Cardiopulmonary, Metabolic, Renal & Hepatic Physiology – Key Vocabulary

A comprehensive set of vocabulary flashcards covering cardiovascular responses and adaptations to exercise, metabolic pathways and energetics, renal structure and function, hepatic and pancreatic physiology, referred pain patterns, and common liver pathologies.

Cardiac Output (Q)

The volume of blood the heart pumps per minute; calculated as Heart Rate × Stroke Volume.

Heart Rate (HR)

The number of heartbeats per minute; rises to maintain cardiac output when stroke volume plateaus.

Stroke Volume (SV)

The amount of blood ejected by the left ventricle with each beat.

Mean Arterial Pressure (MAP)

Average arterial pressure during a single cardiac cycle; MAP = Cardiac Output × Total Peripheral Resistance.

Total Peripheral Resistance (TPR)

The resistance to blood flow offered by the systemic vasculature; decreases during exercise owing to vasodilation.

Systolic Blood Pressure (SBP)

Arterial pressure during ventricular contraction; rises proportionally with dynamic exercise intensity.

Diastolic Blood Pressure (DBP)

Arterial pressure during ventricular relaxation; changes minimally during dynamic exercise.

Myocardial Contractility

The intrinsic ability of cardiac muscle to generate force; contributes to exercise-induced SBP rise.

Arteriolar Vasodilation

Widening of arterioles, especially in active muscles, reducing TPR and stabilising DBP.

Sympathetic Nervous System (SNS)

Autonomic division that increases HR, contractility, and systemic vasoconstriction during exercise.

Epinephrine (Adrenaline)

Catecholamine that boosts HR, contractility, and muscle vasodilation during exercise.

Blood-Flow Redistribution

Shift of cardiac output from 15–20 % at rest to 80–85 % toward skeletal muscle during heavy exercise.

Capillary Recruitment

Opening of previously non-perfused capillaries in exercising muscle to augment blood flow.

Left-Ventricular (LV) Volume

Chamber size that enlarges with endurance training, raising stroke volume.

Plasma Volume (PV)

Liquid component of blood that expands with training, increasing preload and aiding thermoregulation.

Preload (End-Diastolic Volume)

Ventricular filling volume prior to contraction; enhanced by larger plasma and venous return.

Afterload

Arterial resistance against which the heart pumps; reduced by training-induced vasodilation.

Respiratory Exchange Ratio (RER)

VCO₂ / VO₂; indicates substrate use (0.7 = fat, 1.0 = carbohydrate).

Ventilatory Threshold (VT)

Exercise intensity (≈50–75 % VO₂max) where minute ventilation rises exponentially.

Ventilatory Breakpoint

Point where VE increases disproportionately to VO₂ because of accumulating CO₂ and H⁺.

(a-v)O₂ Difference

Difference in O₂ content between arterial and venous blood; widens with exercise intensity.

Lactate Threshold (LT)

Exercise intensity where blood lactate begins an exponential rise; predictor of endurance performance.

ATP-PCr System

Immediate energy system in cytosol using phosphocreatine to regenerate ATP for ~0–10 s efforts.

Glycolytic System

Anaerobic breakdown of glucose to pyruvate/lactate generating ATP for short-term high-intensity work.

Oxidative (Aerobic) System

Mitochondrial ATP production via Krebs cycle and electron transport; dominant during prolonged exercise.

Catabolism

Metabolic pathways that break complex molecules into simpler ones, releasing energy.

Anabolism

Metabolic pathways that build complex molecules from smaller units, requiring energy.

Carbohydrate Energy Content

4 kcal of energy per gram of carbohydrate.

Fat Energy Content

9 kcal of energy per gram of fat.

Glycogenolysis

Breakdown of glycogen into glucose.

Glycogenesis

Formation of glycogen from glucose.

Gluconeogenesis

Creation of glucose from non-carbohydrate precursors.

Lipolysis

Breakdown of triglycerides into glycerol and free fatty acids.

Lipogenesis

Formation of triglycerides from glycerol and fatty acids.

Proteolysis

Breakdown of proteins into amino acids.

Erythropoiesis

Production of red blood cells; increases with aerobic training.

Nephron

Functional unit of the kidney responsible for urine formation.

Glomerulus

Capillary tuft in the renal corpuscle where filtration occurs.

Bowman’s Capsule

Cup-shaped structure surrounding the glomerulus collecting filtrate.

Proximal Convoluted Tubule

First nephron segment where majority of reabsorption occurs.

Loop of Henle

Nephron segment creating medullary osmotic gradient via descending and ascending limbs.

Distal Convoluted Tubule

Nephron portion regulating electrolyte and acid–base balance.

Collecting Duct

Final nephron segment concentrating urine under hormonal control.

Filtration (Kidney)

Movement of plasma constituents from glomerulus into Bowman’s capsule.

Tubular Secretion

Transfer of substances from peritubular capillaries into nephron tubules.

Excretion Formula

Urine excretion = Filtration + Secretion − Reabsorption.

Kidney Core Functions

Regulation of fluid balance, pH, blood pressure, erythrocyte production, bone metabolism & waste removal.

Acute Renal Failure

Sudden loss of kidney function, elevating BUN and creatinine.

Chronic Renal Failure

Progressive kidney function decline leading to end-stage renal disease.

Uremia

Toxic accumulation of nitrogenous waste in blood due to renal failure.

Hepatocyte

Primary functional cell of the liver, comprising 70–80 % of its volume.

Hepatic Artery

Supplies ~25–30 % of liver blood flow with oxygen-rich arterial blood.

Hepatic Portal Vein

Delivers ~70–75 % of liver blood flow rich in nutrients from GI tract.

Drug & Hormone Metabolism (Liver)

Liver detoxifies drugs (e.g., penicillin) and metabolises hormones (e.g., estrogen, cortisol).

Glycogenolysis (Liver)

Liver process converting glycogen back to glucose for blood release.

Gluconeogenesis (Liver)

Liver synthesis of glucose from lactate, amino acids, or glycerol.

Ketogenesis

Hepatic production of ketone bodies as alternate fuel during low-carbohydrate states.

Beta-Oxidation

Mitochondrial oxidation of fatty acids to acetyl-CoA for energy.

Pancreatic Endocrine Function

Secretion of insulin, glucagon, and somatostatin regulating blood glucose.

Insulin

Hormone that promotes cellular uptake and storage of glucose.

Glucagon

Hormone stimulating hepatic glycogenolysis and gluconeogenesis to raise blood glucose.

Somatostatin (Pancreas)

Hormone inhibiting release of insulin and glucagon.

Pancreatic Exocrine Function

Secretion of digestive enzymes and bicarbonate into the duodenum.

Trypsin

Pancreatic protease that digests proteins in the small intestine.

Pancreatic Amylase

Enzyme that hydrolyses starch to maltose and glucose.

Pancreatic Lipase

Enzyme that breaks triglycerides into fatty acids and monoglycerides.

Nucleases (Pancreas)

Enzymes that digest DNA and RNA.

Referred Pain

Perception of visceral pain at a distant somatic site (e.g., liver to right shoulder).

Right Upper Quadrant (RUQ) Organs

Gallbladder, right lobe of liver, small intestine, transverse/ascending colon, right kidney.

Left Upper Quadrant (LUQ) Organs

Left lobe of liver, stomach, spleen, pancreas, small intestine, transverse/descending colon, left kidney.

Hepatitis A Virus (HAV)

Acute, non-chronic hepatitis transmitted via fecal-oral route; preventable with vaccine.

Hepatitis B Virus (HBV)

Hepatitis transmitted via blood/body fluids; vaccine available; can co-infect with HDV.

Cirrhosis

Irreversible chronic liver injury leading to fibrosis and impaired function.

Dupuytren’s Contracture

Hand deformity (4th & 5th digits) associated with cirrhosis.

Palmar Erythema

Redness of palms due to vasodilation from elevated estradiol in liver disease.

Ascites

Pathological accumulation of fluid in the peritoneal cavity, common in cirrhosis.

Angiomas

Dilated superficial blood vessels seen with chronic liver disease.