Bone marrow is the flexible tissue found in the hollow interior of bones. Tissue is a cellular organizational level intermediate between cells and a complete organism Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce In adults, marrow in large bones produces new blood cells. A blood cell (also called blood corpuscle) is any cell of any type normally found in Blood. It constitutes 4%[1] of total body weight, i. e. approximately 2. 6 kg (5. 7 lbs. ) in adults.
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Anatomy
Marrow types
There are two types of bone marrow: red marrow (consisting mainly of myeloid tissue) and yellow marrow (consisting mainly of fat cells). Myeloid tissue is a Biologic tissue with the ability to perform Hematopoiesis. "Adipose" redirects here For the Doctor Who monster see " Partners in Crime " Red blood cells, platelets and most white blood cells arise in red marrow; some white blood cells develop in yellow marrow. Red blood cells are the most common type of Blood cell and the Vertebrate body's principal means of delivering Oxygen to the body tissues via the Blood Platelets, or Thrombocytes, are small cytoplasmic bodies derived from cells They circulate in the Blood of Mammals and are involved
Both types of bone marrow contain numerous blood vessels and capillaries.
At birth, all bone marrow is red. With age, more and more of it is converted to the yellow type. About half of the bone marrow is red. [1] Red marrow is found mainly in the flat bones, such as the hip bone, breast bone, skull, ribs, vertebrae and shoulder blades, and in the cancellous ("spongy") material at the proximal ends of the long bones femur and humerus. Flat Bones.—Where the principal requirement is either extensive protection or the provision of broad surfaces for muscular attachment the bones are expanded into broad flat plates The pelvis (pl pelvises or pelves) or pelvic girdle is the irregular bony structure located at the base of the spine (properly known The sternum (from Greek στέρνον sternon, "chest" or breastbone) is a long flat Bone located in the center of the thorax (chest In Vertebrate Anatomy, ribs ( Latin costae) are the long curved Bones which form the ribcage. A vertebra (plural vertebrae) is an individual Irregular bone in the spinal or Vertebral column ( aka ischis a flexuous and flexible column In Anatomy, the scapula, omo, or shoulder blade, is the Bone that connects the Humerus (arm bone with the Clavicle (collar Cancellous Bone is a type of Osseous tissue with a low density and strength but very high Surface area, that fills the inner cavity of long bones In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species The long bones are those that are longer than they are wide and grow primarily by elongation of the Diaphysis, with an Epiphysis at the ends of the growing Bone The femur is the thigh bone In Humans, it is the longest, most voluminous and strongest Bone. The humerus is a Long bone in the Arm or Forelimb that runs from the Shoulder to the Elbow. Yellow marrow is found in the hollow interior of the middle portion of long bones.
In cases of severe blood loss, the body can convert yellow marrow back to red marrow in order to increase blood cell production.
Stroma
The stroma of the bone marrow is all tissue that isn't directly involved in the primary function of hematopoiesis. Haematopoiesis (from Ancient Greek haima blood poiesis to make (or hematopoiesis in the United States sometimes also haemopoiesis or The yellow bone marrow belongs here, and makes the majority of the bone marrow stroma, in addition to stromal cells located in the red bone marrow.
Still, the stroma is indirectly involved in hematopoiesis, since it provides the hematopoietic microenvironment that facilitates hematopoiesis by the parenchymal cells. Parenchyma is a term used to describe a bulk of a substance It is used in different ways in Animals and in Plants. For instance, they generate colony stimulating factors, affecting hematopoiesis. Colony-stimulating factors (CSFs are secreted Glycoproteins which bind to receptor proteins on the surfaces of Hemopoietic stem cells and thereby activate Intracellular Haematopoiesis (from Ancient Greek haima blood poiesis to make (or hematopoiesis in the United States sometimes also haemopoiesis or
Cells that constitute the bone marrow stroma are:
- fibroblasts (reticular connective tissue)
- macrophages
- adipocytes
- osteoblasts
- blood vessels (sinusoid)
Macrophages contribute especially to red blood cell production. A fibroblast is a type of cell that synthesizes and maintains the Extracellular matrix of many Animal tissues Older textbooks typically refer to elastic and reticular connective tissues as specialized connective tissues Macrophages ( Greek: "big eaters" from makros "large" + phagein "eat" ( Mø) are cells within the tissues that Adipocytes are the cells that primarily compose Adipose tissue, specialized in storing energy as Fat. An osteoblast (from the Greek words for " Bone " and "germ" or embryonic is a mononucleate cell that is responsible for bone formation The blood vessels are part of the Circulatory system and function to transport Blood throughout the body A sinusoid is a small Blood vessel similar to a Capillary but with a Discontinuous Endothelium. Red blood cells are the most common type of Blood cell and the Vertebrate body's principal means of delivering Oxygen to the body tissues via the Blood They deliver iron for hemoglobin-production. Hemoglobin ( also spelled haemoglobin and abbreviated Hb or Hgb) is the Iron -containing Oxygen -transport Metalloprotein
Bone marrow barrier
The blood vessels constitute a barrier, inhibiting immature blood cells from leaving the bone marrow. Only mature blood cells contain the membrane proteins required to attach to and pass the blood vessel endothelium. Also see Transmembrane protein. A membrane protein is a Protein molecule that is attached to or associated with the membrane The endothelium is the thin layer of cells that line the interior surface of Blood vessels forming an interface between circulating Blood in the
Hematopoietic stem cells may also cross the bone marrow barrier, and may thus be harvested from blood. Hematopoietic stem cells (HSCs are Stem cells that give rise to all the blood cell types including Myeloid ( Monocytes and Macrophages, Neutrophils
Stem cells
The bone marrow stroma contain mesenchymal stem cells (also called marrow stromal cells). Mesenchymal stem cells or MSCs are Multipotent Stem cells that can differentiate into a variety of cell types These cells are multipotent stem cells that can differentiate into a variety of cell types. Multipotent Progenitor cells can give rise to several other cell types but those types are limited in number Stem cells are cells found in most if not all multi-cellular Organisms. In Developmental biology, cellular differentiation is the process by which a less specialized cell becomes a more specialized Cell type. Cell types that MSCs have been shown to differentiate into in vitro or in vivo include osteoblasts, chondrocytes, myocytes, adipocytes, and, as described lately, beta-pancreatic islets cells. In vitro ( Latin: within the glass refers to the technique of performing a given experiment in a controlled environment outside of a living Organism In vivo ( Latin: within the living means that which takes place inside an organism. An osteoblast (from the Greek words for " Bone " and "germ" or embryonic is a mononucleate cell that is responsible for bone formation Chondrocytes (from Greek chondros cartilage + kytos cell are the only cells found in Cartilage. A myocyte (also known as a myocardial cell is the type of cell found in heart muscles. Adipocytes are the cells that primarily compose Adipose tissue, specialized in storing energy as Fat. Beta cells ( beta-cells, β-cells) are a type of cell in the Pancreas in areas called the Islets of Langerhans. They can also transdifferentiate into neuronal cells. Neurons (ˈnjuːɹɒn also known as neurones and nerve cells) are responsive cells in the Nervous system that process and transmit information
Compartmentalization
There is biologic compartmentalization in the bone marrow, in that certain cell types tend to aggregate in specific areas. In biology compartmentalization mainly refers to the formation of Cellular compartments However it may also refer to cellular aggregations e A cell type is a distinct morphological or functional form of cell. For instance, erythrocytes, macrophages and their precursors tend to gather around blood vessels, while granulocytes gather at the borders of the bone marrow. Red blood cells are the most common type of Blood cell and the Vertebrate body's principal means of delivering Oxygen to the body tissues via the Blood Macrophages ( Greek: "big eaters" from makros "large" + phagein "eat" ( Mø) are cells within the tissues that The blood vessels are part of the Circulatory system and function to transport Blood throughout the body Granulocytes are a category of White blood cells characterised by
Types of stem cells
Bone marrow contains three types of stem cells:[2]
- Hematopoietic stem cells give rise to the three classes of blood cells that are found in the circulation: white blood cells (leukocytes), red blood cells (erythrocytes), and platelets (thrombocytes). Stem cells are cells found in most if not all multi-cellular Organisms. Hematopoietic stem cells (HSCs are Stem cells that give rise to all the blood cell types including Myeloid ( Monocytes and Macrophages, Neutrophils Red blood cells are the most common type of Blood cell and the Vertebrate body's principal means of delivering Oxygen to the body tissues via the Blood Platelets, or Thrombocytes, are small cytoplasmic bodies derived from cells They circulate in the Blood of Mammals and are involved
- Mesenchymal stem cells are found arrayed around the central sinus in the bone marrow. Mesenchymal stem cells or MSCs are Multipotent Stem cells that can differentiate into a variety of cell types They have the capability to differentiate into osteoblasts, chondrocytes, myocytes, and many other types of cells. An osteoblast (from the Greek words for " Bone " and "germ" or embryonic is a mononucleate cell that is responsible for bone formation Chondrocytes (from Greek chondros cartilage + kytos cell are the only cells found in Cartilage. A myocyte (also known as a myocardial cell is the type of cell found in heart muscles. They also function as "gatekeeper" cells of the bone marrow.
- Endothelial stem cells
Diseases involving the bone marrow
The normal bone marrow architecture can be displaced by malignancies or infections such as tuberculosis, leading to a decrease in the production of blood cells and blood platelets. Endothelial stem cells are multipotent Stem cells They are one of the three types of stem cells to be found in Bone marrow. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled Tuberculosis (abbreviated as TB for tubercle bacillus or T u' b' erculosis Bacillus --> is a common In addition, cancers of the hematologic progenitor cells in the bone marrow can arise; these are the leukemias. Leukemia or leukaemia (Greek leukos λευκός, "white" aima αίμα, "blood" is a Cancer of the Blood
To diagnose diseases involving the bone marrow, a bone marrow aspiration is sometimes performed. Bone marrow examination refers to the pathologic analysis of samples of Bone marrow obtained by bone marrow biopsy (often called a Trephine biopsy This typically involves using a hollow needle to acquire a sample of red bone marrow from the crest of the ilium under general or local anesthesia. The crest of the ilium (or iliac crest) is the superior border of the Wing of ilium and the superolateral margin of the Greater pelvis. Local anesthesia is any technique to render part of the body insensitive to pain without affecting consciousness The average number of cells in a leg bone is about 440,000,000,000.
Exposure to radiation or chemotherapy will kill many of the rapidly dividing cells of the bone marrow and will therefore result in a depressed immune system. Image talkNew_radiation_symbol_ISO_21482svg for details --> Ionizing radiation Chemotherapy, in its most general sense refers to treatment of disease by chemicals that kill cells specifically those of micro-organisms or Cancer. An immune system is a collection of mechanisms within an Organism that protects against Disease by identifying and killing Pathogens and Tumor Many of the symptoms of radiation sickness are due to damage to the bone marrow cells. Radiation poisoning, also called " radiation sickness " or a " creeping dose " is a form of damage to organ tissue due to excessive exposure to
Examination
Bone marrow examination is the pathologic analysis of samples of bone marrow obtained by bone marrow biopsy and bone marrow aspiration. Pathology (from Greek grc πάθος pathos, "fate harm" and grc -λογία -logia) is the study and Bone marrow examination is used in the diagnosis of a number of conditions, including leukemia, multiple myeloma, anemia, and pancytopenia. Leukemia or leukaemia (Greek leukos λευκός, "white" aima αίμα, "blood" is a Cancer of the Blood Multiple myeloma (also known as MM, myeloma, plasma cell myeloma, or as Kahler's disease after Otto Kahler) is a type of Anemia ( AmE) or anæmia/anaemia ( BrE) (from the Ancient Greek grc-Latn anaîmia, meaning “without blood” is defined as a qualitative Pancytopenia is a medical condition in which there is a reduction in the number of red and White blood cells as well as Platelets The bone marrow produces the cellular elements of the blood, including platelets, red blood cells and white blood cells. Blood is a specialized Bodily fluid that delivers necessary substances to the body's cells such as nutrients and oxygen—and transports Waste products Platelets, or Thrombocytes, are small cytoplasmic bodies derived from cells They circulate in the Blood of Mammals and are involved Red blood cells are the most common type of Blood cell and the Vertebrate body's principal means of delivering Oxygen to the body tissues via the Blood While much information can be gleaned by testing the blood itself (drawn from a vein by phlebotomy), it is sometimes necessary to examine the source of the blood cells in the bone marrow to obtain more information on hematopoiesis; this is the role of bone marrow aspiration and biopsy. Haematopoiesis (from Ancient Greek haima blood poiesis to make (or hematopoiesis in the United States sometimes also haemopoiesis or
Donation and transplantation of bone marrow
It is possible to take hematopoietic stem cells from one person and then infuse them into another person (Allogenic) or into the same person at a later time (Autologous). If donor and recipient are compatible, these infused cells will then travel to the bone marrow and initiate blood cell production.
Transplantation from one person to another is performed in severe cases of disease of the bone marrow. The patient's marrow is first killed off with drugs or radiation, and then the new stem cells are introduced.
Before radiation therapy or chemotherapy in cases of cancer, some of the patient's hematopoietic stem cells are sometimes harvested and later infused back when the therapy is finished to restore the immune system. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled
Harvesting
The stem cells are harvested directly from the red marrow in the crest of the ilium, usually under general anesthesia. The crest of the ilium (or iliac crest) is the superior border of the Wing of ilium and the superolateral margin of the Greater pelvis. In modern medical practice general anaesthesia ( AmE: anesthesia) is a state of total unconsciousness resulting from General anaesthetic drugs Contrary to popular belief, it is a minimally invasive outpatient procedure with only minor discomfort. Another option is to administer certain drugs that stimulate the release of stem cells from the bone marrow into circulating blood. An IV is inserted into the donor's arm, and the stem cells are filtered out of the blood. The procedure is similar to donating blood or platelets.
It may also be taken from the sternum. The sternum (from Greek στέρνον sternon, "chest" or breastbone) is a long flat Bone located in the center of the thorax (chest The tibia may seem a good source, since it is very superficial. The tibia, shinbone, or shankbone is the larger and stronger of the two Bones in the Leg below the Knee in vertebrates and connects However, except in children, this bone marrow doesn't contain any substantial amount of red bone marrow, but rather only yellow bone marrow. [1]
In newborns, stem cells may be retrieved from the umbilical cord. In placental Mammals the umbilical cord (also called the birth cord or funiculus umbilicalis) is the connecting cord from the developing Embryo
Bone marrow as a food
Though once used in various preparations, including pemmican, bone marrow for human consumption in America has recently fallen out of favor as a food. Pemmican is a concentrated mixture of Fat and Protein used as a nutritious emergency foodstuff Now, it is commonly used only as a flavoring for soups and sauces, although dishes with intact bone marrow can still be found in some European restaurants. Bone marrow is a source of protein and high in monounsaturated fats. Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl An unsaturated fat is a Fat or Fatty acid in which there are one or more Double bonds in the fatty acid chain These fats are known to decrease LDL cholesterol levels resulting in a decreased risk of cardiovascular disease, prompting some to make bone marrow a dietary staple. Low-density lipoprotein ( LDL) is a type of Lipoprotein that transports Cholesterol and Triglycerides from the Liver to peripheral Cholesterol is a Lipid found in the Cell membranes and transported in the Blood plasma of all Animals It is an essential component of mammalian Cardiovascular disease or cardiovascular diseases refers to the class of diseases that involve the Heart or Blood vessels ( arteries and This article is primarily about the human diet For a discussion of animal diets see List of feeding behaviours. A staple food is a Food that forms the basis of a Traditional diet. The actual health effects of the addition of bone marrow to the diet remain unclear.
References
- ^ a b c Semester 4 medical lectures at Uppsala University 2008 by Leif Jansson
- ^ Raphael Rubin and David S. Strayer (2007). Rubin's Pathology: Clinicopathologic Foundations of Medicine. Lippincott Williams & Wilkins, 90. ISBN 0781795168.
See also
- Leukemia
- Bone marrow transplant
- Bone marrow examination
- Aplastic anemia
- Osso buco
- John Raymond Hobbs (Professor)
External links
- Bioweb at UWLAX Microscopic slides of bone marrow, with explanations
- Marrow Balls
- Tostadas de tuetano
- Asian American Donor Program
- Organ Donation Blog
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