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Inflammatory Reflex
The inflammatory reflex is a neural circuit that regulates the immune response to injury and invasion. All reflexes have an afferent and efferent arc. The Inflammatory reflex has a sensory afferent arc, which is activated by cytokines, and a motor or efferent arc, which transmits action potentials in the vagus nerve to suppress cytokine production. Increased signaling in the efferent arc inhibits inflammation and prevents organ damage. It has also been shown that the brain can use this circuit not only to regulate the immune response but also to extend the immunological memory Molecular mechanism The molecular basis of cytokine-inhibiting signals requires the neurotransmitter acetylcholine, and the Alpha-7 nicotinic receptor receptor expressed on cytokine-producing cells. The release of acetylcholine in spleen suppresses the production of TNF and other cytokines which causes damaging inflammation. Signaling in the efferent arc of the inflammatory reflex, termed the " Chol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afferent Nerve Fiber
Afferent nerve fibers are the axons (nerve fibers) carried by a sensory nerve that relay sensory information from sensory receptors to regions of the brain. Afferent projections ''arrive'' at a particular brain region. Efferent nerve fibers are carried by efferent nerves and ''exit'' a region to act on muscles and glands. In the peripheral nervous system afferent and efferent nerve fibers are part of the somatic nervous system and arise from outside of the spinal cord. Sensory nerves carry the afferent fibers to enter into the spinal cord, and motor nerves carry the efferent fibers out of the spinal cord to act on skeletal muscles. In the central nervous system non-motor efferents are carried in efferent nerves to act on glands. Structure Afferent neurons are pseudounipolar neurons that have a single process leaving the cell body dividing into two branches: the long one towards the sensory organ, and the short one toward the central nervous system (e.g. spinal cord). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spleen
The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .σπλήν Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus Digital Library The spleen plays very important roles in regard to s (erythrocytes) and the . It removes old red blood cells and holds a reserve of blood, which can be valuable in case of |
Pavlovian Conditioning
Classical conditioning (also known as Pavlovian or respondent conditioning) is a behavioral procedure in which a biologically potent stimulus (e.g. food) is paired with a previously neutral stimulus (e.g. a triangle). It also refers to the learning process that results from this pairing, through which the neutral stimulus comes to elicit a response (e.g. salivation) that is usually similar to the one elicited by the potent stimulus. Classical conditioning is distinct from operant conditioning (also called instrumental conditioning), through which the strength of a voluntary behavior is modified by reinforcement or punishment. However, classical conditioning can affect operant conditioning in various ways; notably, classically conditioned stimuli may serve to reinforce operant responses. Classical conditioning was first studied in detail by Ivan Pavlov, who conducted experiments with dogs and published his findings in 1897. During the Russian physiologist's study of digestion, Pav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interoception
Interoception is contemporarily defined as the collection of senses perceiving the internal state of the body. This can be both conscious and unconscious. It encompasses the brain's process of integrating signals relayed from the body into specific subregions—like the brainstem, thalamus, insula, somatosensory, and anterior cingulate cortex—allowing for a nuanced representation of the physiological state of the body. This is important for maintaining homeostatic conditions in the body and, potentially, facilitating self-awareness. Interoceptive signals are projected to the brain via a diversity of neural pathways, in particular from the lamina I of the spinal cord along the spinothalamic pathway and through the projections of the solitary nucleus, that allow for the sensory processing and prediction of internal bodily states. Misrepresentations of internal states, or a disconnect between the body's signals and the brain's interpretation and prediction of those signals, have b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-inflammatory Drugs
Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of use, but largely include an increased risk of gastrointestinal ulcers and bleeds, heart attack, and kidney disease. The term ''non-steroidal'', common from around 1960, distinguishes these drugs from corticosteroids, which during the 1950s had acquired a bad reputation due to overuse and side-effect problems after their initial introduction in 1948. NSAIDs work by inhibiting the activity of cyclooxygenase enzymes (the COX-1 and COX-2 isoenzymes). In cells, these enzymes are involved in the synthesis of key biological mediators, namely prostaglandins, which are involved in inflammation, and thromboxanes, which are involved in blood clotting. There are two general types of NSAIDs available: non-selective, and COX-2 selective. Most N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congestive Heart Failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, and leg swelling. The shortness of breath may occur with exertion or while lying down, and may wake people up during the night. Chest pain, including angina, is not usually caused by heart failure, but may occur if the heart failure was caused by a heart attack. The severity of the heart failure is measured by the severity of symptoms during exercise. Other conditions that may have symptoms similar to heart failure include obesity, kidney failure, liver disease, anemia, and thyroid disease. Common causes of heart failure include coronary artery disease, heart attack, high blood pressure, atrial fibrillation, valvular heart disease, excessive alcohol consumption, infection, and cardiomyopathy. These cause heart failure by altering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock (circulatory)
Shock is the state of insufficient blood flow to the tissues of the body as a result of problems with the circulatory system. Initial symptoms of shock may include weakness, fast heart rate, fast breathing, sweating, anxiety, and increased thirst. This may be followed by confusion, unconsciousness, or cardiac arrest, as complications worsen. Shock is divided into four main types based on the underlying cause: low volume, cardiogenic, obstructive, and distributive shock. Low volume shock, also known as hypovolemic shock, may be from bleeding, diarrhea, or vomiting. Cardiogenic shock may be due to a heart attack or cardiac contusion. Obstructive shock may be due to cardiac tamponade or a tension pneumothorax. Distributive shock may be due to sepsis, anaphylaxis, injury to the upper spinal cord, or certain overdoses. The diagnosis is generally based on a combination of symptoms, physical examination, and laboratory tests. A decreased pulse pressure (systolic blood pressure m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sepsis
Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is followed by suppression of the immune system. Common signs and symptoms include fever, tachycardia, increased heart rate, hyperventilation, increased breathing rate, and mental confusion, confusion. There may also be symptoms related to a specific infection, such as a cough with pneumonia, or dysuria, painful urination with a pyelonephritis, kidney infection. The very young, old, and people with a immunodeficiency, weakened immune system may have no symptoms of a specific infection, and the hypothermia, body temperature may be low or normal instead of having a fever. Severe sepsis causes organ dysfunction, poor organ function or blood flow. The presence of Hypotension, low blood pressure, high blood Lactic acid, lactate, or Oliguria, low urine o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colitis
Colitis is swelling or inflammation of the large intestine ( colon). Colitis may be acute and self-limited or long-term. It broadly fits into the category of digestive diseases. In a medical context, the label ''colitis'' (without qualification) is used if: * The cause of the inflammation in the colon is undetermined; for example, ''colitis'' may be applied to ''Crohn's disease'' at a time when the diagnosis is unknown, or * The context is clear; for example, an individual with ulcerative colitis is talking about their disease with a physician who knows the diagnosis. Signs and symptoms The signs and symptoms of colitis are quite variable and dependent on the cause of the given colitis and factors that modify its course and severity. Common symptoms of colitis may include: mild to severe abdominal pains and tenderness (depending on the stage of the disease), persistent hemorrhagic diarrhea with pus either present or absent in the stools, fecal incontinence, flatulence, fatigu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthritis
Arthritis is a term often used to mean any disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In some types of arthritis, other organs are also affected. Onset can be gradual or sudden. There are over 100 types of arthritis. The most common forms are osteoarthritis (degenerative joint disease) and rheumatoid arthritis. Osteoarthritis usually occurs with age and affects the fingers, knees, and hips. Rheumatoid arthritis is an autoimmune disorder that often affects the hands and feet. Other types include gout, lupus, fibromyalgia, and septic arthritis. They are all types of rheumatic disease. Treatment may include resting the joint and alternating between applying ice and heat. Weight loss and exercise may also be useful. Recommended medications may depend on the form of arthritis. These may include pain medications such as ibuprofen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Innate Immune System
The innate, or nonspecific, immune system is one of the two main immunity strategies (the other being the adaptive immune system) in vertebrates. The innate immune system is an older evolutionary defense strategy, relatively speaking, and is the dominant immune system response found in plants, fungi, insects, and primitive multicellular organisms (see Beyond vertebrates).. The major functions of the innate immune system are to: * recruit immune cells to infection sites by producing chemical factors, including chemical mediators called cytokines * activate the complement cascade to identify bacteria, activate cells, and promote clearance of antibody complexes or dead cells * identify and remove foreign substances present in organs, tissues, blood and lymph, by specialized white blood cells * activate the adaptive immune system through antigen presentation * act as a physical and chemical barrier to infectious agents; via physical measures such as skin and chemical measures such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Efferent Nerve Fiber
Efferent nerve fibers refer to axonal projections that ''exit'' a particular region; as opposed to afferent projections that ''arrive'' at the region. These terms have a slightly different meaning in the context of the peripheral nervous system (PNS) and central nervous system (CNS). The efferent fiber is a long process projecting far from the neuron's body that carries nerve impulses away from the central nervous system toward the peripheral effector organs (mainly muscles and glands). A bundle of these fibers is called an efferent nerve (if it connects to muscles, then it is a motor nerve). The opposite direction of neural activity is afferent conduction, which carries impulses by way of the afferent nerve fibers of sensory neurons. In the nervous system there is a "closed loop" system of sensation, decision, and reactions. This process is carried out through the activity of sensory neurons, interneurons, and motor neurons. In the CNS, afferent and efferent projections ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
