Flashcards in Synaptic Communication 2 Deck (16):
What does it mean that a neuron is plastic
Basically the more you use it the stronger and more efficient it becomes.
If you dont use it, you lose it
What is a Spinal Reflex?
Sensory and motor loops that function independently of the brain
Explain the Hebbian theory
Neuronal networks undergo activity dependent plasticity throughout life.
When does Synapse Pruning occur?/Long term potentiation and depression?
Synapse pruning occurs in development
While LTP & LTD occur in adulthood (Strength of connection & Number of connections)
What are the 3 types of Somatosensation?
2. Pain & Temp
What is a sensory field and how does it relate to dermatomes?
Sensory fields are discrete areas of touch discrimination
-sensory fields overalp and are determined by # neurons and the degree of neuronal arborization.
Define the 1st, 2nd & 3rd order sensory neurons
1st: Mechanosensory neuron --> Brainstem (Medulla)
2nd: Brainstem --> Thalamus
3rd: Thalamus --> Somatosensory cortex
Remember touch sensory is processed CONTRALATERALLY
What is another name for a Pain receptor?
List the 4 types of Mechanoreceptors
1. Merkel's Cells
-Fine form and texture
2. Meissner Corpuscle
-Skin movement & vibration
3. Ruffini Endings
-Pressure & Vibration
4. Pacinian Corpuscle
-Skin stretch & Limb movement
How do nociceptors differ from other mechanosensory Neurons?
They have free nerve endings
How do pain networks differ from touch networks?
2nd order neurons cross at the spinal cord instead of in the brain.
How does the body gate pain?
Pain is gated at the spinal cord.
That is to say, pain is regulated at the level of the spinal cord.
Peripheral touch can inhibit nociception
How do NSAIDs and Opiates Block pain?
NSAIDS: Peripherally (reduce inflammation)
Opiates: Centrally (Inhibit nociceptor to 2nd order neuron transmission)
What role do muscle spindle fibers and Golgi tendons play in proprioception?
-Muscle spindles correct muscle length
-Golgi tendons monitor muscle force
How do spinal reflexes work?
They synapse in the spinal cord, they do not need to communicate with the brain to send a response to stimulation.