BioPsych MidTerm Study

What does “endogenous” mean?

Originating from within the body.

What does “exogenous” mean?

Originating from outside the body.

What is a drug?

Any exogenous substance that exerts a pharmacological effect at a site of action within the body.

What is the site of action?

The location in the body where a drug interacts, such as receptors, enzymes, or transporters.

What is the mechanism of action?

How a drug produces its effects in the body, such as receptor agonism or enzyme inhibition.

What is pharmacokinetics?

The study of drug absorption, distribution, metabolism, and excretion (ADME).

What is pharmacodynamics?

The study of how drugs interact with body systems to exert their effects.

What is a general (systemic) dose?

A dose that circulates throughout the entire body.

What is a local dose?

A dose applied to a specific area for a localized effect.

What is a chemical name of a drug?

The name describing its molecular structure, used to predict reactions.

What is a generic name?

The nonproprietary name of a drug, commonly used in medicine and research.

What is a proprietary or brand name?

The patented trade name under which a drug is sold.

What are street names for drugs?

Informal or slang terms often used to disguise drug use.

What is the first rule of pharmacology?

The dose is critical; toxicity and efficacy depend on it.

What does ED50 mean?

The dose at which 50% of individuals show the desired effect.

What does LD50 mean?

The dose at which 50% of individuals die from the drug.

What is the therapeutic index (TI)?

The ratio LD50/ED50; higher TI means a safer drug.

What is potency?

How much of a drug is needed to produce an effect (leftward shift = more potent).

What is effectiveness?

The maximum effect a drug can produce (upward shift = more effective).

What are side effects?

Any unintended effects of a drug, which can be harmful or beneficial.

What is the second rule of pharmacology?

The route of administration greatly affects a drug’s potency, effectiveness, and duration.

What is a drug vehicle?

The substance used to deliver a drug (e.g., capsule, solution).

What does parenteral mean?

Administration outside the gastrointestinal tract.

What is a subcutaneous (s.c.) injection?

Injection under the skin; slow absorption.

What is an intramuscular (i.m.) injection?

Injection into a muscle; moderate absorption.

What is an intraperitoneal (i.p.) injection?

Injection into the abdominal cavity; rapid absorption (used in lab animals).

What is an intravenous (i.v.) injection?

Injection into a vein; fastest absorption.

What is an intrathecal (i.t.) injection?

Injection into cerebrospinal fluid; bypasses blood-brain barrier.

What is intracerebroventricular (i.c.v.) injection?

Injection directly into brain ventricles; extremely fast CNS effects.

What are arteries?

Vessels carrying blood away from the heart.

What are veins?

Vessels carrying blood toward the heart.

What are capillaries?

Tiny blood vessels allowing exchange of gases and drugs.

Why are lungs efficient for drug absorption?

They have high surface area, rich blood supply, and direct access to the brain.

What is intranasal administration?

Drug absorption through nasal mucosa; rapid effects due to weak BBB in sinuses.

What is oral administration (p.o.)?

Taking drugs by mouth; absorption depends on solubility and resistance to stomach acid.

What is transdermal administration?

Absorption through the skin; slow and steady delivery for lipid-soluble drugs.

What kind of drugs can cross the blood-brain barrier (BBB)?

Lipid-soluble drugs.

What is metabolism?

Enzymatic breakdown of drugs into metabolites, usually in the liver.

What is first-pass metabolism?

Metabolism by the liver or stomach before a drug reaches the brain.

What factors affect metabolism?

Age, genetics, weight, species, enzyme presence, and experience with drugs.

What is half-life?

Time required for 50% of a drug to be removed from the blood.

What is tolerance?

Decreased response to a drug after repeated use.

What is sensitization?

Increased response to a drug after repeated use.

What is withdrawal?

Opposite symptoms that occur when a drug is discontinued.

What is a receptor?

A protein that binds a chemical (ligand) to produce a cellular effect.

What is an agonist?

A drug that binds to and activates a receptor.

What is an antagonist?

A drug that binds to and blocks a receptor.

What is a partial agonist?

A drug that produces a weaker effect than a full agonist.

What is a competitive antagonist?

A drug that competes with a natural ligand for the same binding site.

What is a noncompetitive (indirect) antagonist?

A drug that binds elsewhere on the receptor to reduce its activity.

What is binding affinity?

The strength of the bond between a drug and its receptor.

What are the main excitatory and inhibitory neurotransmitters?

Glutamate (excitatory) and GABA (inhibitory).

What does glutamate do?

Facilitates learning and synaptic plasticity through NMDA and AMPA receptors.

What drugs block NMDA receptors?

PCP and ketamine.

What does GABA do?

Inhibits neurons by opening Cl⁻ channels and causing hyperpolarization.

What drugs act on GABA receptors?

Alcohol, benzodiazepines, and Xanax (GABA agonists).

What is acetylcholine (ACh) responsible for?

Muscle contraction and attention.

What enzyme breaks down ACh?

Acetylcholinesterase (AChE).

What are muscarinic receptors?

Metabotropic ACh receptors found in smooth muscle and brain.

What are nicotinic receptors?

Ionotropic ACh receptors found in muscles and the brain (VTA).

What does botulinum toxin do?

Prevents ACh release, causing paralysis.

What does black widow spider venom do?

Triggers excess ACh release, causing muscle spasms.

What does curare do?

Blocks nicotinic receptors, causing paralysis.

What does atropine do?

Blocks muscarinic receptors, relaxing muscles.

What does neostigmine do?

Inhibits AChE, used to treat myasthenia gravis.

What neurotransmitters are catecholamines?

Dopamine, norepinephrine, and epinephrine.

What are the four main dopamine pathways?

Nigrostriatal (movement), mesolimbic (reward), mesocortical (attention), and tuberoinfundibular (hormonal).

What is the main dopamine reward pathway?

The mesolimbic pathway (VTA → nucleus accumbens).

What do drugs like cocaine and amphetamine do?

Block dopamine reuptake or increase release.

What do D1 receptors do?

Stimulate dopamine signaling (excitatory).

What do D2 receptors do?

Inhibit dopamine signaling (autoreceptors).

What does norepinephrine (NE) do?

Increases arousal, alertness, and attention.

What is a drug example that affects NE?

Beta-blockers (reduce NE effects); amphetamine increases NE release.

What does serotonin (5-HT) regulate?

Mood, sleep, and perception.

What drugs act on serotonin?

LSD, psilocybin, MDMA (agonists or reuptake inhibitors).

What is adenosine involved in?

Sleep and relaxation; caffeine blocks adenosine receptors.

What are endocannabinoids?

Natural cannabinoids (anandamide, 2-AG) acting on CB1 and CB2 receptors.

What drug mimics endocannabinoids?

THC (CB1 agonist).

What are endogenous opioids?

Natural painkillers like endorphins acting on μ, δ, and κ receptors.

What do opiate drugs do?

Agonize μ-opioid receptors for pain relief (e.g., morphine, heroin).

What is naloxone (Narcan)?

An opioid receptor antagonist that reverses overdoses.

What is the function of the soma in a neuron?

Contains the nucleus and machinery for cell function.

What are dendrites?

Branches that receive signals from other neurons.

What is an axon?

A structure that conducts impulses away from the soma.

What is myelin’s function?

Insulates axons to speed up action potentials.

What are the cells that make myelin?

Oligodendrocytes (CNS) and Schwann cells (PNS).

What is the blood-brain barrier (BBB)?

A selective barrier that protects the brain from toxins.

What are glial cells?

Supportive cells in the nervous system.

What are astrocytes?

Glial cells that supply nutrients and remove waste.

What are microglia?

Immune cells of the brain that clean up debris.

What are oligodendrocytes?

CNS cells that form myelin sheaths.

What are Schwann cells?

PNS cells that form myelin and assist in repair.

What is an action potential?

An electrical impulse that travels down the axon.

What is the resting potential of a neuron?

Approximately –70 mV.

What is depolarization?

The inside of the neuron becomes more positive.

What is hyperpolarization?

The inside of the neuron becomes more negative.

What ions are involved in the action potential?

Na⁺ influx and K⁺ efflux.

What is the all-or-none law?

A neuron fires completely or not at all.

What is saltatory conduction?

Action potentials jumping between nodes of Ranvier.

What is synaptic transmission?

Communication between neurons at synapses.