Human Immunity and Blood

Kupffer cells are specialized macrophages located in the liver, lining the walls of sinusoids. Kupffer cells are a part of the mononuclear phagocytic system. The main function of kupffer cells is clearing any bacteria or foreign substances which are harmful to the body. Hence, Kupffer cells of the liver are the phagocytic cell.

In mammalian bodies, Kupffer cells are the most abundant tissue macrophages as they constitute 80-90% of them. Also known as Kupffer-Browicz cells or stellate macrophages; these specialized macrophages are specifically found in the liver.

Kupffer cells are specialized macrophages located in the liver lining the walls of the sinusoids, that form part of the reticuloendothelial system.

Liver is the largest gland of human body. Liver sinusoids are lined by the endothelial cells mostly but a few macrophages cells are also present. These are called as Kupffer's cells (phagocytic cells).

Heparin is an anticoagulant that prevent blood clotting by the release of specific proteins like tissue plasminogen activator and tissue factor pathway inhibitor, into the blood.

Liver is the largest gland of human body that accomplishes a diverse set of functions. Liver is known as chemical factory of the body. Most of the biochemical functions of the body are done by the liver. Detoxification is a major function of liver. Thus, conversion of toxic substances into non-toxic substances is done by liver. The toxic substances include xenobiotic compounds or may be formed by metabolic activities of the body. e.g., Prussic acid is converted into Potassium sulfocyanide (it is a non-toxic salt) by the liver.

The liver is the site of synthesis for most plasma proteins, including albumin, fibrinogen, and prothrombin.

Kupffer cells are the resident macrophages of the liver that phagocytose old blood cells and pathogens.

In many lower vertebrates, the liver serves as a hematopoietic organ, producing various blood cells including lymphocytes, unlike in mammals where this is primarily the role of bone marrow.

Fibrin is a tough protein substance that is arranged in long fibrous chains; it is formed from fibrinogen, a soluble protein that is produced by the liver and found in blood plasma. In the clotting mechanism, fibrin threads form a meshwork for the basis of a blood clot. Most of the fibrinogen in the circulating blood is formed in the liver.

Antibodies are highly specific proteins that bind to unique antigens found on the surface of specific pathogens. Because of this specificity, one type of antibody cannot destroy all different types of microbes.

When antibodies bind to a microbe, they often act as a marker that makes it easier for phagocytes (a type of white blood cell) to identify and engulf the pathogen through a process called phagocytosis.

Non-specific immune responses are the body's first line of defense, such as skin, mucus, and tears, which act as physical or chemical barriers. Antibodies and memory cells are part of the specific (adaptive) immune response.

Blood plasma, which makes up about 55% of blood volume, is roughly 90-92% water. When considering whole blood (including red blood cells, white blood cells, and platelets), water constitutes about 80% of the total composition.

O-negative (O-) blood is known as the universal donor type because its red blood cells lack A, B, and Rh antigens, meaning it can be transfused to patients of any blood type without triggering an immune reaction.