For the Heart Muscle, the Most Important Substance in the Blood

question 188

Multiple Choice

For the heart muscle, the most important substance in the blood is:

• A)glucose
• B)iron
• C)protein
• D)oxygen

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Definitions:

Winter Months

The coldest season of the year in polar and temperate zones, typically marked by short days, long nights, and lower temperatures.

Suprachiasmatic Nucleus

A tiny region in the brain's hypothalamus responsible for controlling circadian rhythms.

Circadian Rhythms

Physical, mental, and behavioral changes that follow a 24-hour cycle, responding primarily to light and darkness in an organism's environment, affecting sleep patterns among other bodily functions.

Biological Clock

An internal mechanism that regulates bodily rhythms and cycles, such as sleep and wakefulness, on a roughly 24-hour cycle.