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Blood Cell
A blood cell (also called a hematopoietic cell, hemocyte, or hematocyte) is a cell produced through hematopoiesis and found mainly in the blood. Major types of blood cells include red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). Together, these three kinds of blood cells add up to a total 45% of the blood tissue by volume, with the remaining 55% of the volume composed of plasma, the liquid component of blood. Red blood cells Red blood cells or ''erythrocytes'' primarily carry oxygen and collect carbon dioxide through the use of hemoglobin. Hemoglobin is an iron-containing protein that gives red blood cells their color and facilitates transportation of oxygen from the lungs to tissues and carbon dioxide from tissues to the lungs to be exhaled. Red blood cells are the most abundant cell in the blood, accounting for about 40–45% of its volume. Red blood cells are circular, biconcave, disk-shaped and deformable to allow them to sque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematopoiesis Simple
Haematopoiesis (; ; also hematopoiesis in American English, sometimes h(a)emopoiesis) is the formation of blood cellular components. All cellular blood components are derived from haematopoietic stem cells. In a healthy adult human, roughly ten billion () to a hundred billion () new blood cells are produced per day, in order to maintain steady state levels in the peripheral circulation.Semester 4 medical lectures at Uppsala University 2008 by Leif Jansson Process Haematopoietic stem cells (HSCs) Haematopoietic stem cells (HSCs) reside in the medulla of the bone (bone marrow) and have the unique ability to give rise to all of the different mature blood cell types and tissues. HSCs are self-renewing cells: when they differentiate, at least some of their daughter cells remain as HSCs so the pool of stem cells is not depleted. This phenomenon is called asymmetric division. The other daughters of HSCs (myeloid and lymphoid progenitor cells) can follow any of the other differen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erythropoiesis
Erythropoiesis (from Greek ''erythro'', meaning ''red'' and ''poiesis'', meaning ''to make'') is the process which produces red blood cells (erythrocytes), which is the development from erythropoietic stem cell to mature red blood cell. It is stimulated by decreased O2 in circulation, which is detected by the kidneys, which then secrete the hormone erythropoietin.Sherwood, L, Klansman, H, Yancey, P: ''Animal Physiology'', Brooks/Cole, Cengage Learning, 2005. This hormone stimulates proliferation and differentiation of red cell precursors, which activates increased erythropoiesis in the hemopoietic tissues, ultimately producing red blood cells (erythrocytes). In postnatal birds and mammals (including humans), this usually occurs within the red bone marrow. In the early fetus, erythropoiesis takes place in the mesodermal cells of the yolk sac. By the third or fourth month, erythropoiesis moves to the liver. After seven months, erythropoiesis occurs in the bone marrow. Increased ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granule (cell Biology)
In cell biology, a granule is a small particle barely visible by light microscopy. The term is most often used to describe a secretory vesicle containing important components of cell physiology. Examples of granules include granulocytes, platelet granules, insulin granules, germane granules, starch granules, and stress granules. It is considered as a cell organelle. Types There are mainly 2 types of granules based on presence or absence of membrane: # Membrane bound granules. # Non Membrane bound granules. Eosinophilic Granules, Basophilic Granules, Secretory Granules are examples of Membrane bound granules. P-granules, Stress granules are examples for Non Membrane bound granules. In leukocytes A group of leukocytes, called granulocytes, are white blood cells containing enzyme granules that play a significant role in the immune system. Granulocytes include neutrophils, eosinophils, and basophils which attack bacteria or parasites, and respond to allergens. Each type of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agranulocyte
In immunology, agranulocytes (also known as nongranulocytes or mononuclear leukocytes) are one of the two types of leukocytes (white blood cells), the other type being granulocytes. Agranular cells are noted by the absence of granules in their cytoplasm, which distinguishes them from granulocytes. Leukocytes are the first level of protection against disease. The two types of agranulocytes in the blood circulation are lymphocytes and monocytes. These make up about 35% of the hematologic blood values. The distinction between granulocytes and agranulocytes is not useful for several reasons. First, monocytes contain granules, which tend to be fine and weakly stained (see monocyte entry). Second, monocytes and the granulocytes are closely related cell types developmentally, physiologically and functionally. Third, this distinction is not used by haematologists; it is an erroneous separation that has no meaning. Lymphocytes are much more common in the lymphatic system and includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granulocyte
Granulocytes are cells in the innate immune system characterized by the presence of specific granules in their cytoplasm. Such granules distinguish them from the various agranulocytes. All myeloblastic granulocytes are polymorphonuclear, that is, they have varying shapes (morphology) of the nucleus (segmented, irregular; often lobed into three segments); and are referred to as polymorphonuclear leukocytes (PMN, PML, or PMNL). In common terms, ''polymorphonuclear granulocyte'' refers specifically to "neutrophil granulocytes", the most abundant of the granulocytes; the other types ( eosinophils, basophils, and mast cells) have varying morphology. Granulocytes are produced via granulopoiesis in the bone marrow. Types There are four types of granulocytes (full name polymorphonuclear granulocytes): * Basophils * Eosinophils * Neutrophils * Mast cells Except for the mast cells, their names are derived from their staining characteristics; for example, the most abundant granulocy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphatic System
The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphoid organs, lymphatic tissue and lymph. Lymph is a clear fluid carried by the lymphatic vessels back to the heart for re-circulation. The Latin word for lymph, , refers to the deity of fresh water, "Lympha". Unlike the circulatory system that is a closed system, the lymphatic system is open. The human circulatory system processes an average of 20 litres of blood per day through Starling equation, capillary filtration, which removes blood plasma, plasma from the blood. Roughly 17 litres of the filtered blood is reabsorbed directly into the blood vessels, while the remaining three litres are left in the interstitial fluid. One of the main functions of the lymphatic system is to provide an accessory return route to the blood for the surplus three litres. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Marrow
Bone marrow is a semi-solid biological tissue, tissue found within the Spongy bone, spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It is composed of Blood cell, hematopoietic cells, marrow adipose tissue, and supportive stromal cells. In adult humans, bone marrow is primarily located in the Rib cage, ribs, vertebrae, sternum, and Pelvis, bones of the pelvis. Bone marrow comprises approximately 5% of total body mass in healthy adult humans, such that a person weighing 73 kg (161 lbs) will have around 3.7 kg (8 lbs) of bone marrow. Human marrow produces approximately 500 billion blood cells per day, which join the Circulatory system, systemic circulation via permeable vasculature sinusoids within the medullary cavity. All types of Hematopoietic cell, hematopoietic cells, including both Myeloid tissue, myeloid and Lymphocyte, lymphoid lineages, are create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infectious Disease
An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disease, is an Disease#Terminology, illness resulting from an infection. Infections can be caused by a wide range of pathogens, most prominently pathogenic bacteria, bacteria and viruses. Hosts can fight infections using their immune systems. Mammalian hosts react to infections with an Innate immune system, innate response, often involving inflammation, followed by an Adaptive immune system, adaptive response. Treatment for infections depends on the type of pathogen involved. Common medications include: * Antibiotics for bacterial infections. * Antivirals for viral infections. * Antifungals for fungal infections. * Antiprotozoals for protozoan infections. * Antihelminthics for infections caused by parasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune System
The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic worms, and also objects such as wood splinters, distinguishing them from the organism's own healthy biological tissue, tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use humoral immunity, molecules and cell-mediated immunity, cells to perform their functions. Nearly all organisms have some kind of immune system. Bacteria have a rudimentary immune system in the form of enzymes that protect against bacteriophage, viral infections. Other basic immune mechanisms evolved in ancien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Blood Cell
White blood cells (scientific name leukocytes), also called immune cells or immunocytes, are cells of the immune system that are involved in protecting the body against both infectious disease and foreign entities. White blood cells are generally larger than red blood cells. They include three main subtypes: granulocytes, lymphocytes and monocytes. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system. All white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells (RBCs) and platelets. The different white blood cells are usually classified by cell lineage ( myeloid cells or lymphoid cells). White blood cells are part of the body's immune system. They help the body fight infection and other diseases. Types of white blood cells are granulocytes (neutrophils, eosino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red White Blood Cells
Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–750 nanometres. It is a primary color in the RGB color model and a secondary color (made from magenta and yellow) in the CMYK color model, and is the complementary color of cyan. Reds range from the brilliant yellow-tinged scarlet and vermillion to bluish-red crimson, and vary in shade from the pale red pink to the dark red burgundy. Red pigment made from ochre was one of the first colors used in prehistoric art. The Ancient Egyptians and Mayans colored their faces red in ceremonies; Roman generals had their bodies colored red to celebrate victories. It was also an important color in China, where it was used to color early pottery and later the gates and walls of palaces. In the Renaissance, the brilliant red costumes for the nobility and wealthy were dyed with kermes and cochineal. The 19th century brought ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycythemia
Polycythemia (also known as polycythaemia) is a laboratory finding in which the hematocrit (the volume percentage of red blood cells in the blood) and/or hemoglobin concentration are increased in the blood. Polycythemia is sometimes called erythrocytosis, and there is significant overlap in the two findings, but the terms are not the same: polycythemia describes any increase in hematocrit and/or hemoglobin, while erythrocytosis describes an increase specifically in the number of red blood cells in the blood. Polycythemia has many causes. It can describe an increase in the number of red blood cells ("absolute polycythemia") or a decrease in the volume of plasma ("relative polycythemia"). Absolute polycythemia can be due to genetic mutations in the bone marrow ("primary polycythemia"), physiologic adaptations to one's environment, medications, and/or other health conditions. Laboratory studies such as serum Erythropoietin, erythropoeitin levels and genetic testing might be helpful t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
