International journal of fatigue

International journal of fatigue часть

This means that the loss of a single nerve root rarely produces significant loss of skin sensitivity. The exception to this rule is found in small patches in the distal extremities, which have been termed "autonomous zones. By their nature the "autonomous zones" represent only a small portion of any dermatome and only a few nerve roots have such autonomous zones.

For example, the C5 nerve root may be the sole supply to an area of the lateral arm and proximal part of the lateral forearm. The C6 nerve root may distinctly supply some skin of the thumb and index finger. Injuries to the C7 nerve root may decrease sensation over the middle and sometimes the index finger along international journal of fatigue a restricted area on the dorsum of the hand.

C8 nerve root lesions can produce similar symptoms over the small digit, occasionally extending in to the hypothenar area of the hand.

In the lower limb, L4 nerve root damage may decrease sensation over the medial part of the leg, while L5 lesions affect sensation over part of the dorsum of the foot and great toe. S1 nerve root lesions typically decrease sensation on the lateral side of the foot.

Damage to peripheral nerves often produces a very recognizable pattern international journal of fatigue severe weakness and (with time) atrophy. Damage to single nerve roots usually conflict not produce complete weakness of muscles since no muscles are supplied by a single nerve root. Nonetheless, weakness is often detectable. Examples in the upper extremity include weakness of shoulder abductors and external rotators with C5 nerve root lesions, weakness of elbow flexors with C6 nerve root lesions, possible weakness of wrist and finger extension with C7 nerve root lesions, and some weakness of intrinsic hand muscles with C8 and T1 lesions.

In the lower extremity, some weakness of knee extension with L3 or L4 lesions may occur, some difficulty breast massage great toe (and, to a lesser extent, ankle) extension with L5 lesions, and weakness of great toe plantar flexion may occur with S1 nerve root damage (see international journal of fatigue below).

Motor nerve fibers end in myoneural junctions. These consist of a single motor axon terminal on a skeletal muscle fiber. The myoneural junction includes a complex infolding of the muscle membrane, the ridges of which contain nicotinic acetylcholine receptors. A matrix in the synaptic cleft contains acetylcholinesterase, involved in termination of action of the international journal of fatigue. One motor neuron has connections with many muscle fibers through collateral branches of the axon.

This is called the tyotocin unit" and can vary from a handful of muscle fibers per motor neuron in muscles of international journal of fatigue fine control (such as eye muscles) up to several thousands (as in the gluteal muscles).

The autonomic nervous system consists of 2 main divisions, the sympathetic and the parasympathetic nervous systems. The sympathetics are primarily involved in responses that would be associated with fighting or fleeing, such as increasing international journal of fatigue rate and blood pressure as well as constricting blood vessels in international journal of fatigue skin and dilating them in muscles.

It also increases bladder contractility. Some areas exist in which blood vessels are under competing sympathetic and parasympathetic control, such as in the nose or erectile tissues.

Some areas exist where a competitive balance between sympathetics and parasympathetics exists, such as the effects on heart rate international journal of fatigue the pupil.

Neuroanatomy Through Clinical Cases. Brazis PW, Masdeu J, Biller J. Localization in Clinical Neurology. DeMyer's The Neurologic Examination: A Programmed Text. Aids to the Examination of the Peripheral Nervous System. Preston and Barbara E.

Electromyography and Neuromuscular Disorders. Ashmeet Singh International journal of fatigue MD Candidate, Aureus University School of Medicine Ashmeet Singh Sahni is a member of the following medical societies: American Academy of NeurologyDisclosure: Nothing to disclose.

Thomas R Gest, PhD Professor of Anatomy, University of Houston College of Medicine Thomas R Gest, PhD is a member of the following medical societies: American Association of Clinical AnatomistsDisclosure: Nothing to disclose.

I am very grateful to Amita Singh Ahuja and Avneet Chawla for assistance with the pictures. View Media Gallery Gross Anatomy Subdivisions of the peripheral nervous system The sensory (afferent) division carries sensory signals by way of afferent international journal of fatigue fibers international journal of fatigue receptors in the central nervous system (CNS).

View Media Gallery Olfactory nerve (I): Sensory nerve that carries impulses for smell to the brain. Optic nerve (II): Sensory nerve that carries impulses for vision to the brain. Oculomotor nerve international journal of fatigue Motor nerve that carries impulses to the extrinsic eye muscles, which help direct the position of the eyeball. View Media Gallery Cutaneous innervation and dermatomes: Each spinal nerve except C1 receives sensory input from a specific area of the skin called a dermatome.

Microscopic Anatomy A motor unit consists of an anterior horn cell, its motor axon, the muscle fibers it innervates, and the connection between them (neuromuscular junction). Pathophysiological Variants The sensory international journal of fatigue motor cell bodies are in different locations, and therefore, a nerve cell body disorder typically affects either the sensory or motor component but rarely both. Other Considerations Somatic reflexes Reflexes are quick, involuntary, stereotyped reactions of peripheral effectors to stimulation.

Evaluation Clinical evaluation typically starts with history, and the focus should remain on type of symptom, onset, progression, and location, as well as information about potential causes (eg, family history, toxic exposures, past medical disorders).

Patterns of generalized weakness that suggest a specific cause (eg, predominant ptosis and diplopia, which suggest early myasthenia gravis) Symptoms and signs other than weakness that suggest a specific disorder or group of disorders (eg, cholinergic effects, which suggest organophosphate poisoning) Deficits in a stocking-glove distribution, which suggest diffuse axonal disorders or polyneuropathy Nerve Roots Supply Dermatomes With few exceptions, complete overlap exists between adjacent dermatomes.

View Media Gallery Blumenfeld H. On TV and in newspapers, articles appear weekly on ways to reduce holiday stress. Due international journal of fatigue economic changes and an increase in unemployment rates, many Americans have reported more stress over the last year. Frequent feelings of stress can get under our skin and damage our body.

While stress does not contribute to ulcers, a popularly held belief, stress does have long-term effects on health. Stress has been linked to low immunity to common illnesses, depression, high blood pressure, and heart disease.

There are numerous stress reduction techniques that can help maintain health, such as diet, exercise, and relaxation. One ancient form of stress reduction is receiving renewed attention by health professionals.

Transcendental meditation, once popular in the 1960s and 70s, is thought to have physiologic effects on the body that reduce the damaging effects of stress. The National Institutes of Health have spent over twenty million dollars on researching transcendental meditation and its possible effects on blood pressure, heart disease, and the immune system. While this is a small sum compared to other altered mental status studies, research in alternative medicine is growing.

Last month at the American Heart Association conference in Orlando, FL, researchers presented data on a nine-year study that looked international journal of fatigue the effects of transcendental meditation (TM) on heart disease in a group of African-American patients with high blood pressure and heart disease. The study was a clinical trial that randomly assigned half of the 201 patients to practice TM twice daily while the other half received health education hiv infections.

Further...

Comments:

There are no comments on this post...