Plasma

Plasma (pronounced plaz-muh)

(1) In anatomy, physiology & hematology, the liquid part of blood or lymph, as distinguished from the suspended elements; A clear component of blood or lymph containing fibrin.

(2) In cell biology, a former name for protoplasm; cytoplasm

(3) In cheese-making, a less common term for whey (a milk serum, separating as liquid from the curd after coagulation, as in cheese making).

(4) In mineralogy, a green, faintly translucent chalcedony.  Heliotrope is a green variety of chalcedony, containing red inclusions of iron oxide that resemble drops of blood, giving heliotrope its alternative name of bloodstone. In a similar variety, the spots are yellow instead, known as plasma.

(5) In physics, a highly ionized gas containing an approximately equal number of positive ions and electrons.

(6) In historic medicine, a mixture of starch and glycerin, once used as a substitute for ointments.

(7) In digital graphics (as demoscene), a visual effect in which cycles of changing colors are warped in various ways to give the illusion of liquid organic movement.

1712: From the Late Latin plasma (literally "mold") from the Ancient Greek πλάσμα (plásma) (something molded or formed, hence "image, figure; counterfeit, forgery; formed style, affectation”), akin to plássein (to form, mold; (and related to the modern plastic).  The Ancient Greek plásma originally meant "to spread thin" from the primitive Indo-European plath-yein, from the root pele (flat; to spread).  The original meaning in English was the now obsolete "form; shape" which reflected the classical form of the earlier plasm, the sense of a "liquid part of blood" dating from 1845 while that of "ionized gas" was from 1928.  Plasma is a noun and plasmatic & plasmic are adjectives; the noun plural is plasmas.

Plasma physics

Although plasma was first observed (and named “radiant matter”) in 1879 by British chemist and physicist Sir William Crookes (1832–1919),its nature wasn’t identified until work in 1897 by British physicist Sir Joseph Thomson (1856–1940).  The term “plasma” was first used in 1928 by American chemist, physicist, and engineer Irving Langmuir (1881–1957), the word chosen as a description of ionised gas because Langmuir noted the similarity between the transport of electrons from thermionic filaments and the way blood plasma carries the red and white corpuscles. 

Almost all observable matter in the universe is in the plasma state. Formed at high temperatures, plasmas consist of freely moving ions and free electrons and are known as the “fourth state of matter” because their unique physical properties distinguish them from solids, liquids and gases.  Plasma densities and temperatures greatly vary, from the cold gases of interstellar space to the extraordinarily hot, dense cores of stars and inside a detonating nuclear weapon.  Plasma and ionized gases possess unique properties quite unlike those of the other three states, the transition between them more a definitional question of the point(s) at which nomenclature shifts from one to the other; a kind of demarcation dispute between physicists.  A wholly speculative dispute is whether plasma is the most abundant form of ordinary matter in the universe, something impossible to determine because of uncertainty surrounding the existence and properties of dark matter.  Based on the existing mathematical models of the universe, there should be a great deal more matter and energy than has ever been observed, hence the “dark” fudge.  The assumption is that both are there but because they’re “dark” we can’t see them.  That assumption is however based on other known orthodoxies and either the existence or the deduced volume of dark matter may be found to be errors if any of those orthodoxies are either disproved or proved to have been wrongly calculated.  In the history of science, probably most orthodoxies have be overturned.

Plasma and blood

Plasma & platelets not separated: Lindsay Lohan in a blood-soaked photo-shoot by Tyler Shields (b 1982), Los Angeles, 2011.  Shields had worked with blood before, once completing a painting with blood from twenty donors, obtained using a commercial service after physicians declined to be involved in the project.

Plasma is the liquid component of blood and in human blood and by volume, some 55% of blood is plasma, the remainder made of red & white blood cells and platelets, all of which is suspended in the plasma which is about 92% water, a further 7% containing vital proteins such as albumin, gamma globulin and anti-hemophilic factor while the remaining 1% consists of mineral salts, sugars, fats, hormones and vitamins.  Plasma is vital for human function because it (1) assists in the maintenance of blood pressure and volume (2) transports the proteins critical for blood clotting and immunity, (3) carries electrolytes such as sodium and potassium on which muscles depends and (4) assists cell function by maintaining the body's pH balance.

In clinical medicine, plasma is given to trauma, burn and shock patients, as well as people with severe liver disease or multiple clotting factor deficiencies.  It boosts a patient’s blood volume, helping to prevent shock and encouraging clotting.  Pharmaceutical companies use plasma to make treatments for conditions such as immune deficiencies and bleeding disorders and in blood donations, the liquid portion can be separated from the cells.  As blood is drawn from the arm, it is fed through a machine which collects the plasma, the donor’s red blood cells and platelets then returned to the donor along with some saline. Remarkably, the process takes little longer than donating whole blood.  Donated plasma is frozen within 24 hours of being donated to preserve its clotting factors and can then safely be stored for up to a year, thawed for transfusion when needed.