Nurs 116 Quiz 2 Flashcards
what is pharmacodynamics?
branch of pharmacology that is concerned with how drugs produce change and differences in patient responses to medications
what is the frequency of distribution curve?
graphical representation of the number of individuals who respond to a drug at different doses
What’s the median effective dose?
the dose of the middle of the frequency distribution curve
What does higher therapeutic index mean?
safer drug
What’s the calculation for therapeutic index?
TD50/ED50
What is the median lethal dose (LD50)?
dose of drug that will be lethal in 50% of the population
what is the margin of safety?
amount of drug that will be lethal to 1% (LD1) of the population divided by the dose that produces therapeutic effect in 99% of animals (ED99)
what is the graded dose response relationship?
describes how the therapeutic response to a drug changes as the medication dose is increased
what are the 3 phases of dose-response curve?
- Phase 1 - at lowest
- phase 2 - straight line portion of the curve - shows degree of response
- phase 3 - plateue - increasing dose doesn’t change anything -
why is there no effect in phase 3 of the dose-response curve?
- receptors occupied
- no additional relief needed
what is potency?
dose of medication required to produce a particular response
what is efficacy?
the magnitude of maximum response to a drug
what do analgesics do?
relieve severe pain
how do drugs that are more potent work?
produces a therapeutic effect at a lower dose compared to another drug in the same class
why is efficacy more important than potency?
average dose is unimportant to the client but headache relief is essential
how is mechanism of action explained?
drugs don’t create new actions in the body - rather, they enhance or inhibit existing physiological & biochemical processes
what is cell signalling?
it is a process part a complex system of communication that enables cells to perceive & correctly respond to their environemet
what are receptor ligands?
molecules that activate or inhibit receptors
what are examples of ligands?
hormones, nuerotransmitters, cytokines, or growth factors
how does information that cells recieve get processed?
through signalling pathways
what is the receptor theory?
explains the mechanism by which most drugs produce their effects
how do agonist affect cells?
they stimulate cells
how do antagonist affect cells?
inhibit receptors
what are the 2 types of beta receptors & where are they found?
B1- heart
B2 - lungs
what are receptors made of?
3-dimensional protein + a cellular plasma membrane
what does the extracellular structural component of a receptor consist of?
several protein subunits arranged around a central canal/channel + transmembrane segements
what is the structure of a voltage gated channel?
single strand with 4 domains, each with 6 transmembrane segments
ion pore
what is the structure of the chemical-gated channels?
5 strands joined in a pentamer, each with 4 transmembrane segments
Ion pore + binding site
what is the structure of g-protein-linked channel?
one strand with 7 transmembrane segments
ion pore (g-protein-linked channel)
binding site
what happens when drugs bind to receptor?
a serioes of second messenger events will occur - these biochemical cascades initiate the drug’s action by either stimulating or inhibiting normal drug activity of cell
what are non-specific cellular responses?
- these are responses exhibated by drugs that act independently of cellular receptors
what are examples of agents that have non-specific mechanisms?
- ethyl alcohol
- general anesthetics
- osmotic diuretics
what are the main types of drug-receptor interactions?
- agonists
- partial agonists
- antagonists
what are the drugs that compete for receptor binding?
- agonists, partial agonists, antagonists
what are agonists?
drugs that produce the same type of response as the endogenous substance - mimics
what is an example of agonist drug interaction?
- bethanechol binds to acetylcholine receptors in the ANS and produces same actions as acetylcholine
what are partial agonists?
drugs that produce weaker, or less efficacious response than an agonist
what is antagonist drugs?
drugs that occupy a receptor and prevent the endogenous chemical from acting
what are examples of antagonist drugs?
- protamine sulfate = anti-dote to heparin (anti-coagulant)
- naloxone (narcan) = antagonist to opiods
what are functional antagonists?
inhibit the effects of anantagonist not by competing for a receptor but by changing the pharmacokinetic factors.
what is pharmacogenetics?
area of pharmacology that examines the role of genetic variation in drug response
what is the lymphatic system?
primary organ system that protects the body from invasion
what is the lymphatic system made up of?
network of cells, vessels and tissues that provide immune surveilance
what is lymph?
the fluid that leaves capillaries due to osmotic forces and high pressure in the capillaries which then enters the blind-ended lymphatic vessels and begins its journey in the lymphatic system
what is the function of lymph nodes?
these are the main lymphoid organs in the body in which the lymph must pass through to catch any pathogens.
what is the structure of lymph nodes?
solid, spherical bodies that are packed with macrophages and lymphocytes to recognize anything that is “non-self”
what are lymphoid tissues?
they line the connective tissues and contain lymphocytes at the portal of entrance of the body - GI tract
what are the lymph organs?
larger collection lymph tissues - tonsils, spleen and thymus
what is innate body defences?
body’s first line of defence against pathogens
presnt before an infection has occured
aka non-specific as they can’t differentiate pathogens and respond same
what are the 3 types of non-specific body barriers?
- physical barriers
- Cellular barriers
- Process barriers
what’s included in physical bariers?
- skin - forms mechanical barrier
- mucuous membranes - lines portals of entry
what’s included in cellular barriers?
- Phagocytes - ingest antigens
- Natural killer cells - directly attack virus-infected and cancer cells
- interferons - proteins secreted by cells infected by viruses - stimulate the activity of phagocytes & NK cells
what’s included in process barriers?
- complement - promotes inflammation & phagocytosis
- fever - systemic response that increases body temperature
- Inflammation - releases substances that attract phagocytes
