09/25 Flashcards
Sensory information goes what direction in the spinal cord?
up
Motor information goes what direction in the spinal cord?
down
Which pathways are there more of? Sensory or motor
sensory
What kind of sensory sensors do we have?
pressure
temperature
vibration
pain
Where does decision making happen in the spinal cord?
The grey matter
What is the grey matter of the spinal cord made of?
cell bodies and part of neurons that communicate with each other,
lots of synapses.
What does “tract” refer to?
a bundle of axons within the CNS
What is a bundle of axons called in the PNS?
Nerves
The main descending motor pathways are separated into what groups?
pyramidal tract
Extrapyramidal Tract
What does the Pyramidal tract take care of?
The primary motor function we think of: moving an arm or leg around
primarily voluntary
What does the extrapyramidal tract take care of?
accessory motor pathways that help us coordinate complex tasks
primarily involuntary(we don’t have realization or knowledge of these)
-help us find tune our motor commands
What is the ascending sensory pathway called?
dorsal column pathways
Where does the dorsal column pathway sit?
in the back of the cord- dorsal column
What do the does the dorsal column pathway do?
transmit information regarding pressure sensors located in the skin
Perception
helps us figure out if we’re holding onto something or have our hands in the air
Where are the pain signals sent in the spinal cord?
in the anterolateral system
What are the 2 pathways that pain can take in the spinal cord?
the lateral or anterior routes
What is another term that is used to describe pain pathways in the spine besides anterolateral system?
spinalthalamic tracts or pathways
Pain travels through the _____ and then the _______ followed by the ______ which is why it is called spinal thalamic tracts
cord within the spine
thalamus
parietal cortex where it can be sorted out
What are some ways the parietal cortex sorts pain information it receives?
where is the bad pain coming from?
How severe is it?
What is Rexed’s Laminae?
A way to divide up and name the parts of grey matter in the cord
In what direction is Rexed’s Laminae numbered?
back to front
The most dorsal part of the grey matter found in the horn (the tip) is called
Lamina I
What is lamina I known for?
Part of the cord that sends fast pain up to the brain
What kind of neuron is fast pain transmitted through?
Myelinated pain fibers (nociceptors)
These are A-Delta fibers
Fast pain comes in through the dorsal root, through the rootlet, into the cord, and has synapses on
Lamina I
After pain is in Lamina I where does it go?
It crosses over to the other side of the cord and ascends into an anterolateral pathway
Anterior to lamina I in the dorsal horn is
Lamina II and Lamina III
collectively known as Substantia Gelatinosa
What is another name for Lamina I?
Lamina Marginalis
What does the Substantia Gelatinosa send to the brain?
Slow pain
Sometimes with slow pain there is also synaptic connections to _______ in addition to the substantia gelatinosa
Lamina V
Slow pain is typically routed through
non-myelinated nociceptors
C Fibers
Where does slow pain signals go after the Substantia gelatinosa?
The signal hops over to the other side of the cord and goes up towards the brain via the anterolateral or spinal thalamic pathway
What relays information to Lamina I-VI?
mechanoreceptors found in the hands and skin
Where are our motor neuron bodies headquartered?
in the anterior horn
What activates the motor neurons?
The descending motor pathways
How many different Laminae are there in the grey matter of the spinal cord?
IX
Where is lamina X?
around the central canal
What does lamina X allow for?
signals to be routed to the opposite side of the cord
The portion of tissue that can relay information to the other side of the cord that’s made of white matter is called the
anterior white commisur
How many different categories of spinal tracts are there?
5