of the 31 spinal cord segments supply?
A Dermatome and myotome on each side
What is a Dermatome?
A region of skin who’s sensation is supplied by a single specific spinal nerve root
What is a myotome?
A group of muscles supplied by a single spinal nerve
Where is the grey and white matter positioned in the brain?
Grey matter peripheral
White matter central
How is the grey and white matter positioned in the spinal cord?
Central core = grey matter
Outer shell = white matter
What is the structure of a spinal nerve?
Made up of a sensory and motor spinal nerve root (it’s mixed)
Which spinal nerve root is the sensory spinal nerve root?
Ventral or dorsal?
Dorsal root
Which spinal nerve root is the motor spinal nerve root?
Ventral or dorsal?
Ventral
Where is the lesion likely to be if a patient suffers a sensory deficit in the L4 Dermatome?
At the L4 dorsal root or spinal nerve
Where is the lesion likely to be if there a sensory deficit across multiple Dermatomes/segments?
Cord lesion
What are the 3 different types of structures of white matter in the spinal cord?
Funiculus
Tract
Fasciculus
What is a funiculus?
Large block of white matter containing multiple distinct pathways which both ascend and descend (sensory and motor so impulses go in both directions)
What is a tract?
White matter pathways that connect 2 distinct regions of grey matter
Which direction do impulses travel in a tract?
Single direction only
What does the spinothalamic tract connect?
Spinal cord dorsal horn to thalamus
What does the corticospinal tract connect?
Cerebral cortex to spinal cord ventral horn
What is a fasciculus?
Subdivision of a tract that supplies a distinct body region
What is the gracile fasciculus?
Subdivision of dorsal column tract supplying lower half of body
What is the cuneate fasciculus?
Subdivision of dorsal column tract supplying upper half of body BUT NOT THE HEAD
How are the cell bodies of spinal cord grey matter arranged?
Cell columns
What is a nucleus?
Collection of functionally related cell bodies
What is a cortex?
Folded sheet of cell bodies/grey matter found on the surface of the brain (cerebral hemispheres and cerebellum)
What is a fibre?
An axon in association with its supporting cells (axon+multiple Schwann cells)
What do association fibre connect?
Cortical regions within a hemisphere (parts on same side)
What do the commisural fibres connect?
Give an example:
The hemispheres
Corpuscle callosum
What are the key functions of the midbrain?
Eye movement (Oculomotor and trochlea)
Reflex response to visual and auditory stimuli
What are some key structures of the midbrain?
Oculomotor nucleus
Edinger-Westphal nucleus
What are the main functions of the pons?
How to remember this?
Feeding
Sleep
Once you’ve had a good feed you want to sleep