Page 80 - Photosynthesis: The Green Miracle

The scent laboratories in plants never make mistakes.
Thanks to their perfection, we always obtain the same
smell from the same species of flower anywhere in the
world. Fruits also smell the same everywhere.
Plants, rivaling perfume laboratories as they do,
are among the proofs of the glory of Allah’s cre-
ation.

Smell and Memory

Smells can bring memories back to life—a frequent phenomenon.
When a human being smells something, molecules belonging to that odor
have entered the nose. Scent molecules are transported through the air at

even quite low temperatures. A light wind will carry these scent molecu-
les to the back of the nose, where they encounter a moist tissue consisting
of some 5 million cells known as neurons that detect smell.
Receptors—tiny protrusions, at the end of each one of these cells—
traps scent molecules. These sensors are linked to the cell interior. When
a scent molecule lands on this trap, it sends a series of signals, and the req-
uisite message thus passes from inside the cell to the olfactory center at

the base of the brain, all in less than a second. These signals then leave
there and head for the limbic system of the brain thought to be responsi-
ble for sensation and motivation. 26
We can then determine what this resulting smell actually belongs to,
and whether it’s pleasant or not. Attractive smells lead to senses of pleas-
ure. A familiar smell immediately stimulates memories regarding its
source. For example, when you smell a lemon, you may think of lemon-

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