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What is the definition of "pCO2?"

Lower levels of carbon dioxide in the arterial system are often given as carbon dioxide partial pressure or pCO2. The venous system carries carbon dioxide throughout a human body, and the carbon dioxide is breathed out through a person's lungs. Carbon dioxide content is therefore low in the respiratory system and high in the venous system, which results in the aforementioned low carbon dioxide levels in the arterial system.

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What is meant by the all-or-none principle of neuronal firing?

Neuronal activation is controlled by an electrical potential that is created through the separation of sodium and potassium ions across the neuron's membrane. The voltage measures the difference in this electric charge between the inside and outside of the cell.\nAt rest, the sodium ions are kept outside the cell and the potassium ions are kept inside the cell by the sodium-potassium pump. The resting potential is -70mV (millivolt), which means the charge inside the cell is 70 mV less than outside the cell.\nWhen the neuron cell receives a signal, some of the sodium channels open, and the..

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What is a blood moon?

Different atmospheric conditions during an eclipse, including humidity, dust, temperature and more, can make the blood moon vary in color, from a more coppery hue to a deep red. In folklore, the term hunter's moon is also sometimes used interchangeably with the term blood moon. This blood moon refers to a specific full moon, however, which occurs after the harvest moon and the autumn equinox, usually in October.

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What are some noteworthy magnetism experiments?

William Gilbert, the royal physician to Queen Elizabeth I, experimented with a scale model of the planet Earth made from a lodestone. He was curious about why a compass needle pointed north, and he hypothesized that the Earth itself was a giant magnet. Passing a compass over his scale model, he demonstrated that the compass pointed towards the magnetic pole of the model, just like it did with the Earth.\nDanish physicist Hans Christian Orsted was the first scientist to discover a link between magnetism and electricity. During a lecture in 1820, Orsted noticed that a compass needle deflected fr..

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Which two continents are similar in physical shape?

Billions of years ago, Earth was home to one giant land mass known as Pangaea. As time has passed, the movement of the tectonic plates under Earth's crust has separated this land mass into seven continents. When examining the edges of continents on a globe, one can not only see how similar the continents are but also see the way they would fit together if the earth shifted back to its original state.

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How is gravity created?

Newton famously described the mechanics of gravity using the inverse square law, stating that the attractive force between two masses is proportional to the square of the distance between them. His equation works well, but never addresses why gravity works, or why the distance between the two masses matters. Einstein’s theory addressed the distance issue, showing how gravity works using the curvature of space-time, and why it gets stronger as the two objects get closer. Einstein’s theory also predicts gravitational waves that would propagate the force, but these remain theoretical.\nGravit..

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What is a solution in scientific terms?

Solutions are formed by having one substance, which is called the solute, dissolve into another substance, which is known as the solvent. According to HowStuffWorks, one of the most abundant solutions in the world is seawater. Seawater consists mostly of salt, which in this case is the solute, and water, which is the solvent.\nA solution can occur in any of three states of matter: liquid, solid and gas. Most commonly solutions are liquids that are made of a solid, liquid or gas that gets dissolved into a liquid solvent. Other solutions can be the result of a liquid dissolving into a gas, a sol..

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What is a temperate phage?

Such a phage is known as a lysogen, and it is said to display lysogeny. The phages can integrate their complete genetic information (genome) into that of the bacteria that host them, and a temperate phage can infect the host bacteria. On infecting the bacteria, it can either behave like virulent phage by entering into the lytic cycle or can get into a symbiotic relationship with the hosting bacteria. When behaving in the latter way, the phage is carried on to the descendants of the hosting bacteria.

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What element has four neutrons?

In appearance, lithium has a lustrous, silvery-gray color. Its atomic weight is 6.941 grams per mole. It is a soft metal that is not present in pure form in nature. It is found in a mineral called petalite. Although lithium is considered the lightest among metals, its heat capacity is very high. Some uses of lithium are in the fabrication of batteries, ceramics, glass and as a coolant for nuclear reactors. The lithium compound lithium carbonate also has medical uses, such as for the treatment of manic depression.

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What is the function of a test tube?

Test tubes are usually made of borosilicate glass so they can resist reaction with chemicals and withstand temperature changes without breaking. Some test tubes are made from plastic and in most cases they are disposed of after use unlike the ones made from glass.\nTest tubes come in several sizes and shapes. The standard laboratory test tube size measures 18 x 150mm. Test tubes that come without a lip are called culture tubes. They are usually used in biology for culturing live organisms such as bacteria, molds and seedlings. In medicine, culture tubes are used to store fluids and samples of ..

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