Organ system

An organ system is a group of organs that work together as a biological system to perform one or more functions. Each organ system does a particular job in the body, and is made up of certain tissues.

SystemExample
An example of a system: the nervous system
TE-Nervous system diagram
The nervous system in its place in the body

Organ systems and their functions

These specific systems are widely studied in anatomy. They are present in many types of animals.

  • Nervous system: collecting, transferring and processing information with brain, spinal cord, peripheral nervous system and sense organs.
Anatomical Therapeutic Chemical Classification System

The Anatomical Therapeutic Chemical (ATC) Classification System is a drug classification system that classifies the active ingredients of drugs according to the organ or system on which they act and their therapeutic, pharmacological and chemical properties. It is controlled by the World Health Organization Collaborating Centre for Drug Statistics Methodology (WHOCC), and was first published in 1976.This pharmaceutical coding system divides drugs into different groups according to the organ or system on which they act, their therapeutic intent or nature, and the drug's chemical characteristics. Different brands share the same code if they have the same active substance and indications. Each bottom-level ATC code stands for a pharmaceutically used substance, or a combination of substances, in a single indication (or use). This means that one drug can have more than one code, for example acetylsalicylic acid (aspirin) has A01AD05 (WHO) as a drug for local oral treatment, B01AC06 (WHO) as a platelet inhibitor, and N02BA01 (WHO) as an analgesic and antipyretic); as well as one code can represent more than one active ingredient, for example C09BB04 (WHO) is the combination of perindopril with amlodipine, two active ingredients that have their own codes (C09AA04 (WHO) and C08CA01 (WHO) respectively) when prescribed alone.

The ATC classification system is a strict hierarchy, meaning that each code necessarily has one and only one parent code, except for the 14 codes at the topmost level which have no parents. The codes are semantic identifiers, meaning they depict in themselves the complete lineage of parenthood.

Biological system

A biological system is a complex network of biologically relevant entities.

Biological organization spans several scales. Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system.

On the micro to the nanoscopic scale, examples of biological systems are cells, organelles, macromolecular complexes and regulatory pathways.

A biological system is not to be confused with a living system, such as a living organism.

Boil

A boil, also called a furuncle, is a deep folliculitis, infection of the hair follicle. It is most commonly caused by infection by the bacterium Staphylococcus aureus, resulting in a painful swollen area on the skin caused by an accumulation of pus and dead tissue. Boils which are expanded are basically pus-filled nodules. Individual boils clustered together are called carbuncles.

Most human infections are caused by coagulase-positive S. aureus strains, notable for the bacteria's ability to produce coagulase, an enzyme that can clot blood. Almost any organ system can be infected by S. aureus.

Cardiotoxicity

Cardiotoxicity is the occurrence of heart electrophysiology dysfunction or muscle damage. The heart becomes weaker and is not as efficient in pumping and therefore circulating blood. Cardiotoxicity may be caused by chemotherapy treatment, complications from anorexia nervosa, adverse effects of heavy metals intake, or an incorrectly administered drug such as bupivacaine.One of the ways to detect cardiotoxicity at early stages when there is a subconical dysfunction is by measuring changes in regional function of the heart using strain.

Circulatory system

The circulatory system, also called the cardiovascular system or the vascular system, is an organ system that permits blood to circulate and transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body to provide nourishment and help in fighting diseases, stabilize temperature and pH, and maintain homeostasis.

The circulatory system includes the lymphatic system, which circulates lymph. The passage of lymph for example takes much longer than that of blood. Blood is a fluid consisting of plasma, red blood cells, white blood cells, and platelets that is circulated by the heart through the vertebrate vascular system, carrying oxygen and nutrients to and waste materials away from all body tissues. Lymph is essentially recycled excess blood plasma after it has been filtered from the interstitial fluid (between cells) and returned to the lymphatic system. The cardiovascular (from Latin words meaning "heart" and "vessel") system comprises the blood, heart, and blood vessels. The lymph, lymph nodes, and lymph vessels form the lymphatic system, which returns filtered blood plasma from the interstitial fluid (between cells) as lymph.

The circulatory system of the blood is seen as having two components, a systemic circulation and a pulmonary circulation.While humans, as well as other vertebrates, have a closed cardiovascular system (meaning that the blood never leaves the network of arteries, veins and capillaries), some invertebrate groups have an open cardiovascular system. The lymphatic system, on the other hand, is an open system providing an accessory route for excess interstitial fluid to be returned to the blood. The more primitive, diploblastic animal phyla lack circulatory systems.

Many diseases affect the circulatory system. This includes cardiovascular disease, affecting the cardiovascular system, and lymphatic disease affecting the lymphatic system. Cardiologists are medical professionals which specialise in the heart, and cardiothoracic surgeons specialise in operating on the heart and its surrounding areas. Vascular surgeons focus on other parts of the circulatory system.

Dermatoxin

A dermatoxin (from derma, the Greek word for skin) is a toxic chemical that damages skin, mucous membranes, or both, often leading to tissue necrosis. Dermatoxins can be drugs, natural chemicals, or synthetic chemicals.

The severity of the effects of a dermatoxic agent is strongly dependent on the dose, route of exposure, rate at which it spreads, and the health of the afflicted individual.

Dysautonomia

Dysautonomia or autonomic dysfunction is a condition in which the autonomic nervous system (ANS) does not work properly. This may affect the functioning of the heart, bladder, intestines, sweat glands, pupils, and blood vessels. Dysautonomia has many causes, not all of which may be classified as neuropathic. A number of conditions can feature dysautonomia, such as Parkinson's disease, HIV/AIDS, multiple system atrophy, autonomic failure, postural orthostatic tachycardia syndrome, and autonomic neuropathy.The diagnosis is achieved through functional testing of the ANS, focusing on the affected organ system. Investigations may be performed to identify underlying disease processes that may have led to the development of symptoms or autonomic neuropathy. Symptomatic treatment is available for many symptoms associated with dysautonomia, and some disease processes can be directly treated.

Enterotoxin

An enterotoxin is a protein exotoxin released by a microorganism that targets the intestines.Enterotoxins are chromosomally encoded or plasmid encoded exotoxins that are produced and secreted from several bacterial organisms. They are often heat-stable, and are of low molecular weight and water-soluble. Enterotoxins are frequently cytotoxic and kill cells by altering the apical membrane permeability of the mucosal (epithelial) cells of the intestinal wall. They are mostly pore-forming toxins (mostly chloride pores), secreted by bacteria, that assemble to form pores in cell membranes. This causes the cells to die.

Gastrointestinal tract

The gastrointestinal tract (digestive tract, digestional tract, GI tract, GIT, gut, or alimentary canal) is an organ system within humans and other animals which takes in food, digests it to extract and absorb energy and nutrients, and expels the remaining waste as feces. The mouth, esophagus, stomach and intestines are part of the gastrointestinal tract. Gastrointestinal is an adjective meaning of or pertaining to the stomach and intestines. A tract is a collection of related anatomic structures or a series of connected body organs.

All bilaterians have a gastrointestinal tract, also called a gut or an alimentary canal. This is a tube that transfers food to the organs of digestion. In large bilaterians, the gastrointestinal tract generally also has an exit, the anus, by which the animal disposes of feces (solid wastes). Some small bilaterians have no anus and dispose of solid wastes by other means (for example, through the mouth). The human gastrointestinal tract consists of the esophagus, stomach, and intestines, and is divided into the upper and lower gastrointestinal tracts. The GI tract includes all structures between the mouth and the anus, forming a continuous passageway that includes the main organs of digestion, namely, the stomach, small intestine, and large intestine. However, the complete human digestive system is made up of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver and gallbladder). The tract may also be divided into foregut, midgut, and hindgut, reflecting the embryological origin of each segment. The whole human GI tract is about nine metres (30 feet) long at autopsy. It is considerably shorter in the living body because the intestines, which are tubes of smooth muscle tissue, maintain constant muscle tone in a halfway-tense state but can relax in spots to allow for local distention and peristalsis.The gastrointestinal tract contains trillions of microbes, with some 4,000 different strains of bacteria having diverse roles in maintenance of immune health and metabolism. Cells of the GI tract release hormones to help regulate the digestive process. These digestive hormones, including gastrin, secretin, cholecystokinin, and ghrelin, are mediated through either intracrine or autocrine mechanisms, indicating that the cells releasing these hormones are conserved structures throughout evolution.

Genitourinary system

The genitourinary system or urogenital system is the organ system of the reproductive organs and the urinary system. These are grouped together because of their proximity to each other, their common embryological origin and the use of common pathways, like the male urethra. Also, because of their proximity, the systems are sometimes imaged together.The term "apparatus urogenitalis" is used in Nomina Anatomica (under Splanchnologia), but not in Terminologia Anatomica.

Hemotoxin

Hemotoxins, haemotoxins or hematotoxins are toxins that destroy red blood cells (that is, cause haemotoxin), disrupt blood clotting, and/or cause organ degeneration and generalized tissue damage. The term hemotoxin is to some degree a misnomer since toxins that damage the blood also damage other tissues. Injury from a hemotoxic agent is often very painful and can cause permanent damage and in severe cases death. Loss of an affected limb is possible even with prompt treatment.

Hemotoxins are frequently employed by venomous animals, including vipers and pit vipers. Animal venoms contain enzymes and other proteins that are hemotoxic or neurotoxic or occasionally both (as in the Mojave rattlesnake, the Japanese mamushi, and similar species). In addition to killing the prey, part of the function of a hemotoxic venom for some animals is to aid digestion. The venom breaks down protein in the region of the bite, making prey easier to digest.

The process by which a hemotoxin causes death is much slower than that of a neurotoxin. Snakes which envenomate a prey animal may have to track the prey as it flees. Typically, a mammalian prey item will stop fleeing not because of death, but due to shock caused by the venomous bite. Symptoms are dependent upon species, size, location of bite and the amount of venom injected. In humans, symptoms include nausea, disorientation, and headache; these may be delayed for several hours.

Hemotoxins are used in diagnostic studies of the coagulation system. Lupus anticoagulans is detected by changes in the dilute Russell's viper venom time (DRVVT), which is a laboratory assay based on—as its name indicates—venom of the Russell's viper.

Hepatotoxin

A hepatotoxin (Gr., hepato = liver) is a toxic chemical substance that damages the liver.

It can be a side-effect of medication, or found naturally, as microcystins, or in laboratory environments.

The effects of hepatotoxins depend on the amount, point of entry and distribution speed of the toxin, and on the health of the person.

Human musculoskeletal system

The human musculoskeletal system (also known as the locomotor system, and previously the activity system) is an organ system that gives humans the ability to move using their muscular and skeletal systems. The musculoskeletal system provides form, support, stability, and movement to the body.

It is made up of the bones of the skeleton, muscles, cartilage, tendons, ligaments, joints, and other connective tissue that supports and binds tissues and organs together. The musculoskeletal system's primary functions include supporting the body, allowing motion, and protecting vital organs. The skeletal portion of the system serves as the main storage system for calcium and phosphorus and contains critical components of the hematopoietic system.This system describes how bones are connected to other bones and muscle fibers via connective tissue such as tendons and ligaments. The bones provide stability to the body. Muscles keep bones in place and also play a role in the movement of bones. To allow motion, different bones are connected by joints. Cartilage prevents the bone ends from rubbing directly onto each other. Muscles contract to move the bone attached at the joint.

There are, however, diseases and disorders that may adversely affect the function and overall effectiveness of the system. These diseases can be difficult to diagnose due to the close relation of the musculoskeletal system to other internal systems. The musculoskeletal system refers to the system having its muscles attached to an internal skeletal system and is necessary for humans to move to a more favorable position. Complex issues and injuries involving the musculoskeletal system are usually handled by a physiatrist (specialist in physical medicine and rehabilitation) or an orthopaedic surgeon.

Multiple organ dysfunction syndrome

Multiple organ dysfunction syndrome (MODS), also known as multiple organ failure (MOF), total organ failure (TOF) or multisystem organ failure (MSOF), is altered organ function in an acutely ill patient requiring medical intervention to achieve homeostasis.

Although Irwin-Rippe cautions in 2005 that the use of "multiple organ failure" or "multisystem organ failure" should be avoided, both Harrison's (2015) and Cecil's (2012) medical textbooks still use the terms "multi-organ failure" and "multiple organ failure" in several chapters, and do not use "multiple organ dysfunction syndrome" at all.

Muscular system

The muscular system is an organ system consisting of skeletal, smooth and cardiac muscles. It permits movement of the body, maintains posture and circulates blood throughout the body. The muscular systems in vertebrates are controlled through the nervous system although some muscles (such as the cardiac muscle) can be completely autonomous. Together with the skeletal system, it forms the musculoskeletal system, which is responsible for movement of the human body.

Nephrotoxicity

Nephrotoxicity is toxicity in the kidneys. It is a poisonous effect of some substances, both toxic chemicals and medications, on renal function. There are various forms, and some drugs may affect renal function in more than one way. Nephrotoxins are substances displaying nephrotoxicity.

Nephrotoxicity should not be confused with the fact that some medications have a predominantly renal excretion and need their dose adjusted for the decreased renal function (e.g., heparin).

The nephrotoxic effect of most drugs is more profound in patients already suffering from kidney failure.

Organ (anatomy)

Organs are collections of tissues with similar functions. Plant and animal life relies on many organs that coexist in organ systems.Organs are composed of main tissue, parenchyma, and "sporadic" tissues, stroma. The main tissue is that which is unique for the specific organ, such as the myocardium, the main tissue of the heart, while sporadic tissues include the nerves, blood vessels, and connective tissues. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Functionally-related organs often cooperate to form whole organ systems. Organs exist in all organisms. In single-celled organisms such as bacteria, the functional analogue of an organ is known as an organelle. In plants there are three main organs. A hollow organ is an internal organ that forms a hollow tube, or pouch such as the stomach, intestine, or bladder.

In the study of anatomy, the term viscus is used to refer to an internal organ, and viscera is the plural form. 79 organs have been identified in the human body.

Ototoxicity

Ototoxicity is the property of being toxic to the ear (oto-), specifically the cochlea or auditory nerve and sometimes the vestibular system, for example, as a side effect of a drug. The effects of ototoxicity can be reversible and temporary, or irreversible and permanent.

It has been recognized since the 19th century.

There are many well-known ototoxic drugs used in clinical situations, and they are prescribed, despite the risk of hearing disorders, to very serious health conditions.

Ototoxic drugs include antibiotics such as gentamicin, loop diuretics such as furosemide and platinum-based chemotherapy agents such as cisplatin. A number of nonsteroidal anti-inflammatory drugs (NSAIDS) have also been shown to be ototoxic. This can result in sensorineural hearing loss, dysequilibrium, or both. Some environmental and occupational chemicals have also been shown to affect the auditory system and interact with noise.

Scintigraphy

Scintigraphy ("scint", Latin scintilla, spark), also known as a Gamma scan, is a diagnostic test in nuclear medicine, where radioisotopes attached to drugs that travel to a specific organ or tissue (radiopharmaceuticals) are taken internally and the emitted gamma radiation is captured by external detectors (gamma cameras) to form two-dimensional images in a similar process to the capture of x-ray images. In contrast, SPECT and positron emission tomography (PET) form 3-dimensional images, and are therefore classified as separate techniques to scintigraphy, although they also use gamma cameras to detect internal radiation. Scintigraphy is unlike a diagnostic X-ray where external radiation is passed through the body to form an image.

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