Venous (darker) and arterial (brighter) blood

venous and arterial blood

Blood is a body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells.

In vertebrates, it is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains proteins, glucose, mineral ions, hormones, carbon dioxide (plasma being the main medium for excretory product transportation), and blood cells themselves. Albumin is the main protein in plasma, and it functions to regulate the colloidal osmotic pressure of blood. The blood cells are mainly red blood cells (also called RBCs or erythrocytes), white blood cells (also called WBCs or leukocytes) and platelets (also called thrombocytes). The most abundant cells in vertebrate blood are red blood cells. These contain hemoglobin, an iron-containing protein, which facilitates oxygen transport by reversibly binding to this respiratory gas and greatly increasing its solubility in blood. In contrast, carbon dioxide is mostly transported extracellularly as bicarbonate ion transported in plasma.

Vertebrate blood is bright red when its hemoglobin is oxygenated and dark red when it is deoxygenated. Some animals, such as crustaceans and mollusks, use hemocyanin to carry oxygen, instead of hemoglobin. Insects and some mollusks 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 with 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.


Blood performs many important functions within the body, including:

Herbal remedies beneficial to blood
Burdock plant Ctas claw plant
30 capsules
Ashwagandha root  
90 capsules
Burdock root  
30 capsules
Fenugreek plant Ginkgo biloba leaf Horse chestnut
90 capsules
Fenugreek seeds  
30 capsules
30 capsules
Hawthorne berry Horny goat weed plant Juniper berry
60 capsules
90 capsules
Horny goat
90 capsules
Milk thistle Red clover America Skullcap
30 capsules
60 capsules
clover flower
90 capsules
Stinging nettle plant Sarsaparrilla berry Schizandra berry
90 capsules
Stinging nettle
60 capsules
90 capsules
Schizandra berry  
Yarrow flower Lion's mane mushroom Shiitake mushroom
60 capsules
60 capsules
Lion's mane
30 capsules
(Withania somnifera)
(Astragalus membranaceus)
(Bacopa monnieri)
(Arctium lappa)
*Black Cohosh
(Cimicifuga racemosa)
(Focus vesiculosus)
*Celery seeds
(Apium graviolens)
*Chanca piedra
(Phyllanthus niruri)
*Ceylon cinnamon
(Cinnamomum zeylanicum)
*Cat's claw
(Uncaria tomentosa)
*Dandelion root
(Taraxacum officinale)
(Trigonella foenum graecum)
*Ginkgo biloba
(Ginkgo biloba)
*Horse chestnut
(Aesculus hippocastanum)
*Hawthorn berry
(Crateagus oxicanthus)
*Horny goat weed
(Epimedium sagittatum)
*Juniper berry
(Juniperus communis)
*Milk thistle
(Sylibum marianum)
(Lepidium meyenii)
*Red clover
(Trifolium pratense)
*American Skullcap
(Scutellaria lateriflora)
*Saw palmetto
(Serenoa repens/serrulata)
*Stinging nettle
(Urtica dioica)
*St John's wort
(Hypericum perforatum)
(Smilax aristolochiifolia)
*Schizandra berry
(Schisandra chinensis)
(Agnus castus)
*Valerian root
(Valeriana officinalis)
*White willow
(Salix alba)
(Achillea millefolium)
*Lion's mane
(Hericium erinaceous
(Lentinula edodes