WK 2 Toxicology & ADME Principles: Cleaner M and Carbon Monoxide Investigations

Comprehensive vocabulary flashcards covering the core principles of ADME (Absorption, Distribution, Metabolism, Excretion), exposure pathways versus internal dose, biomonitoring, and the toxicokinetics of Cleaner M and carbon monoxide.

ADME

The framework of four toxicokinetic processes—Absorption, Distribution, Metabolism, and Excretion—that determine how a substance enters, moves through, is transformed by, and exits the body.

Absorption

The toxicokinetic process describing how much of an external substance crosses a biological barrier (such as the respiratory tract, gastrointestinal tract, or skin) to enter systemic circulation.

Distribution

The toxicokinetic process governing the movement and partitioning of an absorbed substance throughout bodily tissues, fluids, and organs via circulation.

Metabolism

The biological and enzymatic transformation of a chemical into different compounds (metabolites), which can convert substances into more water-soluble forms or modify their biological reactivity.

Excretion

The physical elimination of a parent chemical or its metabolites from the body, primarily occurring through the kidneys (urine), biliary system (feces), or lungs (exhalation).

Environmental Concentration

The measured quantity of a chemical present within an ambient environmental medium, such as sampled workplace or room air, which does not equal absorbed internal dose.

Exposure

Contact between an environmental agent and an external biological barrier of the body; contact provides an opportunity for entry but does not guarantee absorption.

Internal Dose

The actual quantity of an exposed agent that crosses a bodily barrier and enters the bloodstream or internal fluids.

Target-Tissue Dose

The exact amount of biologically active chemical or reactive metabolite that successfully reaches and interacts with the specific tissue or organ where toxic injury occurs.

Biomonitoring

The measurement of a parent chemical or its metabolites in biological specimens (such as blood or urine) to evaluate internal exposure at the time of sampling.

Detoxification

A metabolic pathway converting a chemical into a metabolite that is less biologically active, less toxic, and/or easier to eliminate, exemplified by Cleaner M forming M-1.

Bioactivation

A metabolic pathway converting a chemical into a metabolite that is more biologically reactive or toxic than the original parent compound, exemplified by Cleaner M forming M-2.

Phase I Enzymes

A group of modifying enzymes, notably the Cytochrome P450 family, that chemically alter parent substances into reactive intermediates or products that can either detoxify or activate a toxicant.

Upstream Intervention

A preventive control measure applied directly at the source or exposure pathway (such as eliminating use or using containment) to block contact before internal entry and harm can occur.

Blood Flow (Distribution Factor)

A physiological determinant of toxicant distribution wherein well-perfused organs (such as the liver, kidneys, and brain) receive delivered toxicants more rapidly than poorly perfused tissues.

Tissue Affinity

The selective preference of specific toxicants to partition into or bind within certain organs and tissues based on their individual chemical properties.

Blood-Brain Barrier (BBB)

A specialized biological barrier that restricts the migration of many circulating toxicants from the bloodstream into brain tissue.

Renal Function

The physiological ability of the kidneys to filter systemic blood; impairment can retard toxicant excretion, prolonging internal persistence and predisposing to toxicity.

Carbon Monoxide ($\text{CO}$)

A colorless, odorless toxic gas generated by the incomplete combustion of carbon-based fuels that enters the body primarily through inhalation and binds to heme proteins.

Carboxyhemoglobin ($\text{COHb}$)

A complex formed when carbon monoxide binds to hemoglobin binding sites, reducing oxygen-carrying capacity, tightening the hold on remaining oxygen, and serving as a blood biomarker of $\text{CO}$ exposure.

Oxyhemoglobin

The normal physiological complex formed by molecular oxygen ($\text{O}_2$) reversibly bound to hemoglobin for systemic tissue transport.

Blood Co-oximetry

A clinical laboratory spectrophotometric blood analysis capable of distinguishing and directly quantifying the fraction of carboxyhemoglobin ($\text{COHb}$) in systemic blood.

Pulse Oximetry

A standard non-invasive transcutaneous finger-clip measurement that assesses apparent oxygen saturation but may fail to differentiate oxyhemoglobin from carboxyhemoglobin ($\text{COHb}$).

Exhalation ($\text{CO}$ Elimination)

The primary elimination pathway for absorbed carbon monoxide, in which $\text{CO}$ dissociates from hemoglobin in the pulmonary capillaries and is expired intact via the lungs without undergoing significant hepatic metabolism.

Carbon Monoxide Alarm

An indoor safety instrument that alerts occupants to dangerous concentrations of airborne $\text{CO}$, signaling a hazardous environment without establishing personal absorbed dose or individual health outcome.