(PNS, or occasionally PeNS) consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect thecentral nervous system (CNS) to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain barrier, leaving it exposed to toxins and mechanical injuries. The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system; some textbooks also include sensory systems. It is also a part of the nervous system.
The cranial nerves are part of the PNS with the exception of cranial nerve II, the optic nerve, along with the retina. The second cranial nerve is not a true peripheral nerve but a tract of the diencephalon.Cranial nerve ganglia originate in the CNS. However, the remaining eleven cranial nerve axons extend beyond the brain and are therefore considered part of the PNS.
Reflex tests
are simple physical tests of nervous system function.
Purpose
A reflex is a simple nerve circuit. A stimulus, such as a light tap with a rubber hammer, causes sensory neurons (nerve cells) to send signals to the spinal cord. There, the signals are conveyed both to the brainand to nerves that control muscles affected by the stimulus. Without any brain intervention, these muscles may respond to an appropriate stimulus by contracting.
Reflex tests measure the presence and strength of a number of reflexes. In so doing, they help to assess the integrity of the nerve circuits involved. Reflex tests are performed as part of a neurological exam, either a "mini-exam" done to quickly confirm integrity of the spinal cord, or a more complete exam performed to diagnose the presence and location of a spinal cord injury or neuromuscular disease.
Deep tendon reflexes are responses to muscle stretch. The familiar "knee-jerk" reflex is an example of a reflex. This tests the integrity of the spinal cord in the lower back region. The usual set of deep tendon reflexes tested, involving increasingly higher regions of the spinal cord, includes:
ankle
knee
abdomen
forearm
biceps
triceps
patellar
Another type of reflex test is called the Babinski test, which involves gently stroking the sole of the foot to assess proper development and function of the spine and cerebral cortex.
Deep Tendon Reflexes
In a normal person, when a muscle tendon is tapped briskly, the muscle immediately contracts due to a two-neuron reflex arc involving the spinal or brainstem segment that innervates the muscle. The afferent neuron whose cell body lies in a dorsal root ganglion innervates the muscle or Golgi tendon organ associated with the muscles; the efferent neuron is an alpha motoneuron in the anterior horn of the cord. The cerebral cortex and a number of brainstem nuclei exert influence over the sensory input of the muscle spindles by means of the gamma motoneurons that are located in the anterior horn; these neurons supply a set of muscle fibers that control the length of the muscle spindle itself.
Hyporeflexia is an absent or diminished response to tapping. It usually indicates a disease that involves one or more of the components of the two-neuron reflex arc itself.
Hyperreflexia refers to hyperactive or repeating (clonic) reflexes. These usually indicate an interruption of corticospinal and other descending pathways that influence the reflex arc due to a suprasegmental lesion, that is, a lesion above the level of the spinal reflex pathways.
Infants
An infantis the very young offspring of a human or other mammal. When applied to humans, the term is usually considered synonymous with baby, but the latter is commonly applied to the young of any animal. When a human child learns to walk, the term toddler may be used instead.
The term infant is typically applied to young children between the ages of 1 month and 12 months; however, definitions may vary between birth and 3 years of age. A newborn is an infant who is only hours, days, or up to a few weeks old. In medical contexts, newborn or neonate (from Latin, neonatus, newborn) refers to an infant in the first 28 days after birth; the term applies topremature infants, postmature infants, and full term infants. Before birth, the term fetus is used.
Infant is also a legal term referring to any child under the age of legal adulthood.
Low back pain
Low back pain or lumbago is a common musculoskeletal disorder affecting 80% of people at some point in their lives. In the United States it is the most common cause of job-related disability, a leading contributor to missed work, and the second most common neurological ailment — only headache is more common.It can be either acute, subacute or chronic in duration. With conservative measures, the symptoms of low back pain typically show significant improvement within a few weeks from onset.
(CNS) is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except radially symmetric animals such as sponges and jellyfish. It contains the majority of the nervous system and consists of the brain and the spinal cord. Some classifications also include the retina and the cranial nerves in the CNS. Together with the peripheral nervous system, it has a fundamental role in the control of behavior. The CNS is contained within the dorsal cavity, with the brain in the cranial cavity and the spinal cord in the spinal cavity. Invertebrates, the brain is protected by the skull, while the spinal cord is protected by the vertebrae, and both are enclosed in the meninges.
Poliomyelitis
is a viral disease that can affect nerves and can lead to partial or full paralysis.
Poliomyelitis is a disease caused by infection with the poliovirus. The virus spreads by:
Direct person-to-person contact
Contact with infected mucus or phlegm from the nose or mouth
Contact with infected feces
The virus enters through the mouth and nose, multiplies in the throat and intestinal tract, and then is absorbed and spread through the blood and lymph system. The time from being infected with the virus to developing symptoms of disease (incubation) ranges from 5 - 35 days (average 7 - 14 days).
Sclerosis
In medicine, sclerosis (also spelled sclerosus in the names of a few disorders) refers to the stiffening of a structure, usually caused by a replacement of the normal organ-specific tissue with connective tissue.
Types include:
Amyotrophic lateral sclerosis, sometimes known as Lou Gehrig's disease, a progressive, incurable, usually fatal disease of motor neurons.
Atherosclerosis, a deposit of fat in the arteries which causes hardening.
Focal Segmental Glomerulosclerosis is a disease that attacks the kidney's filtering system (glomeruli) causing serious scarring and thus a cause of nephrotic syndrome in children and adolescents, as well as an important cause of kidney failure in adults
Hippocampal sclerosis, a brain damage often seen in individuals with temporal lobe epilepsy.
Lichen sclerosus, a disease hardening and connecting flesh of the vagina of women and the penis of men. An autoimmune disorder.
Liver sclerosis is a common misspelling of cirrhosis of the liver.
Multiple sclerosis, or Focal Sclerosis, is a central nervous system disease which affects coordination.
Osteosclerosis, a condition where the bone density is significantly increased.
Otosclerosis, a disease of the ears.
Systemic sclerosis (progressive systemic scleroderma), a rare, chronic disease which affects the skin, and in some cases also blood vessels and internal organs.
Tuberous sclerosis, a rare genetic disease which affects multiple systems.
Primary sclerosing cholangitis, a hardening of the bile duct by scarring and repeated inflammation.
Primary lateral sclerosis, progressive muscle weakness in the voluntary muscles.
Meningitis
is inflammation of the thin tissue that surrounds the brain and spinal cord, called the meninges. There are several types of meningitis. The most common is viral meningitis, which you get when a virus enters the body through the nose or mouth and travels to the brain. Bacterial meningitis is rare, but can be deadly. It usually starts with bacteria that cause a cold-like infection. It can block blood vessels in the brain and lead to stroke and brain damage. It can also harm other organs.Pneumococcal infections and meningococcal infections can cause bacterial meningitis.
Anyone can get meningitis, but it is more common in people whose bodies have trouble fighting infections. Meningitis can progress rapidly. You should seek medical care quickly if you have
A sudden fever
A severe headache
A stiff neck
Early treatment can help prevent serious problems, including death. Vaccines can prevent some of the bacterial infections that cause meningitis. Parents of adolescents and students living in college dorms should talk to a doctor about the vaccination.
Encephalitis
is an inflammation of the brain. The usual cause is a viral infection, but bacteria can also cause it. Cases can range from mild to severe. For mild cases, you could have flu-like symptoms. Serious cases can cause
Severe headache
Sudden fever
Drowsiness
Vomiting
Confusion
Seizures
For mild cases, you may just need rest, plenty of fluids and a pain reliever. For severe cases, you might need to be hospitalized. Fortunately, encephalitis is uncommon in the United States.
Traumatic brain injury
Traumatic brain injury happens when a bump, blow, jolt, or other head injury causes damage to the brain. Every year, millions of people in the U.S. suffer brain injuries. More than half are bad enough that people must go to the hospital. The worst injuries can lead to permanent brain damage or death.
Half of all traumatic brain injuries (TBIs) are due to motor vehicle accidents. Military personnel are also at risk. Symptoms of a TBI may not appear until days or weeks following the injury. Serious traumatic brain injuries need emergency treatment.
Treatment and outcome depend on the injury. TBI can cause a wide range of changes affecting thinking, sensation, language, or emotions. TBI can be associated with post-traumatic stress disorder. People with severe injuries usually need rehabilitation.
is one of four major classes of vertebrate tissue. It is the specialized tissue that makes up the central nervous system and the peripheral nervous system, consisting of neuronswith their processes, other specialized or supporting cells, and extracellular material.
Nervous tissue is the main component of the nervous system - the brain, spinal cord, and nerves-which regulates and controls body functions. It is composed of neurons, which transmit impulses, and the neuroglia cells, which assist propagation of the nerve impulse as well as provide nutrients to the neuron.
Nervous tissue is made of nerve cells that come in many varieties, all of which are distinctly characteristic by the axon or long stem like part of the cell that sends action potential signals to the next cell.
Functions of the nervous system are sensory input, integration, controls of muscles and glands, homeostasis, and mental activity.
All living cells have the ability to react to stimuli. Nervous tissue is specialized to react to stimuli and to conduct impulses to various organs in the body which bring about a response to the stimulus. Nerve tissue (as in the brain, spinal cord and peripheral nerves that branch throughout the body) are all made up of specialized nerve cells called neurons. Neurons are easily stimulated and transmit impulses very rapidly. A nerve is made up of many nerve cell fibers (neurons) bound together by connective tissue. A sheath of dense connective tissue, the epineurium surrounds the nerve. This sheath penetrates the nerve to form the perineurium which surrounds bundles of nerve fibers. Blood vessels of various sizes can be seen in the epineurium. Theendoneurium, which consists of a thin layer of loose connective tissue, surrounds the individual nerve fibers.
The cell body is enclosed by a cell (plasma) membrane and has a central nucleus. Granules called Nissl bodies are found in the cytoplasm of the cell body. Within the cell body, extremely fine neurofibrils extend from the dendrites into the axon. The axon is surrounded by the myelin sheath, which forms a whitish, non-cellular, fatty layer around the axon. Outside the myelin sheath is a cellular layer called the neurilemma or sheath of Schwann cells. The myelin sheath together with the neurilemma is also known as the medullary sheath. This medullary sheath is interrupted at intervals by the nodes of Ranvier.
Disorders of the Nervous System
Term
Definition
Cause
Effect
Bell's Palsy
A form of Neuritis that involves paralysis of the facial nerve causing weakness of the muscles of one side of the face and an inability to close the eye.
Unknown. (Recovery may occur spontaneously.)
Paralysis of the facial nerve; weakness of the muscles of one side of the face; may result in inability to close the eye. (In some cases the patient's hearing may also be affected in such a way that sounds seem to him/her to be abnormally loud. Loss of taste sensation may also occur.)
Cerebal Palsy
A nonprogressive disorder of movement resulting from damage to the brain before, during, or immediately after birth.
Cerebal Palsy is attributed to damage to the brain, generally occuring before, during, or immediately after birth. It is often associated with other neurological and mental problems.There are many causes including birth injury, hypoxia, hypoglycaemia, jaundice and infection.
The most common disability is a spastic paralysis. Sensation is often affected, leading to a lack of balance, and intelligence, posture and speech are frequently impaired. Contractures of the limbs may cause fixed abnormalities. Other associated features include epilepsy, visual impairment, squint, reduced hearing, and behavioural problems.
Motor Neurone Disease
A progressive degenerative disease of the motor system occurring in middle age and causing muscle weakness and wasting.
Some forms of Motor Neurone Disease are inherited.
Motor Neurone disease primarily affects the cells of the anterior horn of the spinal cord, the motor nuclei in the brainstem, and the corticospinal fibres.
Multiple Sclerosis
A chronic disease of the nervous system that can affect young and middle-aged adults. The course of this illness usually involves recurrent relapses followed by remissions, but some patients experience a chronic progressive course.
The myelin sheaths surrounding nerves in the brain and spinal cord are damaged, which affects the function of the nerves involved. The underlying cause of the nerve damage remains unknown.
Multiple Scerosis affects different parts of the brain and spinal cord, resulting in typically scattered symptoms.
These can include:
Unsteady gait and shaky movement of the limbs (ataxia);
Rapid involuntary movements of the eyes (nystagmus);
Defects in speech pronunciation (dysarthria);
Spastic weakness and retrobulbar neuritis (= inflammation of the optic nerve).
Myalgic Encephalomyelitis (ME)
A condition characterized by extreme disabling fatigue that has lasted for at least six months, is made worse by physical or mental exertion, does not resolve with bed rest, and cannot be attributed to other disorders.
Unknown. Often occurs as a sequel to such viral infections as glandular fever.
Extreme disabling fatigue that has lasted for at least six months, is made worse by physical or mental exertion, does not resolve with bed rest, and cannot be attributed to other disorders.
The fatigue is accompanied by at least some of the following:
Muscle pain or weakness;
Poor co-ordination;
Joint pain;
Sore throat;
Slight fever;
Painful lymph nodes in the neck and armpits;
Depression;
Inability to concentrate;
General malaise.
Neuralgia
Maybe due to previous attack of shingles (Postherpetic Neuralgia).
A severe burning or stabbing pain often following the course of a nerve.
Neuritis
A disease of the peripheral nerves showing the pathological changes of inflammation. (This term may also be less precisely used to refer to anydisease of the peripheral nerves, usually causing weakness and numbness.)
Inflammation of the nerves, which may be painful.
Parkinson's Disease
Degenerative disease process (associated with aging) that affects the basal ganglia of the brain.
Associated with a deficiency of the neurotransmitter dopamine. Also associated with aging.
Tremor, rigidity and poverty of spontaneous movements. The commonest symptom is tremor, which often affects one hand, spreading first to the leg on the same side then to the other limbs. It is most profound in resting limbs, interfering with such actions as holding a cup. The patient has an expressionless face, an unmodulated voice, an increasing tendency to stoop, and a shuffling walk.
Sciatica
A common condition arising from compression of, or damage to, a nerve or nerve root.
Usually caused by degeneration of an intervertebral disc, which protrudes laterally to compress a lower lumbar or an upper sacral spinal nerve root.The onset may be sudden, brought on by an awkward lifting or twisting movement.
Pain felt down the back and outer side of the thigh, leg, and foot. The back is stiff and painful. There may be numbness and weakness in the leg.
Guillain-Barre syndrome
is a rare disorder that causes your immune system to attack your peripheral nervous system (PNS). The PNS nerves connect your brain and spinal cord with the rest of your body. Damage to these nerves makes it hard for them to transmit signals. As a result, your muscles have trouble responding to your brain. No one knows what causes the syndrome. Sometimes it is triggered by an infection, surgery or a vaccination.
The first symptom is usually weakness or a tingling feeling in your legs. The feeling can spread to your upper body. In severe cases, you become almost paralyzed. This is life-threatening. You might need a respirator to breathe. Symptoms usually worsen over a period of weeks, then stabilize. Most people recover. Recovery can take a few weeks to a few years. Treatment options during the symptom period include medicines or a procedure called plasma exchange.
Multiple sclerosis (MS) is a nervous system disease that affects your brain and spinal cord. It damages the myelin sheath, the material that surrounds and protects your nerve cells. This damage slows down or blocks messages between your brain and your body, leading to the symptoms of MS. They can include
Visual disturbances
Muscle weakness
Trouble with coordination and balance
Sensations such as numbness, prickling, or "pins and needles"
Thinking and memory problems
No one knows what causes MS. It may be an autoimmune disease, which happens when your body attacks itself. Multiple sclerosis affects women more than men. It often begins between the ages of 20 and 40. Usually, the disease is mild, but some people lose the ability to write, speak or walk. There is no cure for MS, but medicines may slow it down and help control symptoms. Physical and occupational therapy may also help.
Multiple sclerosis
(MS) is a nervous system disease that affects your brain and spinal cord. It damages the myelin sheath, the material that surrounds and protects your nerve cells. This damage slows down or blocks messages between your brain and your body, leading to the symptoms of MS. They can include
Visual disturbances
Muscle weakness
Trouble with coordination and balance
Sensations such as numbness, prickling, or "pins and needles"
Thinking and memory problems
No one knows what causes MS. It may be an autoimmune disease, which happens when your body attacks itself. Multiple sclerosis affects women more than men. It often begins between the ages of 20 and 40. Usually, the disease is mild, but some people lose the ability to write, speak or walk. There is no cure for MS, but medicines may slow it down and help control symptoms. Physical and occupational therapy may also help.
Glioma
is a type of tumor that starts in the brain or spine. It is called a glioma because it arises from glial cells. The most common site of gliomas is the brain
A stroke
happens when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack.
If blood flow is stopped for longer than a few seconds, the brain cannot get blood and oxygen. Brain cells can die, causing permanent damage.
There are two major types of stroke: ischemic stroke and hemorrhagic stroke.
Ischemic stroke occurs when a blood vessel that supplies blood to the brain is blocked by a blood clot. This may happen in two ways:
A clot may form in an artery that is already very narrow. This is called a thrombotic stroke.
A clot may break off from another place in the blood vessels of the brain, or from some other part of the body, and travel up to the brain. This is called cerebral embolism, or an embolic stroke.
Ischemic strokes may be caused by clogged arteries. Fat, cholesterol, and other substances collect on the artery walls, forming a sticky substance called plaque.
Muscle is a very specialized tissue that has both the ability to contract and the ability to conduct electrical impulses. Muscles are are classified both functionally as either voluntary or involuntary and structurally as either striated or smooth. From this, there emerges three types of muscles: smooth involuntary (smooth) muscle, striated voluntary (skeletal) muscle and striated involuntary (cardiac) muscle. The names in the brackets are the common names given to the particular classification of muscle.
Muscle atrophy is the wasting or loss of muscle tissue.
There are two types of muscle atrophy.
Disuse atrophy occurs from a lack of physical activity. In most people, muscle atrophy is caused by not using the muscles enough. People with seated jobs, medical conditions that limit their movement, or decreased activity levels can lose muscle tone and develop atrophy. This type of atrophy can be reversed with exercise and better nutrition. Bedridden people can have significant muscle wasting. Astronauts who are away from the Earth's gravity can develop decreased muscle tone after just a few days of weightlessness.
The most severe type of muscle atrophy is neurogenic atrophy. It occurs when there is an injury to, or disease of, a nerve that connects to the muscle. This type of muscle atrophy tends to occur more suddenly than disuse atrophy.
Examples of diseases affecting the nerves that control muscles:
Amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease)
Guillain-Barre syndrome
Neuropathy
Polio (poliomyelitis)
Although people can adapt to muscle atrophy, even minor muscle atrophy usually causes some loss of movement or strength.
Neuromuscular disorders
Neuromuscular disorders affect the nerves that control your voluntary muscles. Voluntary muscles are the ones you can control, like in your arms and legs. Your nerve cells, also called neurons, send the messages that control these muscles. When the neurons become unhealthy or die, communication between your nervous system and muscles breaks down. As a result, your muscles weaken and waste away. The weakness can lead to twitching, cramps, aches and pains, and joint and movement problems. Sometimes it also affects heart function and your ability to breathe.
Examples of neuromuscular disorders include
Amyotrophic lateral sclerosis
Multiple sclerosis
Muscular dystrophy
Myasthenia gravis
Spinal muscular atrophy
Many neuromuscular diseases are genetic, which means they run in families or there is a mutation in your genes. Sometimes, an immune system disorder can cause them. Most of them have no cure. The goal of treatment is to improve symptoms, increase mobility and lengthen life.
Botulism
is a rare but serious illness caused by a bacterium called Clostridium botulinum, which occurs in soil. It produces a toxin that affects your nerves. There are three kinds of botulism. Foodborne botulism comes from eating foods contaminated with the toxin. Wounds infected with toxin-producing bacteria result in wound botulism. Infant botulism is caused by consuming the spores of the bacteria, usually from honey. All three forms can be deadly and are medical emergencies.
Symptoms include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth and muscle weakness. Treatment may include antitoxins, intensive medical care or surgery of infected wounds.
To prevent botulism:
Be very careful when canning foods at home
Do not let babies eat honey
Get prompt medical care for infected wounds
Tetanus
is a serious illness caused by tetanus bacteria. The bacteria live in soil, saliva, dust and manure. The bacteria usually enter the body through a deep cut, like those you might get from cutting yourself with a knife or stepping on a nail.
The infection causes painful tightening of the muscles, usually all over the body. It can lead to "locking" of the jaw, which makes it impossible to open your mouth or swallow. If this happens, you could die of suffocation.
If you get tetanus, there is usually a long course of treatment. The tetanus vaccine can prevent tetanus but its protection does not last forever. Adults should get a tetanus shot, or booster, every 10 years. If you get a bad cut or burn, see your doctor--you may need a booster.
The muscular dystrophies
(MD) are a group of more than 30 genetic diseases characterized by progressive weakness and degeneration of the skeletal muscles that control movement. Some forms of MD are seen in infancy or childhood, while others may not appear until middle age or later. The disorders differ in terms of the distribution and extent of muscle weakness (some forms of MD also affect cardiac muscle), age of onset, rate of progression, and pattern of inheritance.
The muscular system is a system of tissues - called muscles - throughout the body which allow you to move. Most of the muscles in the body are under conscious control and are moved by commands sent to the muscles from the brain via the nervous system. However, some muscles (such as the cardiac muscles) are involuntary - that is, they move regularly without any conscious control. Except for the involuntary muscles, muscle fibers are connected to the skeletal system by tendons and other tissues; the muscles exert force by converting chemical energy into tension and contraction. Muscles are made up of millions of tiny protein filaments which work together to produce motion in the body. They move and make us capable of a variety of actions by simply contracting and becoming shorter or by relaxing and becoming longer. Muscles pull, but they cannot push.
Each person has over six hundred muscles; these are served by nerves which link each individual muscle to the brain and spinal cord. Our bodily needs demand that muscles accomplish different chores, so we are equipped with three types of muscles. Cardiac muscles, found only in the heart, power the action that pumps blood throughout the body. Smooth muscles surround - or are part of - the internal organs. Both cardiac and smooth muscles are called involuntary muscles, because they cannot be consciously controlled. The skeletal muscles are the third muscle type. These carry out voluntary movements and are what ache after strenuous exercise. Skeletal muscles are the body's most abundant tissue, comprising about 23% of a woman's body weight and around 40% of a man's body weight.
Functions of Muscular System:
Muscular system has the following important functions in human body;
MOVEMENTS OF BODY PARTS: Skeletal muscles are responsible for all voluntary movements of human body parts. They provide the force by contracting actively at the expense of energy. In other words, muscles are motors of body where chemical energy of food is converted into mechanical work.
STABILITY AND POSTURE: Skeletal muscles stabilize human skeleton and give a proper posture to human beings. Some joints of human body are weak and they require the support of muscular system to achieve stability. Skeletal muscles are very important for such joints.
HEAT PRODUCTION: A large share of body’s energy is used by muscular system. As a result of high metabolic rate, muscles produce great amount of heat in the body. Heat produced by muscles is very important in cold climates.
CIRCULATION: Cardiac muscles provide the main force for circulation of blood throughout human body. The regular pumping of heat keeps the blood in motion and nutrients are readily available to every tissue of human body.
HELP IN DIGESTION: Smooth muscles of organs like stomach and intestine help the digestive system in the process of digestion of food.
Muscular Disorders
Term
Definition
Cause
Effect
Atony
A state in which muscles are floppy, lacking their normal elasticity.
Many possible causes.
Muscles are floppy, lacking their normal elasticity.
Atrophy
Generally, the wasting away of a normally developed organ or tissue due to degeneration of cells. In the case of muscle tissue, the individual muscle fibers decrease in size due to a progressive loss of myofibrils.
Generally, possible causes include undernourishment, disuse or ageing. (a) Disuse Atrophy : muscles atrophy because they are not used. Bedridden individuals and people with casts that immobilize large muscle groups may experience disuse atrophy because the flow of nerve impulses to the inactive muscle is greatly reduced. (b) Denervation atrophy : occurs when a muscle's nerve impulses cease in it's motor neurons.
(a) Need physiotherapy to gradually re-build the muscle. (b) In 6-24 months the denervated muscle will be one quarter of it's original size and the muscle fibers will be replaced by fibrous connective tissue. The transition to fibrous connective tissue, when complete, cannot be reversed.
Cramp
Prolonged painful involuntary contraction of skeletal muscle.
It is sometimes caused by an imbalance of the salts in the body, but is more often a result of fatigue, imperfect posture, or stress.
Pain. Possibly inability to perform specific tasks (e.g. of 'occupational cramp' is 'writer's cramp')
Fibrositis
Inflammation of fibrous connective tissues in muscles. It often affects the muscles of the trunk and back.
It may be a symptom of another disease, such as Sciatica, but in most cases the cause is unknown.
Pain and stiffness.
Muscle Fatigue
Tiredness following prolonged or intense activity.
May be due to de-hydration (loss of water and NaCl, that is "sodium chloride", or "common salt"), and the waste products of metabolism accumulating in the muscles faster than they can be removed by the venous blood.
Tired/aching muscles.
Myositis
Inflammation of muscle fibers / Any of a group of muscle diseases in which inflammation and degenerative changes occur.
(A minority are caused by bacterial or parasitic infections.)
Spasm
A sustained involuntary muscular contraction (which may occur either as part of a generalized disorder such as spastic paralysis, or as a local response to an otherwise unconnected painful condition.)
May occur either as part of a generalized disorder such as spastic paralysis, or as a local response to an otherwise unconnected painful condition.
Painful. Lack of use of body parts normally moved by the muscle in spasm.
Spasticity
= Muscular Hypertonicity (i.e. an increase in the state of readiness of muscle fibers to contract; an increase in partial contraction) with an increased resistance to stretch. Moderate cases show movement requiring great effort and a lack of normal coordination, while slight cases show exaggerated movements that are coordinated. = Resistance to the passive movement of a limb that is maximal at the beginning of the movement and gives way as more pressure is applied.
This is a symptom of damage to the cortiscospinal tracts in the brain or spinal cord. It is usually accompanied by weakness in the affected limb.
Increase in the state of readiness of muscle fibers to contract with an increased resistance to stretch. Moderate cases show movement requiring great effort and a lack of normal coordination, while slight cases showexaggerated movements that are coordinated.
Sprain
Injury to a ligament, caused by overstretching.
Overstretching of ligament.
As the ligament is not severed it gradually heals, but this may take several months.
Strain
Excessive stretching or working of a muscle, resulting in pain and swelling of the muscle.
Damage to muscle caused by overstretching.
Pain
Skeletal and Smooth Muscle Tumors
Rhabdomyomas are rare benign tumors of skeletal muscle usually found in the area of the head and neck.
Rhabdomyosarcomas are malignant tumors of skeletal muscle. These tumors are typically found on the arms and legs. Over 85% of rhabdomyosarcomas occur in infants, children, and teenagers.
Leiomyomas are benign tumors of smooth muscle. These tumors are uncommon.
Leiomyosarcomas are malignant tumors of smooth muscle tissue. These are rare tumors in the USA.
