Capillaries are the smallest of a body's blood vessels, measuring 5-10 μm. They connect arteries and veins, and most closely interact with tissues. Capillaries have walls composed of a single layer of cells, the endothelium. This layer is so thin that molecules such as oxygen, water and lipids can pass through them by diffusion and enter the tissues. Waste products such as carbon dioxide and urea can diffuse back into the blood to be carried away for removal from the body. Capillary permeability can be increased by the release of cer ...
A capillary wave is a wave travelling along a meniscus, whose dynamics are dominated by the effects of surface tension. Capillary waves are common in nature and the home and are often referred to as ripples. The wavelength of capillary waves is typically less than about a centimeter.
The dispersion relation for capillary waves is
ω2 = gk + (σ / ρ)k3
where ω is the frequency, g the acceleration due to gravity, σ the surface energy, ρ the density and k the wave ...
Capillary electrophoresis (CE) can be used to separate ionic species by their charge and frictional forces. In traditional electrophoresis, electrically charged analytes move in a conductive liquid medium under the influence of an electric field. Introduced in the 1960’s, the technique of capillary electrophoresis (CE) was designed to separate species based on their size to charge ratio in the interior of a small capillary filled with an electrolyte.
Other related archives1960’s, c
Capillary action or capillarity (also known as capillary motion) is the ability of a narrow tube to draw a liquid upwards against the force of gravity. It occurs when the adhesive intermolecular forces between the liquid and a solid are stronger than the cohesive intermolecular forces within the liquid. The effect causes a concave meniscus to form where the liquid is in contact with a vertical surface. The same eff ...
With notes on the dimension in SI units, the height h of a liquid column (m) is given by:
...where:
T = surface tension (J/m²)
θ = contact angle
ρ = density of liquid (kg/m3)
g = acceleration due to gravity (m/s²)
r = radius of tube (m)
For a water-filled glass tube in air at sea level,
T = 0.0728 J/m² at 20 °C
θ = 20° (0.35 rad)
ρ = 1000 kg/m3
g = 9.8 m/s²
...and so the height of the wat ...
A venule is a small blood vessel that allows blood to return from the capillary beds to the larger blood vessels called veins. Venules have three layers: An inner endothelium composed of squamous epithelial cells that act as a membrane, a middle layer of muscle and elastic tissue and an outer layer of fibrous connective tissue. The middle layer is poorly developed so that venules have thinner wal ...
Arteries are muscular vessels that carry blood away from the heart to the tissues and organs of the body (The vessels which return blood to the heart are veins).
The circulatory system is extremely important in sustaining life. Its proper functioning is responsible for the delivery of oxygen and nutrients to all cells, as well as the removal of carbon dioxide, waste products, maintenance of optimum pH, and the mobility of the elements, proteins and cells, of the immune system. In First World countries the two leading causes of ...
A wave is a disturbance that propagates in a periodically repeating fashion, often transferring energy. A mechanical wave exists in a medium (which on deformation is capable of producing elastic restoring forces) through which they travel and can transfer energy from one place to another without any of the particles of the medium being displaced permanently; there is no associated mass transport. Instead, any particular point oscillates around a fixed position. However, electromagnetic radiation, and probably gravitational radiation are not mechanical waves, and can ...
An arteriole is a blood vessel that extends and branches out from an artery and leads to capillaries.
Arterioles have thick muscular walls and are the primary site of vascular resistance. The mean blood pressure in the arteries supplying the body is a result of the interaction between the cardiac output (the volume of blood the heart is pumping per minute) and the vascular resistance, usually termed total peripher ...
A bruise or contusion or ecchymosis is a kind of injury, usually caused by blunt impact, in which the capillaries are damaged, allowing blood to seep into the surrounding tissue. Normally minor but painful, bruises can be serious, leading to hematoma, or can be associated with serious injuries, including fractures and internal bleeding. Minor bruises are easily recognized by their characteristic blue or p ...
Cohesion or cohesive attraction or cohesive force in chemistry is the intermolecular attraction between like-molecules. Cohesion explains phenomena such as surface tension. Capillary action for example described in the Cohesion-tension theory related to botany is considered a mix of cohesion and adhesion. Cohesion is produced by the intermolecular forces.
Other related archivesCapillary action, Cohesion-tension theory, adhesion, botany, chemistry, intermolecular attracti
In biology, a vein is a blood vessel which returns blood from the microvasculature to the heart. Veins form part of the circulatory system. The vessels carrying blood away from the heart are known as arteries.
Vein - Biological Vein.
Veins have one-way valves to prevent backflow caused by gravity.
In systemic circulation de-oxygenated blood from the capillary blood vessels is taken by veins to the right part of the heart. Differently, in the pulmonary circulation oxygenated blood from the lun ...
A viscometer (also called viscosimeter) is an instrument used to measure the viscosity and flow parameters of a fluid.
The classical method of measuring due to Stokes, consisted of measuring the time for a fluid to flow through a capillary tube. Refined by Cannon, Ubbelohde and others, the glass tube viscometer is still the master method for the standard determination of the viscosity of water. The vis ...
CE is an abbreviation which can have the following meanings:
Capillary electrophoresis
the CE mark is a stylized "CE" placed on products to signify conformance with European Union regulations. CE stands for Conformité Européenne (European health & safety product label).
Central European, an alternate name for Windows-1250
Civil Engineer (Engineer's degree in civil engineering)
Civil engineering
Collector's Edition (Used with special editions of software and movies)
< ...
The growth of helictites is still quite enigmatic. Until now, there has been no satisfactory explanation for how they formed. Currently, formation by capillary forces is the most likely theory, but another theory based on wind formation is also viable.
Helictite - Capillary forces.
The most likely theory explains helictites as a result of capillary forces. If the helictite has a very thin central tube where the water flows like it does in straws, capillary forces would be able to transport water against gr ...
Hematophagy is the habit of certain animals of feeding on blood (from the Greek words, haima, blood, and phagein, eat). Since blood is a fluid tissue rich in nutritious proteins and lipids and can be taken without enormous effort, hematophagy has evolved as a preferred form of feeding in many small animals, such as worms and arthropods. Some intestinal helminth worms, such as the Ascaris, feed on blood extracted from the capillaries of the gut and about 75% of all species of leeches (Hirudo medicinalis), a free-li ...
Exocrine gland refers to glands that secrete their products via a duct. This is as opposed to endocrine glands that release their products directly into the circulatory system via the capillary network. Typical exocrine glands include sweat glands, salivary glands, mammary glands and many glands of the digestive system.
Exocrine gland - Types.
Exocrine glands are named apocrine, holocrine, or merocrine based on how their product is secreted.
Apocrine glands - a portion of the sec ...
A Candle wick is a wick specifically adapted for use in a candle. A candle wick works by providing a mechanism, known as capillary action, to transport the fuel, typically melted candle wax, to the flame. When the liquid fuel reaches the flame it then vaporizes and burns.
Most candle wicks are impregnated or coated with wax to provide the initial fuel source when the candle is lighted. While the wick is consumed in the process of burning a candle the real fuel for the flame is the melted wax. As such all wicks are treated with ...
In medicine, vasculitis (plural: vasculitides) is a group of diseases featuring inflammation of the wall of blood vessels. Its main causes are autoimmune disorders and (occasionally) infections. Treatment depends on the cause. While most vasculitides are rare diseases, they generally affect several organ systems and can cause severe disability.
Vasculitis - Diagnosis.
The types of vasculitis are distinguished by the type of blood vessel affected (aorta, large arteries, arterioles, capillaries and vei ...
Water content is a ratio used in hydrogeology and soil mechanics to indicate the amount of water a porous medium contains. In fully saturated groundwater aquifers, all the available pore spaces are filled with water (volumetric water content = porosity). Above the capillary fringe, some of the pore spaces have air in them too. When the porous medium in question is soil, water content is synonymous with soil moisture.
Water content can either be the volumetric (by volume) or gravimetric (by weight) fraction of the total rock whi ...
