Which wbcs are never phagocytic

Inheritance 5. Genetic Modification 4: Ecology 1. Energy Flow 3. Carbon Cycling 4. Climate Change 5: Evolution 1. Evolution Evidence 2. Natural Selection 3. Classification 4. Cladistics 6: Human Physiology 1. Digestion 2. The Blood System 3. Disease Defences 4. Gas Exchange 5. How might that damage affect her blood? A medical technology student is learning to count blood cells the low-tech way: using a microscope and a special slide called a hemocytometer.

She has just found a round, darkly-stained white blood cell that contains large granules. The student is probably looking at a. The experienced, well-educated R. The differential count of a person suffering from both allergies and parasitic worms would probably reveal elevated numbers of. Three year old Juanita has a rare form of leukemia.

The doctors have recommended, and her family has agreed, that her best chance of survival is to destroy her bone marrow and then replace it with stem cells from a donor. Which of the following sources of stem cells would probably be best?

Which of the following does NOT correctly describe a mechanism that prevents excessive blood clotting? Deandray has circulating anti-A, anti-B and anti-D antibodies. Which of the following blood types may safely receive blood from him? A descendent of which U. Sign in. The Cardiovascular System: Blood.

Helpfulness: 0. Set Details Share. Principles of Anatomy and Physiology Chapter Which of the following is NOT function of blood? Which of the following is correct? A lb 45 Kg woman will have about 8 lb 3. Most adult humans have between 4 and 6 L of blood, depending on their size. Normal blood is less viscous than water and has a neutral pH. A and B are correct. A, B and C are correct. Which of the following are plasma proteins made by the liver?

Which of the following are cells found in the blood? Subsequently, the discovery of the colony-stimulating factors greatly improved understanding the regulation of phagocyte production. The discovery of the microbicidal myeloperoxidase-H 2 O 2 -halide system and the importance of NADPH oxidase to the generation of H 2 O 2 also stimulated intense interest in phagocyte disorders. More recent research has focused on membrane receptors and the dynamics of the responses of phagocytes to external factors including immunoglobulins, complement proteins, cytokines, chemokines, integrins, and selectins.

Phagocytes express toll-like receptors that aid in the clearance of a wide range of microbial pathogens and their products.

Phagocytes are also important sources of pro- and anti-inflammatory cytokines, thus participating in host defenses through a variety of mechanisms.

Over the last 50 years, many genetic and molecular disorders of phagocytes have been identified, leading to improved diagnosis and treatment of conditions which predispose patients to the risk of recurrent fevers and infectious diseases.

Pus is therefore a noble substance: it is made of brave cells that never sneak back into the blood vessels to escape; they all die in the line of duty. Note also the double meaning of suppuration: it indicates that there is an infection, but also that the body is fighting it well.

The outcome of the battle can be predicted, to some extent, from the aspect of the pus, as was observed even in ancient times.

Much of what we know about the cellular components of the inflammatory response was gradually discovered in the 19th and early 20th centuries. He is credited with the origin of the terms phagocyte and phagocytosis. He coined the term, regenerative shift, to designate the outpouring of neutrophils in response to infection. The term, degenerative shift, was used to describe a failure of this response.

He gave excellent descriptions of leukemia, agranulocytosis, infectious mononucleosis, and leukopenia with splenomegaly. This pioneering study was instrumental in our understanding the association of fever, leukocytosis, and neutrophilia. Furthermore, findings from his studies provided the fundamental basis for future studies on the physiological effects of endogenous cytokines.

The fifth edition of Wintrobe's Clinical Hematology , published soon after the beginning of Blood , had extensive chapters on phagocytes. The text described their abundant glycogen in the cytoplasm of neutrophils and aerobic glycolysis with oxygen consumption, glucose utilization, and lactic acid. It also described leukocyte alkaline phosphatase and its variation in chronic myeloproliferative diseases.

By , hematology sections in general medical texts, such as Harrison's Principles of Internal Medicine , contained specific sections on leukocyte disorders, particularly leukemia, agranulocytosis, and the diseases causing pancytopenia. This brief review outlines some of the pivotal discoveries in phagocyte biology during the past 50 years. These discoveries have significantly increased our understanding of host defense and immunity, leading to important advances in the practice of medicine.

Radioisotopic tracers were first introduced to study the origin and fate of hematopoietic cells in the early s. At the beginning of this era, studies of bone marrow and blood counts after radiation-induced injury or administration of early chemotherapeutic agents, such as nitrogen mustard, suggested that neutrophil precursors have a very high proliferative rate and that mature neutrophils have a short lifespan. Craddock et al used 32 P to investigate replicating marrow cells in dogs and defined the mature nondividing compartment of neutrophils in the normal marrow, as well as the effects of leukopheresis, endotoxin, and inflammation on developing and mature neutrophils in the marrow.

Model for the total blood granulocyte pool TBCG in normal subjects. Illustration by Kenneth Probst. This research was originally published in Blood. The kinetics of granulopoiesis in normal man. Although kinetics and turnover of radiolabeled blood cells are now rarely done, they were instructive in the s in the development of clinical applications and understanding of the effects of the hematopoietic growth factors, granulocyte colony-stimulating factor G-CSF , and granulocyte-macrophage colony-stimulating factor GM-CSF.

Prior to the s, there were many efforts to define leukopoietins, the myeloid equivalent of erythropoietin, but essentially all of these efforts were unsuccessful. In the mid s, Bradley and Metcalf 23 in Australia and Pluzink and Sachs 24 in Israel independently developed in vitro culture techniques for hematopoietic cells and discovered the colony-stimulating factors Figure 2. Subsequently, rapid advances in molecular biology during the late s allowed cloning of the genes for these growth factors and their receptors.

These studies led to fundamental insights into the mechanisms responsible for physiological regulation of neutrophil production. Colony assay led to the identification of the colony-stimulating factors beginning in the late s.

Bone marrow cells including stem cells were added to form a second layer 2. When the dish was incubated, colonies of white blood cells formed in the second layer 3. The colonies were counted and the cells identified 4.

When the contents of the first layer were varied, different types of colonies formed, implying the existence of a range of colony-stimulating factors. Adapted with permission from original artist Patricia J. Hormones that stimulate the growth of blood cells.

Sci Am. Therapeutically, the development of the colony-stimulating factors as therapeutic agents has had a major impact on the practice of hematology and oncology. Both G-CSF and GM-CSF have a multitude of pharmacological effects, including increasing the proliferative activity of progenitor cells, shortening the time for neutrophil production and maturation in the marrow, accelerating the release of maturing cells from the marrow to the blood, augmenting the production of neutrophil granule proteins, and stimulating the release of proteases and perhaps other constituents from the cells to their surroundings.

Somewhat serendipitously, it was learned that these factors, as part of their effect to expand the hematopoietic tissue mass and the production and deployment of phagocytes, stimulate the release of progenitor cells from the marrow to the blood. The presence of granules in neutrophils, monocytes, and eosinophils was recognized by Metchnikov and Ehrlich, 6 , 7 and the proteins associated with neutrophils were first defined through biochemical and histochemical studies beginning early in the 20th century.

In , Chediak, a Cuban physician, described patients with an autosomal recessive disease with several distinctive characteristics, including abnormal leukocyte granules.

Advances in electron microscopy in this same era allowed dissection of the phagocytic process, and phase contrast microscopy allowed visualization of the killing of microbes. Purification, quantification, and understanding of the role of each of the phagocyte granule proteins have proved a complex task.

From the work of Bainton et al, it was learned that granule proteins are produced in sequence, with the earliest proteins produced in myeloid progenitors and packaged in primary granules. Neutrophil granules serve as reservoirs for digestive and hydrolytic enzymes prior to delivery into the phagosome. Pioneering studies by Spitznagel, 37 Elsbach and Weiss, 38 and Ganz et al 39 indicated that azurophilic granule contents possess microbicidal activity and may play an important role in the tissue destruction observed during inflammatory reactions.

In contrast, congenital deficiency of myeloperoxidase from the primary granules of neutrophils is generally not associated with an increased risk of serious infections. The killing of microbes is a critical physiological function of phagocytes. How this occurs was perhaps the most interesting and important observation related to these cells of the last half century. Before the s, the general aspects of the process of phagocytosis—from the rich glycogen supply of the neutrophil cytoplasm to the enzymatic contents of the neutrophil granules—were already recognized.

In the early s, Valentine and Beck described glycolysis by leukocytes 45 and Sbarra and Karnovsky described the burst of glycolysis that occurs associated with phagocytosis. Although phagocytes have other microbicidal mechanisms, including antimicrobial peptides eg, defensins and broadly acting proteases, phagocytosis with generation of reactive oxygen species and hypochlorous acid is still regarded as the critical killing mechanism for most invading pathogens.

Adapted with permission from Journal of Leukocyte Biology. Klebanoff SJ. Myeloperoxidase: a friend and foe. J Leukoc Biol. It had been known since that a marked increase in neutrophil oxygen consumption, termed the respiratory burst, occurred during phagocytosis. Following the discovery of the importance of NADPH oxidase, mentioned above, investigators elucidated its components and the effects of mutations in the NADPH complex over a period of several decades.

It was referred to as cytochrome b and was later found to be composed of a heavy and light chain. Nunoi et al 68 and Volpp et al 69 identified 2 forms of autosomal CGD in which either a kDa or a kDa protein was genetically altered. Subsequently, defects in the light chain of cytochrome b known as p22 phox were found to account for some CGD cases. Leukopenia is associated with diseases such as typhoid fever, tuberculosis, etc. Some viral diseases such as measles and influenza may also cause a leukopenia.

White blood cell WBC, or leukocytes and red blood cell RBC, or erythrocytes counts are done by diluting a blood sample and counting the number of cells present using a microscope. The blood plasma contains a number of different types of WBC.