Numerous animals and plants living in their natural habitats ,free from human check or interference ,are very important part of the treasure of wildlife in a country .In fact, the wild life is assemblage of such animals and plants .The non -domesticated mammals and birds living in there natural habitats are regarded as wildlifeanimals and their assemblage in a country is called animal wildlife of that country .India is gifted with very rich wildlife because of different eco-system and varying climatic condition therein .The royal bengal tiger ,lion ,elephant , buffalo, different kind of deers and huge assemblage of different kind of birds are considered to be natural wealth of this country. Plants, growing and flourishing in their natiral habitats ,are also important part of the wildlife and like wild animals ,these are also regarded as the natural wealth .However , this chapter will deal only with the wildlifeanimals. IMPORTANCE OF WILDLIFE The wildlife is greatly significant ot our existence and well being .It is important in many respects and its importance can be mainly classified as biological importance , economic importance , and cultural and aesthetic importance . Biological importance; The wildlife is very imprtant component of the nature .It maintains balance balance of different balance of different eco-systems of the nature through food chains .If this balance is disturbed or lost , unfavourable results will follow and these will eventually affect the life of man adversely.In a heterotrophic food chain , if one level is upset ,the other level will flourish at a tremendous rate ,and finally in want of natural food, these will prey upon valuable crops or man .This may be illustrated by an example of afood chain which include deers,antelops ,etc., as primary consumers and tigers,leopards ,wolves ,etc., as secondary consumers .In this food chain if primary consumers fall short in number ,the secondary consumers [tigers,leopards,wolves,etc] will prey upon domestic animals and tereafter if the domesticated animals fall short in number , the above mentioned secondary consumers will consume vegetables and crops raised or cultivated by farmers .Not only this ,they may also turn into man eaters s.This prey and predator chain maintains the balance of the nature .Obviously , the destruction of wild life will endanger our civilization . Bird act as pollinators , cause dispersal of fruits and seeds ,devour abnoxious insect pests or of crops and behave as sca vengers. If these or their habitats are destroyed ,the man will suffer and immense loss.
Friday, August 19, 2011
Thursday, August 18, 2011
BLOOD PRESSURE
The force of the strength of the jerk with which blood flows in blood vessels is called blood pressure .The source of this pressure is strong rythemic contraction of the heart . This force is sufficient for moving the blood from heart to organs through arteries and then from organs to heart through veins . The blood pressure in arteries is more than that in veins .The blood pressure is of two types ;systolic blood pressure and diastolic blood pressure .When heart contracts ,the artery has high blood pressure .This blood pressure is called systolic blood pressure But whe heart relaxes , the artery has reduced or less blood pressure called diastolic blood pressure .The blood pressure is measured by an instrument called sphygmomanometer .It depends upon the upon mental and physical conditions and age .Among young men the systolic blood pressure ranges from 100-140 mm Hg and the diastolic blod pressure fromm 55-80 mm Hg .The systolic pressure is is 90 plus age + 10 .Sometimes ,the blood pressure becomes high or low to the normal level .The high blood pressure develops due to unbalanced diet ,or heavy work ,or mental tension [anxiety ,worry an emotion ] or in old age because the diameter of arteries is reduced .Therefore, heart has to use more force for moving blood to organs .This may lead to heart failure . The low blood pressure develops due to fatigue and reduction in blood volume .There fore heart propels blood in arteries with less force. Consequently , body organs donot get nutrients and other substances in adequate quantities .Therfore , body becomes weak and this may lead to heart failure . Control of Body Heat By Blood All the invertebrates and lower vertebrates animals like fish , amphibia and reptiles are poikilothermic,that is , thier body temperature varies with that of thei surroundings .The temperature of such animal is usually a few degrees above that of its environment , but a rise or fall in the temperature of the air or water in which it lives will produce acorresponding change in the animal's body temperature .These animals produce heat but thy have very little capacity for conserving it or for adjusting supply and demand . Since the speed of most chemical changes that takes place in living organisms increased by a rise in temperature , it follow that the rate of activity of a poikilothermic animal will depend to a large extent on the surrounding temperature ; in cold conditions their low body temperature slows down all chemical changes and reduces the organism to a state of inactivity . Insects can be immobilized by a sudden fall of temperature . The quality of homiothermic condition is restricted to birds and mammals and means the ability ok keeping the temperature of the body constant, day and night , year in and year out Take your own example .A certain amount of heat is always produced by oxidation .Human muscles are about 40 % efficient as mechanical machines .This means that about 40% of energy produced by a muscle is available for machanical work and the other 60% appears as heat .the heat produced in cotracting muscle cells warms the blood in the surrounding capilaries .The warm warm blood transfers the heat to cooler tissues through which it passes .This is much like the distribution of heat by a hot water system Birds and mammals produce considerable amount of heat which is well distributed by the rapid circulating blood .This ,plus the mechanism for excreting excess heat, makes it possible for them to maintain a constant temperature of the body.
BLOOD
The blood is a liquid connective tissue ,consisting of a liquid part called plasma and a cellular or solid part called formed elements ,consisting of blood cells or blood corpuscles .It is a dynamic connective tissue which adjusts its composition continuosly according to need of the body . PLASMA ;It is a whole blood minus formed element [blood corpuscles and blood platelets] , and can be separated from the whole body by centrifugation .If it is left to stand , it coagulates , forming a gel-like matter and a clear fluid called serum .The serum is similar to the plasma excepts that is lack coagulation factors .The plasma, atransparent ,alkaline and yellow fluid is composed of about 90% water and about 10% solid and it contributes to about 55% of the blood volume .The solid part of the plasma consists of proteins , inorganic salts and other substances such as glucose , amino acids , urea , enzymes ,hormones, anti bodies , oxygen ,carbon -dioxide , etc. The inorganic constituents of the plasma are Na,K,CL,HCO3, CA,etc. The main plasma proteins include albumin , globulin and fibrinogen which are large molecules and cannot pass through the thin wall of the blood capillaries.These proteins contribute mostly to the osmotic pressure of the plasma .Besides ,these also help to buffer changes in the blood acidity [ph] .The albumin is most abundants and the plasma proteins and accounts for the most osmotic pressure of the plasma .It checks excess loss of fliud from the blood .It also help many substance dissolved in the plasma by binding to them .Thus it plays important role in plasma transport .The globulin exists as alpha , beta and gamma globulins . the gamma globulins are antibodies which are involved in the immunological defence of the body.The alpha and beta globulins contribute to the osmotic pressure of the blood and also seve as carrier for substances.The fibrinogen, produced in the liver , serves as foundation of the coagulation of the blood during which it gets converted into insoluble fibrins as a networks of fibres . Blood corpuscles or blood cells ; The formed element of the blood are represent by blood corpuscles which are of three basic types ,the erythrocytes[=red blood corpusles , or red blood cells written as RBCin the abbreviated form] ,Leucocytes [=whitwe blood corpuscles or cells written as WBC in the abbreviate form] . Red blood cells [RBC] These blood cells are called erythrocytes are very small ,circular , bicon cave and dislike , about 8 u in diameter and 2u in thicknesss .Their bicon cave area provides more surface area , favouring more diffusion in and out .These4 are pliable elastic cells that bend , flex and twist while passing through tiny vehicles the cappilaries In mammals ,including man except camel and limma , the mature red blood cells lacks nucleus ,i.e., it is not nucleated .The red blood cells contain haemoglobin which gets more spaces for its accomodation in them due to absence of the nucleus .The individual red blood cells are pale yellow but when aggregated ,these appear reddish.The outer surface of the RBC has plasma membrane compose of lecithin nad cholesterol .This membrane enclose a homogenos matrix called stroma .containing loosely arranged network of fibrous and globular proteins which form the cyto skeleton .This is attached to the inner surface of the plasma membrane and gives disc-like shape to the RBC .However , other other cell organelles are absent due to absence of the nucleus .The stroma contain haemoglobin which gives pale red colour to the cell .Each erythrocyte has 200 to 300 molecules of the haemoglobin accounting fo the one- third of its volume .
RABBIT;CIRCULATORY SYSTEM
The circulatory system is the transport system of the body,it transports various substances from tissues to tissues .Besides ,it maintains the chemical composition and physical environment of the body fluids ,essential for the metabolic reactions on which the life wheels on smoothly .Moreover , in certain animals such as birds and mammals ,it also it also maintains a body temperature to a constant level. The circulatory system of vertebrates , including mammal fall under two categories ,[1] blood vascular system and [2] lymphatic system .These are distinguishable on the basis of the circulatory or transporting medium; it is blood in the blood vascular system and lymph in the lymphatic system .However , the remarkable fact about the circulatory system of mammals is that it is of closed type i.e., the circulatory medium flows in vessels; even the lymph does not flow in open spaces within the body. 1.BLOOD VASCULAR SYSTEM ;The blood vascular system of the rabbit or any other mammal ,like that of other vertebrates , consists of the rabbit of higher muscular and highly contractile heart ,blood vessels,pervading every part of the body and blood vessels due to the pumping action of the heart . HEART The heart of the rabbit and other mammals, including man ,lies in the mediastinal space between the lungs ,inclined slightly to the left,.It is somewhat pear -shaped with broad -base ,lying toward the trachea ,and a narrow apex ,lying toward the diaph ragm .The heart is covered by the pericardium which is composed of two thin membranes between which is present a lymph like fluid called pericardial fluid .This fluid ensures free movement of the heart and absorbs shocks which oterwise may hurt the heart . External Structure ; The heart is extenally distinguishable into a broad anterior part called atrial or auricular part and a poterior narrow part called ventricular part .These two parts are demarcated by a transverse shallow groove like coronary sulcus which is placed far forward ,making the auricular part smaller than the ventricular part .The auricular part consists of the right and left auricles .Like wise , the ventri cular is also divided into the right and left auricles .Likewise , the ventricular part is also divided into the left and right ventricles by a logitudinal sulcus which starts from the base of the ventricular part , almost medially and extends backward obliquely toward the right not reaching the apex and therefore the left ventricle is large than the right ventricle . The sinus venosus and trunkus arteriosus are not found in the heart of the rabbit or any other mammal .The sinus venosus is merged into the right auricle and is represanted only by the sinu - auricular node[sanode] . Likewise , the trunkus arteriosus is completely merged in the left ventricle .The right auricle recieves venous or deoxygeneted blood from all parts of the body , except lungs by two superior vena cavae [anteroir vaena cavae or precavals ] and an inferior vena cava [= posterior vena cavae or postcaval ], whereas the left auricles recieves ithe oxygeneted blood from lung by two pulmanary veins The aorotid arches arise from the ventricles ; the pulmonary aorta arises from the right ventricle and the caratico- systemic aorta from the left ventricle .The pulmonary aorta and caratico -systemic aorta are joined by a liga ment called ligamentum arteriosus . The blood supply of the heart is maintain by acoronary artery and a coronery vein .
ABSORPTION OF DIGESTED FOOD
While within the alimentary canal the food ,strictly speaking , is still outside the body .In order to be use to organism ,it most be absorbed in the blood stream .The entry of the digested food from the lumen of the gut ,specially intestine , into the blood stream is called absorption . Very little absorption takes place either in the buccal cavity or in the stomach but these can be scarcely classified as food .By far the greater part of the absorption takes place in the ileum .The food is in a very soluble and easily diffusible form and hence it can be easiy absorbed throug its wall into the blood and lymph cappilaries . The absorptive area of the small intestine is enormously increased by the development of villi in this region .In man ther are 5,000,000 minute waving villi , providing a very large inner surface area [5 times the body surface ] for absorption .Each villus is wellsupplied with the capillary blood vessels and lacteals are concerned with the absorption of fat .The oval peyer's patches or lymphoid nodules manufacture certain white corpuscles known as lymphocytes which also helps in the absorption of fat .The vermiform appendix which has the structure of peyer's patches is also absrptive in a high degree. The digested carbohydrates chiefly as glucose and protein must pass through where it break up into cappilaries .Thus all the carbohydrates chiefly as glucose and proteins as amino acids are observed into the villus cappilaries and lead to the factor of the hepatic portal vein .The hepatic portal vein passes into the liver where it break up into capillaries .Thus all the carbohydrates and proteins must pass through the liver before entering to the general circulation .In this respect the liver provides a very important regulatory mechanism .Any exccess of blood sugar is always changed into glucose and stored in liver cells .On the other hand , if there is shortage of sugar in the blood , the glycogen stored in the liver is turned once again into glucose by and enzyme known as glycogenase and released into the blood .In this way the liver not only acts as a regulator but also as a store house of carbohydrates . The amino acids are brought by the hepatic vein to the liver and are allowed to go into the general circulation. Thecells of the body absorb amino acids are dealt with in the liver ; by a complex actions the amino acids are split up. The carbon , hydrogen and oxygen unite to form glycogen or fat and the nitrogen forms ammonia .Ammonia is highly poisonous and is not released into the blood in any quantity in mammals .It combines with carbon dioxide under the influence of certain enzymes to form urea .The breaking down of amino acids is known as deamination. The digested fat , as fatty acids and glycerol , passes directly into the lacteals where it is at once changed into minute droplet of fat so that this vessels contain a milky white emulsion .The removal from the intestinal contents of the digested carbohydrates ,proteins and fats leaves afluid residue containing undigested and indigestable food , remais of bacteria and largely of undigested cellulose .This residue passes into the caecum and colon where further process of absorption takes place but it is chiefly of water .A largely proportion of water is absorbed during the passage of this fluid residue through the colon so that by the time it reaches the rectum the residue becomes semi-solid and form the faeces , which is thrown out at intervals.
INGESTION AND DIGESTION
[The account of the digestion presented under this section is applicable to maost mamals including man ] .As his already been stated , the rabbit gnaws its food.By means of chisel-shaped incisors , small portion of the vegetables matter are cut up and after being caught by the mobile lips are taken into the buccal cavity .Here the food is throughly mixed with saliva and subjecte to the action of the grinding cheek-teeth .During later process which is called mastication , the food is turned round and round in the buccal cavity by movements of the tongue and chhek -muscles until the whole forms a pulpy mass..Through mastication is of very great importance in herbivores animals like rabbit which live entirely on vegetable matter containing a great deal of starch.It should be noted that in such animals the molar and pre-molar have special transverse ridges for grinding the food . Further the surfaces of the tongue is hard and helps by rubbing the food against the palatine ridges on the roof of the mouth cavity. . When mastication is completed , the pulpy mass is swallowed .This is affected by the bonus being pushed into pharynx by the raising of the tongue, prevented from entering the posterior nares by the soft palate and isa finally forced into the beginning of the oesophagus by the contraction of the pharyngeal wall.During the contraction of the pharynx and entry of the bolus into the oeso phagus the food is prevented from entering into the larynx through the glottis by a flap- like epiglottis .The oeso phagus conveys the food to the stomach through the activity of the layer s of the muscles in its walls.This activity causes peristalsis . The first stages in the conversaion of food into the protoplasm of the animal is its partial breaking down into simpler compounds . In all cases the digestion consists of a process of hydro lysis,during which the molecular size of the subsances is progressively reduced until the true sollution is possible .These changes are brought about by the familiar biocatalysts known as enzymes or ferments. Inmouth , the food comes in contact with the colourless wateryfluid or saliva , secreted in the mouth cavity by the front pairs of salivary glands , which keeps the mouth continuosly moist under normal conditions.When the food is in mouth ,its smell and tastes considerably increase the rates of its secretion .Since food stays for a very short time in a mouth , it is not in the mouth but in the stomach where thwe main bulk of the salivary digestion takes place Besides ptyalin ,saliva contains 99% water ,mucin albumin ,globumin ,etc.The function of saliva are as follows ; 1 It changes insoluble starch and glycogen into soluble maltose . 2; It helps in swallowing and moistening and lubricating the food.3 It dissolves soluble substance and thus make them fit for tasting .4It has a cleaning effect on the mouth and the teeth . In the mouth ,3-5 percent of the carbohydrates are digested in the suceeding part of the alimentry canal . The digestion doesnot takes place in the oeso phagus because the oeso phagus secretly only mucin ; it doesnot produce any digestive enzyme .The mucin is simply added to the bolus so that it easily passes from the oesophagus to the stomach .However . the action of the ptyalin , which has already started in the mouth , continues . Digestive in the stomach . The food is subjected to the action of the gastric juice , secreted by the tubular gastric glands .As soon as the food reaches the stomach ,its wall is mechanically simulated to produce the gastrin harmone , which , in turn stimulates gastric glands to pour gastric juice into the lume of the stomach The gastric juice is composed of water , mucin ,hci an three digestive enzymes such as pepsin ,rennin [in young ones of rabbit and calves of cattles] and gastric lipase The mucin protects the tissue from the action of enzymes .It is amphoteric [a substance that can act as both acid and base according to conditions] in nature and can thus nutralises both acids and alkalies besides providing a mechanical buffer between hard food substance and the living tissues
Wednesday, August 17, 2011
BALANCED DIET
The food that we take daily constitutes diet .It must be balanced with work.Adiet that contains allcomponent of foods in adequate quantities is called a blalanced diet . According to Bulletin 23 of our government ,an adult doing average work should eat everyday different component of food in quantiites . The dietary requirements depend upon age ,sex and work..These can be obtained from cereal , pulses , leaf and other vegetables ,roots and tubers, milk , oil and fat and ,sugar and jaggery.The common food that we take daily have major constituents of food in varying proportions .Inlight of these , the quantity of the common food s can be adjusted to the type of work one does . The main aim of the balanced diet is tto provide sufficient calories [energy] for work and materials in adequate quantities to body for growth and repair .The energy requirements depend upon the amount of work done ,sex and age .An average adult man rquires about 1800 kilo calories per day to keep him alive and an average adult woman needs 1500 kilo calories per day for the same purpose .At complete rest , an average adult man requires about 1600 kilo calories per day, while an average adult woman needs 1450 kilo calories per day .A young labourer, who does lot of physical work , reqires a diet which can provide him with about 3600 kilo calories per day and a young woman doing the same ,requires a diet which can provide her with about 3000 kilo calories .Ayoung man and a young woman ,who do ordinary works for 8 hour per day ,require everyday about 3000 and 250 kilo calories respectively .The light work everyday demands less calories ; ayoung man needs 2500 kilo calories and ayong woman requires about 2100 kilo calories .Growing children need more energy with the increasing age ; but the energy requirement for both sexes is almost similar upto 12 years but male need more energy than female after 12 years . If the the daiy intake of food does not provide sufficient calories , the capacity for the work is reduced and the body loses weight because the reserved food areoxidised .The continous starvation leads to rapid weight -loss. Malnutrition This is condition in which aperson suffers due to lack of one or more components of food.This is characterized by poor growth and weakness . Deficiency of proteins ,carbohydrates and fats leads to protein energy mal-nutriton [pem] . It is the most common in indian children ,specially in the age period of 1-5 yrs and its symptom is poor body growth and retarded mental growth .Two common forms of the above - mentioned malnutrition are kwashiorker and marasmus . Deficiency of vitamin in the diet im pairs growth and body function s .Lack of vitamin A[retinol ] leads to retarded mental growth ,dryskin , night blindness and defective formation of teeth .Likewise, dificiency of vitamin b1 [thiamine] and b2 [ribo flavin] also lead to retarded growth and adversely affect eyes ,skin tongue and other organs .Thiamine[b1] deficiency result in a disease called beri-beri .This is cahracterised by water logging of tissues , much weakness ,headache ,paralysis and even heart failure . Like the mineral deficiency dieseases, the vitamins deficiency diseases , the vitamins de ficiency deficiency can be cured by recommend dosage.
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