Definitions Flashcards
Lung Compliance
The change in lung volume per unit change in trans pulmonary pressure
Heat
The form of energy that passes between two substances due to their difference in temperature
Temperature
The property of a substance that will determine whether it loses or receives heat from another substance
Critical Temperature
The temperature above which a vapour cannot be liquified regardless of pressure
Critical Pressure
The pressure required to liquify a gas at its critical temperature
Latent Heat
The energy required to change the state of a substance without raising its temperature
Absolute Humidity
The mass of water vapour per unit volume of gas at a given temperature and pressure
Relative Humidity
The mass of water vapour present in a given volume of air compared to the mass required to saturate the same volume at the same temperature
Flow
The quantity of fluid passing a point per unit time
Bernoulli’s Principle
An increase in velocity of an ideal fluid undergoing laminar flow is accompanied by a simultaneous reduction in its pressure
Coanda Effect
A stream of fluid flowing close to a convex surface follows the line of the surface, rather than its original course
Venturi Principle
When a fluid flows through a constriction within a tube there is a consequent reduction in pressure which can be used to entrain a second fluid into the main fluid flow
Osmolality
The number of active osmoles of solute per kilogram of solvent
Osmolarity
The number of active osmoles of solute per litre of solution
Hypoxia
The inadequate oxygen supply or the inability to use oxygen at a cellular level.
Dead space (respiratory)
Respiratory dead space is the volume of inspired gas that does not take part in gas exchange. (Anatomical and alveolar. Phyiological = anatomical + alveolar)
Bainbridge Reflex
A rapid increase in venous return to the right atrium leads to a tachycardia
Bezold-Jarisch reflex
AKA vasovagal syncope
Reduced venous return to the heart leads to activation of left ventricle chemo- and baroreceptors leads to unopposed parasympathetic tone
Bradycardia, Vasodilation and hypotension
Nausea
the sensation of the need to vomit
Vomiting
the involuntary, forceful expulsion of gastric contents via the mouth
Acid/ strong acid
proton donor/ fully dissociates in solution
Base
proton acceptor or hydroxide producer
pKa
the pH of an acid at which it is 50% dissociated
Buffer
An acid-base buffer solution resists a change of pH when an acid or base is added. It consists of a weak acid and its conjugate base.
Glomerular Filtration Rate
A unit of measure of kidney excretory function.
The volume of plasma cleared of an ideal substance per unit time/ the volume of plasma filtered at the glomerulus per unit time.
Filtration fraction
The ratio of GFR to Renal Plasma Flow
Osmosis
The diffusion of water molecules across a semi-permeable membrane from a dilute to a concentrated solution
Osmotic pressure
the pressure required to prevent solvent migration by osmosis across a semi-permeable membrane
Portal Circulation
Blood from a capillary bed of one organ structure drains into the capillary bed of another organ through a larger vessel (usually a vein).
