lecture 3 LOs

Question 1

what do competitve antagonsits do to the potency, and how does the dose/response curve chage

Answer 1

reduces potency, shifts the curve

Question 2

what do non competitve antagonists do to the dose/response curve

Answer 2

change the shape of the curve
often prevent agonist from acieing maximal effect, irrespective of how much agonsit is available

Question 3

physiological antagonism def

Answer 3

two drugs interact to reduce the effectiveness of both

Question 4

additive effects def

Answer 4

both drugs work together to create an effect which is equal to the sum of the two drugs

Question 5

potentiation def

Answer 5

combination of two drugs produces effects greater than the sum of the individual effects

Question 6

drug tolerance def

Answer 6

diminished response to a drug after repeated exposure

Question 7

cross tolerance def

Answer 7

tolerance to one drug can diminish effectiveness of another drug (usually one that works on a similar mechanism)

Question 8

characteristics of drug tolerance

Answer 8

revisable when drug use stops
dependent on dose/frequency of drug use and drug taking environment
may occur rapidly (acute tolerance), after long periods of chronic use, or never
several different mechanisms explain multiple forms of tolerance

Question 9

metabolic (drug-dispositional) tolerance def

Answer 9

repeated drug use reduces the amount of drug available at the target tissue (body/liver becomes more efficient at metabolizing drug, less drug gets to sites of action)

Question 10

functional (pharmacodynamic) tolerance def

Answer 10

changes in cell function compensates for repeated drug exposure. typically occurs at site in brain/body where drug exerts its effects (like receptor sensitivity to the ligand decreases)

Question 11

behavioural tolerance def

Answer 11

pavlovian conditioning can impact tolerance
brain makes associations between the drug effects and the context where they occurred

Question 12

conditioned tolerance def

Answer 12

tolerance is maximal when drug is given in environments similar to those where drug effects previously experienced

Question 13

conditioned tolerance study (rats)

Answer 13

give rats 20 shots of alcohol in one environment (over 20 days). on test day one group gets alc in same context and other gets alc in different context. rats who received in same context displayed tolerance and in different context there was no tolerance

Question 14

three main parts of neuron

Answer 14

soma (cell body): nucleus and all other organelles. all proteins are made here and transported to more distant targets
dendrites: extensions that receive info (inputs). composed of shafts (main branches) and spines (smaller bumps where most synaptic connections reside)
axon: extension that conducts electrical signals from the cell body to the terminal boutons (outputs). one neuron may have multiple projection sites via axon collaterals

Question 15

glial cell def

Answer 15

not exitable cell, but play key role that influences neural activity and transmissions (structural support, ion concentration around cells, reuptake of certain NTs)

Question 16

projection (principle) neuron def

Answer 16

main integrating/processing neurons of a brain region. axons project out of region in which its soma resides and/or to local neurons within the same region

Question 17

interneurons def

Answer 17

cell whose axon remain within a particular brain region that can connect to projection neurons and other interneurons
smaller than projection neurons
usually inhibitory, often use GABA or ACh as transmitter
excitatory neurons often can connect to both inhibitory interneurons and other excitatory cells via collaterals

Question 18

receptor def

Answer 18

initial site of action of neurotransmitters (or drugs)

Question 19

enzymes def

Answer 19

metabolize NTs and other functions

Question 20

ion channels allow

Answer 20

charged molecules and amino acids, glucose, etc

Question 21

which can only move through ion channels

Answer 21

Na+, K+, Cl-, Ca2+

Question 22

gated channels:

Answer 22

normally closed, open in response to specific stimuli. tend to stay open for a brief period before closing

Question 23

what does opening a channel excite or inhibit

Answer 23

excite: Na+, Ca2+
inhibit: K+, Cl-

Question 24

when does voltage gated open

Answer 24

when electrical potential across membrane is altered
may open when cell depolarizes, some open when cell is hyperpolarized

Question 25

when does ligand gated open

Answer 25

when ligand binds to receptor
2nd messenger is special case of ligand gated channel. activated by attachment of phosphate group on intracellular side of receptor

Question 26

resting membrane potential

Answer 26

is negative, driven primarily by high conc of positive ions (Na+, Ca2+, K+) outside the cell, and higher conc of negative ions inside the cell

Question 27

Action potential def and steps

Answer 27

occurs when neurons depolarize to a threshold
depolarization causes voltage gated Na+ channels to open, causes Na+ to enter cell
AP causes voltage gated K+ channels to open, K+ exits cell and hyperpolarizes it causing Na+ and K+ channels to close

Question 28

local potentials

Answer 28

often induced via depolarization or hyperpolarization

Question 29

excitatory or ihibitory post synaptic potentials

Answer 29

caused by local potentials

Question 30

local potentials grading

Answer 30

larger stimulus = greater magnitude of hyperpolarization or depolarization

Question 31

action potential grading

Answer 31

all or nothing

Question 32

peripheral nervous system components

Answer 32

somatic: controls voluntary muscles, delivers sensory input to the brain
autonomic system (ANS): regulates internal environment by innervating smooth muscles (intestines and bladder), cardiac muscles and glands (adrenal, salivary). also controls digestion, BP, body temp, and other functions

Question 33

autonomic nervous system divisions

Answer 33

sympathetic: fight or flight. dominates in times of stress, excitement, exertion. increases heart rate, BP, blood flow to skeletal muscles, adrenal secretion
parasympathetic: dominates when energy reserves can be conserved. increases digestion, storage of glucose and other nutrients, slows heart rate and decreases respiration.

Question 34

what do ANS neurons use as transmitters

Answer 34

norepinephrine and acetylcholine

Question 35

spinal cord sends which transmitter to where

Answer 35

Ach to sympathetic ganglia and adrenal glands
typically excitatory, acts on nicotinic receptors

Question 36

sympathetic ganglia send what transmitter where

Answer 36

norepinephrine to organs

Question 37

where else is NE secreted

Answer 37

blood stream. can be excitatory or inhibitory depending on the receptor subtype

Question 38

when drugs increase/decrease NE activity what do they tend to cause

Answer 38

increase or decrease in sympathetic activation

Question 39

when drugs increase Ach or stimulate nicotonic receptors, what do they cause

Answer 39

sympathetic functioning

Question 40

parasympathetic uses which transmitter exclusively

Answer 40

ACh

Question 41

spinal cord projects to where

Answer 41

para-sympathetic ganglia

Question 42

muscarinic antagonists do what

Answer 42

reduce parasympathetic function

Question 43

muscarinic agonists do what

Answer 43

increase the parasympathetic function