Nerve Growth Factor: From 1 Different Sources
(NGF) a protein (see growth factor), consisting of two polypeptide chains, that is required for the development and longevity of some neurons, including those in the sympathetic nervous system and some central nervous system and sensory neurons. Nerve growth factor is necessary for axon growth and also for initiating new neuronal connections with other cells. The role of NGFs in preventing the degeneration of brain cells is being explored in research into Alzheimer’s disease.
One of two proteins secreted from the lining of the stomach whose sole purpose is (it seems) to cradle B12 in a pre-fitted styrofoam mold and (A) carry it through the Seven Levels of Digestive Hell until it reaches those few absorption sites in the last foot of small intestine that understand its “Special Needs” (sounds either sexually kinky or the airplane dinner label on kosher food for flying Hassidim jewelers) and finally (B) slip it from one protein to the other, and thence into the cell membranes where its is turn handed over to (C) the specialized blood protein that can carry it safely to the final target tissues (3 times out of 4, the bone marrow). Cyanocobalamin (B12) has parts that fall off, radicals that twirl around in five directions on three charge potentials, and is as durable as a 49¢ water pistol. And, if we have an ulcer, chronic enteritis or long-standing steatorrhea, we either get B12 shots (and hope the liver still makes that blood carrier) or walk around with pernicious anemia and a hematocrit of 16.... intrinsic factor
An aspect of personal behaviour or lifestyle, an environmental exposure, or an inborn or inherited characteristic, which, on the basis of scientific evidence, is known to be associated with health-related condition(s) considered important to prevent.... risk factor
See VESTIBULOCOCHLEAR NERVE.... auditory nerve
The seventh cranial nerve (arising from the BRAIN), supplying the muscles of expression in the face, being purely a motor nerve. It enters the face immediately below the ear after splitting up into several branches. (See BELL’S PALSY.)... facial nerve
A coagulative blood protein that is a constituent of the COAGULATION cascade – an essential component in the clotting of blood. Those people with the inherited disorder, HAEMOPHILIA, have abnormally low amounts of factor VIII and so bleed more when cut. They are treated with a concentrated version to reduce the tendency to bleed.... factor viii
The 12th cranial nerve, which supplies the muscles of the tongue, together with some others lying near it. This nerve is responsible for movements required for swallowing and talking. (See also NERVOUS SYSTEM.)... hypoglossal nerve
See ANAESTHESIA – Local anaesthetics.... nerve block
This NERVE arises from the BRACHIAL plexus in the axilla. At ?rst descending posteriorly and then anteriorly, it ends just above the elbow by dividing into the super?cial radial and interosseous nerves. It supplies motor function to the muscles which extend the arm, wrist, and some ?ngers, and supplies sensation to parts of the posterior and lateral aspects of the arm, forearm and hand.... radial nerve
The ?fth cranial nerve (arising from the BRAIN). It consists of three divisions: (1) the ophthalmic nerve, which is purely sensory in function, being distributed mainly over the forehead and front part of the scalp; (2) the maxillary nerve, which is also sensory and distributed to the skin of the cheek, the mucous membrane of the mouth and throat, and the upper teeth; and (3) the mandibular nerve, which is the nerve of sensation to the lower part of the face, the tongue and the lower teeth, as well as being the motor nerve to the muscles concerned in chewing. The trigeminal nerve is of special interest, owing to its liability to NEURALGIA – TRIGEMINAL NEURALGIA, or tic douloureux as it is also known, being the most painful form known.... trigeminal nerve
The fourth cranial nerve (arising from the BRAIN), which acts upon the superior oblique muscle of the EYE.... trochlear nerve
A major NERVE in the arm, it runs from the brachial plexus to the hand. The nerve controls the muscles that move the ?ngers and thumb and conveys sensation from the ?fth and part of the fourth and from the adjacent palm. Muscle weakness and numbness in the areas supplied by the nerve is usually caused by pressure from an abnormal outgrowth from the epicondyle at the bottom of the humerus (upper-arm bone).... ulnar nerve
Also called the pneumogastric nerve, this is the tenth cranial nerve, with many fibers leading to parasympathetic ganglia in internal organs, and can be considered the presynapse starter for the upper parts of the parasympathetic functions.... vagus nerve
The eighth cranial nerve. It consists of two sets of ?bres, which constitute two separate nerves. One is known as the vestibular nerve, which connects the semicircular canals and inner ear to the BRAIN and conveys information on posture and movement of the body; it is the nerve of equilibration or balance. The other is known as the cochlear nerve, which links the COCHLEA (organ that responds to sounds) with the brain and is the nerve of hearing. Disturbance of the former causes giddiness (VERTIGO), whilst disturbance of the latter causes DEAFNESS.... vestibulocochlear nerve
This is the sixth nerve rising from the brain and controls the external rectus muscle of the EYE, which turns the eye outwards. It is particularly liable to be paralysed in diseases of the nervous system, thus leading to an inward squint.... abducent nerve
A popular term applied to any new formation in any part of the body. (See CANCER; CYSTS; GANGLION; TUMOUR.) For growth of children, see WEIGHT AND HEIGHT.... growth
A branch of the ophthalmic nerve supplying the lacrimal gland and conjunctiva of the EYE.... lacrimal nerve
See NEURON(E).... nerve cell
The NERVE which chie?y supplies the DIAPHRAGM. A phrenic nerve arises on each side of the SPINAL CORD from the third, fourth and ?fth cervical spinal nerves; both follow a long course down the neck, and through the chest to the diaphragm. They play a key part in RESPIRATION through control of the diaphragm. Injury to one nerve paralyses one half of the diaphragm. Occasionally the phrenic nerve may be surgically crushed as part of the treatment to repair a HIATUS HERNIA or, rarely, to stop intractable hiccups.... phrenic nerve
The nerve that operates the lowest muscles of the ?oor of the PELVIS and also the anal SPHINCTER muscle. It may be damaged in childbirth, resulting in INCONTINENCE.... pudendal nerve
See BLOOD GROUPS.... rh factor
See BLOOD GROUPS.... rhesus factor
The 11th cranial nerve. Unlike the other cranial nerves, most of the accessory nerve originates from the spinal cord. The small part of the nerve that originates from the brain supplies many muscles of the palate, pharynx (throat), and larynx (voice box). Damage to this part of the nerve may cause difficulty in speaking and swallowing. The spinal part of the nerve supplies large muscles of the neck and back, notably the sternomastoid and trapezius. Damage to the spinal fibres of the nerve paralyses these muscles.... accessory nerve
The part of the vestibulocochlear nerve (the 8th cranial nerve) that is concerned with hearing. It is also known as the auditory nerve.... acoustic nerve
A protein in blood that plays an important role in the clotting mechanism. A deficiency of factor causes a rare genetic bleeding disorder known as Christmas disease.... factor ix
The 3rd cranial nerve, controlling most of the muscles that move the eye. The oculomotor nerve also supplies the muscle that constricts the pupil, that which raises the upper eyelid, and the ciliary muscle, which focuses the eye. The nerve may be damaged due to a fracture to the base of the skull or a tumour. Symptoms include ptosis, squint, dilation of the pupil, inability to focus the eye, double vision, and slight protrusion of the eyeball. (See also trochlear nerve; abducent nerve.)... oculomotor nerve
The first cranial nerve, which conveys sensations of smell as nerve impulses from the nose to the brain. Each of the 2 olfactory nerves has receptors in the mucous membrane lining the nasal cavity. These receptors detect smells and send signals along nerve fibres, which pass through tiny holes in the roof of the nasal cavity and combine to form the olfactory bulbs. From here, nerve fibres come together to form the olfactory nerve, leading to the olfactory centre in the brain. Sense of smell may be lost or impaired due to damage to the olfactory nerves, usually as a result of head injury.... olfactory nerve
The main nerve in each leg and the largest nerve in the body.The sciatic nerves are formed from nerve roots in the spinal cord.... sciatic nerve
See TENS.... transcutaneous electrical nerve stimulation
A chemical, psychological, physiological, social, environmental or genetic factor or conditions that predisposes an individual to the development of a disease or injury.... health risk factor
The study of the interrelationships between humans, the tools they use, and the environment in which they live and work.... human-factor research
See BELL’S PALSY.... idiopathic facial nerve palsy
An agent involved in the clotting mechanism of the blood. It helps in the activation of THROMBOPLASTIN in the blood PLASMA (see COAGULATION).... lipoid factor
Various compounds and processes that enable the liver to metabolize fats properly or prevent the formation of cholesterolic stones in the gall bladder by supporting the continued emulsification of gall bladder bile. EXAMPLES: Lecithin, choline, Aristolochia... lipotropic factors
A method of electrical stimulation that is being used for the relief of PAIN, including that of MIGRAINE, NEURALGIA and phantom limbs (see AMPUTATION). Known as TENS, its mode of action appears to have some resemblance to that of ACUPUNCTURE. Several controlled trials suggest that it provides at least a modicum of relief of pain after operations, thereby reducing the amount of ANALGESICS that may be called for.... transcutaneous electrical nerve stimulation (tens)
See: SEDATIVE. ... nerve relaxant
The increase in height and weight as a child develops. The period of most rapid growth occurs before birth. After birth, although growth is still rapid in the first few years of life, especially in the first year, the rate of
growth steadily decreases. Puberty marks another major period of growth, which continues until adult height and weight are reached, usually at about age 16–17 in girls and 19–21 in boys.
Body shape changes during childhood because different areas grow at different rates. For example, at birth, the head is already about three quarters of its adult size; it grows to almost full size during the first year. Thereafter, it becomes proportionately smaller because the body grows at a much faster rate.
Growth can be influenced by heredity and by environmental factors such as nutrition and general health. Hormones also play an important role, particularly growth hormone, thyroid hormones, and, at puberty, the sex hormones.
A chronic illness, such as cystic fibrosis, may retard growth. Even a minor illness can slow growth briefly, although the growth rate usually catches up when the child recovers. In some cases, slow growth may be the only sign that a child is ill or malnourished, in which case it is known as failure to thrive. However, short stature does not necessarily indicate poor health. Abnormally rapid growth is rare. Usually, it is a familial trait, but it may occasionally indicate an underlying disorder, such as a pituitary gland tumour causing gigantism. (See also age; child development.)... growth, childhood
One of a pair of nerves that carry instructions from the brain to the larynx and send sensations from the larynx to the brain.... laryngeal nerve
Factors that lead to increased susceptibility to a disease.... predisposing factors
See nerve, trapped.... trapped nerve
the sixth *cranial nerve (VI), which supplies the lateral rectus muscle of each eyeball, responsible for turning the eye outwards.... abducens nerve
a group of *growth factors that promote new bone formation. Bone morphogenic protein (BMP), a naturally occurring substance that induces *osteoblast formation, has been genetically synthesized to form bone morphogenetic protein, which stimulates new bone formation and assists with fracture healing. Other bone growth factors include a type of transforming growth factor (TGF?) and insulin-like growth factor II (IGF-II), which encourage collagen formation.... bone growth factors
a mixed sensory and motor nerve of the upper arm. It arises from the fifth and sixth cervical segments of the spinal cord and is distributed to the deltoid muscle of the shoulder and the overlying skin.... circumflex nerve
see coagulation factors.... clotting factors
(clotting factors) a group of substances present in blood plasma that, under certain circumstances, undergo a series of chemical reactions leading to the conversion of blood from a liquid to a solid state (see blood coagulation). Although they have specific names, most coagulation factors are referred to by an agreed set of Roman numerals (e.g. *Factor VIII, *Factor IX). Lack of any of these factors in the blood results in the inability of the blood to clot. See also haemophilia.... coagulation factors
(acoustic nerve, auditory nerve) the nerve connecting the cochlea to the brain and therefore responsible for transmitting the nerve impulses relating to hearing. It forms part of the *vestibulocochlear nerve (cranial nerve VIII).... cochlear nerve
(CSF) one of a group of substances (haemopoietic growth factors or hormones) that are produced in the bone marrow and stimulate the production of specific blood cells. Genetically engineered granulocyte colony-stimulating factor (G-CSF) stimulates neutrophil production and also limits bone marrow toxicity from chemotherapy.... colony-stimulating factor
either of two nerves that supply the teeth; they are branches of the trigeminal nerve. The inferior dental nerve supplies the lower teeth and for most of its length exists as a single large bundle; thus anaesthesia of it has a widespread effect (see inferior dental block). The superior dental nerve, which supplies the upper teeth, breaks into separate branches at some distance from the teeth and it is possible to anaesthetize these individually with less widespread effect for the patient.... dental nerve
(EGFR) a protein on the surface of cells (see receptor) that binds with epidermal *growth factor and is therefore involved in cell division. EGFR is expressed at increased levels in numerous tumours, particularly of the head and neck, and in colorectal cancer, in which it can be a target for antibody therapy with *cetuximab. *Tyrosine kinase inhibitors acting specifically on the EGFR include gefitinib and erlotinib in lung and pancreatic cancer.... epidermal growth factor receptor
n. (in biochemistry) a substance that is essential to a physiological process, often a substance the nature of which is unknown. See also coagulation factors; growth factor.... factor
an inherited mutation in the gene coding for coagulation Factor V, which results in an increased susceptibility to develop venous *thrombosis.... factor v leiden
a *coagulation factor normally present in blood. Deficiency of the factor is inherited, but rarely causes spontaneous bleeding. However, bleeding does occur after surgery or trauma to the blood vessels.... factor xi
a graph, customized to a pregnant woman’s height, weight, and other factors, that plots *fundal height and estimated fetal weight on ultrasound against weeks of gestation. The graph, which shows centile lines (see centile chart), improves prediction of a baby who is *small for gestational age.... fetal growth chart
see intrauterine growth restriction.... fetal growth restriction
see physis.... growth plate
(House–Brackmann score, House–Brackmann scale, House–Brackmann facial weakness scale) a six-point grading system for patients with *Bell’s palsy or other forms of facial nerve palsy. Grade I is normal function; grade VI is a total palsy. [J. W. House and D. E. Brackmann (21st century), US otorhinolarygologists]... house–brackmann facial nerve grading system
(IUGR, fetal growth restriction) failure of a fetus to achieve its growth potential, resulting in the birth of a baby whose birth weight is abnormally low in relation to its gestational age (see small for gestational age). Causes include *uteroplacental insufficiency, maternal disease (e.g. infection, malnutrition, high blood pressure, smoking, and alcoholism), poor socioeconomic conditions, multiple pregnancy (e.g. twins), and fetal disease or chromosomal abnormalities. It may be associated with *preterm birth.... intrauterine growth restriction
(myelinated nerve fibre) see myelin.... medullated nerve fibre
one of the nerves that carry impulses outwards from the central nervous system to bring about activity in a muscle or gland. Compare sensory nerve.... motor nerve
a nerve of the *brachial plexus that supplies some muscles of the arm and the skin of the lateral part of the forearm.... musculocutaneous nerve
a test done to assess the peripheral nervous system. It involves activating the nerves electronically with electrical pulses and measuring the responses obtained.... nerve conduction study
the final part (terminal) of one of the branches of a nerve fibre, where a *neuron makes contact either with another neuron at a synapse or with a muscle or gland cell at a neuromuscular or neuroglandular junction.... nerve ending
any syndrome resulting from pressure on a nerve from surrounding structures. Examples include the *carpal tunnel syndrome and *meralgia paraesthetica.... nerve entrapment syndrome
the long fine process that extends from the cell body of a *neuron and carries nerve impulses. Bundles of nerve fibres running together form a *nerve. Each fibre has a sheath, which in medullated nerve fibres is a relatively thick layer containing the fatty insulating material *myelin.... nerve fibre
any gas that disrupts the normal functioning of nerves and thus of the muscles they supply. There are two groups, the G agents and the V agents. The latter are more than 300 times as deadly as mustard gas: one inhalation can kill by paralysing the respiratory muscles. V agents also act through the skin, therefore gas masks are ineffective protection against them.... nerve gas
the electrical activity in the membrane of a *neuron that – by its rapid spread from one region to the next – is the means by which information is transmitted within the nervous system along the axons of the neurons. The membrane of a resting nerve is charged (polarized) because of the different concentrations of ions inside and outside the cell. When a nerve impulse is triggered, a wave of *depolarization spreads, and ions flow across the membrane (see action potential). Until the nerve has undergone *repolarization no further nerve impulses can pass.... nerve impulse
the growth of new nerve tissue, which occurs at a very slow rate (1–2 mm per day) after a nerve has been severed and is often partially or totally incomplete. *Microsurgery has improved the results by facilitating primary repair in the immediate aftermath of injury. See also axonotmesis; neurotmesis.... nerve regeneration
the smallest of the three branches of the *trigeminal nerve. It supplies sensory fibres to the eyeball, conjunctiva, and lacrimal gland, to a small region of the nasal mucous membrane, and to the skin of the nose, brows, and scalp.... ophthalmic nerve
(PDGF) see growth factor.... platelet-derived growth factor
a large branch of the *femoral nerve that arises in the upper thigh, travels down on the inside of the leg, and supplies the skin from the knee to below the ankle with sensory nerves.... saphenous nerve
a nerve that carries information inwards, from an outlying part of the body towards the central nervous system. Different sensory nerves convey information about temperature, pain, touch, taste, etc., to the brain. Compare motor nerve.... sensory nerve
a small subdivision of the *vestibular nerve that carries information from the posterior *semicircular canal to the brain. Singular neurectomy is a surgical procedure to divide the singular nerve, occasionally used in the treatment of *benign paroxysmal positional vertigo.... singular nerve
see accessory nerve.... spinal accessory nerve
(TGF) a protein – a *cytokine – that controls growth, proliferation, and other functions in most cells. It plays a role in asthma and other respiratory diseases and is also involved in diseases elsewhere in the body. There are two classes: TGF-? and TGF-?.... transforming growth factor
(TNF) either of two proteins, TNF-? or TNF-?, that function as *cytokines. Produced by macrophages, monocytes, T lymphocytes, and various other cells, they mediate many responses, including inflammation, and have a marked action against tumour cells. Anti-TNF drugs (see cytokine inhibitor) are used in the treatment of several disorders, especially rheumatoid arthritis and ankylosing spondylitis.... tumour necrosis factor
(VEGF) a *growth factor made by both normal cells and their abnormal or malignant counterparts to stimulate new blood vessel formation (see angiogenesis). It can be targeted by a family of drugs known as *angiogenesis inhibitors, which include *bevacizumab.... vascular endothelial growth factor
any nerve, usually belonging to the autonomic nervous system, that controls the circulation of blood through blood vessels by its action on the muscle fibres within their walls or its action on the heartbeat. The *vagus nerve slows the heart and reduces its output, but sympathetic nerves increase the rate and output of the heart and increase blood pressure by causing the constriction of small blood vessels at the same time.... vasomotor nerve
the division of the *vestibulocochlear nerve that carries impulses from the semicircular canals, utricle, and saccule of the inner ear to the brain, conveying information about the body’s posture and movements in space and allowing coordination and balance.... vestibular nerve
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