Background: When you go to the dentist to get a tooth pulled, you really don’t want to feel any pain. The dentist injects an anesthetic into your gum and it eventually becomes numb. One theory as to why anesthetics work deals with the movement of ions across the cell membrane. The anesthetic gets into the membrane structure and causes shifts in how ions move across the membrane. If ion movement is disrupted, nerve impulses will not be transmitted and you will not sense pain – at least not until the anesthetic wears off.

Situation: Two men, Sam and Frodo, go into the doctor's office to have the exact same procedure done to one of their arms. They won't need to be knocked out for this, but they will be given anesthetic to help with the pain. After the nurse administers the anesthetic to both men, the ions in Sam's arm continue moving across the membrane, but the ions in Frodo's arm stop moving. The doctor then comes in to begin the procedure.

Question: Who will experience pain when the doctor starts the procedure?
Answer: Sam

Situation: Two men, Sam and Frodo, go into the doctor's office to have the exact same procedure done to one of their arms. They won't need to be knocked out for this, but they will be given anesthetic to help with the pain. After the nurse administers the anesthetic to both men, the ions in Sam's arm continue moving across the membrane, but the ions in Frodo's arm stop moving. The doctor then comes in to begin the procedure.

Question: Who will not experience pain when the doctor starts the procedure?
Answer: Frodo

Situation: Two men, Sam and Frodo, go into the doctor's office to have the exact same procedure done to one of their arms. They won't need to be knocked out for this, but they will be given anesthetic to help with the pain. After the nurse administers the anesthetic to both men, the ions in Sam's arm continue moving across the membrane, but the ions in Frodo's arm stop moving. The doctor then comes in to begin the procedure.

Question: Which man's nerve impulses are being transmitted?
Answer: Sam

Situation: Two men, Sam and Frodo, go into the doctor's office to have the exact same procedure done to one of their arms. They won't need to be knocked out for this, but they will be given anesthetic to help with the pain. After the nurse administers the anesthetic to both men, the ions in Sam's arm continue moving across the membrane, but the ions in Frodo's arm stop moving. The doctor then comes in to begin the procedure.

Question: Which man's nerve impulses are not being transmitted?
Answer: Frodo

Situation: Two men in the Vietnam War needed to have their arms amputated. Unfortunately, the men were not able to be knocked unconscious for the operation. The doctor asked each patient if they wanted anesthetic injected into their arm or not. Marco replied that he wanted some, and Luke declined any anesthetic.

Question: Which person's arm will be numb?
Answer: Marco

Situation: Two men in the Vietnam War needed to have their arms amputated. Unfortunately, the men were not able to be knocked unconscious for the operation. The doctor asked each patient if they wanted anesthetic injected into their arm or not. Marco replied that he wanted some, and Luke declined any anesthetic.

Question: Which person's arm will not be numb?
Answer: Luke

Situation: Two men in the Vietnam War needed to have their arms amputated. Unfortunately, the men were not able to be knocked unconscious for the operation. The doctor asked each patient if they wanted anesthetic injected into their arm or not. Marco replied that he wanted some, and Luke declined any anesthetic.

Question: Which person's ions will not be able to move across the cell membrane?
Answer: Marco

Situation: Two men in the Vietnam War needed to have their arms amputated. Unfortunately, the men were not able to be knocked unconscious for the operation. The doctor asked each patient if they wanted anesthetic injected into their arm or not. Marco replied that he wanted some, and Luke declined any anesthetic.

Question: Which person's ions will be able to move across the cell membrane?
Answer: Luke

Situation: Two men in the Vietnam War needed to have their arms amputated. Unfortunately, the men were not able to be knocked unconscious for the operation. The doctor asked each patient if they wanted anesthetic injected into their arm or not. Marco replied that he wanted some, and Luke declined any anesthetic.

Question: Whose nerve impulses will not be transmitted?
Answer: Marco

Situation: Two men in the Vietnam War needed to have their arms amputated. Unfortunately, the men were not able to be knocked unconscious for the operation. The doctor asked each patient if they wanted anesthetic injected into their arm or not. Marco replied that he wanted some, and Luke declined any anesthetic.

Question: Whose nerve impulses will be transmitted?
Answer: Luke

Situation: In a doctor's office, two siblings both are having a small operation performed on their fingers in order to correct an identical injury. The movement of Joe's ions has been disrupted completely, but Emily's ions are still able to move normally.

Question: Which person was given anesthetic?
Answer: Joe

Situation: In a doctor's office, two siblings both are having a small operation performed on their fingers in order to correct an identical injury. The movement of Joe's ions has been disrupted completely, but Emily's ions are still able to move normally.

Question: Which person was not given anesthetic?
Answer: Emily

Situation: In a doctor's office, two siblings both are having a small operation performed on their fingers in order to correct an identical injury. The movement of Joe's ions has been disrupted completely, but Emily's ions are still able to move normally.

Question: Who will be more comfortable during the operation?
Answer: Joe

Situation: In a doctor's office, two siblings both are having a small operation performed on their fingers in order to correct an identical injury. The movement of Joe's ions has been disrupted completely, but Emily's ions are still able to move normally.

Question: Who will be more uncomfortable during the operation?
Answer: Emily