Ch4 Mechanisms of Anesthesia

Question 2

What is the definition of anesthesia?

Answer 2

A state where the patient cannot remember and does not move.

Question 3

True or False: Consciousness is a relevant factor in defining anesthesia.

Answer 3

False

Question 4

What role do opioids play in anesthesia?

Answer 4

They are used to prevent pain, as inhaled anesthetics are not effective analgesic agents.

Question 5

What is the importance of muscle relaxation in anesthesia?

Answer 5

It allows surgeons to perform operations without patient movement.

Question 6

What is the Meyer-Overton hypothesis?

Answer 6

It states that anesthetic potency is directly related to its lipophilicity.

Question 7

What constant is associated with the Meyer-Overton hypothesis?

Answer 7

Approximately 1.8 atmospheres.

Question 8

What does the five-carbon hypothesis suggest about anesthetics?

Answer 8

Anesthetics act on two sites within the molecule, separated by about five angstroms.

Question 9

Which receptors are emphasized as relevant to immobility in anesthesia?

Answer 9

Glycine and NMDA receptors.

Question 10

What is a non-immobilizer?

Answer 10

A compound that does not create immobility even when combined with anesthetics.

Question 11

What is the relationship between amnesia and immobility in anesthesia?

Answer 11

Achieving immobility also results in amnesia.

Question 12

Fill in the blank: Anesthesia is a reversible state mediated by the _______.

Answer 12

[central nervous system]

Question 13

What historical figure is noted for contributions to ether anesthesia?

Answer 13

John Snow.

Question 14

What is the significance of the oil/gas partition coefficient in anesthesia?

Answer 14

It correlates with anesthetic potency (MAC).

Question 15

True or False: All inhaled anesthetics produce amnesia.

Answer 15

True

Question 16

What is indicated by an increase in heart rate or blood pressure during surgery under anesthesia?

Answer 16

The patient may be experiencing pain.

Question 17

What is a characteristic of transitional compounds in relation to anesthetics?

Answer 17

They are less potent than their lipophilicity predicts.

Question 18

How do anesthetics affect neuronal transmission mechanisms?

Answer 18

They disrupt normal neuronal transmission mechanisms.

Question 19

What is the implication of the affinity to water in anesthetic potency?

Answer 19

It distinguishes anesthetics from non-immobilizers.

Question 20

Fill in the blank: The constant of the Meyer-Overton hypothesis does not change with _______.

Answer 20

[affinity to water]

Question 21

What is the proposed action site of anesthetics in the body?

Answer 21

The spinal cord.

Question 22

What is the significance of the Toyota test in assessing amnesia?

Answer 22

It measures the animal’s response to a tone associated with a shock.

Question 23

What do inhaled anesthetics provide in terms of muscle relaxation?

Answer 23

They provide some muscle relaxation but may not be sufficient for all procedures.

Question 24

What does the term ‘lipophilicity’ refer to in the context of anesthetics?

Answer 24

The affinity of a substance for lipids or fats.

Question 25

What is the relationship between affinity to water and the myrobertin constant?

Answer 25

The greater the affinity to water, the lower the myrobertin constant ## Footnote Myrobertin constant is a measure of the potency of anesthetics, with lower values indicating higher potency.

Question 26

Where do anesthetics actually work according to the broader definition?

Answer 26

Inside the cell itself ## Footnote Anesthetics may work at interfaces, such as between hydrophilic and hydrophobic regions, or within proteins.

Question 27

What components must anesthetics have to be effective?

Answer 27

Both polar and non-polar components ## Footnote This allows anesthetics to interact at interfaces within biological membranes.

Question 28

What are some potential targets for anesthetics?

Answer 28

* Aqueous pockets within proteins * Ion channels * Lipid bilayer * Aqueous interface * Protein-aqueous interface * Excitatory and inhibitory ionophores ## Footnote These targets can influence the anesthetic effects by modulating neuronal activity.

Question 29

True or False: Plausible targets for anesthesia are always relevant.

Answer 29

False ## Footnote Plausibility does not guarantee relevance; not all targets that anesthetics influence contribute to the anesthetic effect.

Question 30

Which receptors may have relevance to anesthesia?

Answer 30

* Glycine receptor * Glutamate receptors (particularly NMDA receptors) ## Footnote Other receptors, such as acetylcholine receptors, show effects but are not relevant to anesthetic requirements.

Question 31

What is the five carbon hypothesis?

Answer 31

The hypothesis suggests that effective anesthetics have two anesthetizing components separated by about five carbons ## Footnote This relationship between carbon chain length and anesthetic potency has been observed in various experiments.

Question 32

What happens to anesthetic potency when the carbon chain exceeds five carbons?

Answer 32

Potency is lost ## Footnote This pattern has been observed in both alkanes and alcohols, indicating that there is an optimal chain length for anesthetic efficacy.

Question 33

Where do inhaled anesthetics primarily act to produce immobility?

Answer 33

On the spinal cord ## Footnote This site of action is distinct from the brain, which is associated with amnesia.

Question 34

What is the Toyota test used to measure?

Answer 34

The association of light with shock in animals, indicating memory retention ## Footnote This test assesses the ability of animals to remember and respond to stimuli, providing insights into amnesia effects of anesthetics.

Question 35

How do non-immobilizers affect amnesia according to the Toyota test?

Answer 35

They suppress the jumping response in a manner similar to immobilizers ## Footnote This suggests that amnesia may occur at similar sites of action as immobilization, despite the drugs not causing immobility.

Question 36

What is the relationship between amnesia and immobility in anesthesia?

Answer 36

Amnesia is achieved when immobility is achieved ## Footnote Clinically, achieving the anesthetic state that includes immobility also results in amnesia.