Reflexes

Question 1

What are the 3 types of reflex?

Answer 1

“1. Muscle stretch reflex

2. Golgi tendon reflex
3. Flexor-withdrawl reflex”

Question 2

Which type is mono-synaptic; 2 neurons

Answer 2

muscle stretch

Question 3

Which type is di-synaptic; 3 neurons

Answer 3

golgi tendon reflex

Question 4

In which type does stimulation of a body part cause a reflex?

Answer 4

flexor-withdrawl reflex

Question 5

What are the steps in a muscle stretch reflex?

Answer 5

“1. Muscle is stretched, activating primary sensory fibers (dynamic response) of spindle, creating action potentials

2. action potentials travel to spinal cord to synapse with alpha motor neurons
3. Alpha motor neurons for homonymous cause muscles to contract, decreasing stretch on the muscle
4. muscle spindles return to original length, static level
5. Motor commands to contract synergistic muscles and relax antagonistic muscles”

Question 6

How else is a muscle stretch reflex used?

Answer 6

“1. Prevent antagonistic muscles from contracting during voluntary muscle contraction

2. stabilization of body postures (intense motor action)
3. smooth/dampen muscle action”

Question 7

What are the functions of the golgi tendon reflex?

Answer 7

“1. prevent too much tension in the muscle, prevent damage

2. equalize contraction strength of muscle fibers”

Question 8

What are the steps in a golgi tendon reflex?

Answer 8

“1. muscle contracts, activate type Ib fibers, action potential goes to spinal cord

2. AP synapses with inhibitory interneurons, which then synapse with alpha motor neurons
3. Alpha motor neurons are inhibited from firing, relaxing the muscle
4. Motor commands are sent to relax synergistic muscles and contract antagonistic muscles”

Question 9

What are the steps in the flexor-withdrawal reflex?

Answer 9

“1. diverging neural circuits spread reflex signal

2. reciprocal inhibition circuits inhibit contraction of antagonists
3. Afterdischarge produced by circuits (prolong contraction of flexors)
4. crossed extensor reflex for opposite limb “

Question 10

Which reflex pathway synapses with inhibitory interneurons?

Answer 10

Golgi tendon reflex

Question 11

Which reflex pathway synapses on alpha motor neurons?

Answer 11

muscle stretch reflex

Question 12

Which reflex pathway equalizes contraction strength of muscle fibers?

Answer 12

golgi tendon reflex

Question 13

What does an afterdischarge do? Which reflex pathway has this reaction?

Answer 13

“prolongs the contraction of flexor muscle after stimulus has stopped
flexor-withdrawal reflex”