a muscle that is contained entirely within the organ or part it acts on. For example, there are intrinsic muscles of the tongue, whose contractions change the shape of the tongue.
Structure of muscle Skeletal or voluntary muscle forms the bulk of the body’s musculature and contains more than 600 such muscles. They are classi?ed according to their methods of action. A ?exor muscle closes a joint, an extensor opens it; an abductor moves a body part outwards, an adductor moves it in; a depressor lowers a body part and an elevator raises it; while a constrictor (sphincter) muscle surrounds an ori?ce, closing and opening it. Each muscle is enclosed in a sheath of ?brous tissue, known as fascia or epimysium, and, from this, partitions of ?brous tissue, known as perimysium, run into the substance of the muscle, dividing it up into small bundles. Each of these bundles consists in turn of a collection of ?bres, which form the units of the muscle. Each ?bre is about 50 micrometres in thickness and ranges in length from a few millimetres to 300 millimetres. If the ?bre is cut across and examined under a high-powered microscope, it is seen to be further divided into ?brils. Each ?bre is enclosed in an elastic sheath of its own, which allows it to lengthen and shorten, and is known as the sarcolemma. Within the sarcolemma lie numerous nuclei belonging to the muscle ?bre, which was originally developed from a simple cell. To the sarcolemma, at either end, is attached a minute bundle of connective-tissue ?bres which unites the muscle ?bre to its neighbours, or to one of the connective-tissue partitions in the muscle, and by means of these connections the ?bre affects muscle contraction. Between the muscle ?bres, and enveloped in a sheath of connective tissue, lie here and there special structures known as muscle-spindles. Each of these contains thin muscle ?bres, numerous nuclei, and the endings of sensory nerves. (See TOUCH.) The heart muscle comprises short ?bres which communicate with their neighbours via short branches and have no sarcolemma.
Plain or unstriped muscle is found in the following positions: the inner and middle coats of the STOMACH and INTESTINE; the ureters (see URETER) and URINARY BLADDER; the TRACHEA and bronchial tubes; the ducts of glands; the GALL-BLADDER; the UTERUS and FALLOPIAN TUBES; the middle coat of the blood and lymph vessels; the iris and ciliary muscle of the EYE; the dartos muscle of the SCROTUM; and in association with the various glands and hairs in the SKIN. The ?bres are very much smaller than those of striped muscle, although they vary greatly in size. Each has one or more oval nuclei and a delicate sheath of sarcolemma enveloping it. The ?bres are grouped in bundles, much as are the striped ?bres, but they adhere to one another by cement material, not by the tendon bundles found in voluntary muscle.
Development of muscle All the muscles of the developing individual arise from the central layer (mesoderm) of the EMBRYO, each ?bre taking origin from a single cell. Later on in life, muscles have the power both of increasing in size – as the result of use, for example, in athletes – and also of healing, after parts of them have been destroyed by injury. An example of the great extent to which unstriped muscle can develop to meet the demands made on it is the uterus, whose muscular wall develops so much during pregnancy that the organ increases from the weight of 30–40 g (1–1••• oz.) to a weight of around 1 kg (2 lb.), decreasing again to its former small size in the course of a month after childbirth.
Physiology of contraction A muscle is an elaborate chemico-physical system for producing heat and mechanical work. The total energy liberated by a contracting muscle can be exactly measured. From 25–30 per cent of the total energy expended is used in mechanical work. The heat of contracting muscle makes an important contribution to the maintenance of the heat of the body. (See also MYOGLOBIN.)
The energy of muscular contraction is derived from a complicated series of chemical reactions. Complex substances are broken down and built up again, supplying each other with energy for this purpose. The ?rst reaction is the breakdown of adenyl-pyrophosphate into phosphoric acid and adenylic acid (derived from nucleic acid); this supplies the immediate energy for contraction. Next phosphocreatine breaks down into creatine and phosphoric acid, giving energy for the resynthesis of adenyl-pyrophosphate. Creatine is a normal nitrogenous constituent of muscle. Then glycogen through the intermediary stage of sugar bound to phosphate breaks down into lactic acid to supply energy for the resynthesis of phosphocreatine. Finally part of the lactic acid is oxidised to supply energy for building up the rest of the lactic acid into glycogen again. If there is not enough oxygen, lactic acid accumulates and fatigue results.
All of the chemical changes are mediated by the action of several enzymes (see ENZYME).
Involuntary muscle has several peculiarities of contraction. In the heart, rhythmicality is an important feature – one beat appearing to be, in a sense, the cause of the next beat. Tonus is a character of all muscle, but particularly of unstriped muscle in some localities, as in the walls of arteries.
Fatigue occurs when a muscle is made to act for some time and is due to the accumulation of waste products, especially sarcolactic acid (see LACTIC ACID). These substances affect the end-plates of the nerve controlling the muscle, and so prevent destructive overaction of the muscle. As they are rapidly swept away by the blood, the muscle, after a rest (and particularly if the rest is accompanied by massage or by gentle contractions to quicken the circulation) recovers rapidly from the fatigue. Muscular activity over the whole body causes prolonged fatigue which is remedied by rest to allow for metabolic balance to be re-established.... muscle
Alternatives. Internal. Prickly Ash bark, Plantain, Mullein, Yarrow, White Willow, Black Cohosh, Guaiacum, Feverfew.
Tablets/capsules. Prickly Ash bark, Black Cohosh, Guaiacum.
Formula. White Willow 2; Black Cohosh 1; Guaiacum quarter; few grains Cayenne or drops Tincture Capsicum. Dose: Liquid Extracts: 1 teaspoon. Tinctures: 2 teaspoons. Powders: 500mg (two 00 capsules or one-third teaspoon). Thrice daily.
Topical. Castor oil packs. Massage oils. Gold Fire ointment, Epsom salt baths.
Supplements. Niacin, B-complex, B6, Kelp, Dolomite, Calcium, Zinc.
See: RHEUMATIC and other relative disorders for specific treatments. ... muscles
forearm. The biceps femoris at the back of the thigh bends the leg at the knee and extends the thigh.... biceps muscle
The gastrocnemius muscle starts behind the knee and forms the bulky part of the calf; under it is the soleus muscle which starts at the back of the tibia (shin).
The 2 muscles join to form the Achilles tendon, which connects them to the heel.
Contraction of the calf muscles pulls the heel up and is important in walking, running, and jumping.
Pain in these muscles occurs because of cramp, sciatica, or, more rarely, deep vein thrombosis.
The calf muscles may be affected by claudication (pain caused by walking and relieved by rest).... calf muscles
and plays an important role in breathing. There are openings in the diaphragm for the oesophagus and major nerves and blood vessels. To inhale, the diaphragm’s muscle fibres contract, pulling the whole diaphragm downwards and drawing air into the lungs. (See also breathing.)... diaphragm muscle
Cramp Painful spasm of a muscle usually caused by excessive and prolonged contraction of the muscle ?bres. Cramps are common, especially among sportsmen and women, normally lasting a short time. The condition usually occurs during or immediately following exercise as a result of a build-up of LACTIC ACID and other chemical by-products in the muscles
– caused by the muscular e?orts. Cramps may occur more frequently, especially at night, in people with poor circulation, when the blood is unable to remove the lactic acid from the muscles quickly enough.
Repetitive movements such as writing (writer’s cramp) or operating a keyboard can cause cramp. Resting muscles may suffer cramp if a person sits or lies in an awkward position which limits local blood supply to them. Profuse sweating as a result of fever or hot weather can also cause cramp in resting muscle, because the victim has lost sodium salts in the sweat; this disturbs the biochemical balance in muscle tissue.
Treatment is to massage and stretch the affected muscle – for example, cramp in the calf muscle may be relieved by pulling the toes on the affected leg towards the knee. Persistent night cramps sometimes respond to treatment with a drug containing CALCIUM or QUININE. If cramp persists for an hour or more, the person should seek medical advice, as there may be a serious cause such as a blood clot impeding the blood supply to the area affected.
Dystrophy See myopathy below.
In?ammation (myositis) of various types may occur. As the result of injury, an ABSCESS may develop, although wounds affecting muscle generally heal well. A growth due to SYPHILIS, known as a gumma, sometimes forms a hard, almost painless swelling in a muscle. Rheumatism is a vague term traditionally used to de?ne intermittent and often migratory discomfort, sti?ness or pain in muscles and joints with no obvious cause. The most common form of myositis is the result of immunological damage as a result of autoimmune disease. Because it affects many muscles it is called POLYMYOSITIS.
Myasthenia (see MYASTHENIA GRAVIS) is muscle weakness due to a defect of neuromuscular conduction.
Myopathy is a term applied to an acquired or developmental defect in certain muscles. It is not a neurological disease, and should be distinguished from neuropathic conditions (see NEUROPATHY) such as MOTOR NEURONE DISEASE (MND), which tend to affect the distal limb muscles. The main subdivisions are genetically determined, congenital, metabolic, drug-induced, and myopathy (often in?ammatory) secondary to a distant carcinoma. Progressive muscular dystrophy is characterised by symmetrical wasting and weakness, the muscle ?bres being largely replaced by fatty and ?brous tissue, with no sensory loss. Inheritance may take several forms, thus affecting the sex and age of victims.
The commonest type is DUCHENNE MUSCULAR DYSTROPHY, which is inherited as a sex-linked disorder. It nearly always occurs in boys.
Symptoms There are three chief types of myopathy. The commonest, known as pseudohypertrophic muscular dystrophy, affects particularly the upper part of the lower limbs of children. The muscles of the buttocks, thighs and calves seem excessively well developed, but nevertheless the child is clumsy, weak on his legs, and has di?culty in picking himself up when he falls. In another form of the disease, which begins a little later, as a rule at about the age of 14, the muscles of the upper arm are ?rst affected, and those of the spine and lower limbs become weak later on. In a third type, which begins at about this age, the muscles of the face, along with certain of the shoulder and upper arm muscles, show the ?rst signs of wasting. All the forms have this in common: that the affected muscles grow weaker until their power to contract is quite lost. In the ?rst form, the patients seldom reach the age of 20, falling victims to some disease which, to ordinary people, would not be serious. In the other forms the wasting, after progressing to a certain extent, often remains stationary for the rest of life. Myopathy may also be acquired when it is the result of disease such as thyrotoxicosis (see under THYROID GLAND, DISEASES OF), osteomalacia (see under BONE, DISORDERS OF) and CUSHING’S DISEASE, and the myopathy resolves when the primary disease is treated.
Treatment Some myopathies may be the result of in?ammation or arise from an endocrine or metabolic abnormality. Treatment of these is the treatment of the cause, with supportive physiotherapy and any necessary physical aids while the patient is recovering. Treatment for the hereditary myopathies is supportive since, at present, there is no cure – although developments in gene research raise the possibility of future treatment. Physiotherapy, physical aids, counselling and support groups may all be helpful in caring for these patients.
The education and management of these children raise many diffculties. Much help in dealing with these problems can be obtained from Muscular Dystrophy Campaign.
Myositis ossi?cans, or deposition of bone in muscles, may be congenital or acquired. The congenital form, which is rare, ?rst manifests itself as painful swellings in the muscles. These gradually harden and extend until the child is encased in a rigid sheet. There is no e?ective treatment and the outcome is fatal.
The acquired form is a result of a direct blow on muscle, most commonly on the front of the thigh. The condition should be suspected whenever there is severe pain and swelling following a direct blow over muscle. The diagnosis is con?rmed by hardening of the swelling. Treatment consists of short-wave DIATHERMY with gentle active movements. Recovery is usually complete.
Pain, quite apart from any in?ammation or injury, may be experienced on exertion. This type of pain, known as MYALGIA, tends to occur in un?t individuals and is relieved by rest and physiotherapy.
Parasites sometimes lodge in the muscles, the most common being Trichinella spiralis, producing the disease known as TRICHINOSIS (trichiniasis).
Rupture of a muscle may occur, without any external wound, as the result of a spasmodic e?ort. It may tear the muscle right across – as sometimes happens to the feeble plantaris muscle in running and leaping – or part of the muscle may be driven through its ?brous envelope, forming a HERNIA of the muscle. The severe pain experienced in many cases of LUMBAGO is due to tearing of one of the muscles in the back. These conditions are usually relieved by rest and massage. Partial muscle tears, such as occur in sport, require more energetic treatment: in the early stages this consists of the application of an ice or cold-water pack, ?rm compression, elevation of the affected limb, rest for a day or so and then gradual mobilisation (see SPORTS MEDICINE).
Tumours occur occasionally, the most common being ?broid, fatty, and sarcomatous growths.
Wasting of muscles sometimes occurs as a symptom of disease in other organs: for example, damage to the nervous system, as in poliomyelitis or in the disease known as progressive muscular atrophy. (See PARALYSIS.)... muscles, disorders of
The drugs may cause muscle weakness and drowsiness. In rare cases, dantrolene causes liver damage.... muscle-relaxant drugs
There are 2 parts: psoas major and psoas minor.
Psoas major acts to flex the hip and rotate the thigh inwards.
Psoas minor bends the spine down to the pelvis.... psoas muscle
The most common disorder of the quadriceps is a haematoma caused by a direct blow.... quadriceps muscle
It is attached to the top and back of the shoulderblade and to the outermost part of the collarbone.
The trapezius helps support the neck and spine and is involved in moving the arm.... trapezius muscle
Accumulation of toxins (M,S,B):
Angelica, white birch, carrot seed, celery seed, coriander, cumin, sweet fennel, grapefruit, juniper, lovage, parsley.
Aches and pains (M,C,B):
Ambrette, star anise, aniseed, French basil, West Indian bay, cajeput, calamintha, camphor (white), chamomile (German & Roman), coriander, eucalyptus (blue gum & peppermint), silver fir, galbanum, ginger, immortelle, lavandin, lavender (spike & true), lemongrass, sweet marjoram, mastic, mint (peppermint & spearmint), niaouli, nutmeg, black pepper, pine (longleaf & Scotch), rosemary, sage (clary & Spanish), hemlock spruce, thyme, turmeric, turpentine, vetiver.
Arthritis (M,S,C,B):
Allspice, angelica, benzoin, white birch, cajeput, camphor (white), carrot seed, cedarwood (Atlas, Texas & Virginian), celery seed, chamomile (German & Roman), clove bud, coriander, eucalyptus (blue gum & peppermint), silver fir, ginger, guaiacwood, juniper, lemon, sweet marjoram, mastic, myrrh, nutmeg, parsley, black pepper, pine (longleaf & Scotch), rosemary, Spanish sage, thyme, tumeric, turpentine, vetiver, yarrow.
Cellulitis (M,S,B):
White birch, cypress, sweet fennel, geranium, grapefruit, juniper, lemon, parsley, rosemary, thyme.
Debility/poor muscle tone (M,S,B):
Allspice, ambrette, borneol, ginger, grapefruit, sweet marjoram, black pepper, pine (longleaf & Scotch), rosemary, Spanish sage.
Gout (M,S,B):
Angelica, French basil, benzoin, carrot seed, celery seed, coriander, guaiacwood, juniper, lovage, mastic, pine (longleaf & Scotch), rosemary, thyme, turpentine.
High blood pressure & hypertension (M,B,V):
cananga, garlic, true lavender, lemon, sweet marjoram, melissa, clary sage, yarrow, ylang ylang.
Muscular cramp & stiffness (M,C,B):
Allspice, ambrette, coriander, cypress, grapefruit, jasmine, lavandin, lavender (spike & true), sweet marjoram, black pepper, pine (longleaf & Scotch), rosemary, thyme, vetiver.
Obesity (M,B):
White birch, sweet fennel, juniper, lemon, mandarin, orange (bitter & sweet).
Oedema & water retention (M,B):
Angelica, white birch, carrot seed, cypress, sweet fennel, geranium, grapefruit, juniper, lavage, mandarin, orange (bitter & sweet), rosemary, Spanish sage.
Palpitations (M):
Neroli, orange (bitter & sweet), rose (cabbage & damask), ylang ylang.
Poor circulation & low blood pressure (M,B):
Ambrette, Peru balsam, West Indian bay, benzoin, white birch, borneol, cinnamon leaf, coriander, cumin, cypress, eucalyptus blue gum, galbanum, geranium, ginger, lemon, lemongrass, lovage, neroli, niaouli, nutmeg, black pepper, pine (longleaf & Scotch), rose (cabbage & damask), rosemary, Spanish sage, hemlock spruce, thyme, violet.
Rheumatism (M,C,B):
Allspice, angelica, star anise, aniseed, Peru balsam, French basil, West Indian bay, benzoin, white birch, borneol, cajeput, calamintha, camphor (white), carrot seed, cedarwood (Atlas, Texas & Virginian), celery seed, chamomile (German & Roman), cinnamon leaf, clove bud, coriander, cypress, eucalyptus (blue gum & peppermint), sweet fennel, silver fir, galbanum, ginger, immortelle, juniper, lavandin, lavender (spike & true), lemon, lovage, sweet marjoram, mastic, niaouli, nutmeg, parsley, black pepper, pine (longleaf & Scotch), rosemary, Spanish sage, hemlock spruce, thyme, turmeric, turpentine, vetiver, violet, yarrow.
Sprains & strains (C):
West Indian bay, borneol, camphor (white), chamomile (German & Roman), clove bud, eucalyptus (blue gum & peppermint), ginger, immortelle, jasmine, lavandin, lavender (spike & true), sweet marjoram, black pepper, pine (longleaf & Scotch), rosemary, thyme, turmeric, vetiver.... circulation, muscles and joints:
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