Chapter 28: Chemical Messengers: Hormones, Neurotransmitters, and Drugs

________ plays a role in the brain in processes that control movement, emotional responses, and the experiences of pleasure and pain.

________ is a chemical messenger that travels between a neuron and a neighbouring neuron or other target cell to transmit a nerve impulse.

________ (guanosine diphosphate) associated with the G protein is exchanged for GTP (guanosine triphosphate) from the cytosol.

________ is representative of the tricyclic antidepressants, which were the first generation of these drugs.

________ is absorbed back into the presynaptic neuron, where new acetylcholine is synthesized.

________ represents the newest class of antidepressants, the selective serotonin re- uptake inhibitors (SSRI)

________ classify some drugs as agonists- substances that act to produce or prolong the normal biochemical response of a receptor.

________ catalyses production within the cell of the second messenger- cyclic AMP- from adenosine triphosphate (ATP)

________ crosses the synapse and binds to receptors on the postsynaptic neuron, causing a change in membrane permeability to ions.

Epinephrine, a hormone carried in the ________, binds to a receptor on the surface of a cell.

The polypeptide and amine hormones are ________ and can not cross the hydrophobic cell membranes.

________ is a molecule or portion of a molecule with which a hormone, neurotransmitter, or other biochemically active molecule interacts to initiate a response in a target cell.

________ is a monoamine oxidase (MAO) inhibitor, one of a group of medications that inhibit the enzyme that breaks down monoamine neurotransmitters.

________ initiates reactions that activate glycogen phosphorylase, the enzyme responsible for release of glucose from storage.

Because the cell is surrounded by a membrane composed of ________, only nonpolar, ________ can move across it on their own.

________ move to the cell membrane, fuse with it, and release their acetylcholine molecules (several thousand molecules from each ________)

It is also widely distributed in the brain, where it plays a role in the ________ cycle, learning, memory, and mood.

________ are the chemical messengers of the endocrine system.

A drug is any molecule that alters normal functions when it enters the body from a(n) ________.

Other drugs are classified as ________ that block or inhibit the normal response of a receptor.

A(n) ________ is associated with schizophrenia, and an undersupply results in the loss of fine motor control in Parkinsons disease.

The ________ are nonpolar, so they can enter the cell directly by diffusion; this is one of the ways a hormone delivers its message.

The signal enters the cell in ways determined by the ________ of the hormone.

________ is important in mood- control pathways and functions more slowly than other neurotransmitters; slowing its re- uptake often improves mood in depressed patients.

________ is a system of specialized cells, tissues, and ductless glands that secretes hormones and shares with the nervous system the responsibility for maintaining constant internal body conditions and responding to changes in the environment.

In general, three membrane- bound proteins participate in release of the second messenger: (1) the receptor and (2) a(n) ________ (a member of the guanine nucleotide- binding protein family) that transfer the message to (3) an enzyme.

The tricyclics prevent the ________ and norepinephrine from within the synapse.

________ are synthesized in presynaptic neurons and stored there in vesicles for release when needed.

________ is a neurotransmitter responsible for the control of skeletal muscles.

________ (Prozac) has rapidly become the most widely prescribed drug for all but the most severe forms of depression.

________ is synthesized in presynaptic neurons and stored in their vesicles.

(1) the receptor and (2) a G protein (a member of the guanine nucleotide-binding protein family) that transfer the message to (3) an enzyme

cyclic AMP-from adenosine triphosphate (ATP)

amitriptyline, phenelzine, and fluoxetine

a molecule or portion of a molecule with which a hormone, neurotransmitter, or other biochemically active molecule interacts to initiate a response in a target cell.