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Answer:
The ability of caffeine to inhibit adenosine receptors, plays a very important role in heightened alertness and sleeplessness.
Explanation:
"<em><u>Caffeine</u></em>" (<em>1,3,7-trimethylxanthine</em>) is an alkaloid obtained from plants. It has a chemical formula of C8H10N4O2.
Caffeine is generally <em>hydrophillic</em> but sufficiently <em>lipophilic</em> to pass through all biological membranes and readily cross the blood-brain barrier.
Therefore can bind with the adenosine receptors. Due to the blocking of adenosine inhibitory effects through its receptors held by paraxanthine and caffeine, it indirectly affects the release of <u>norepinephrine, dopamine, acetylcholine, serotonin, glutamate</u> e.t.c.
The release of the above-mentioned hormones have a great impact on the heightened alertness of the body, especially <em>dopamine</em> and <em>serotonin</em>.
At short focusing distances, ciliary muscles contract causing the suspensory ligaments to tighten.
The ciliary muscle is an integral muscle of the eye that is constructed as a ring of smooth muscle in the middle layer of the eye, the uvea (vascular layer). It regulates the passage of aqueous humor into Schlemm's canal and governs accommodation for observing objects at different distances.
A suspensory ligament is a ligament that provides support to a body part, particularly an organ. The suspensory ligament protects the fetlock from hyperextension (i.e., falling too low) during exercise. The ligament begins in both the fore and hindlimbs at its connection to the back of the upper cannon bone.
When the ciliary muscle relaxes, its diameter increases; when the suspensory ligaments tighten, the lens becomes thinner. This occurs when concentrating on a celestial object. When the ciliary muscle contracts, the lens becomes much more circular and has more focusing power because the pressure on the zonular fibers is reduced. When the ciliary muscles relax, these fibers contract, pulling the lens out and creating a flatter shape with less focusing power
For more information on suspensory ligaments, visit :
brainly.com/question/12999415
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Remains as snake is a cold blooded animal
