News tagged with blood

Related topics: red blood cells · blood vessels · blood cells · cells · white blood cells

Sleep apnea devices lower blood pressure

(HealthDay)—For those suffering from sleep apnea, the disrupted sleep and reduction of oxygen getting to the brain can contribute to high blood pressure, but the two common treatments for the condition both lower blood ...

4 hours ago
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Blood test reveals how old your body really is

Now a simple blood test can reveal your biological age—how old your body really is. This was found in a new study from Uppsala University, the results of which are now being published in the open-access journal Scientific ...

9 hours ago
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Scientists create a multifunctional endoscope

Cancer is a malignant force of nature that holds no prejudice when it invades tissue, permeates and forms new body sites. Ninety percent of deaths caused by cancer are due to tumors spreading throughout the body, a process ...

11 hours ago
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Combining tests leads to better prediabetes detection

Using a combination of two blood sugar tests rather than a single test would improve detection of prediabetes in American children and adults, according to a new study by researchers at the School of Public Health at Georgia ...

Nov 30, 2015
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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

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