Formulae

Absorption

CWF-0012

$$Diffusion\;\propto{{1\over\sqrt{Molecular Weight}} \times {Surface\;Area \over Thickness} \times \Delta concentration}$$

Concepts in Pharmacology Obstetrics and Neonatal B1.ii B1.iv P2.v

3 answers · 1 alias

Absorption (First pass metabolism)

CWF-0013

$$F_{B} \; = \; F_{A} \; \times \; F_{G} \; \times \; F_{H}$$

Concepts in Pharmacology B1.iv

1 answer

Acetyl Choline

CWF-0150

$$Choline \; + \; Acetyl-CoA \;\; \xrightarrow{Choline \; Acetyltransferase} \;\; Acetylcholine$$

Musculoskeletal System I1.iii

1 answer

Airway Resistance

CWF-0028

$$Re\;={\;2\;r\;ρ\;v\;\over η}={diameter\;\times\;density\;\times\;velocity\;\over viscosity}$$

Respiratory System C3.vi

2 answers

Ammonia

CWF-0109

$$NH_4^+ \rightleftharpoons NH_3 + H^+$$

Renal System E1.v

1 answer

Ammonia (Urine)

CWF-0128

$$NH_3 \;+\; H^+ \; ⇌ \; NH_4^+$$

Acid–Base G1.iii

1 answer

Apparent SID and effective SID

CWF-0131

$$Abbreviated \; SID = [Na^+] - [Cl^-]$$

Acid–Base G1.iv

1 answer

Apparent SID and effective SID

CWF-0134

$$SIDe = [HCO_3^-] + [Alb^-] + [Pi^-]$$

Acid–Base G1.iv

1 answer

Bicarb (Plasma, Interstitium, Urine (minimal))

CWF-0135

$$H^+ \;+\; HCO_3^- \;⇌\; H_2CO_3 \;⇌\; H_2O \;+\; CO_2$$

Acid–Base G1.iii

1 answer

Bohr’s Method

CWF-0038

$${{V_D} \over {V_T}} = { {PA_{CO_2} \; - \; P\bar{E}_{CO_2}} \over {PA_{CO_2}}}$$

Respiratory System C6.ii

1 answer

Bohr’s Method

CWF-0039

$${{V_D} \over {V_T}} = { {Pa_{CO_2} \; - \; P\bar{E}_{CO_2}} \over {Pa_{CO_2}}}$$

Respiratory System C6.ii

1 answer

Bohr’s Method

CWF-0040

$${{V_D} \over {V_T}} = { {V_T \; - \; V_A} \over {V_T}}$$

Respiratory System C6.ii

1 answer

Boyle’s Law

CWF-0001

$$P\;\propto\;{1\over V}$$

General / Historical

1 answer

Cardiac Output

CWF-0085

$$Preload \; = \; {{{(LVEDP \; - \; ITP)} \times LVEDR} \over {2h}}$$

Cardiovascular System D3.ii

1 answer

Cardiac Output

CWF-0086

$$Right \, Ventricular \, Output \, = \, CO$$

Cardiovascular System D3.ii

1 answer

Cardiac Output

CWF-0087

$$VR \; = \; CO$$

Cardiovascular System D3.ii

1 answer

Cardiac Output

CWF-0088

$$VR \; = \; {{MSFP \; - \; RAP} \over {Venous \; Resistance}}$$

Cardiovascular System D3.ii

1 answer

Carriage of O2

CWF-0041

$$C_dO_2 \; = \; a_{O_2} \; \times \; P_{O_2}$$

Respiratory System C7.i

1 answer

Changes in Cerebral Blood Flow (CBF)

CWF-0148

$$CBF \; = {{CPP} \over {CVR}} = \; {{MAP - (greater \; of \; CVP \; or \; ICP)} \over {CVR}}$$

Nervous System Cardiovascular System H2.i D5.i

2 answers · 1 alias

Changes in Inspired and Alveolar PO2

CWF-0043

$$P_AO_2 \; = \; FiO_2 (P_{ATM} \; – \; SVP_{H2O}) \; – \; {{P_aCO_2} \over {RER}}$$

Respiratory System Obstetrics and Neonatal C8.iii C6.iv P1.i

3 answers · 2 aliases

Dalton’s Law (of partial pressures)

CWF-0002

$$P_{total}\;=\;P_{1}\;+\;P_{2}\;+\;P_{3}\;+\;.\;.\;.\;+P_{n}\;\equiv\;\sum_{i=1}^{n}\;P_{i}$$

General / Historical

1 answer

Definition

CWF-0014

$$Vd = {{Amount\;of\;drug\;in\;body} \over {Plasma\; concentration\;}}$$

Concepts in Pharmacology B1.iii

1 answer · 1 alias

Determinants of CBF

CWF-0149

$$Cerebral \; Blood \; Flow \; (CBF) \; = {{CPP} \over {CVR}} = \; {{Cerebral \; Perfusion \; Pressure} \over {Cerebrovascular \; Resistance}}$$

Nervous System H2.ii

2 answers

Diffusing capacity

CWF-0045

$$Flow \; of \; gas \; ∝ \; {{A} \over {T}} \; . \; D \; (P_1- P_2)$$

Respiratory System C7.v

1 answer

Diffusion via Fick’s Law

CWF-0046

$$D=Diffusion\;constant\;\propto\;{{Solubility}\over{\sqrt{Molecular\;Weight}}}$$

Cellular Physiology Respiratory System Obstetrics and Neonatal A.iv C7.i C7.vi P2.v

4 answers

Diffusion via Fick’s Law

CWF-0047

$$J\;={{D\;A\;\Delta C}\over{T}}$$

Cellular Physiology Respiratory System Obstetrics and Neonatal A.iv C7.i C7.vi P2.v

4 answers

Direct GFR Determinants

CWF-0110

$$GFR \; = \; K_f \; \times \; NFP$$

Renal System E1.iv

3 answers

Direct GFR Determinants

CWF-0111

$$NFP ={ [(P_{GC} - P_T) - \sigma \; (\pi_{GC} - \pi_T)]}$$

Renal System E1.iv

3 answers

Dynamic Compliance

CWF-0049

$$C_d \; ∼ \; {{\Delta volume} \over {initial \; \Delta transmural \; pressure}}$$

Respiratory System C3.iii

2 answers

Effect of ↑P in pulmonary vessels

CWF-0050

$$Vascular \; distensibility \; = {{increase \; in \; volume} \over {Increase \; in \; pressure\; \times \; original \; volume}}$$

Respiratory System C5.i

1 answer

Fick’s Law of Diffusion

CWF-0003

$$Diffusion \propto \;Diffusion\;Coefficient\;\:{(Concentration\;gradient\;×\;Surface\;area) \over Thickness}$$

General / Historical

1 answer

Filtered Load

CWF-0112

$$Filtered \; Load \; = \; GFR \; \times \; plasma \; concentration \; of \; substance \; (Px)$$

Renal System E1.iv

1 answer

Gibbs – Donnan Effect

CWF-0008

$$[Na^+]_A \;\times\; [Cl^−]_A \;=\; [Na^+]_B \;\times\; [Cl^−]_B$$

Cellular Physiology A.iv

1 answer

Gibbs-Donnan Effect

CWF-0009

$$Osmotic \; pressure \; (\pi) \; = \; {{nRT \times c} \over {M}}$$

Cellular Physiology A.iv

1 answer

Goldman-Hodgkin-Katz Equation

CWF-0010

$$E(mV) \;=\; {{R.T} \over {F}} \; \ln \; {{P_K[K^+]_o \; + \; P_{Na}[Na^+]_o \; + \; P_{Cl}[Cl^-]_i } \over { P_K[K^+]_i \; + \; P_{Na}[Na^+]_i \; + \; P_{Cl}[Cl^-]_o }}$$

Cellular Physiology A.iv

1 answer

Graham’s Law

CWF-0004

$$Diffusion\;\propto\;{1 \over \sqrt{MW}}$$

General / Historical

1 answer

Haemoglobin (Blood)

CWF-0137

$$H.Hb \;+\; KHCO_3 \;⇌\; K.Hb \;+\; H_2CO_3$$

Acid–Base G1.iii

2 answers

Haemoglobin (Blood)

CWF-0138

$$H.Hb \;⇌\; H^+ \;+\; Hb^-$$

Acid–Base G1.iii

2 answers

Haemoglobin (Blood)

CWF-0139

$$HA \;+\; K.Hb \; ⇌ \; H.Hb \;+\; KCl$$

Acid–Base G1.iii

2 answers

Henry’s Law

CWF-0005

$$p\;=\;k_{H}\;c$$

General / Historical

1 answer

Hepatic clearance

CWF-0017

$$Cl_{Hep} \; = \; Q_{H} \; \times \; ER_{Hep}$$

Concepts in Pharmacology Gastrointestinal System B1.iv J2.ii

2 answers · 1 alias

Hepatic clearance

CWF-0018

$$Cl_{Hep} \; = \; Q_{H} \; \times \; {{FU \; \times \; Cl_{Int}} \over {Q_{H} \; + \; FU \; \times \; Cl_{Int}}}$$

Concepts in Pharmacology B1.iv

1 answer

Hepatic Extraction Ratio

CWF-0016

$$ER_{Hep} \; = \; {{FU \; \times \; Cl_{Int}} \over {Q_{H} \; + \; FU \; \times \; Cl_{Int}}}$$

Concepts in Pharmacology B1.iv

1 answer

High Extraction Ratio

CWF-0094

$$CPP \; = \; ADP \; - \; (larger \; of \; LVDP \; or \; RAP)$$

Cardiovascular System D4.iv D3.v

2 answers · 2 aliases

In an alveolus

CWF-0055

$$Distending \; pressure \; = \; {{4 \, T} \over {r}}$$

Respiratory System C3.ix

1 answer

Laminar Flow

CWF-0006

$$\dot{Q} = {\Delta P \over R} = {(π\;r^4.\;\Delta P) \over{8\;η\;L}}$$

Renal System E2.i E1.i

3 answers · 3 aliases

Laminar Flow

CWF-0056

$$R\;=\;{8\;η\;l \over {π\;r^4}}$$

Respiratory System Cardiovascular System C3.vi D4.iii

3 answers · 1 alias

Lung compliance

CWF-0057

$$C_S \; = \; {{C_{Tot}} \over {FRC}}$$

Respiratory System C3.iii

2 answers

Measurement of Airway Resistance

CWF-0058

$$AWR \; = \; {{\Delta \, P} \over {Q}}$$

Respiratory System C3.vi

1 answer

Measurement of Airway Resistance

CWF-0059

$$V_{Lung} \; = \; { {P_{Atm} \; V_{init}} \over {P_{insp}}}$$

Respiratory System C3.vi

1 answer

Measurement of FRC

CWF-0060

$$FRC \; = \; {{Concentration \; \times Volume \; of \; Helium \; inhaled} \over {Concentration \; of \; helium \; exhaled}}$$

Respiratory System C4.ii

1 answer

Measurement of Volume of Distribution

CWF-0019

$$Vd = {Vd_1\; +\; Vd_2\; +\; ...}$$

Concepts in Pharmacology B1.iii

1 answer

Measurement of Volume of Distribution

CWF-0020

$$Vd = {{Dose} \over {C^0_p}}$$

Concepts in Pharmacology B1.iii

1 answer

Mechanism / Measurement

CWF-0061

$$FO_2Hb \; = \; {{oxy-Hb} \over {oxy-Hb \; + \; deoxy-Hb \; + \; carboxy-Hb \; + \; met-Hb}}$$

Respiratory System C9.i

2 answers

Modified Laplace Equation

CWF-0095

$$T \; = \; {{P \; R} \over {2 \; H}}$$

Cardiovascular System D3.ii

3 answers

Normal O2 supply to tissues

CWF-0154

$$C_aO_2 \; = \; (1.34 \times [Hb] \times S_aO_2) \; + \; 0.03(P_aO_2)$$

Haematological and Immunological System Renal System N1.vi E1.i

2 answers · 1 alias

Overview of renal Na + regulation

CWF-0123

$$Na \; excretion \; = \; Na^+ \; filtered \; - \; Na^+ reabsorbed$$

Body Fluids and Electrolytes F1.v

1 answer

Oxygen Content

CWF-0096

$$O_2 \; content \; = \; (O_2 \; carried \; by \; Hb) \; + \; (Dissolved \; O_2)$$

Respiratory System Cardiovascular System C7.i D3.viii

2 answers

Oxygen Delivery

CWF-0098

$$DO_2 \; = \; CO \; \times C_aO_2$$

Respiratory System Cardiovascular System Cellular Physiology Haematological and Immunological System C9.i D3.viii A.i C7.i N1.vi

5 answers · 3 aliases

Oxygen Delivery

CWF-0114

$$Oxygen \; delivery \; = \; Renal \; Blood \; flow \; \times \; CaO_2$$

Renal System E1.i

1 answer

Oxygen Demand

CWF-0099

$$VO_2 \; = \; CO \; \times (C_aO_2 \; - \; C_vO_2)$$

Respiratory System Cardiovascular System C9.i D3.viii

2 answers

Oxygen in the arterial blood

CWF-0027

$$Q_t \times C_aO_2 \;\; = \;\; (Q_{t-s} \times C_cO_2) \;\; + \;\; (Q_s \times C_{MV}O_2)$$

Respiratory System C7.i

1 answer

Oxyhaemoglobin dissociation curve

CWF-0068

$$O_2 \; concentration \; : \; (1.39 \; \times \; Hb \; \times \; sats) \; + \; (0.003 \; \times \; PO_2)$$

Respiratory System C7.ii

1 answer

pCO 2

CWF-0160

$$P_ACO_2 \; = {{CO_2 \; production} \over {Alveolar \; Ventilation}}$$

Obstetrics and Neonatal P1.i

1 answer

PD – Affinity and dissociation

CWF-0022

$$k = Ae^{-Ea \over RT}.$$

Concepts in Pharmacology Thermoregulation B2.i M1.iv

2 answers · 1 alias

PD – Affinity and dissociation

CWF-0023

$$k = Ae^{-\Delta G^0 \over RT}.$$

Concepts in Pharmacology B2.i

1 answer

Phenytoin or Aspirin

CWF-0024

$${Rate\;of\;elimination}={{\delta P} \over {\delta t}}={{V_{max} \times S} \over {K_m + S}}$$

Concepts in Pharmacology B1.iv

1 answer

Phosphate (Urine, Bone)

CWF-0143

$$H_3PO_4 \; ⇌ \; H^+ \;+\; H_2PO_4^-$$

Acid–Base G1.iii

1 answer

Potassium flux is dictated by

CWF-0124

$$E(mV) \;=\; {{R.T} \over {z.F}} \; \ln {{[ion]_{outside}} \over {[ion]_{inside}}}$$

Cellular Physiology Body Fluids and Electrolytes A.iv F1.v

2 answers

Principles

CWF-0069

$$R \; = \; { {Pulsatile_{660} \; / \; Non-Pulsatile_{660} } \over { Pulsatile_{940} \; / \; Non-Pulsatile_{940} } }$$

Respiratory System C9.i

1 answer

Proximal tubule

CWF-0119

$$H_2O + CO_2 \to H_2CO_3 \to H^+ + HCO_3^-$$

Renal System E1.v

1 answer

Regulation of Renal Blood Flow

CWF-0120

$$Renal \; Blood \; Flow \; = \; {{Renal \; arterial \; pressure \; - \; Renal \; venous \; pressure} \over {Renal \; vascular \; resistance}}$$

Renal System E1.i E1.iii

4 answers

Relative Humidity

CWF-0070

$$Relative \, Humidity \, = \, {{absolute \, humidity \, (actual) \, in \, the \, gas} \over {absolute \, humidity \, (saturated) \, at \, that \, temperature}}$$

Respiratory System C8.v

1 answer

Renal Drug Excretion

CWF-0025

$${Renal\;Drug\;Clearance} = { {Urine\; [Drug] \times V} \over {Plasma\; [Drug]} }$$

Concepts in Pharmacology B1.iv

1 answer

Resp Mechanics – Compliance

CWF-0071

$$Compliance \; = \; {{\Delta \, V} \over {\Delta \, P}}$$

Respiratory System C3.iii

2 answers

Resp Mechanics – Compliance

CWF-0072

$$\Delta \, P \; = \; Alveolar \; - \; Intrapleural \; pressure$$

Respiratory System C3.iii

2 answers

Resp Mechanics – Compliance

CWF-0074

$${{1} \over {Respiratory \, Compliance}} \; = \; {{1} \over {Lung\, Compliance}} + {{1} \over {Chest \, Wall\, Compliance}}$$

Respiratory System C3.iii

2 answers

Shunt equation

CWF-0075

$$Q_t (C_aO_2) \; = \; Q_{ns} (C_cO_2) \; + \; Q_s (C_{mv}O_2)$$

Respiratory System C6.iv

1 answer

SIG

CWF-0147

$$SIG \; = \; SIDa - SIDe$$

Acid–Base G1.iv

1 answer

Simplified equation for half life

CWF-0026

$$T_{1/2} = {{\ln(2)\; \times\; Vd} \over {Cl}}$$

Concepts in Pharmacology B1.iv

1 answer

Specific Compliance

CWF-0076

$$C_S \; = \; {{Static \; Compliance} \over {Lung \; Volume}}$$

Respiratory System C3.iii

2 answers

Starling Forces

CWF-0125

$$J_v={\kappa \; ([P_{capil} - P_{interstit}] - \sigma \; [\pi_{plasma} - \pi_{interstit}])}$$

Cellular Physiology Respiratory System Cardiovascular System Body Fluids and Electrolytes A.iv C5.i D4.v F1.ii

5 answers

Starling Forces

CWF-0126

$$P_{cap} \; \propto \; {{Post-capil\;resist} \over {Pre-capil \; resist}}$$

Cellular Physiology Cardiovascular System Body Fluids and Electrolytes A.iv D4.v F1.ii

4 answers

Systemic Vascular Resistance (Total Peripheral Resistance)

CWF-0104

$$Flow \; = \; {Pressure \over Resistance}$$

Cardiovascular System D4.iii

1 answer

Systemic Vascular Resistance (Total Peripheral Resistance)

CWF-0105

$$SVR \; = \; {{MAP \; - \; CVP} \over CO}$$

Cardiovascular System D4.iii

1 answer

Systemic Vascular Resistance (Total Peripheral Resistance)

CWF-0106

$${1 \over SVR} = {1 \over R_{1}} \; + \; {1 \over R_{2}}$$

Cardiovascular System D4.iii

1 answer

TBW distribution between ISF and intravascular compartments

CWF-0127

$$Net \; H_{2}O \; Flux = K_{f} \times { [(P_{CAP} - P_{ISF}) - \sigma \; (\pi_{CAP} - \pi_{ISF})]}$$

Body Fluids and Electrolytes F1.ii

1 answer

Temperature

CWF-0153

$$K \; = \; °C \; + \; 273.15$$

Thermoregulation M1.iii

1 answer

Total work and efficiency of breathing

CWF-0077

$$\% \; Efficiency \; = \; {{Useful \, Work} \over {Total \, energy \, expended \, (O_{2} \, cost)}} \; \times \; {100 \, \%}$$

Respiratory System C3.x

1 answer

Transfer

CWF-0156

$$Diffusion\;constant \; = \; {{Solubility \; \times \; Δ conc } \over {\sqrt{Molecular\;Weight}}} \; \times {{surf \; area} \over {thickness}}$$

Obstetrics and Neonatal P2.i

1 answer

Turbulent Flow

CWF-0007

$$\dot{Q} \propto \sqrt{\Delta P \over {ρ \times l} }$$

General / Historical

1 answer

Turbulent Flow

CWF-0078

$$R ∝ {ρ\;l \over {π\;r^5}}$$

Respiratory System C3.vi

2 answers

Uteroplacental blood flow

CWF-0159

$$UBF \; = \; {{(UAP \; - \; UVP)} \over {UVR} }$$

Obstetrics and Neonatal P2.i

1 answer

West Zone 1

CWF-0079

$$P_A \; > \; P_a \; > \; P_v$$

Respiratory System C5.i

1 answer

West Zone 2

CWF-0080

$$P_a \; > \; P_A \; > \; P_v$$

Respiratory System C5.i

1 answer

West Zone 3

CWF-0081

$$P_a \; > \; P_v \; > \; P_A$$

Respiratory System C5.i

1 answer

West Zone 4

CWF-0082

$$P_a \; > \; P_i \; > \; P_v \; > \; P_A$$

Respiratory System C5.i

1 answer