BLOOD

White Blood Cells



BLOOD:
" INTRODUCTION
" ROLE OF BLOOD
" COMPOSITION OF BLOOD
" Plasma
" Red Blood Cells
" Blood Type
" White Blood Cells
" Platelets and Clotting
" PRODUCTION AND ELIMINATION OF BLOOD CELLS
" Red Blood Cell Diseases
" White Blood Cell Diseases
" Coagulation Diseases
" BLOOD BANKS
" Blood Transfusion
" Blood Count
" Blood donation and registry
" Blood gas analysis
" Blood sugar tests
" Blood typing and crossmatching
" Blood urea nitrogen test
" Blood-viscosity reducing drugs
Circulatory System:
" INTRODUCTION
" COMPONENTS OF THE CIRCULATORY SYSTEM
" OPERATION AND FUNCTION
" Systemic Circulation
" Pulmonary Circulation
" Additional Functions
" Blood Pressure
" DISEASES AND DISORDERS
" HEART
Vasculature System:
" Arteries
" Veins
" Capillaries
" Vasculature of the Arm
" Vasculature of the Head
" Vasculature of the Leg
" Vasculature of the Torso

White Blood Cells

White blood cells only make up about 1 percent of blood, but their small number belies their immense importance. They play a vital role in the body’s immune system—the primary defense mechanism against invading bacteria, viruses, fungi, and parasites. They often accomplish this goal through direct attack, which usually involves identifying the invading organism as foreign, attaching to it, and then destroying it. This process is referred to as phagocytosis.

Lymphocyte - White Blood Cells

Scanning electron micrograph of a normal T lymphocyte. Lymphocytes are specialized white blood cells whose function is to identify and destroy invading organisms such as bacteria and viruses. Some T lymphocytes directly destroy invading organisms, whereas other T lymphocytes regulate the immune system by directing immune responses.

White blood cells also produce antibodies, which are released into the circulating blood to target and attach to foreign organisms. After attachment, the antibody may neutralize the organism, or it may elicit help from other immune system cells to destroy the foreign substance. There are several varieties of white blood cells, including neutrophils, monocytes, and lymphocytes, all of which interact with one another and with plasma proteins and other cell types to form the complex and highly effective immune system.

World Health Organization

Blood Clot in the Legs

Deep venous thrombosis (DVT) refers to a blood clot embedded in one of the major deep veins of the lower legs, thighs, or pelvis. A clot blocks blood circulation through these veins, which carry blood from the lower body back to the heart. The blockage can cause pain, swelling, or warmth in the affected leg.

Next: Blood Clot in the Legs

Blood Culture

A blood culture is done when a person has symptoms of a blood infection, also called bacteremia. Blood is drawn from the person one or more times and is tested in a laboratory to find and identify any microorganism present and growing in the blood. If a microorganism is found,...

Next: Blood Culture