Why Respiration is Necessary for Propagation of Life ?

One can survive without food and water for many hours but survival without the air or oxygen is not possible beyond a few minutes. Every cell in our body is programmed to perform a definite metabolic function necessary for our life. By means of breathing we assimilate oxygen from the air for intracellular metabolism. Through metabolic processes, cells of our body release carbon dioxide (CO₂) and water (H₂O), which are transported away by the circulating blood. Respiration is a two fold process: (1) The interchange of gases in the lungs is called external respiration and (2) The interchange of gases in the tissues is called internal respiration. In the external respiration, oxygen is taken in through the nose and mouth and flows down to the alveoli in the lungs, where it comes in contact with the alveolar capillary membrane and is taken up by the hemoglobin of the red blood cells (RBCs). The oxygenated blood goes to the heart and is further pumped to the various parts of our body. In the lungs, carbon dioxide (CO₂), a waste product of the metabolism is released out through the alveolar capillary membranes and breathed out through the nose and mouth.

The air we breathe in, contains 79% of nitrogen, 20% of oxygen and 0.04 carbon dioxide (CO₂) along with atmospheric water vapors; where as the air we breathe out, contains 79% of nitrogen, 16% of oxygen and 4.04 carbon dioxide (CO₂) along with water vapors released from the alveoli. The total air capacity of our lungs is about 4.5 to 5.0 liters of air and only ¹/₁₀th (500 ml) is generally inspired or expired. The volume of the air under exchange is also termed as tidal air. Our breathing is controlled by two factors: (1) The chemical control of respiration and (2) The nervous control of respiration through the medulla oblongata of our brain. The normal rate of respiration in different age groups is as under:

Status of Age	Respiration Rate per minute
Newborn	38 - 42
Up to 12 months	28 - 32
2 years to 5 years	24 - 26
6 years to 16 years	20 - 24
Adults	10 - 20

The oxygen need of our body varies with the type of activity we perform. Rate of respiration goes up during exercise or running and is considered a vital health parameter for medical fitness evaluation of an individual. As stated above the oxygen (O₂) is the essence of the life force and lack of it may lead to a state of hypoxia or anoxia and brain damage.

What causes Pyelonephritis and How Serious is It?

The pyelonephritis is said to be very serious renal disease. The well documented cause of pyelonephritis is an infection of interstitial (intertubular) tissue with pyogenic bacteria, most frequently E. coli and Staphylococci, and sometimes Proteus vulgaris and Pseudomonas pyocyaneus. In almost 66% of cases the infection could be secondary to the urinary tract infection and in 33% of cases the infection could be primary through infection of blood. The ascending infection of kidney or kidneys from the urinary tract is quite common in infants. There could be ascending infection of kidneys in pregnant women and also in women with the cancer of the cervix. In the elderly male patients, the ascending infection of kidneys is possible if their prostate is enlarged and the urethra is obstructed causing partial or full retention of urine. Irrespective of the sex of the patient, the obstruction plays a vital role in causing the infection of kidneys. It has been proved through experimental study on rabbits that the obstruction of urinary system was the main cause of renal infection and pyelonephritis. In man infection of blood may cause unilateral or bilateral pyelonephritis depending on the obstruction. The obstruction may be functional or organic. The ultrasonography or the serial radiographical study is required to rule out the obstruction.

The pyelonephritis in its chronic form is very dangerous disease. The kidney may become a bag of pus due to infection with pyogenic bacteria cited above. The condition is also called pyonephrosis. A pure hydronephrosis (nephrosis caused due to back pressure of accumulated urine) in an advanced stage may become infected. The kidneys get much enlarged due to hydronephrosis or pyelonephritis. There is possibility of complete erosion of functional architecture in side the kidney due to pyogenic infection. Pyelonephritis may also develop in a gradual manner with little frank suppuration. The early detection of disease could be better for the patient as it could be treated effectively.

Acute Glomerulonephritis

The term acute glomerulonephritis is used by clinicians as well as pathologists to describe the sudden onset of kidney disease. Irrespective of the cause, there would be enlargement of a kidney or kidneys and the capsule around the kidney is strained and stretched. Ultrasonography is always helpful to ascertain the size of kidneys. Histological examination of kidney biopsy would present densely cellular glomerular tuft with polymorphonuclear cells (a type of white blood cells) in the glomerular capillaries. Accumulation of leukocytes (white blood cells) in the glomerular capillaries with swelling and proliferation of the vascular endothelium (inner lining of capillaries) is rapidly followed by edema (swelling) and mesangial proliferation (enlargement of inner stalk of a cluster of glomerular capillaries)leading to capillary ischemia (poor blood supply).

The glomerular basement membrane (GBM) is the other important component affected by acute glomerulonephritis. By electron microscopic study of kidney biopsy, electron dense deposits of antigen-antibody complexes could be revealed in and around the glomerular basement membrane. The ultrastructural features of normal GBM have been depicted in the figure-1 and the figure-2 is from a case affected by acute glomerulonephritis.

Figure-1: Electron micrograph of a capillary loop of glomerular tuft showing normal features; CL: capillary lumen, US; urinary space, En: endothelium, GBM: glomerular basement membrane, EpC: epithelial cell or podocyte.

Figure-2: Electron micrograph of a capillary loop of glomerular tuft from a case affected by acute glomerulonephritis is showing sub-epithelial deposits; CL: capillary lumen, US; urinary space, GBM: glomerular basement membrane, dep: deposits on sub-epithelial site of GBM.

The tubules in the kidney may show slight degenerative changes. The degree of degenerative changes in the tubules depends on the extent of the glomerular obstruction. The interstitial tissue and the blood vessels are observed to be normal on the histological study of kidney biopsy.

The Mind and Brain: Functions and Physiology

The most important fact is that the brain is the organ of the mind and the mind is like the software of a computer. The mental functions are related to the cerebral cortex of the brain. In humans the cerebral cortex is better developed than the inferior animals. Our sense organs are like input devices of a computer. Our brain processes and stores the data in encapsulated form with respect to attributes. Our ears transmit sound signals to our brain, which are analyzed by our mind and classified as noise, vocal audio and music. Music files are further categorized as per specific attributes and stored in our brain. Whenever we listen to the same sound again we could easily name a person as per tonal quality of voice, instrument as per the pitch and rhythm of the music and the birds and animals as per their specific vocal attributes. Human mind is capable of distinguishing a variety of fragrances and odors, human faces and pictures, fonts and shapes, smooth and rough surfaces, bitter, sweet or sour tastes etc. Expressions of thoughts and emotions are special functions of our mind.

The brain, like other organs is powered by chemicals. Whenever the chemistry of brain is disturbed, mental symptoms are an early result. The glucose and oxygen have a vital role in the physiology and bio-energy generation of our body. The anoxia (low oxygen supply) of airmen and in the early stages of anesthesia may lead to chock. The hypoglycemia in diabetics on insulin therapy has been known to cause insulin shock or hypoglycemic shock. Certain groups of chemicals or drugs can cause mental disturbance and there are other chemicals or drugs which are capable of improving the mental function. For example hallucinogens like LSD disturb the mental functioning of normal people whereas tranquilizers and psychic energizers are known to improve the mental functioning of abnormal people. Except the numerical ability, the human mind and brain are faster than any computer in answering a variety of questions related to memory and experiences. Till date no computer could store the attributes of taste, smell, feelings and emotions. The super programming and coding of our mind is updated every moment through our observation and experience.

Azotemic or Hydropic Glomerulonephritis

The high concentration of non protein nitrogen (NPN) in the blood of a patient, mainly due to elevated level of urea is termed as azotemia. Elevated level of urea in blood is termed as uremia and it may be due to renal abnormality or due to other health problems like dehydration and excessive burns on the body. The glomerulonephritis (inflammation of glomeruli of kidneys) may be azotemic or hydropic type depending on the nature of glomerular lesions. There may be marked narrowing of the glomerular capillaries leading to azotemia with renal insufficiency and hypertension. On the other hand the status of glomerular capillaries may remain normal but there could be an increase in the permeability of glomerular basement membrane (GBM), the filtration barrier of kidneys. The clinical picture would be hydropic (accumulation of water in the tissues of the body) in character. The hydropic glomerulonephritis is clinically represented with edema associated with hypoproteinemia (low level of protein in blood) and hyperlipemia (high concentration of lipids or cholesterol in blood).

A child or an adult affected with fever or some other acute disease finds the increase in the daily output of urine. There may be tinge of blood in the urine of the patient affected by glomerulonephritis. Sudden appearance of features like puffiness or swelling on face (facial edema), ankles and hands after any acute disease needs expert medical attention and medication. The urine of such patients would show notable excretion of albumin. The patient may be less perspiring with dry skin. The pulse could be full and hard. The loin pain and a feeling of heaviness in the lower abdominal region are the associated symptoms. The polyuria (excessive output of urine) is probably compensatory action of affected kidneys to flush out solid wastes of metabolism form the body. An effective therapy would definitely reverse the associated symptoms and lesions.