Synaptic Communication 2

Question 1

What does it mean that a neuron is plastic

Answer 1

Basically the more you use it the stronger and more efficient it becomes.

If you dont use it, you lose it

Question 2

What is a Spinal Reflex?

Answer 2

Sensory and motor loops that function independently of the brain

Question 3

Explain the Hebbian theory

Answer 3

Neuronal networks undergo activity dependent plasticity throughout life.

Question 4

When does Synapse Pruning occur?/Long term potentiation and depression?

Answer 4

Synapse pruning occurs in development

While LTP & LTD occur in adulthood (Strength of connection & Number of connections)

Question 5

What are the 3 types of Somatosensation?

Answer 5

1. Touch
2. Pain & Temp
3. Propioception

Question 6

What is a sensory field and how does it relate to dermatomes?

Answer 6

Sensory fields are discrete areas of touch discrimination

-sensory fields overalp and are determined by # neurons and the degree of neuronal arborization.

Question 7

Define the 1st, 2nd & 3rd order sensory neurons

Answer 7

1st: Mechanosensory neuron –> Brainstem (Medulla)
2nd: Brainstem –> Thalamus
3rd: Thalamus –> Somatosensory cortex

Remember touch sensory is processed CONTRALATERALLY

Question 8

What is another name for a Pain receptor?

Answer 8

Nociceptor

Question 9

List the 4 types of Mechanoreceptors

Answer 9

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

Question 10

How do nociceptors differ from other mechanosensory Neurons?

Answer 10

They have free nerve endings

Question 11

How do pain networks differ from touch networks?

Answer 11

2nd order neurons cross at the spinal cord instead of in the brain.

Question 12

How does the body gate pain?

Answer 12

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

Question 13

How do NSAIDs and Opiates Block pain?

Answer 13

NSAIDS: Peripherally (reduce inflammation)
Opiates: Centrally (Inhibit nociceptor to 2nd order neuron transmission)

Question 14

What role do muscle spindle fibers and Golgi tendons play in proprioception?

Answer 14

• Muscle spindles correct muscle length

- Golgi tendons monitor muscle force

Question 15

How do spinal reflexes work?

Answer 15

They synapse in the spinal cord, they do not need to communicate with the brain to send a response to stimulation.

Question 16

How do opiates block pain?

Answer 16

Opiates interact with central pain receptors to block the transmission of nociceptive stimuli to the somatosensory cortex.