ANZCA Primary Definitions 2025 with
Correct Answers
Term - ....ANSWER☑️☑️...-Definition
A-a Gradient - ....ANSWER☑️☑️...-The numerical difference between ideal alveolar
PAO2 and PaO2. An index of the amount of V/Q inequality and shunting which is
present.
Absolute Humidity - ....ANSWER☑️☑️...-Mass of H2O vapour in a given volume of
air mg/L
Absorption - ....ANSWER☑️☑️...-The rate at which a drug leaves its site of
administration and the extent to which this occurs.
Acid - ....ANSWER☑️☑️...-A proton (or H+ ion) donor
Acidaemia - ....ANSWER☑️☑️...-Arterial blood pH < 7.35 or [H+] > 44 nmol/L
Acidosis - ....ANSWER☑️☑️...-An abnormal process or condition which tends to
lower arterial pH if there are inadequate secondary changes in response to the
primary disease process. Two types: Respiratory and metabolic.
Acquired Immunity - ....ANSWER☑️☑️...-"The delayed onset but specific and
memory immunity after the first line innate immunity is breached. First exposure
allows identification and learning, and the second exposure initiates quick
mobilisation of lymphocytes. Major components: Humoral Immunity (B lymphocytes
producing specific antibodies), and Cellular Immunity (T lymphocytes)"
FOR STUDY PURPOSES ONLY ©️ 2025 ALL RIGHTS RESERVED 1
,Active Tension (Muscle) - ....ANSWER☑️☑️...-Active tension: the difference
between passive and total tension
Activity (Acid-Base) - ....ANSWER☑️☑️...-The effective concentration of a
substance in a reacting system
Adiabetic Heat - ....ANSWER☑️☑️...-Heat produced when a gas is compressed
Affinity - ....ANSWER☑️☑️...-"Avidity with which a drug binds to a receptor
(analogous to potency), or ability to bind to a receptor and form a stable complex.
Inverse of Kd."
Afterload - ....ANSWER☑️☑️...-Physiological def: Force restricting muscle fibre
shortening or weight/load that a contracting muscle must overcome prior to
shortening. <br>Clinical def: The impedance to the ejection of blood from the left
ventricle into the aorta
Aging - ....ANSWER☑️☑️...-"A normal physiological process of degeneration
beginning around age 30 and proceeding at a variable rate with obvious changes
becoming apparent at around age 60, and the end point being death."
Agonist - ....ANSWER☑️☑️...-Binds to receptor to produce responses that may be
excitatory or inhibitory. Partial agonist displays intermediate efficacy.
Airway Resistance - ....ANSWER☑️☑️...-"The resistance to the movement of air
through the airways. It is dependent on lung volume, bronchial smooth muscle tone,
bronchial mucosal engorgement, density and viscosity of the inspired gas, and the
respiratory rate."
Alkalaemia - ....ANSWER☑️☑️...-Arterial blood ph > 7.45 or [H+] < 36 mmol/L
Alkalosis - ....ANSWER☑️☑️...-An abnormal process or condition which tends to
raise arterial pH if there are inadequate secondary changes.
FOR STUDY PURPOSES ONLY ©️ 2025 ALL RIGHTS RESERVED 2
,Allodynia - ....ANSWER☑️☑️...-Pain due to a stimulus which does not normally
provoke pain. Stimulation of A beta fibres causes pain.
Alveolar Dead Space - ....ANSWER☑️☑️...-Part of inspired gas which passes
through the anatomical dead space and enters the alveoli but is not effective in gas
exchange given impaired perfusion.
Alveolar Ventilation - ....ANSWER☑️☑️...-"Effective ventilation of the alveoli, where
gas exchange with the blood takes place."
Ampere - ....ANSWER☑️☑️...-One Coulomb per second
Amplitude Linearity - ....ANSWER☑️☑️...-Amplifications of the signal should be
equal throughout the entire signal range to prevent distortion.
Anabolism - ....ANSWER☑️☑️...-Synthesis of cellular macromolecules
Anaesthesia - ....ANSWER☑️☑️...-Without sensation.
Analgesia - ....ANSWER☑️☑️...-Absence of pain in response to stimulation which
would normally be painful.
Analog Signal - ....ANSWER☑️☑️...-"A <b>continuous</b> signal for which the time
varying feature (variable) of the signal is a representation of some other time varying
quantity, i.e., analogous to another time varying signal."
Anaphylactoid Reaction - ....ANSWER☑️☑️...-"Clinically indistinguishable from
anaphylaxis but caused by complement activation or direct histamine release from
mast cells. *c.f. Anaphylaxis is a clinical syndrome produced by IgE type I
hypersensitivity resulting from antigen-antibody reaction at surface of mast cells. The
syndrome manifests as red rash/flush, bronchospasm, collapse, angioedema, GIT
symptoms. Requires prior exposure to antigen."
FOR STUDY PURPOSES ONLY ©️ 2025 ALL RIGHTS RESERVED 3
, Anaphylatoxins - ....ANSWER☑️☑️...-C3a and C5a which bind specific receptors on
mast cells and basophils causing degranulation.
Anaphylaxis - ....ANSWER☑️☑️...-"A clinical syndrome produced by IgE type I
hypersensitivity resulting from antigen-antibody reaction at surface of mast cells. The
syndrome manifests as red rash/flush, bronchospasm, collapse, angioedema, GIT
symptoms. Requires prior exposure to antigen."
Anatomical Dead Space - ....ANSWER☑️☑️...-The internal volume of the
conducting airways or that part of the inspired TV which is expired unchanged.
Anion - ....ANSWER☑️☑️...-Negatively charged ion.
Anion Gap - ....ANSWER☑️☑️...-"An estimate of unmeasured cations (Ca2+ and
Mg2+) and unmeasured anions (plasma proteins, phosphate, sulphate, lactate,
citrate, ketones) Some causes of metabolic acidosis release anions into the ECF
therefore creating an increased anion gap."
Anode - ....ANSWER☑️☑️...-Positive electrode to which anion is attracted.
Anrep Effect - ....ANSWER☑️☑️...-Intrinsic regulatory mechanism of the heart
whereby an abrupt increase in afterload produces transient increase in LVEPD and
decrease in SV allowing prompt restoration to near baseline values.
Antagonist - ....ANSWER☑️☑️...-"A substance that interacts with receptor or other
parts of effector mechanism to inhibit the action of an agonist, while initiating no
effect themselves."
ATPS - ....ANSWER☑️☑️...-"Ambient temperature and pressure, saturated with
water vapour (T amb, Pb, PH2O)"
FOR STUDY PURPOSES ONLY ©️ 2025 ALL RIGHTS RESERVED 4
Correct Answers
Term - ....ANSWER☑️☑️...-Definition
A-a Gradient - ....ANSWER☑️☑️...-The numerical difference between ideal alveolar
PAO2 and PaO2. An index of the amount of V/Q inequality and shunting which is
present.
Absolute Humidity - ....ANSWER☑️☑️...-Mass of H2O vapour in a given volume of
air mg/L
Absorption - ....ANSWER☑️☑️...-The rate at which a drug leaves its site of
administration and the extent to which this occurs.
Acid - ....ANSWER☑️☑️...-A proton (or H+ ion) donor
Acidaemia - ....ANSWER☑️☑️...-Arterial blood pH < 7.35 or [H+] > 44 nmol/L
Acidosis - ....ANSWER☑️☑️...-An abnormal process or condition which tends to
lower arterial pH if there are inadequate secondary changes in response to the
primary disease process. Two types: Respiratory and metabolic.
Acquired Immunity - ....ANSWER☑️☑️...-"The delayed onset but specific and
memory immunity after the first line innate immunity is breached. First exposure
allows identification and learning, and the second exposure initiates quick
mobilisation of lymphocytes. Major components: Humoral Immunity (B lymphocytes
producing specific antibodies), and Cellular Immunity (T lymphocytes)"
FOR STUDY PURPOSES ONLY ©️ 2025 ALL RIGHTS RESERVED 1
,Active Tension (Muscle) - ....ANSWER☑️☑️...-Active tension: the difference
between passive and total tension
Activity (Acid-Base) - ....ANSWER☑️☑️...-The effective concentration of a
substance in a reacting system
Adiabetic Heat - ....ANSWER☑️☑️...-Heat produced when a gas is compressed
Affinity - ....ANSWER☑️☑️...-"Avidity with which a drug binds to a receptor
(analogous to potency), or ability to bind to a receptor and form a stable complex.
Inverse of Kd."
Afterload - ....ANSWER☑️☑️...-Physiological def: Force restricting muscle fibre
shortening or weight/load that a contracting muscle must overcome prior to
shortening. <br>Clinical def: The impedance to the ejection of blood from the left
ventricle into the aorta
Aging - ....ANSWER☑️☑️...-"A normal physiological process of degeneration
beginning around age 30 and proceeding at a variable rate with obvious changes
becoming apparent at around age 60, and the end point being death."
Agonist - ....ANSWER☑️☑️...-Binds to receptor to produce responses that may be
excitatory or inhibitory. Partial agonist displays intermediate efficacy.
Airway Resistance - ....ANSWER☑️☑️...-"The resistance to the movement of air
through the airways. It is dependent on lung volume, bronchial smooth muscle tone,
bronchial mucosal engorgement, density and viscosity of the inspired gas, and the
respiratory rate."
Alkalaemia - ....ANSWER☑️☑️...-Arterial blood ph > 7.45 or [H+] < 36 mmol/L
Alkalosis - ....ANSWER☑️☑️...-An abnormal process or condition which tends to
raise arterial pH if there are inadequate secondary changes.
FOR STUDY PURPOSES ONLY ©️ 2025 ALL RIGHTS RESERVED 2
,Allodynia - ....ANSWER☑️☑️...-Pain due to a stimulus which does not normally
provoke pain. Stimulation of A beta fibres causes pain.
Alveolar Dead Space - ....ANSWER☑️☑️...-Part of inspired gas which passes
through the anatomical dead space and enters the alveoli but is not effective in gas
exchange given impaired perfusion.
Alveolar Ventilation - ....ANSWER☑️☑️...-"Effective ventilation of the alveoli, where
gas exchange with the blood takes place."
Ampere - ....ANSWER☑️☑️...-One Coulomb per second
Amplitude Linearity - ....ANSWER☑️☑️...-Amplifications of the signal should be
equal throughout the entire signal range to prevent distortion.
Anabolism - ....ANSWER☑️☑️...-Synthesis of cellular macromolecules
Anaesthesia - ....ANSWER☑️☑️...-Without sensation.
Analgesia - ....ANSWER☑️☑️...-Absence of pain in response to stimulation which
would normally be painful.
Analog Signal - ....ANSWER☑️☑️...-"A <b>continuous</b> signal for which the time
varying feature (variable) of the signal is a representation of some other time varying
quantity, i.e., analogous to another time varying signal."
Anaphylactoid Reaction - ....ANSWER☑️☑️...-"Clinically indistinguishable from
anaphylaxis but caused by complement activation or direct histamine release from
mast cells. *c.f. Anaphylaxis is a clinical syndrome produced by IgE type I
hypersensitivity resulting from antigen-antibody reaction at surface of mast cells. The
syndrome manifests as red rash/flush, bronchospasm, collapse, angioedema, GIT
symptoms. Requires prior exposure to antigen."
FOR STUDY PURPOSES ONLY ©️ 2025 ALL RIGHTS RESERVED 3
, Anaphylatoxins - ....ANSWER☑️☑️...-C3a and C5a which bind specific receptors on
mast cells and basophils causing degranulation.
Anaphylaxis - ....ANSWER☑️☑️...-"A clinical syndrome produced by IgE type I
hypersensitivity resulting from antigen-antibody reaction at surface of mast cells. The
syndrome manifests as red rash/flush, bronchospasm, collapse, angioedema, GIT
symptoms. Requires prior exposure to antigen."
Anatomical Dead Space - ....ANSWER☑️☑️...-The internal volume of the
conducting airways or that part of the inspired TV which is expired unchanged.
Anion - ....ANSWER☑️☑️...-Negatively charged ion.
Anion Gap - ....ANSWER☑️☑️...-"An estimate of unmeasured cations (Ca2+ and
Mg2+) and unmeasured anions (plasma proteins, phosphate, sulphate, lactate,
citrate, ketones) Some causes of metabolic acidosis release anions into the ECF
therefore creating an increased anion gap."
Anode - ....ANSWER☑️☑️...-Positive electrode to which anion is attracted.
Anrep Effect - ....ANSWER☑️☑️...-Intrinsic regulatory mechanism of the heart
whereby an abrupt increase in afterload produces transient increase in LVEPD and
decrease in SV allowing prompt restoration to near baseline values.
Antagonist - ....ANSWER☑️☑️...-"A substance that interacts with receptor or other
parts of effector mechanism to inhibit the action of an agonist, while initiating no
effect themselves."
ATPS - ....ANSWER☑️☑️...-"Ambient temperature and pressure, saturated with
water vapour (T amb, Pb, PH2O)"
FOR STUDY PURPOSES ONLY ©️ 2025 ALL RIGHTS RESERVED 4
