Drugs Acting on the Central and Peripheral Nervous System

Question 1

Afferent Fibers

Answer 1

-nerve axons that run from peripheral receptors INTO the CNS.

Question 2

Efferent Fibers

Answer 2

-nerve axons that carry nerve impulses FROM the CNS to the periphery to stimulate muscles or glands.

Question 3

Action Potentials

Answer 3

-sudden change in electrical charge of a nerve cell membrane; the electrical signal by which neurons send information.

Question 4

Depolarization

Answer 4

-opening of the Na+ channels in a nerve membrane to allow the influx of positive Na+ ions, reversing the membrane charge from negative to positive.

Question 5

Repolarization

Answer 5

-return of a membrane to a resting state, with more Na+ ions outside the membrane and a relatively negative charge inside the membrane.

Question 6

Nerve Synapse

Answer 6

-junction between a nerve and an effector; consists of the presynaptic nerve ending, a space called the synaptic cleft, and the postsynaptic cell.

Question 7

Neurotransmitter

definition

Answer 7

-chemical produced by a nerve and released when the nerve is stimulated; reacts with a specific receptor site to cause a reaction.

Question 8

Neurotrasnmitter

types

Answer 8

1. Acetylcholine: communicates between nerves and muscles.
2. Catecholamines (Norepinephrine and epinephrine): released by nerves in the sympathetic brance of the autonomic nervous system and are classived as hormones when released from cells in adrenal medulla.
3. Dopamine: found in high concentrations in certain areas of the brain, is involved in the coordination of impulses and responses, both motor and intellectual.
4. Gamma-aminobutyric acid (GABA): found in the brain, inhibits nerve activity and is important in preventing overexcitability or stimulation such as seizure activity.
5. Serotonin: found in limbic system, important in arousal and sleep, as well as preventing depression and promoting motivation.

Question 9

Hindbrain

Answer 9

-most primitive area of the brain, the brainstem; consists of the pons and medulla, which control basic, vital functions and arousal, and the cerebellum, which controls motor functions that regulate balance.

Question 10

Midbrain

Answer 10

-the middle area of the brain; it consists of the hypothalamus and thalamus and includes the limbic system.

Question 11

Limbic System

Answer 11

-area in the midbrain that is rich in epinephrine, norepineprhine, and serotonin and seems to control emotions.

Question 12

Forebrain

Answer 12

-upper level of the brain; consists of the 2 cerebral hemispheres, where thinking and coordination of sensory and motor activity occur.

Question 13

Drugs Acting on the Central and Peripheral Nervous Systems

Answer 13

1. Anxiolytic and Hypnotic Agents
2. Antidepressant Agents
3. Psychotherapeutic Agents
4. Antiseizure Agents
5. Antiparkinsonism Agents
6. Muscle Relaxants
7. Narcotics, Narcotic Antagonists, and Antimigraine Agents
8. General and Local Anesthetic Agents
9. Neuromuscular Junction Blocking Agents

Question 14

Antiseizure Agents

Answer 14

1. Drugs for Treating Generalized Seizures
   a. Hydantoins
   b. Barbiturates and Barbiturate-Like Drugs
   c. Benzodiazepines
   d. Succinimides
   e. Drugs that Modulate the Inhibitory Neurotransmitter
   GABA
2. Drugs for Treating Partial Seizures

Question 15

Seizure

Answer 15

-sudden discharge of excessive electrical energy from nerve cells in the brain

Question 16

Convulsion

Answer 16

-tonic-clonic muscular reaction to excessive electrical energy arising from nerve cells in the brain.

Question 17

Epilepsy

Answer 17

-collection of various syndromes, all of which are characterized by seizures.

Question 18

Generalized Seizure

Answer 18

• seizure that begins in one area of the brain and rapidly spreads throughout both hemispheres.
• 5 types: tonic-clonic, absence, myoclonic, febrile, jacksonian, psychomotor, status epilepticus.

Question 19

Partial Seizure

Answer 19

• also called focal seizures; seizures involving one area of the brain that do not spread throughout the entire organ.
• may be simple or complex.