Folded paper creates portable lab for field laboratory tests

Monitoring and tracking biological threats or epidemics require the ability to carry out medical and laboratory tests in the field during a disaster or other austere situations. Expensive laboratory equipment is often unavailable ...

Philippines: Still-unknown disease prompts culling of pigs

The Philippine agriculture chief said Monday that an unspecified number of pigs has died or been culled in backyard farms in recent weeks and a crisis team has been established to try to contain the still-unidentified disease ...

Damage found in the bit area of most Finnish trotting horses

In a Finnish study, damage was found in the part of the mouth affected by the bit in more than 80 percent of trotters examined after a race. However, such damage is easily overlooked due to being out of sight.

Direct detection of circulating tumor cells in blood samples

Tumor cells circulating in blood are markers for the early detection and prognosis of cancer. However, detection of these cells is challenging because of their scarcity. In the journal Angewandte Chemie, scientists have now ...

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Blood

Blood is a specialized bodily fluid that delivers necessary substances to the body's cells — such as nutrients and oxygen — and transports waste products away from those same cells.

In vertebrates, it is composed of blood cells suspended in a liquid called blood plasma. Plasma, which comprises 55% of blood fluid, is mostly water (90% by volume), and contains dissolved proteins, glucose, mineral ions, hormones, carbon dioxide (plasma being the main medium for excretory product transportation), platelets and blood cells themselves. The blood cells present in blood are mainly red blood cells (also called RBCs or erythrocytes) and white blood cells, including leukocytes and platelets. The most abundant cells in vertebrate blood are red blood cells. These contain hemoglobin, an iron-containing protein, which facilitates transportation of oxygen by reversibly binding to this respiratory gas and greatly increasing its solubility in blood. In contrast, carbon dioxide is almost entirely transported extracellularly dissolved in plasma as bicarbonate ion.

Vertebrate blood is bright-red when its hemoglobin is oxygenated. Some animals, such as crustaceans and mollusks, use hemocyanin to carry oxygen, instead of hemoglobin. Insects and some molluscs use a fluid called hemolymph instead of blood, the difference being that hemolymph is not contained in a closed circulatory system. In most insects, this "blood" does not contain oxygen-carrying molecules such as hemoglobin because their bodies are small enough for their tracheal system to suffice for supplying oxygen.

Jawed vertebrates have an adaptive immune system, based largely on white blood cells. White blood cells help to resist infections and parasites. Platelets are important in the clotting of blood. Arthropods, using hemolymph, have hemocytes as part of their immune system.

Blood is circulated around the body through blood vessels by the pumping action of the heart. In animals having lungs, arterial blood carries oxygen from inhaled air to the tissues of the body, and venous blood carries carbon dioxide, a waste product of metabolism produced by cells, from the tissues to the lungs to be exhaled.

Medical terms related to blood often begin with hemo- or hemato- (also spelled haemo- and haemato-) from the Ancient Greek word αἶμα (haima) for "blood". In terms of anatomy and histology, blood is considered a specialized form of connective tissue, given its origin in the bones and the presence of potential molecular fibers in the form of fibrinogen.

This text uses material from Wikipedia, licensed under CC BY-SA