cells science

8/14/2019 Cells Science

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-A little mor e than half of the ad ults inthe Un ited Sta tes ar e o verw eight.Statist ics s how tha t an incr edible 65.2per cent o f the U .S . po pula tion iscons idered to be "o verwe igh t" or " obes e."Accor ding t o the Center s for Diseas eContr ol and Pr evention ( CDC ), obes ity andoverw eight st atus i s deter mined in adultsby finding a per son' s "Body Mass Inde x"or BMI .BMI is a calcula tion tha t takes intocons ideration b oth a per son' s bo dyweight and height to deter mine whetherthey a re underw eight, o verw eight or a t ahealthy weight. A n ad ult w ho iscons idered "o verwe igh t" has a BM Isomew her e bet ween 25 and 29.9. An ad ult

Fat cell


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Is an excitable cell in the nervous systemthat processes and transmitsinformation by electrochemicalsignalling. Neurons are the corecomponents of the brain, the vertebrate

spinal cord, the invertebrate ventralnerve cord, and the peripheral nerves. Anumber of specialized types of neuronsexist: sensory neurons respond to touch,sound, light and numerous other stimuliaffecting cells of the sensory organs thatthen send signals to the spinal cord and

brain. Motor neurons receive signalsfrom the brain and spinal cord and causemuscle contractions and affect glands.Interneurons connect neurons to otherneurons within the same region of thebrain or spinal cord. Neurons respond tostimuli, and communicate the presenceof stimuli to the central nervous system,which processes that information andsends responses to other parts of thebody for action. Neurons do not gothrough mitosis, and usually cannot be

Nervie cell


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Red blood cells are the most commontype of blood cell and the vertebratebody's principal means of deliveringoxygen to the body tissues via theblood. They take up oxygen in the lungsor gills and release it while squeezingthrough the body's capillaries. The cellsare filled with hemoglobin, abimolecular that can bind to oxygen.The blood's red color is due to the colorof oxygen-rich hemoglobin. In humans,

red blood cells develop in the bonemarrow and live for about 120 days;they take the form of flexible biconcavedisks that lack a cell nucleus andorganelles and they cannot synthesizeprotein.

Red blood cells are also known as RBCs,red blood corpuscles (an archaic term),haematids or erythrocytes (from Greekerythros for "red" and kytos for"hollow", with cyte translated as "cell"

Red blood cell


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Capillaries are the smallest of abody's blood vessels and arepart of the microcirculation.

These microvessels, measuring5-10 m in diameter, connectarterioles and venules, andenable the exchange of water,oxygen, carbon dioxide, andmany other nutrient and waste

chemical substances between

Cells in the wall of a

blood capillary


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Each nerve cell in the nose can sense more than oneodor, but picks up the smell to a different degree.An odor's unique signature depends on which cellsrespond to it, and how intensely.What happens when you inhale a rose is that a

group of cells is stimulated, and that group sends acombination of signals to the olfactory bulbthesite at the very front of the brain where smellperception takes place. This unique combination ofsignals tells the brain the odor is the smell of a

How the olfactory bulb interprets this signal as the smellof a rose is not well understood, but scientists do havesome insights into the process. For example, manyresearchers have used brain scans to see what areas ofthe brain become active after people are exposed todifferent smells. It is unclear, however, whether thatactivation corresponds to recognizing a given smell. Andother factorsfor example our past experiences withcertain smells, and whether we liked them or were turned

offalso play a role in how we perceive them.

Cells in the

cells science

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