Let’s learn about adrenaline

adrenal glands: Hormone-producing glands that sit at the top of the kidneys.

adrenaline: A hormone produced by glands (adrenal) when someone is stressed by fear, anger or anxiety. It can make the heart beat faster and allow muscles to perform better than normal. Adrenaline is part of the body’s “fight or flight” response to stress. It can briefly help someone run faster or temporarily boost the performance of muscles (as for lifting weights).

chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H₂O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.

chemical messenger: (in physiology) Molecules that send signals from one place to another within the body. Messages pass from one neuron to another via chemical messengers. Hormones are another family of chemical messengers that relay signals from one body part to another.

epinephrine: A type of stress hormone, commonly called adrenaline, that is secreted by the adrenal glands. It constricts blood vessels. It also increases the force and rate at which the heart contracts.

fight-or-flight response: The body’s response to a threat, either real or imagined. During the fight-or-flight response, digestion shuts down as the body prepares to deal with the threat (fight) or to run away from it (flight).

gland: A cell, a group of cells or an organ that produces and discharges a substance (or “secretion”) for use elsewhere in the body or in a body cavity, or for elimination from the body.

hormone: (in zoology and medicine) A chemical produced in a gland and then carried in the bloodstream to another part of the body. Hormones control many important body activities, such as growth. Hormones act by triggering or regulating chemical reactions in the body.

kidney: Each in a pair of organs in mammals that filters blood and produces urine.

muscle: A type of tissue used to produce movement by contracting its cells, known as muscle fibers. Muscle is rich in protein, which is why predatory species seek prey containing lots of this tissue.

nerve: A long, delicate fiber that transmits signals across the body of an animal. An animal’s backbone contains many nerves, some of which control the movement of its legs or fins, and some of which convey sensations such as hot, cold or pain.

organ: (in biology) Various parts of an organism that perform one or more particular functions. For instance, an ovary is an organ that makes eggs, the brain is an organ that makes sense of nerve signals and a plant’s roots are organs that take in nutrients and moisture.

oxygen: A gas that makes up about 21 percent of Earth’s atmosphere. All animals and many microorganisms need oxygen to fuel their growth (and metabolism).

stressor: Something that induces stress in an individual or system.

system: A network of parts that together work to achieve some function. For instance, the blood, vessels and heart are primary components of the human body’s circulatory system. Similarly, trains, platforms, tracks, roadway signals and overpasses are among the potential components of a nation’s railway system. System can even be applied to the processes or ideas that are part of some method or ordered set of procedures for getting a task done.

tissue: Made of cells, it is any of the distinct types of materials that make up animals, plants or fungi. Cells within a tissue work as a unit to perform a particular function in living organisms. Different organs of the human body, for instance, often are made from many different types of tissues.

vein: (in zoology) Part of a body’s circulation system. These tubes usually carry blood toward the heart.