Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FRCA Notes > Definitions > Flashcards

Definitions Flashcards

1
Q

What is one second?

A

The base SI unit of time

Defined as the duration of 9.2x109 oscillations of the caesium-133 atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a metre?

A

The base SI unit of distance

Defined as the length of the path travelled by light in a vacuum during a given fraction of a second (1/3 x108)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a mole?

A

The base SI unit of the amount of a substance

Defined as the amount of a substance that contains as many elementary particles as there are atoms in 0.012kg of carbon-12.

This corresponds to Avogadro’s number - 6.02 x 1023

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is an ampere?

A

The base SI unit of current

Defined as the current which, if maintained in 2 parallel conductors of infinite length and negligible cross-sectional area, placed 1 metre apart in a vacuum, would produce between those conductors a force of 2 x 10-7 N per metre of length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a candela?

A

The base SI unit of luminous intensity.

Defined as the luminous intensity in a given direction of a source that emits monochromatic light at a specific frequency and radiant intensity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a kilogram?

A

The base SI unit of mass.

Defined as the mass of the international prototype of the kilgram held in Sevres, France.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a Kelvin?

A

The base SI unit of temperature.

Defined as 1/273.16 times the thermodynamic temperature of the triple point of water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is force?

A

An influence that changes the state of motion of an object.

Force (N) = Mass (kg) x Acceleration (m/s2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a Newton?

A

The derived SI unit of force.

The force at which gives an object of 1 kg mass an acceleration of 1m/s per second (1 N = 1 kg/ms-2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a Pascal?

A

The derived SI unit of pressure, defined as the pressure created when a foce of one Newton is applied over an area of 1 m2

(1 Pa = 1Nm-2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is work?

A

Work is done when a force acts upon an object and causes motion in the direction that the force is applied.

Work (J) = Force (N) x Distance (m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is energy?

A

The potential to do work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a joule?

A

The derived SI unit of work and energy, defined as the work done when a force of 1 N is exerted through a distance of 1m, in the direction which the force is applied

(1 J = 1 Nm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Power?

A

The rate at which work is done.

Power (W) = Work (J) x Time (s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a Watt?

A

The derived SI unit of power, defined as the power when 1 J of work is done every second, or 1 J of energy is expended every second (J/s).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a volt?

A

The derived SI unit of potential difference, defined as the potential difference across a conductor when a current of 1 A dissipates 1 W of power

Power (W) = Current (A) x Voltage (V)

or P = IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a coulomb?

A

The derived SI unit of electrical charge, defined as the charge transported through a conductor by a current of 1A in 1 s.

Charge (C) = Current (A) x time (s)

Q = It

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a capacitor?

A

An electrical component that stores electrical charge. Used in circuits as a low frequency filter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is capacitance?

A

A measure of a capacitor to store electrical charge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a farad?

A

The derived SI unit of capacitance, defined as the capacitance of a capacitor which has a potential which holds 1 C of charge when a potential difference of 1V is applied across it.

Charge (C) = Capacitance (F) x Voltage (V)

Q = CV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is resistance?

A

Opposition to flow, either flow of direct electrical current or fluid flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is reactance?

A

Opposition to flow of alternating electrical current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is impedance?

A

The total of resistive and reactive components of opposition to electrical current.

**when describing resistance in an AC circuit use the term impedance as reactance never exists alone**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is an Ohm?

A

The derived SI unit of resistance.

Defined as the resistance present when a potential difference of 1 V across a conductor produces a current of 1A.

The same unit is used for reactance and impedance.

Voltage (V) = Current (A) x Resistance (Ω)

V = IR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is Ohm’s Law?

A

The strength of an electrical current is directly proportional to the potential difference and inversely proportional to resistance/impedance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is an inductor?

A

An electrical component that opposes changes in current flow by generation of back electromotive force.

Used in circuits as a high frequency filter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is inductance?

A

A measure of the ability of an inductor to generate a resistive electromotive force under the influence of changing current.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is a Henry?

A

The derived SI unit of inductance, defined as the inductance of an inductor when a current 1A flowing in the inductor generates a magentic field strength of 1 weber.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is absolute pressure?

A

Atmospheric pressure plus gauge pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is gauge pressure?

A

The pressure measured in a system relative to the surrounding atmospheric pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is light?

A

Electromagnetic radiation of a wavelength that is visible to the human eye, usually around 400 nm to 700 nm, which, like all electromagnetic radiation, travels at a speed of approx 300,000 km/s in a vacuum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is sound?

A

Waves of pressure oscillations which are transmitted through a medium (which can be solid, liquid or gas) at a frequency detectable by the human auditory apparatus, usually 20 Hz to 20 kHz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the Doppler Effect?

A

The phenomenon by which the frequency of reflected sound changes if the source and observer are in motion relative to each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the ideal gas?

A

A theoretical gas which completely obeys all 3 gas laws on account of it containing molecules of infinitely small size, which therefore occupy no volume themselves, and have no forces of attraction between them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is Boyle’s Law?

A

The first gas law.

Which states that for a given amount of an ideal gas at a constant temperature, pressure is inversely proportional to volume.

P ∝ 1/V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is Charles’ Law?

A

The second gas law, which states that for a given amount of a ideal gas at a constant pressure, volume is directly
proportional to absolute temperature
(V∝ T)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is Guy-Lussac’s Law?

A

The third gas law, which states that for a given amount of a ideal gas at a constant volume, pressure is directly proportional to absolute temperature
(P ∝ T)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is Avogadro’s hypothesis?

A

For an ideal gas at a constant pressure and temperature, volume is directly proportional to the amount i.e. the number of moles of gas.

(V ∝ n).

This means that equal volumes of ideal gases at the same temperature and pressure contain an equal number of elementary particles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is Molar volume?

A

The volume of 1 mole of gas at STP which is 22.4L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the Universal Gas Equation?

A

A combination of the 3 gas laws and Avogadro’s hypothesis, which states that

PV=nRT

where P =pressure, V =volume,
n =number of moles, R = the universal gas constant and T=absolute temp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is Isothermal change?

A

When a gas is compressed or decompressed, it’s heat energy changes. If the pressure change occurs slowly then there is time for equilibration to occur with the surroundings, so the temp of the gas will remain constant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is Adiabatic Change?

A

When a gas is compressed/decompressed, it’s heat energy changes. If the pressure change occurs rapidly then equilibration with surroundings cannot occur and there will be a temperature change.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is partial pressure?

A

The partial pressure of an individual gas in a gas mixture is the pressure which that gas would exert if it alone occupied the same volume as the mixture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is Henry’s Law?

A

The amount of gas dissolved in a liquid is directly proportional to the partial pressure of the gas in equilibrium with the liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is Dalton’s Law of Partial Pressures?

A

The total pressure exerted by a gas mixture is equal to the sum of the partial pressures of the individual gases in the mixture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is an osmole?

A

The amount of solute that exerts an osmotic pressure of 1 atm when placed in 22.4 L of solution at STP.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is osmolaRity?

A

The number of osmoles per litre of solution (mOsm/L)

It is dependent on temperature and pressure, therefore prone to inaccuracy, and difficult to measure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is osmolaLity?

A

The number of osmoles per kg of solvent (mOsm/kg), independent of temperature and pressure. Measured in the lab using colligative properties or estimated using bedside formula.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are colligative properties?

A

Properties of a solution which vary according to the osmolaLity of the solution which are:

  • decrease of freezing point (1.86 K per Osm/kg)
  • decrease of vapour pressure = Raoult’s Law
  • increasing in boiling point
  • increase in osmotic pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is Raoult’s Law?

A

The reduction of vapour pressure of a solution is proportional to the molar concentration of the solute.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is osmotic pressure?

A

The pressure which needs to be applied to a solution to prevent inward flow of pure solvent (water) across a semi-permeable membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is oncotic pressure?

A

Also known as colloid osmotic pressure.

It’s the osmotic pressure exerted by plasma proteins.

Most of the osmotic pressure of fluids in the body is due to electrolytes, however as these can freely diffuse in and out of blood vessels, they don’t influence passage of water between intravascular and interstitial fluid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is oil:gas partition coefficient?

A

The ratio of amount of a vapour or gas present in equal volume phases of gas and oil at equilibrium, at a given temperature 37C)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is the blood:gas partition coefficient?

A

Ratio of the amount of vapour or gas present in equal volume phases of blood and gas, at equilibrium, at a given temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the Fick principle?

A

The total uptake or release of a substance by an organ is equal to the product of the blood flow to the organ and the arterio-venous concentration difference of the substance.

For oxygen:

VO2 = CO x (CaO2 –CvO2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is flow?

A

The quantity of a fluid (which can be gas or liquid) that passes a given point per unit time. Flow can be laminar or turbulent.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is laminar flow?

A

Efficient flow of a fluid in which the particles move in parallel layers, each of which has a constant velocity but is in motion relative to its neighbouring layers. The fastest velocity is found in the centre of the flow (twice the average velocity of the fluid), and the slowest velocity is found at the outsides of the flow. Particles adjacent to the containing vessel walls have, in theory, no motion at all.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is turbulent flow?

A

Inefficient flow of a fluid in which the particles move in errative directions, creating swirls and eddies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the Bernoulli principle?

A

Derived from the principle of conservation of energy, and states that in a fluid flow, an increase in velocity will be accompanied by a reduction in pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is the venturi effect?

A

An application of the Bernoulli principle.

Where a fluid flows within a tube, a constriction in the tube causes an increase in velocity and consequently a reduction in pressure.

The reduction in pressure can be used to entrain other liquids/gases, which allows for applications such as the Venturi mask and nebulizers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is the Coanda effect?

A

The tendency of fluid flowing in proximity to a convex surface to follow the line of the surface rather than it’s original course.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What is temperature?

A

A measure of the average kinetic energy of all the particles within an object or system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is heat?

A

Energy which is transferred between objects or systems at different temperatures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What is latent heat?

A

Energy required for a substance to undergo a phase change.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What is latent heat of vaporisation?

A

The energy required, at a specified temperature, to transform a substance from it’s liquid to gaseous phase, without temperature change (for 1 kg of substance).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What is heat capacity?

A

The energy required to raise the temperature of an object by one degree (for 1kg of substance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is a gas?

A

A substance in it’s gaseous phase above it’s critical temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is a vapour?

A

A substance in it’s gaseous phase below it’s critical temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is critical temperature?

A

The temperature above which the gaseous phase of the substance cannot be liquefied regardless of how much pressure is applied to it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is critical pressure?

A

The pressure required to liquefy the gaseous phase of a substance at it’s critical temperature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What is the Poynting effect?

A

The dissolution of gaseous oxygen when bubbled through liquid nitrous oxide, with vaporization of the liquid to form a gaseous oxygen/nitrous oxygen mix.

The critical temperature of the nitrous oxide is lowered to a pseudocritical temperature, at which the nitrous oxide gas will condense out of the mix.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What is pseudocritical temperature?

A

The temperature at which a gas mixture such as entonox will separate into it’s component parts.

It varies with pressure.

The pseudocritical temperature of entonox is highest at 117 bar when -5.5 °C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What is SVP?

A

The pressure of vapour in thermodynamic equilibrium with it’s liquid phase in a closed system. This is therefore the max pressure of the vapour at a given temperature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What is boiling point?

A

The temp at which the SVP of a substance in it’s liquid phase is equal to the surrounding atmospheric pressure, and therefore all of the substance is changed into the gaseous phase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What is the triple point?

A

The specific temperature and pressure at which all 3 phases of a substance (gas, liquid, solid) exist in equalibrium.

The triple point of water is at 273K and 611.7 Pa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What is STP?

A

273.15 K and 101.3 kPa (1 atm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is humidity?

A

Amount of water vapour pressure in air or another gas mixture which can be absolute/relative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What is absolute humidity?

A

The mass of water vapour present in a gas mixture per unit volume (g/m3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What is relative humidity?

A

The ratio of the vapour pressure of water vapour in a gas mix compared with the saturated vapour pressure of water at the same temperature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What is Dew Point?

A

When a sample of air is cooled (and it’s absolute humidity unchanged) the dew point is the temperature at which the relative humidity reaches 100% and water condenses out of the vapour phase to form liquid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What is a supramaximal stimulus?

A

An electrical stimulus of sufficient current magnitude to depolarize all fibres within a given nerve bundle.

Usually >60mA for a transcutaneous stimulation of a peripheral nerve.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What is train of four?

A

A pattern of peripheral nerve stimulation, where 4 square waves of supramaximal current, each 0.2 ms in duration are delivered at a frequency of 2 Hz every 500ms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What is double burst?

A

A pattern of peripheral nerve stimulation, where 2 bursts of supramaximal current delivered 750ms apart.

Each burst consists of 3 square waves of supramaximal current, each 0.2ms in duration, delivered at a freq of 50Hz.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What is tetanic stimulus?

A

A pattern of peripheral nerve stimulation, where square waves of supramax current, each 0.2ms in duration, are delivered at a frequency of 50Hz for 5s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What is natural frequency?

A

The frequency a system will adopt when freely set in motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

What is resonance?

A

The tendency of a system to oscillate with greater amplitude when driven by a force with a frequency close to it’s natural frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What is damping?

A

A decrease in the amplitude of oscillations in a system as a result of energy loss due to frictional or other resistive forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What is decontamination?

A

The process of removing contaminants such that they are unable to reach a site in sufficient quantities to initiate an infection or other harmful reaction. This always begins with cleaning and is followed by either disinfection or sterilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What is cleaning?

A

Process of physically removing foreign material from an object without necessarily destroying any infective material.

Methods include washing with detergent, ultrasonic bath and low temperature steam.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What is disinfection?

A

The process of rending an object free from all pathogenic organisms except bacterial spores.

Methods include:

  • pasteurization
  • alcohol
  • chlorhexidine

Hydrogen peroxide and gluteraldehyde 2% (for >20mins) are high level disinfectants that have some sporicidal activity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

What is sterilization?

A

The process of rendering an object completely free from all viable infections including bacterial spores.

Methods include:

  • autoclaving
  • ethylene oxide
  • gluteraldelyde 2% (for >10hrs)
  • gas plasma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

What is an exponential?

A

A function where the rate of change of a variable at any point in time is proportional to the value of the variable at that time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

What is a first order reaction?

A

Exponential process, where reaction rate is dependent on the concentration of substrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

What is a zero order reaction?

A

A linear process, where reaction rate is constant and independent of the concentration of substrates.

A small increase in the dosing or plasma concentration will results in a large increase in the availability of the drug eg alcohol, phenytoin, thiopentone, aspirin, theophylline.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

What is summation?

A

The actions of 2 drugs are additive but each has an independent action

96
Q

What is synergism?

A

The combined effect of 2 drugs is greater than can be explained by a purely additive effect.

97
Q

What is potentiation?

A

The action of one drug is amplified by the addition of another, which has no independent action of it’s own.

98
Q

What is antagonism?

A

The action of one drug is inhibited by the addition of another

99
Q

What is a ligand?

A

A molecule that binds to a receptor

100
Q

What is the dissociation constant?

A

The dissociation constant is the molar concentration of a drug at which 50% of receptors are occupied at equilibrium.

This provides a
measure of affinity.

KD=([D].[R])/[DR]

101
Q

What is affinity?

A

A measure of how avidly a drug binds to a receptor

102
Q

What is efficacy?

A

Intrinsic activity, a measure of the magnitude of the effect once the drug is bound.

103
Q

What is potency?

A

A measure of the quantity of drug needed to produce maximal effect.

Quantified using the median effective concentration or median effective dose.

104
Q

What is the median effective concentration? (EC50)

A

The concentration of a drug that induces a response of a magnitude exactly half way between baseline and the maximal response possible,

105
Q

What is the median effective dose? (ED50)

A

The does of a drug that induces a specified response in 50% of subjects in a population.

106
Q

What is the median lethal dose? (LD50)

A

The does of a drug that is lethal in 50% of subjects in a population

107
Q

What is a therapeutic index?

A

Quantifies the balance between a drug’s useful effects and it’s toxic effects, often defined as LD50/ED50

108
Q

What is an interaction?

A

The effect of a drug is modified by another drug.

Can be physicochemical (outside or inside body), pharmacokinetic (ADME) or pharmacodynamic (summation, synergism, potentiation, antagonism).

109
Q

What is an agonist?

A

A drug with receptor affinity and intrinsic activity. Full, partial or inverse.

110
Q

What is a full agonist?

A

A drug with receptor affinity and full intrinsic activity, meaning once bound it can produce a maximal response (eg noradrenaline).

111
Q

What is a partial agonist?

A

A drug with receptor affinity and partial intrinsic activity, meaning once bound it can only produce a sub-maximal response (eg buprenorphine).

Will behave as antagonists in the presence of sufficient doses of full agonist.

112
Q

What is an inverse agonist?

A

Drug with receptor affinity and negative intrinsic activity that produces an effect opposite to that seen in the agonist (eg flumazenil, atropine).

113
Q

What is an antagonist?

A

A drug that inhibits the agonist from producing a response.

Competitive, non-competitive or irreversible.

114
Q

What is a competitive antagonist?

A

Drug with receptor affinity and no intrinsic activity, which blocks the agonist binding site, it’s inhibitory effects can be overcome by increasing the concentration of the agonist (eg atracurium).

115
Q

What is a non-competitive antagonist?

A

A drug that binds at a different site to the agonist and causes a conformational change in the receptor that prevents it’s activation despite agonist binding.

Cannot be overcome by increasing the concentration of the agonist, but will eventually dissociate with time (eg ketamine).

116
Q

What is an irreversible antagonist?

A

A drug that either binds at the agonist binding site or at a distant site, which permanently prevents receptor activation.

Cannot be overcome by increasing the concentration of agonist, and will not dissociate with time (eg phenoxybenzamine).

117
Q

What is an allosteric modulator?

A

Drug that binds at a different site to the agonist and either increases or decreases the affinity of the receptor for the agonist (eg benzodiazepines).

118
Q

What is dose ratio?

A

The factor by which the agonist concentration must be increase when in the presence of a competitive antagonist to produce an equivalent response,

119
Q

What is bioavailability?

A

The fraction of drug that reaches the circulation compared with the same does given intravenously.

Calculated by using the AUC of the given concentration-time curve to the AUC of the IV concentration-time curve.

120
Q

What is hepatic extraction ratio?

A

The fraction of total drug removed from the blood by the liver with each pass through it.

Dependent on rate of uptake of the drug by hepatocytes and the capacity of the enzyme system to metabolise the drug.

The rate of metabolism of drugs with a high ER is most dependent on hepatic blood flow. The rate of metabolism of drugs with a low ER and high PB is most dependent on level of PB. The rate of metabolism of drugs with a low ER and low PB varies little with changes in either hepatic blood flow or PB.

121
Q

What is volume of distribution?

A

Theoretical volume into which a drug distributes following it’s administration

(VD = dose/CO = Cl.τ = Cl/k)

122
Q

What is clearance?

A

The volume of plasma from which a drug is completely removed per unit time (ml/min)

123
Q

What is elimination?

A

Removal of drug from plasma, which may occur due to metabolism or excretion.

Relim = Ct.Cl

124
Q

What is excretion?

A

Removal of drug from the body (either directly or it’s metabolites)

125
Q

What is first order elimination?

A

An exponential process where the rate of elimination at any time depends on the drug concentration at that time.

A constant proportion of drug is eliminated per unit time,

126
Q

What is zero order elimination?

A

A linear process where the rate of elimination at any time is constant and independent of the drug concentration.

A constant amount of drug is eliminated per unit time.

This can occur when enzyme systems become saturated.

127
Q

What is elimination half life?

A
  1. The time taken for the plasma concentration to drop to 50% of it’s original value.
  2. Time constant multiplied by natural logarithm of 2.
128
Q

What is the time constant?

A
  1. The time it would taken for all the drug to be eliminated if elimination continued at the initial rate.
  2. Time taken for plasma concentration to drop to 37% of it’s original value.
  3. Reciprocal of the rate constant.
  4. Half life divided by the natural logarithm of 2.
129
Q

What is context sensitive half time?

A

The time taken for plasma concentration of a drug to fall to 50% of it’s value on cessation of an infusion designed to maintain a steady state plasma concentration.

130
Q

What is a compartmental model?

A

Pharmacokinetic models which help us predict how the body will handle a given dose of drug.

These assist with calculation of doses and are the basis of target-controlled infusions.

131
Q

What is tachyphylaxis?

A

Rapid decrease in magnitude of response to the same dose of a drug, eg ephedrine due to exhausted NA stores

132
Q

What is desensitization?

A

Slower decrease in magnitude of response to the same dose of a drug.

Thought to be due to decrease in receptor or G-protein numbers, or reduced receptor affinity (eg opioids, nitrates, adrenaline).

133
Q

What is tolerance?

A

The need to give larger doses to obtain the same magnitude of response with desensitization.

134
Q

What are isomers?

A

Molecules with the same molecular formula (therefore same number of individual atoms) but different atomic arrangements.

135
Q

What are structural isomers?

A

Molecules with the same molecular formula but a different order of atomic bonds.

Subdivided into static (chain, position or functional group) and dynamic (tautomers).

136
Q

What are stereoisomers?

A

Molecules with the same molecular formula and same order of atomic bonds, but different spatial atomic arrangement.

Subdivided into enantiomers (also known as optical steroisomers) and diasteroisomers (geometric or multichiral).

137
Q

What are enantiomers?

A

Isomers with one chiral centre which form non-superimposable mirror images of each other. Also called optical steroisomers because each isomer rotates plane polarized light in a different direction.

138
Q

What is a chiral centre?

A

An atom with 4 dissimilar groups attached to it, which can be a carbon atom or quaternary nitrogen atom.

139
Q

What are diasteroisomers?

A

Complex stereoisomers which to not form mirror images of each other.

Either have multiple chiral centres or are geometric steroisomers with variation occuring around a rigid molecular structure, usually a double bond or ring.

140
Q

What is a racemic mixture?

A

Preparation of two enantiomers of a compound in equal proportions

141
Q

What is the Seebeck effect?

A

In a circuit composed of 2 dissimilar metals, a potential difference is produced between the junctions of these metals when the junctions are at different temperatures.

The bases of a thermocouple.

142
Q

What is general anaesthesia?

A

Reversible loss of consciousness, awareness and response to pain.

143
Q

What is MAC?

A

A measure of the potency of inhaled anaesthetic agents, defined as the minimum alveolar concentration of the agent at steady state required to prevent reaction to a standard surgical stimulus, usually a skin incision, in 50% of subjects at 1 atm.

144
Q

What is the Meyer-overton hypothesis?

A

The potency of an anaesthetic agent is directly proportional to it’s lipid solubility. Therefore, it is proposed that the mechanism of action of these agents is at a lipid site.

This was further developed to the critical volume hypothesis.

Examples of problems are isoflurane & enflurane, and extreme outliers (eg ketamine).

Superseeded by the protein site-of-action hypothesis.

145
Q

What is tidal volume?

A

The volume of gas inhaled or exhaled during the course of a normal resting breath.

146
Q

What is residual volume?

A

The volume of gas remaining in the lungs after a maximal forced expiration.

147
Q

What is the inspiratory reserve volume?

A

The volume of gas that can be further inhaled at the end of a normal tidal inspiration.

148
Q

What is expiratory reserve volume?

A

The volume of gas that can be further exhaled at the end of normal tidal expiration.

149
Q

What is capacity?

A

The sum of 2 or more lung volumes

150
Q

What is total lung capacity?

A

The total volume of gas in the lungs at the end of a maximal inspiration

151
Q

What is vital capacity?

A

The total volume of gas inhaled when a maximal expiration is followed immediately by a maximal inspiration.

The sum of ERV, VT and IRV.

152
Q

What is functional residual capacity?

A

The total volume of gas that remains in the lungs at the end of a normal tidal expiration.

The sum of ER & RV.

This is the point where the inward elastic recoil forces of the lung are balanced by the outward, springlike forces of the chest wall.

Modified by factors in 3 categories:

lung size, lung pathology, diaphragmatic displacement

153
Q

What is closing volume?

A

The volume of gas exhaled between the beginning of small airway collapse and the end point of maximal expiration.

154
Q

What is closing capacity?

A

Total volume of gas that remains in the lungs when dynamic small airway collapse begins on expiration.

The sum of CV and RV.

Reaches supine FRC by age 44 and standing FRC by age 66.

155
Q

What is FEV1?

A

Following a maximal inspiration, the volume of gas which can be forcibly exhaled in 1 second.

Used to calculate FEV1/FVC ratio in health is >75%.

156
Q

What is a shunt?

A

Areas of the lung that are PERFUSED but not VENTILATED (blood passes through without being involved in gas exchange)

157
Q

What is dead space?

A

Areas of the lung that are VENTILATED but not PERFUSED.

Gas is inhaled then exhaled without being involved in gas exchange. Can be anatomical or alveolar, combined to give physiological dead space.

Physiological dead space can be calculated from Bohr equation.

158
Q

What is anatomical dead space?

A

The volume of the conducting airways that does not contain any respiratory epithelium, which stretches from the nostrils to the 16th generation terminal bronchioles.

Measured using Fowler’s method.

159
Q

What is alveolar dead space?

A

The volume of those alveoli that are ventilated but not perfused.

160
Q

What is the Bohr effect?

A

The reduction in Hb’s affinity for O2 and therefore rightward shift of the oxyHb dissociation curve when there is a reduction in blood pH.

161
Q

What is the haldane effect?

A

The phenomenon where deoxy-Hb can carry more CO2 than oxyHb

162
Q

What is the Hamburger effect?

A

Bicarbonate ions diffuse out of erythrocytes and to maintain electroneutrality chloride ions diffuse in.

163
Q

What is compliance?

A

The change in volume per unit change of pressure.

164
Q

What is static compliance?

A

The compliance of the lung measured when all gas flow has ceased.

Higher than dynamic compliance.

165
Q

What is dynamic compliance?

A

The compliance of the lung measured during the respiratory cycle when gas flow is ongoing

166
Q

What is lung resistance?

A

The change in pressure per unit change of volume

167
Q

What is cardiac output?

A

The volume of blood ejected by the left ventricle into the systemic circulation every minute

168
Q

What is preload?

A

The length of the cardiac muscle fibres immediately prior to contraction which is dependent on the end-diastolic volume. Clinically equated to the end-diastolic pressure which is estimated using CVP for the RV and PCWP for the LV.

169
Q

What is afterload?

A

The tension developed in the cardiac muscle fibres during contraction which is dependent on the mechanical resistance to shortening of the muscle fibres.

Often clinically equated to SVR although this is a poor surrogate as afterload is also depdent on wall thickness and aortic valve.

170
Q

What is contractility?

A

The intrinsic ability of cardiac muscle fibres to contract given a particular preload and afterload.

171
Q

What is the Frank-Starling mechanism?

A

The strength of cardiac muscle fibre contraction is dependent on the initial fibre length.

EDV reflects initial fibre length, but as this cannot be measured we used EDP instead (although this assumes normal compliance) .

Strength of the fibre contraction can be equated to SV (although this assumes afterload and inotropy are constant).

172
Q

What is end-diastolic pressure volume relationship?

A

If multiple pressure-volume loops for one ventricle are recorded, and the multiple end diastolic points taken, a line drawn through these points is the EDPVR.

Within normal parameters the relationship is a linear increase, but becomes curved upwards at higher volumes.

The line is moved up and left by decreases in compliance.

173
Q

What is the end-systolic pressure volume relationship?

A

If multiple pressure-volume loops for one ventricle are recorded, and the end-systolic points taken, a line drawn through them is the ESPVR.

The relationship is a linear increase.

The line is moved up and left by increases in contractility, and down and right by decreases in contractility.

174
Q

What is the anrep effect?

A

The phenomenon by which an increase in afterload causes an increase in myocardial contractility. The mechanism for which is unknown.

175
Q

What is the Bowditch Effect?

A

The phenomenon by which an increase in HR causes an increase in myocardial contractility

176
Q

What is the neuromuscular junction?

A

The chemical bridge between the motor neurone (usually an A alpha fibre) and the skeletal muscle fibre.

ACh is the neurotransmitter released from pre-synaptic membrane.

The post synaptic membrane is folded, the shoulders being covered with nicotinic ACh receptors and the clefts covered with AChEsterase enzyme.

177
Q

What is an acid?

A

A proton donor (HA)

178
Q

What is a base?

A

Proton acceptor (A)

179
Q

What is a weak acid/base?

A

Not completely dissociated in solution

180
Q

What is a strong acid/base?

A

Completely dissociated in solution

181
Q

What is a buffer?

A

A solution which resists changes to pH when an acid or base is added to it. Normally composed of a weak acid and it’s conjugate base.

182
Q

What is base excess?

A

The amount of strong acid which must be added to 1 litre of blood at 37C and with PaCO2 corrected to 5.3 kPa in order to restore its pH to 7.4

When the value is negative, this is the base deficit and is therefore the amount of strong base which must be added.

(standard BE is corrected to Hb 5 g/dL which is supposed to better reflect ECF acid-base)

183
Q

What is pKa?

A

The pKa of a weak acid/base is the negative logarith to the base 10 of the dissociation constant.

This is also the pH at which the weak acid or base is 50% dissociated in solution.

For a bugger system the pKa is the pH around which the buffer has it’s greatest buffering capability.

184
Q

What is the Henderson-Hasselbach equation?

A

Relates pH to the pKa and concentrations of proton donor and acceptor

185
Q

What is the Gibbs Donnan equalibrium?

A

The equilbrium reached by a charged ion on either side of a semi permeable membrane, which reflects a balance of the concentration and electrochemical gradients acting on it.

186
Q

What is pain?

A

An unpleasant sensory or emotional experience associated with actual or potential tissue damage

187
Q

What is chronic pain?

A

Pain persisting for >12 weeks

188
Q

What is neuropathic pain?

A

Pain caused by a primary lesion or dysfunction of the peripheral or CNS

189
Q

What is BMR?

A

The amount of energy liberated by catabolism per unit time, under standardised conditions, these being a relaxed subject at a comfortable temperature, over 12 hrs after eating

190
Q

What is Hb?

A

A haemoprotein composed of 4 globin chains

Each associated with it’s own haem moeity, which is a porphyrin ring with an iron ion at it’s centre.

Each Hb molecule therefore has 4 haem groups within it, allowing it to carry 4 O2 molecules.

191
Q

What is cytochrome P450?

A

A family of haemoproteins which are enzymes contained within the smooth ER of hepatocytes in zone 3 of the hepatic acinus.

Responsible for many phase 1 oxidative reactions of hepatic drug metabolism.

192
Q

What is a phase 1 reaction?

A

Hydrolysis, oxidation and reduction (HOR)

193
Q

What is a phase 2 reaction?

A

Glucuronidation, acetlyation, sulphation and methlyation (GASM)

Phase 1 + 2 = (HOR) (GASM)

194
Q

What is the portal circulation?

A

A circulation which drains the capillary bed of one organ structyre to the capillary bed of another, usually through a vein or venule.

Eg hepatic portal circulation, hypothalamo-pituitary circulation and renal circulation

195
Q

What is the mean?

A

Measure of central tendency, calculated by summing all the data points then dividing the total by n.

Used to describe parametric data

196
Q

What is the median?

A

Middle data point of the sample, with equal numbers of data points lying above and below it

197
Q

What is the mode?

A

Most frequently occuring variable

198
Q

What is variance?

A

A measure of the spread of data around the mean

199
Q

What is standard deviation?

A

Measure of the spread of data around the mean.

Defined as the square root of the variance.

Easier to understand because it’s in the same units as data being described,

68% of data points lie within 1 SD of either side of the mean, 96% within 2, 99% within 3.

200
Q

What is the standard error of the mean?

A

Used to determine whether the sample mean reflects the mean of the true population.

Calculated by dividing the SD by the square root of n.

Used to determine confidence limits.

201
Q

What is parametric data?

A

Data which there is an assumption of an underlying distribution. Commonly the normal distribution.

202
Q

What is non-parametric data?

A

Data in which we cannot make an assumption of an underlying distribution.

Eg skewed data

203
Q

What is quantitative data?

A

Data represent points on a numerical measurement scale

204
Q

What is qualitative data?

A

Data are placed into descriptive categories. Nominal vs ordinal.

205
Q

What is continous data?

A

Quantitative data which can take any numerical value (eg height)

206
Q

What is discrete data?

A

Quantitative data which can only take certain numerical values (eg number of children)

207
Q

What is ratio data?

A

Any data series that has zero as a baseline (eg Kelvin temp scale)

208
Q

What is interval data?

A

Any data series that includes zero as a point on a larger scale (eg celcius temp scale)

209
Q

What is nominal data?

A

Qualitative data in which categories have an implicit order of magnitude (eg ASA grade)

210
Q

What is ordinal data?

A

Qualitative data in which categories have no implicit order or magnitude (eg ABO blood group)

211
Q

What is the freezing point?

A

Temperature at which liquid and solid phases of a substance of specified composition are in equilibrium at a given pressure. Liquid turns to a solid when it’s temp is below freezing.

212
Q

What is a calorie?

A

Amount of energy required to increase the temperature of 1g of water by 1C.

1 cal = 4.16 J

213
Q

What is the specific heat capacity?

A

Amount of energy required to raise the temperature of 1 kg of a substance by 1C

SHC water = 4.16J/kg

SHC human body = 3.5J/kg

214
Q

1 atm = 1 bar = 101kPa = 14.7 psi = 760mmHg

A

What is atmospheric pressure?

215
Q

What is the concentration effect?

A

Rise in alveolar partial pressure of N2O is disproportionately rapid when administered in high concentrations

216
Q

What is the second gas effect?

A

The phenomenon by which the speed of onset of inhalational anaesthetic agents is increased when they are administered with N2O as the carrier gas,

217
Q

What is kinetic energy?

A

The energy a body possesses because of it’s motion. It’s the energy needed to accelerate the object from a state of rest to it’s given velocity.

This energy = work it would do when decelerating to return to rest.

218
Q

What is potential energy?

A

The energy of a body or system as a result of its position in an electric, magnetic or gravitational field.

It is the potential of that body to do work.

219
Q

What is the latent heat of fusion?

A

Melting.

The amount of heat required to convert a unit mass of solid at it’s melting point into a liquid without an increase in temperature.

220
Q

What is pH the log of?

A

pH = -log10[H+]

the negative log to the base 10 of the H+ ion conc in solution

221
Q

What is pKa the log of?

A

pKa = -log10 (Ka)

the negative log of the dissociation constant = the pH at which 50% of the drug is ionised and 50% is unionised.

222
Q

What is an enzyme?

A

A biological catalyst that increases the speed of a chemical reaction without being consumed in the reaction

223
Q

What is Graham’s law?

A

The rate of diffusion of a gas is inversely proportional to the square root of it’s molecular weight

224
Q

What is Beer’s Law?

A

The absorption of radiation increases (transmission decreases) as the concentration of a substance increases

225
Q

What is Lambert’s Law?

A

The intensity of transmitted light decreases exponentially as the distance travelled through the substance increases.

226
Q

What is the isobestic point?

A

The point at which 2 substances absorb a certain wavelength of light to the same extent (ie reference point where absorption of light is indepedent of degree of saturation).

For oxy/deoxyHb = 590nm in red spectrum and 805 infrared spectrum

227
Q

What does laser stand for?

A

Light amplification by stimulated emission of radiation

228
Q

What is the piezoelectric effect?

A

A potential difference may be produced across crystalline substances when subject to a mechanical stress

229
Q

What is somatic pain?

A

Localised pain due to activation of peripheral nociceptors

230
Q

What is visceral pain?

A

Diffuse pain difficult to localise or referred to a specific structure distant to the source of pain

231
Q

What is allodynia?

A

Painful response to a painless stimulus

232
Q

What is hypovolaemic shock?

A

Loss of circulating volume - reduction in preload and cardiac output

233
Q

What is cardiogenic shock?

A

Myocardial dysfunction - reduced systolic dysfunction and CO (MI/valve lesion)

234
Q

What is obstructive shock?

A

Physical obstruction to cardiac filling - reduction in preload and CO (tamponade/PE)

235
Q

What is distributive shock?

A

Reduction in SVR such that organ perfusion cannot be maintained (sepsis/neurogenic)

236
Q

What is cytotoxic shock?

A

Uncoupling of O2 delivery and uptake (CO or cyanide poisoning)

237
Q
A

FRCA Notes (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions