Anatomy & Physiology Fundamentals Flashcards

Which anatomical structure acts as the blood-brain barrier and limits the passage of many occupational neurotoxins into the central nervous system?

Answer: Tight junctions between cerebral endothelial cells

Tight junctions between the endothelial cells lining cerebral capillaries form the blood-brain barrier, restricting passage of many toxins, though lipid-soluble solvents can penetrate it readily.

The diaphragm's role in respiration is relevant to occupational health because its paralysis or weakness due to toxic exposure would cause:

Answer: Impaired ventilation and potentially fatal respiratory failure

The diaphragm is the primary muscle of inspiration; its paralysis from neurotoxic agents (e.g., organophosphates) eliminates the pressure gradient needed for breathing, causing respiratory failure.

Carpal tunnel syndrome, common in repetitive occupational tasks, involves compression of which nerve as it passes through the wrist?

Answer: Median nerve

The median nerve passes through the carpal tunnel and is compressed by inflammation or edema from repetitive wrist flexion and extension, causing pain, numbness, and weakness.

A toxicologist reports that a chemical is 'hepatotoxic.' A safety specialist should monitor which enzyme levels as a biomarker of liver damage?

Answer: ALT and AST

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are released into the bloodstream when hepatocytes are damaged, making them standard liver injury biomarkers.

Which anatomical feature of the lung is designed to maximize surface area for gas exchange and is estimated to cover approximately 70 square meters?

Answer: Alveolar sacs

The approximately 300–500 million alveolar sacs in both lungs create a combined surface area of about 70 m², optimizing O2/CO2 exchange between air and capillary blood.

During an industrial fire exposure assessment, understanding that hemoglobin's oxygen-dissociation curve shifts RIGHT at higher temperatures means:

Answer: Hemoglobin releases oxygen more readily to tissues under heat stress

A rightward shift in the oxygen-dissociation curve (Bohr effect) indicates reduced hemoglobin-oxygen affinity, facilitating oxygen unloading to metabolically active tissues during heat stress.

Which bone type, classified by shape, forms the vertebral column and is critical in assessing back injury risk in manual material handling jobs?

Answer: Irregular bones

Vertebrae are classified as irregular bones due to their complex shape, and they house and protect the spinal cord while absorbing compressive forces in lifting tasks.