Definitions Flashcards
(207 cards)
1
Q
What is a transducer?
A
Device that converts one form of energy into another
2
Q
Define damping in a system.
A
Describes the resistance of a system to oscillation resulting from a change in the input due to frictional forces
3
Q
What is hysteresis in a system?
A
Where not all the energy put into the system is returned
4
Q
What is resonance?
A
The tendency of a system to oscillate at maximum amplitude at certain frequencies
5
Q
What is the natural frequency of a system?
A
The frequency a system will oscillate at if disturbed and then left alone
6
Q
What is heat?
A
A form of energy associated with the kinetic motion of molecules within a substance
7
Q
How is temperature related to a substance?
A
It is related to the average kinetic energy of a substance and measures its ability to transfer heat energy
8
Q
What is the triple point of water?
A
The temperature (at a set pressure) at which water exists in all 3 phases (0.01°C / 273.16K at 611.73Pa of 0.006atm)
9
Q
What does PEEP stand for?
A
Set level of pressure below which the circuit is not allowed to fall at the end of expiration
10
Q
Define flow in the context of fluids.
A
The quantity of a fluid passing a point per unit time
11
Q
What is laminar flow?
A
Fluid moves in an organized steady parallel manner, greatest at the center of the flow stream
12
Q
What characterizes turbulent flow?
A
Fluid moves in a disorganized and unpredictable fashion, characterized by swirls and eddies
13
Q
State Bernoulli’s principle.
A
An increase in the velocity of flow will be accompanied by a simultaneous reduction in its pressure
14
Q
What is the Venturi effect?
A
The effect by which a constriction in fluid flow causes the velocity of the fluid to increase and pressure to fall
15
Q
Define the Coanda effect.
A
The tendency of a stream of fluid flowing in proximity to a convex surface to follow the line of the surface
16
Q
What is an ampere?
A
The current that produces a force of 2x10^(-7) newtons per meter between 2 parallel wires of infinite length, 1m apart in a vacuum
17
Q
Define molarity.
A
Number of molecules of solute per litre of solution
18
Q
Define molality.
A
Number of molecules of solute per kilogram of solvent
19
Q
What is an osmole?
A
1 osmole is the amount of solute that exerts an osmotic pressure of 1atm in 22.4l of solution at 0 degrees C
20
Q
What is osmotic pressure?
A
The minimum pressure needed to prevent the inward flow of pure solvent across a semipermeable membrane
21
Q
Define osmolarity.
A
Number of osmoles of solute per litre of solution
22
Q
Define osmolality.
A
Number of osmoles of solute per kilogram of solvent
23
Q
What is osmosis?
A
Movement of a solvent across a semipermeable membrane from a less concentrated solution to a more concentrated solution
24
Q
What is humidity?
A
The amount of water vapour present in the atmosphere or a gas
25
Define absolute humidity.
The mass of water vapour (g) present per volume of air (Cubic Metre)
26
What is relative humidity?
Ratio of water vapour present against the maximum possible
27
What is the dew point?
Temperature below which water will begin to condense out of air
28
Define heat capacity.
The amount of energy required to raise the temperature of an object by 1 degree C
29
What is specific heat capacity?
The amount of energy required to raise the temperature of 1kg of an object by 1 degree C
30
What is the critical temperature?
The temperature above which a gas cannot be liquified regardless of the pressure applied to it
31
Define critical pressure.
The pressure required to liquify a gas at its critical temperature
32
What is pseudocritical temperature?
Applies to a mixture of gases; below it, components of the mixture begin to separate out
33
What is an ideal gas?
A theoretical gas where molecules behave as individual particles that move randomly and independently
34
State Boyle's law.
At a constant temperature, the absolute pressure of a given mass of gas is inversely proportional to its volume
35
What is Charles' law?
At a constant pressure, the volume of a given mass of gas is directly proportional to the absolute temperature
36
State Gay-Lussac's law.
At a constant volume, the pressure of a given mass of gas is directly proportional to the absolute temperature
37
What is Avogadro's hypothesis?
Equal volumes of gases at a given temperature and pressure contain the same number of molecules
38
Define Avogadro's number.
The number of particles in one mole of a substance, approximately 6.022x10^23
39
State Dalton's law.
The total pressure exerted by a gaseous mixture equals the sum of the partial pressures of each gas in the mixture
40
What is Henry's law?
The amount of gas dissolved in a liquid is proportional to its partial pressure above that liquid
41
Define latent heat of fusion.
The amount of heat required to convert a unit mass of solid at its melting point into a liquid without temperature increase
42
What is potential energy?
The energy of a body or system as a result of its position in an electrical, magnetic, or gravitational field
43
What is SVP?
The pressure exerted by a vapor in equilibrium with its liquid in a closed system at a given temperature
44
Define boiling point.
The temperature at which the vapor pressure of a liquid equals surrounding pressure, causing it to change into vapor
45
What is pressure?
The amount of force applied to an object per unit surface area
46
What does pH stand for?
'Power of hydrogen', negative log to base 10 of hydrogen ion concentration
47
What is a potentiometric electrode?
A voltage-producing electrode
48
What is an amperometric electrode?
A current-producing electrode
49
What is calibration?
Ensuring the measured value equals the actual value
50
Define accuracy in measurement.
The ability of the measured value to equal the actual value
51
What is precision?
The ability of a device to reproduce a value
52
What is drift in measurement?
The gradual shift in measured value over time when the actual value doesn’t change
53
What is gain?
Measure of a circuit's ability to increase the power or amplitude of a signal from input to output
54
Define viscosity.
Frictional forces between the layers of fluid in the substance
55
What does Beer’s Law state?
Loss of light intensity when light passes through a medium is directly proportional to the concentration of the medium
56
What is Lambert's law?
Loss of light intensity when light passes through a medium is directly proportional to path length
57
What does LASER stand for?
Light amplification by stimulated emission of radiation
58
What is ultrasound?
Sound waves at a frequency above 20kHz
59
Define the Doppler Effect.
The change in apparent wavelength of a wave when the observer is moving relative to the wave source
60
What is the definition of a second in SI units?
Defined according to the frequency of radiation emitted by caesium-133 in its ground state
61
What is a mole?
Quantity of substance containing the same number of particles as there are atoms in 12g of carbon-12
62
Define metre.
Length of the path traveled by light in a vacuum during a time interval of ~1/300,000,000 of a second
63
What is a candela?
SI unit of luminous intensity, defined by a specific radiant intensity
64
What is the SI unit of temperature?
Kelvin, based on the triple point of water
65
What is a kilogram?
The mass of a cylindrical piece of platinum-iridium alloy kept in Sevres, France
66
Define coulomb.
1 C is the amount of charge passing a point per second when a 1 A current is flowing
67
What is a degree Celsius?
A unit of temperature equal to 273 kelvin
68
What is a farad?
The derived unit of electrical capacitance
69
What is a henry?
The derived unit of electrical inductance
70
Define joule.
The work done to an object when applying a force of 1 newton through a distance of 1m
71
What is a newton?
The force required to accelerate a mass of 1kg by 1m/s²
72
What is an ohm?
The resistance between 2 points of a conductor when a potential difference of 1 volt produces a current of 1 amp
73
Define pascal.
The unit of pressure, 1 Pa is the force of 1N acting over 1m²
74
What is a tesla?
The derived unit of magnetic flux density
75
What is a volt?
The electrical potential difference when 1J of work is done to move 1C of charge
76
Define watt.
The derived unit of power, equal to 1J per second
77
What is a weber?
The derived unit of magnetic flux
78
What is the pressure conversion for 1 atm?
1 atm = 101 kPa = 760 mmHg = 1033 cmH2O = 1 bar
79
What is mmHg?
The pressure needed to move a column of mercury up one millimeter
80
What is cmH2O?
The pressure needed to move a column of water up one centimeter
81
What are receptors?
Proteins integrated in the cell membrane with selective ligand binding sites
82
Define ligand.
A substance that binds a receptor and brings about a biological change
83
What does ED50 stand for?
The dose of a drug required to produce 50% of its maximal effect
84
What is EC50?
The plasma concentration of a drug required to produce 50% of its maximal effect
85
Define LD50.
The dose of a drug required to produce a lethal effect in 50% of the population
86
What is potency?
Describes the dose of a drug required to produce an effect of a given magnitude
87
Define affinity in pharmacology.
Describes how avidly a drug binds to its receptor
88
What is intrinsic activity?
The extent to which a drug stimulates a response once bound to a receptor
89
Define efficacy.
The ability of a drug to produce the maximal response once bound to a receptor
90
What is a full agonist?
Has affinity for a receptor with intrinsic activity producing a maximal response
91
What is a partial agonist?
Has affinity for a receptor but with sub-maximal intrinsic activity
92
Define inverse agonist.
Has affinity for a receptor but has the opposite effect to the endogenous agonist
93
What is an antagonist?
Has affinity for a receptor but exhibits no intrinsic activity and blocks the agonist's activity
94
What is a competitive antagonist?
Binds the receptor at the same site as the agonist, competing with it
95
What is a non-competitive antagonist?
Binds the receptor at a different site, preventing the agonist from having an effect
96
What is an allosteric modulator?
Binds to the receptor at a different site, altering the shape and affecting the agonist's affinity
97
What are G proteins?
Regulatory proteins that couple receptor activation to intracellular enzyme activation
98
What does pKa represent?
Negative log to the base 10 of the dissociation constant of an acid/base
99
What is a eutectic mixture?
When two substances are mixed to produce a substance with a single set of physical characteristics
100
Define partition coefficient.
The ratio of the amount of substance in one phase to the amount in another at equilibrium
101
What is the blood gas partition coefficient?
A measure of the solubility of a substance in blood
102
What does oil:gas PC measure?
Lipid solubility and an indicator of potency
103
What is MAC?
The minimum alveolar concentration at which 50% of the population will not respond to a standard surgical stimulus
104
What does the Meyer-Overton theory suggest?
Anesthesia is achieved when a sufficient amount of agent dissolves into a neuronal lipid membrane
105
What is the concentration effect?
Refers to the rise in alveolar partial pressures of gases when N2O is used due to its high solubility
106
What is the volume of distribution?
The theoretical volume necessary to contain the total amount of an administered drug
107
What does the Meyer-Overton theory suggest?
Anaesthesia is achieved when a sufficient amount of agent dissolves into a neuronal lipid membrane
## Footnote
This theory is fundamental in understanding how anesthetics work at a molecular level.
108
What is the concentration effect in anesthesia?
A rise in alveolar partial pressures of other gases due to the high solubility of N2O compared to nitrogen and oxygen
## Footnote
This effect occurs because N2O reduces alveolar volume, increasing the partial pressure of remaining gases.
109
Define volume of distribution.
The theoretical volume necessary to contain the total amount of an administered drug at the same concentration in the blood
## Footnote
It helps in understanding how a drug disperses throughout the body.
110
What is bioavailability?
The fraction (%) of an administered drug that reaches the systemic circulation
## Footnote
This measure is crucial for determining the effectiveness of a drug.
111
What does the second gas effect refer to?
The influence of N2O on the speed of onset of anesthesia from a second gas due to the concentration effect
## Footnote
This effect can enhance the efficiency of anesthetic induction.
112
What is context-sensitive half-life?
The time taken for blood plasma concentration of a drug to decline by one half after stopping an infusion
## Footnote
This concept is important for understanding drug clearance in clinical settings.
113
What is tachyphylaxis?
Reduction in response to repeated doses of a drug
## Footnote
An example of this is seen with ephedrine.
114
Define desensitization in pharmacology.
Reduction in response over a longer time due to receptor morphology changes or loss of receptors
## Footnote
This can occur with beta receptors and dobutamine.
115
What is tolerance?
The need for larger doses to produce the same physiological effect
## Footnote
Tolerance is often seen with opiates.
116
What is summation in pharmacology?
When two drugs have independent actions but produce an additive effect when given together
## Footnote
This principle is important in polypharmacy.
117
Define potentiation.
When two drugs are given together and have an additive action, but one has no independent action alone
## Footnote
This can lead to enhanced therapeutic effects.
118
What is synergism?
When two drugs together have an effect greater than just summation alone
## Footnote
This concept is critical in understanding drug interactions.
119
What are ionotropic receptors?
Membrane-bound receptor proteins that respond to ligand binding by opening an ion channel
## Footnote
They allow ions to flow into the cell, playing a key role in neurotransmission.
120
Define metabotropic receptors.
Subtype of membrane receptors that do not form an ion channel pore but use signal transduction mechanisms
## Footnote
These receptors are involved in more complex cellular responses.
121
What are isomers?
Molecules with the same molecular formula but arranged differently
## Footnote
Isomerism is crucial in organic chemistry and pharmacology.
122
What are structural isomers?
Isomers with the same molecular formula but different chemical structures
## Footnote
This includes chain, positional, and functional tautomers.
123
Define chain isomers.
Isomers where the carbon skeleton varies but functional groups remain the same
## Footnote
This type of isomerism is significant in understanding different chemical properties.
124
What are positional isomers?
Isomers where the carbon skeleton stays the same but the functional group varies in position
## Footnote
An example is enflurane and isoflurane.
125
Define functional isomers.
Isomers where the carbon skeleton stays the same but the functional group changes
## Footnote
This can affect the chemical reactivity of the compounds.
126
What are tautomers?
Dynamic isomers existing in equilibrium, depending on the surrounding environment
## Footnote
An example is thio compounds.
127
Define stereoisomers.
Molecules with the same molecular formula and structure but different spatial arrangements of atoms
## Footnote
This includes optical isomers/enantiomers and geometric isomers.
128
What are enantiomers?
Optical isomers with a single chiral center that are mirror images of each other
## Footnote
An example is ketamine.
129
Define diastereoisomers.
Isomers with more than one chiral center that cannot produce mirror images of each other
## Footnote
An example is atracurium.
130
What are geometric isomers?
Isomers that possess a double bond, preventing rotation; groups can be on the same (cis) or opposite (trans) sides
## Footnote
An example is mivacurium.
131
What is hypoxia?
Inadequate supply of oxygen to the tissues or inability of tissues to use oxygen
## Footnote
This condition can lead to serious health issues.
132
Define hypoxaemia.
Decrease in partial pressure of oxygen in the blood
## Footnote
It is a critical factor in assessing respiratory function.
133
What is the Haldane effect?
Increased capacity of deoxygenated hemoglobin for CO2 transport compared with oxygenated hemoglobin
## Footnote
This effect is important in gas exchange physiology.
134
What is the Bohr effect?
Shift to the right of the oxyhemoglobin curve due to rise in CO2 or fall in pH, favoring O2 delivery to tissues
## Footnote
This phenomenon is vital for understanding oxygen transport.
135
What is a shunt?
Passage of deoxygenated blood from the right side of the heart to the left without gas exchange
## Footnote
Typically accounts for about 5% of cardiac output.
136
Define physiological dead space.
Total dead space equal to anatomical plus alveolar dead space, indicating air volume not participating in gas exchange
## Footnote
This measure is important in respiratory physiology.
137
What is alveolar dead space?
Volume of gas within alveoli not participating in gas exchange
## Footnote
Factors affecting this include lung perfusion.
138
Define anatomical dead space.
Volume of air in the conducting respiratory tract that does not take part in gas exchange
## Footnote
Typically around 2ml/kg in adults.
139
What is compliance in physiology?
Change in volume for a unit change in pressure, indicating how easily a structure can distend
## Footnote
It is a critical factor in lung mechanics.
140
What is specific compliance?
Compliance divided by the functional residual capacity (FRC), accounting for differing body sizes
## Footnote
This measure allows for more accurate comparisons among individuals.
141
Define elastance.
Reciprocal of compliance
## Footnote
This property describes the ability of a structure to return to its original shape.
142
What does hysteresis refer to in respiratory physiology?
Difference between inspiratory and expiratory compliance
## Footnote
Lung volume during inhalation is less than during exhalation at the same pressure.
143
Define static compliance.
Change in lung volume per unit change in pressure in the absence of flow
## Footnote
Composed of chest wall and lung tissue compliance.
144
What is dynamic compliance?
Change in lung volume per unit change in pressure in the presence of flow
## Footnote
It is influenced by airway resistance and frequency.
145
What is surface tension?
Property of the surface of a liquid that allows it to resist external forces due to cohesive molecules
## Footnote
This property is crucial in alveolar stability.
146
What does SVR stand for?
Systemic vascular resistance
## Footnote
Calculated as MAP – CVP / Cardiac output.
147
What is PVR?
Pulmonary vascular resistance
## Footnote
Calculated as MPAP – LAP / CO.
148
Define GFR.
Volume of plasma filtered at the glomerulus per unit time
## Footnote
It is a critical measure of kidney function.
149
What is a buffer solution?
A solution that resists changes in pH when small amounts of acid or alkali are added
## Footnote
Typically consists of a weak acid/base.
150
What is the isohydric principle?
All buffering systems in the body are in equilibrium at a single point in time
## Footnote
Changes in pH affect all buffer systems simultaneously.
151
What is membrane potential?
Difference in electric potential between the interior and exterior of a biological cell
## Footnote
This potential is essential for cell signaling.
152
Define action potential.
Change in electrical potential associated with the passage of an impulse along a muscle or nerve cell membrane
## Footnote
It is fundamental to nerve and muscle function.
153
What is the Gibbs-Donnan effect?
Differential separation of charged ions across a semipermeable membrane
## Footnote
This effect influences osmotic pressure and cell volume.
154
What is autoregulation?
Intrinsic ability of an organ to maintain constant blood flow despite changes in perfusion pressure
## Footnote
Essential for organ function stability.
155
What does Fick's principle state?
Flow to an organ equals uptake of a substance per unit time divided by the A-V concentration difference
## Footnote
This principle is crucial for understanding organ perfusion.
156
Define filtration fraction.
Ratio of GFR to renal plasma flow, normally around 20%
## Footnote
This measure indicates kidney efficiency.
157
What is the Monro-Kellie doctrine?
The skull is a rigid box; an increase in volume of one intracranial component reduces another to maintain ICP
## Footnote
This concept is vital in neurology.
158
What is the Bell-Magendie law?
Ventral nerve roots contain only motor fibers, dorsal roots contain only sensory fibers
## Footnote
Nerve impulses conduct in one direction in each case.
159
Define reflex.
An involuntary and nearly instantaneous movement in response to a stimulus
## Footnote
Reflexes are fundamental to nervous system function.
160
What is a monosynaptic reflex?
A simple reflex involving only one synapse between sensory and motor neurons
## Footnote
An example is the knee jerk reflex.
161
Define polysynaptic reflex.
A reflex involving more than one synapse
## Footnote
An example is the withdrawal reflex.
162
What is a motor unit?
A single motor neuron and all the muscle fibers it innervates
## Footnote
Motor units play a crucial role in muscle contraction.
163
Define pain.
An unpleasant sensory and emotional experience associated with actual or potential tissue damage
## Footnote
Pain perception is a complex physiological process.
164
What is a portal system?
A system where a capillary bed pools into another capillary bed through veins without going through the heart first
## Footnote
This is seen in the hepatic portal circulation.
165
What does VO2 max represent?
The maximum amount of oxygen a subject can utilize at a cellular level to produce ATP
## Footnote
This measure is critical in exercise physiology.
166
Define aging in physiology.
Irreversible process causing gradual reduction in the reserve of each system
## Footnote
Aging affects all physiological functions.
167
What are hormones?
Chemical substances produced in the body that control and regulate activity of certain cells or organs
## Footnote
They play key roles in homeostasis.
168
What is starvation?
Complete absence of dietary intake
## Footnote
This condition can lead to severe metabolic disturbances.
169
Define gluconeogenesis.
Production of glucose from non-carbohydrate sources
## Footnote
This process is crucial during fasting.
170
What does Frank-Starling law state?
The ability of cardiac muscle fiber to contract is proportional to its initial fiber length
## Footnote
This principle is fundamental in cardiac physiology.
171
What is afterload?
Tension required in the ventricular wall to eject stroke volume during systole
## Footnote
Afterload impacts cardiac output.
172
Define contractility.
Intrinsic ability of the myocardium to contract for a given preload and afterload
## Footnote
This property is essential for heart function.
173
What is preload?
Tension in the wall of the ventricle at the end of diastole
## Footnote
Can be thought of as end-diastolic volume (EDV).
174
What is tubuloglomerular feedback?
Process whereby renal tubules regulate their own blood flow and GFR
## Footnote
This mechanism is vital for kidney function.
175
What is the stress response?
A group of neuro-endocrine and metabolic changes occurring in response to injury or trauma
## Footnote
This response is critical for survival.
176
What is the percentage of cardiac output for the brain?
15%
## Footnote
This reflects the brain's high metabolic demand.
177
How much blood flow does the heart receive per 100g?
80 ml/min
## Footnote
The heart extracts about 70% of the oxygen from the flow.
178
What is the GFR at birth?
30 ml/min
## Footnote
This reflects the immature renal function in neonates.
179
What is the primary function of the portal venous system?
To transport blood from one capillary bed to another without going through the heart
## Footnote
This system is crucial for liver function.
180
What is the significance of the Monro-Kellie doctrine?
It explains how intracranial pressure is maintained by balancing volume among brain, blood, and cerebrospinal fluid
## Footnote
This principle is essential in neurology.
181
What is compliance in the context of respiratory physiology?
The ability of the lung to expand with pressure
## Footnote
High compliance indicates ease of lung expansion.
182
What is the molecular weight (MW) of Halothane?
197
183
What is the MAC value of Isoflurane?
1.17
184
What is the pressure in bar for Nitrous?
44
185
Define ASA I in the ASA classification.
A normal healthy patient
186
Define ASA II in the ASA classification.
A patient with mild systemic disease
187
What characterizes ASA III in the ASA classification?
A patient with severe systemic disease
188
What is the definition of ASA IV?
A patient with severe systemic disease that is a constant threat to life
189
Define ASA V in the ASA classification.
A moribund patient who is not expected to survive without the operation
190
What does ASA VI represent in the ASA classification?
A declared brain-dead patient whose organs are being removed for donor purposes
191
What is the lipid solubility of Morphine?
1
192
What is the elimination half-life of Fentanyl?
3.5 hours
193
Fill in the blank: The clearance of Remifentanil is _______ ml/min.
40
194
What is the potency of Lidocaine?
2 (3mg/kg)
195
What is the onset time for Bupivacaine?
M
196
What is the receptor for Propofol?
GABAa β
197
What is the special point for Ketamine?
NMDA non-competitive antagonist
198
What is the general voltage for mains electricity?
240v
199
What is the dose of Adrenaline in cardiac arrest?
10mcg/kg/0.1ml/kg
200
What is the procedure for cleaning items using ultrasound?
Creates small bubbles that expand and collapse, dislodging contamination
201
What is the standard sterilization method for heat-sensitive items?
Gamma irradiation
202
What is the resistance to inactivation order?
prions > spores > mycobacteria > non-lipid small viruses > fungi > bacteria > medium/lipid viruses
203
What is the Sterility Assurance Level (SAL) required?
10^-6
204
What is the formula for cardiac output using Fick's principle?
Q = CO = Urine concentration x
205
What is the content in liters of a cylinder labeled 'D' for Oxygen?
680
206
What is the clearance rate of Tramadol?
Inhibits reuptake of noradrenaline and serotonin
207
Fill in the blank: The dose of Midazolam for children is _______ mg/kg IV.
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