Category Health and Medicine

Giddiness occurs when we lose our sense of balance. The sensations perceived by the eye, inner ear, skin, muscles and joints help the body to know its stability. Several unusual situations, such as travelling in a bus or looking down from a great height, over stimulate and confuse that part of the brain which controls balancing. (This is very close to the part which induces vomiting). When we look down from a great height, abnormal visual signs transmitted to the brain, without any corresponding information from other parts of the body. Likewise, while looking out in a fixed direction while travelling in a bus, the eye sends fast changing visual signals to the brain. Such signals confuse the mechanism in the brain and lead to giddiness and vomiting.

The question of why our temperature goes up during illness can be split into two parts. First, you need to know what makes the temperature go up, and secondly, what advantage an increase in temperature offers.

 The increase in core temperature observed during illness is commonly called fever and occurs in response to infection by a pathogenic organism or certain types of physical injury.

For example, when a person becomes infected with bacteria, the white blood cells of the immune system recognize the incoming pathogen as foreign and initiate the first stages of the immune response – the acute phase. In this reaction, white blood cells called monocytes release a variety of proteins called cytokines. These are central to the immune and inflammatory response.

In particular, there is a predominance of two types of cytokine called interleukin-1 (IL-1) and tumour necrosis factor-alpha. These cytokines are known as pyrogenic because they cause an increase in body temperature. It is not clear how they induce fever, but it is known that they also cause the production of other chemicals in the brain. The main groups of chemicals produced in this effect are the prostaglandins. These react very strongly with the hypothalamus area of the brain, which then sends a signal to the body to increase the temperature.

 

The mechanisms that the brain employs to affect this are not certain but are known to include increasing the metabolic rate and including shivering. These two processes burn metabolic fuel faster than normal and body heat is given off. The question of what advantage fever confers is interesting.

 Experimental work shows that the mortality of animals decreases if the fever is untreated, that elevated temperatures can enhance certain aspects of the immune response. Furthermore, the growth rates of various types of   bacteria are slowed at temperatures above normal body temperature. Indeed, the ancient Greeks believed that fever was beneficial; even in this century fever has been used to treat certain illness. For example, syphilis used to be notoriously difficult to treat, so doctors gave their patients malaria which fought the syphilis knowing that they could get rid of the malaria later.

 

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In the human body the mechanism is such that the oxygen we breathe in and the vital nutrients in the food that we eat are absorbed by the blood and supplied t the different organs.  This job is accomplished efficiently by about 5 litres of blood that circulate in a normal adult.

The amount of blood supplied to each organ depends on the oxygen and nutrition requirement of the tissue of the organ and the importance of the function it plays at any given time.

 Under normal conditions, the liver receives about slightly less than one-third of the blood that the heart pumps. Likewise, the kidneys get about one-fourth, and brain about one-sixth. The remaining goes to the muscles and other parts of the body. These quantities change depending on the body work and needs.

When we eat, the food needs to be digested and the nutrients absorbed by the blood. That is the focus of the work shifts to digesting the food and so more blood is sent to the stomach walls. Automatically the flow of blood to other parts of the body, including the brain, is reduced.

Only a few other very important functions like the functioning of the heart and lungs are continued. Once the blood flow to the brain is reduced, the body becomes lethargic and sleep sets in. So, better take a nap alter meals, it is only natural.

Researchers at the Chennai Institute of Magneto biology, say that sleeping in the  north-south direction could make one lack a sense of well being at times. According to Dr. Sankaranarayanan, director of the institute, when a man lies with his head towards north in pulsating magnetic field, his brain’s electrical activity is suppressed or damped. Measurement reveals that blood circulations in fingertips are affected and the balance between neuro-chemicals is upset. In addition, it gives subjective experiences like headache, confused thinking and lack of a sense of well-being.

As opposed to this, he says, if one sleeps east-west, in the pulsed field, the brain’s activity is considerably enhanced. Also, the peripheral blood circulation all over the body is enhanced. Hence he feels relaxed and alert.

It is known that the Earth’s magnetic field pulses at extremely low frequencies and is typically in the range of human brain’s electrical activity. These pulses are not present always but they peak during certain periods generally associated with solar activity. If one sleeps north-south during such activity headache, general discomfort, nausea and confusion may result. On inactive nights, there may not be any change in the body, he says. This is true for animals also as they are more sensitive to such changes.

Somnambulism is a psychiatric sleep disorder termed under ‘parasomnia’. Parasomnia, a disorder of transition from one sleep stage to another (arousal or partial arousal) can be marked by bizarre or sensual behaviour. Sleep is basically defined as that stage of unconsciousness from which the person can be aroused by sensory stimuli. Sleep can be broadly classified into two types, the slow wave sleep (Non-REM) and the Rapid Eye Movement (REM).  Normally the sleep that one gets is of the slow wave type. This is the deep restful type of sleep experienced in the first hour of sleep, in which the consolidation of the dreams in memory does not occur.

However a normal night of sleep, bouts of REM sleep lasting 15-30 minutes usually appear on the average of every 90 minutes, the first such period occurring 80-100 minutes after the person falls asleep. It is usually associated with active dreaming.

 The brain is highly active in REM sleep. Despite the extreme inhibition of the peripheral muscles, a few irregular muscle movements’ in particular rapid movements of the eye occur.

In the case of Non-REM sleep, the brain waves are very slow. But in the REM type of sleep the eyes undergo rapid eye movements despite the fact that the person is still asleep.

Sleepwalking, somnambulism, is the disorder of the non REM stage of sleep. It is the automatic execution of a sequence of complex behaviours that may include dressing, eating or bathroom visits as well as walking while asleep. It is a fairly common occurrence in childhood and adolescence, but may signify psychological disturbances in adulthood. The frequent episodes of which, more often experienced of which more often experienced by boys has its onset typically between 6-12 years of age.

Sleepwalking usually disappears after adolescence, but many reappear in the 3rd or 4th decade. There seems to be a heredito familial trend. The disorder has been associated with epilepsy, CNS infections and traumas, genito urinary complaints, psychopathology, sleep talking, nocturnal eneuresis and nightmares.

The treatments include besides other things education and appropriate sleep habits, avoiding sleep deprivation and compensatory slow wave sleep rebound by providing guidelines for a regular sleep wake schedule, taking day time naps to decrease pressure for slow wave sleep at night, use of hypnosis and benzodiazepine family of medications in some cases, providing safe environments for sleep and psychotherapy and non REM suppressing psychotropic medications.

      In fact in one review, psychotherapy was recommended to a carefully selected subgroup of patients, only one-third of group were willing to try it. However, of those patients who began psychotherapy 75 per cent rated it as beneficial.

 

 

            Pain is difficult to define as it is subjective and psychological. Probably the best definition is that it is an unpleasant experience associated with the tissue damage.

            Pain is more complex than other sensory systems such as vision or hearing as it involves transfer of sensory information to the nervous system but produces suffering which leads to aversive corrective behaviour like withdrawing from harmful agents. Thus it serves as a useful warning system.

            Pain receptors in the skin and other tissues of our body are nerve terminals which are triggered by a chemical stimulus when a potential damage occurs. Acute pain often has simple and effective treatment regimes. However, chronic pain rarely has simple solutions as it is not fully understood. It is inevitably accompanied by many psychological factors such as depression, anxiety and personal environmental interactions.

            An indirect or inferential measurement of some one’s pain may be made by means of so-called pain thresholds. There are many methods available for measuring this threshold which however are open to criticism.

            A popular method is to employ a dolorimeter which uses a heat source operated by a timing mechanism. An even safer device is a pressure algometer, a rod with a flat end loaded against a calibrated spring. Pressure applied on a flat body surface (for example, the skin) is increased steadily until pain is reported. Under controlled conditions women are more sensitive to pain (have lower thresholds) than men, office workers than manual workers, and anxious people than calm people.

            There are a number of reports of people without the ability to feel pain at all or in some cases very little. They are at a greater risk of suffering and their life expectancy is shorter than average.

            Pain is an alarm initiated upon tissue injury, carried along fairly specific nerves, and ultimately experienced according to the past experience of the sufferer. Our body has its own analgesics to relieve pain. They are a group of opiate proteins called endorphins with special pain-relieving properties. They are naturally found in the brain and are distributed throughout the nervous system. They bind to specific brain tissues involved in the perception of pain.

  All sensation from the body is carried through the spinal cord along the posterior route, says Dr. A.V. Srinivasan, an eminent neuro-physician. It consists of two divisions – medical and lateral. The medical division carries sensation such as pressure, vibration, movement, position and fine touch. The lateral division carries pain and temperature.

            When pain balms are rubbed, the pressure and movement sensations are produced in excess. This is turn sends more sensory input via the larger division of the posterior route which blocks the pain sensation through the lateral division of the posterior route to the spinal cord. The medial division blocks the pain sensation at the gate entry zone of the spinal cord. This mechanism of pain relief can be extended to acupuncture and never stimulations also, he says.

            Therapeutic measures relieve pain by increasing the level of endorphins. Pain balms generally contain 3 components – methyl salicylate, menthol and camphor. These are easily absorbed through the skin. Menthol is a white crystalline substance and a principal constituent of oil of peppermint.

            Role of the balm includes a local anesthetic effect which acts along peripheral nerve endings. These analgesics are chemically similar to endorphins and they relieve pain by binding to the same sites as endorphins. Experience of pain is psychological and subjective.

            Although these analgesics have a special pharmacological effect in relieving pain, it is actually the amount of pressure applied and the movement that plays a significant role. Also other measures that increase confidence also will ease pain.

            While methyl salicylate absorbed through the skin acts as an analgesic, menthol dilates the blood vessels. Because of the increased blood flow one gets a cool sensation in the balm- applied area. This is useful in case of headache and rheumatic pains. Camphor also acts as a rubefacient and mild analgesic.

When a person cries tear fluid is secreted by a lacrimal gland seen bulging the conjunctiva (muscous membrane covering the eyeball and lining the eyelids). This tear passes through numerous ducts into the conjunctival sac, aided by ocular muscle contraction. From there it reaches the lacrimal sac and through the lacrimal duct it is drained into the nasal cavity. (Lacrimal duct is an anatomical drainage canal connects the corner of the eye to the lower surface of the nasal cavity). When there is a sudden discharge of tear, as while crying, the fluid is pooled resulting in congestion.

            Another interesting fact is that Nature has provided a flap valve at the terminal part of the canal to prevent tear fluid from being pushed back by air, while sneezing or blowing.

A yawning is considered as a form of expression indicating boredom or a break in our train of thought. For many, it is relaxing or may occur in response to seeing someone else yawn. Nobody knows why one person yawning can cause others to yawn.

Scientists say that the question can also be asked of our primate relatives. They have presented evidence that yawns are contagious among monkeys, particularly with individuals of similar age and social status. This contagion is interpreted as a synchronization of activities ‘due to the imposition of wake-sleep rhythms on different individuals and to the attention they devote to each other’.

A yawning should be in a process of decreasing arousal according to them. If observed by other animals and if the observers arousal level becomes synchronized as a consequence the observers will also yawn. Accordingly, the yawn should be only a sufficient, not a necessary, factor in electing yawns from other group members.

Watching somebody taking a nap, in other words, might also induce a state of declining arousal and trigger yawns. One would expect observed yawns to be a more powerful stimulus, however, because another’s yawns might precipitate the observer attending to muscular tension in the facial muscles that can be dissipated by the yawn’s stretch. In addition one might expect observed stretches in general to be contagious, and yawns may thus be a particularly obvious example of the general behavioural synchrony of interact ants.