7: Autonomics

Question 1

Reflex

Answer 1

Relationship between an input stimulus and an output action

Question 2

What do 70-80% of interneurons receive?

Answer 2

Input from both visceral and somatic afferents

Question 3

What causes somatic muscle activation with visceral disturbances?

Answer 3

Visceral afferents activate both symp and somatic outflow

Question 4

Cortical inhibition

Answer 4

Controlling reflexes with your conscious mind

Question 5

Cortical excitation vs inhibition

Answer 5

Excitation: sensitization of interneurons increases output -> maintains reflex reactions
Inhibition: reduces somatic and autonomic outflows

Question 6

Why can MSK palpatory findings correlate with visceral disturbances?

Answer 6

Visceral disturbances reflexively cause activation in the somatic musculature -> somatic dysfunction

Question 7

How do utilize a somatic SD to treat visceral components

Answer 7

If the two are linked, treating the somatic SD can result in improvement of visceral function and restoration of homeostasis

Question 8

Denslow’s findings with facilitated segment concept

Answer 8

Found spinal levels with long-lasting low threshold response to afferent inputs from the same + other spinal levels + psychological stress

Question 9

Facilitated segment concept

Answer 9

Constant afferent barrage by injured somatic or visceral structures would lead to segment excitation, facilitating neuronal transmission and producing excess efferent response

Question 10

Sensitization

Answer 10

Increasing response of a neural pathway with repetitive stimulation

Question 11

Habituation

Answer 11

Oppositve of sensitization, decreasing response of a neural pathway with a continuous stimulation

Question 12

Nociception theory

Answer 12

Habituation and sensitization exist together to maintain a homeostasis between over-reaction and under-reaction to a stimulus

Question 13

Explain the steps of the nociception theory

Answer 13

1. Stimulus depolarizes nociceptive neuron
2. Release of peptides at motor neuron level + in peripheral tissue
3. Peptides cause inflammatory cascade with prostaglandins, bradykinins, histamine, etc.
4. Lowering of nociceptive threshold + spinal interneuron transmission
5. Larger than normal motor and autonomic output -> circular pattern

Question 14

Facilitation

Answer 14

Maintenance of a pool of neurons in a state of subthreshold excitation; less afferent stimulation required to trigger discharge of impulses

Question 15

Four possible causes for facilitation

Answer 15

1. Sustained increase in afferent input
2. Aberrant pattern of afferent input
3. Changes within participating neurons themselves
4. Chemical environment

Question 16

Allostasis

Answer 16

The response to stress in an attempt to regain homeostasis

Question 17

Effects observed with allostasis overload

Answer 17

1. HTN, risk of MI
2. depression, anxiety
3. memory loss, decreased cognition
4. Immunosuppression, autoimmune diseases

Question 18

What % sensory is the vagus nerve?

Answer 18

80-90%

Question 19

All visceral nerves contain what?

Answer 19

Sensory fibers

Question 20

Where are cell bodies of sensory fibers?

Answer 20

Dorsal root ganglia or vagal ganglia

Question 21

Which viscerosomatic reflex area does not have parasympathetics?

Answer 21

Upper and lower extremities