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CHAPTER ONETransport in Plants and Animals1.1 IntroductionIn form one, we learnt that animals and plants require nutrients andoxygen for the various metabolic activities taking place in theirbodies. Nutrients and oxygen must be transported to all the livingcells of the body. Metabolic activities release by-products suc... |
State the substances absorbed AUTHOR tothe rest of the plant body?2. What substance is transported from leaves to the rest of thebody?In simple plants such as mosses and liverworts, transport ofsubstances occur from cell to cell through the processes of diffusion,osmosis, and active transport. These plants lack special... |
1.1 a : Transverse section of a young dicotyledonous rootFig. 1.1 b : Longitudinal section through a dicotyledonous root tipThe root cap is at the terminal position of the root tip. It consistsof simple parenchyma cells that protect the apical meristem as theroot tip is pushed past soil particles. The cells of the root... |
Inyoung roots, it forms the extensive region between the epidermisand the vascular bundles. Water molecules pass through this tissueto reach the vascular bundles. The cortex also acts as a storagetissue. NAME is a single layer of cells surrounding the vascular bundles. It ischaracterised AUTHOR : Starch grains that sta... |
Draw a labelled plan diagram of the section.4. Repeat the above procedure with other slide of the dicotyledon. Study Question5. How does the arrangement of vascular tissues in themonocotyledonous roots compare to those of the dicotyledonousroots?The StemThe primary functions of the stem are: i To support and expose the... |
The following simpletissues may be found within it: parenchyma, collenchyma andsclerenchyma. NAME cortex collenchyma tissue lies just beneath the epidermis. Itmay form a complete cylinder or it may occur in separate strands. From a longitudinal view, collenchyma cells are elongated and havea pointed oblique ends. The w... |
Draw a labelled plan diagram of the section.4. Repeat the above procedure with the other slide of the dicot. Study Questions6. What tissues make up the vascular bundles?7. Draw plan diagrams to show the arrangement of vascularbundles in a named: i monocotyledon ii dicotyledon stem. Absorption of water and mineralsalts ... |
This suggests that salts can be drawn fromthe soil even when their concentration is lower than that in the rootcells. This process requires the use of energy and is thereforereferred to as active transport. Any substance that hindersrespiration inhibits active transport. Active transport is believed to involve substanc... |
As water vaporises from the spongymesophyll cells into the sub-stomatal air spaces their cell sapbecomes concentrated than the adjacent cells. This increasesosmotic pressure of the spongy mesophyll cells. As a result, waterflows into the cell from other surrounding cells which in turn take inwater from xylem vessels wi... |
The pits on the sidewalls allow lateral water to cellssurrounding the xylem. See figure 1.7. Aaa ee Fig, 1.6: Xylem vessels - NAME 1.7: NAME makes them less efficient in conducting water than the vessels. Tracheids perform both functions of support and transportation ofwater in the pteridophytes, gymnosperms and angios... |
Fig. 1.8: Water loss and transpiration in plants ii Cohesion and Adhesion forcesWater molecules attract one another in such a way that they alwaysstick together. The forces that keep them together are referred toas cohesion force. At the same time water molecules areattracted to the walls of the container in which the ... |
Respiratory inhibitors such as cyanide, reduce rootpressure. Significance of TranspirationTranspiration makes the plant lose water if unchecked. However,transpiration has some beneficial effects on the plant as follows: i It serves to replace water lost through the leaves. Ii Through the process, mineral salts and wate... |
Water vapour tends toaccumulate in these pits thus reducing transpiration. Many plants close their stomata if the rate of transpiration ishigher than that of water uptake. Plants will close their stomata ona hot dry sunny day to lower the rate of transpiration. Thisphenomenon known as midday closure, protects the plant... |
WindStudy the sketch graph below showing the relationship betweenwind and the rate of transpiration. Wind carries away water vapouras fast as it diffuses out of the leaves through the stomata. Thisprevents the air around the leaves from being saturated with watervapour. This helps to maintain a high diffusion gradient ... |
3. Quickly cover them with the dry glass slides and note the time.4. Secure the slides into position with elastic rubber bands asshown in figure 1.105. Separately note the time taken AUTHOR cobalt II chloride papers to turn pink. Note the time as soon a pink spotappears and also when the whole paper turns pink.6. Hold ... |
Stand the base of the shoot in the water to prevent blockage ofthe water channels with air. Fix a rubber bung over the cut endwhile it is still in water.4. Connect the end of shoot in the bung to the potometer alreadyfilled with water. Apply jelly to the stem around the rubber bungto render the system airtight.5. Trans... |
Like the xylem vessels, the phloem tubes run fromthe roots to the leaves. The organic products translocated aremainly food materials. These products of photosynthesis includesugar, amino acids and vitamins. They are translocated to differentregions of the plant where they are required for various purposes. These region... |
Table 1.1Time of dayWater loss per hour cm3 7 am9 am11 am1 pm3 pm5 pm7 pm9 pm11 pm1 am3 am1323 a Plot the results on a graph. Place time on the x-axis. B Relate time of day to environmental factors. C Explain how the rate of transpiration varies within the 24hours.1.3 Transport in AnimalsThe Circulatory SystemLarge and... |
See figure 1.13. Theblood contains suspended leucocytes white blood cells and somepigments but it is not largely involved in the transport of oxygenand carbon dioxide. Transport of gases in insects is principally bydiffusion in the tubes called tracheal system as will be discussedlater in chapter 2.In a cockroach a typ... |
From theheart, blood is then pumped to the rest of the body organs. This iscalled systemic circulation. Mammals and birds have a four-chambered heart. The righttwo chambers deal with deoxygenated blood while the left twochambers deal with oxygenated blood. Hence deoxygenated andoxygenated blood do not mix. Furthermore,... |
Two auricles atria form the upper chambers. They are thin-walled and smallerin volume than the lower chambers. The right auricle receive deoxygenated blood from the body organsexcept the lungs while left auricle receives oxygenated blood fromthe lungs through the pulmonary vein. The lower chambers are called ventricles... |
Blood from the leftventricle is forced to flow via the semilunar valves through the aortato the body tissues. Oxygenated blood from the lungs flow throughthe pulmonary vein to the left auricle via the bicuspid valve to theleft auricle. Fig. 1.16: The internal structure of the mammalian heartPumping Mechanism of the Hea... |
High temperature and emotions can result in an increasedrate of the heartbeat. The heartbeat is faster in a child than in anadult. Heartbeats may be felt as pulse AUTHOR a fairlylarge artery, such as that at the wrist, against a bone. Fig. 1.17 b : Systole ventricle contractsHeartbeatThe heart is capable of contracting... |
This layer is found in all blood vessels. Itprovides a smooth lining which offers the least possible frictionalresistance to blood flow. The middle layer is composed of elasticfibres and smooth muscles. The outer layer is formed of elasticmuscular fibres collagen fibres as shown in figure 1.20 a .When ventricles contra... |
Phagocytic leucocytes squeeze in between the cells ofthe capillary wall and pass into the tissue fluid. From the tissuefluid, cells extract substances such as glucose, oxygen, amino acids,vitamins, hormones and mineral ions. Fig. 1.20 b : Portion of a capillary blood vesselUltra filtration results to a drop in pressure... |
This explains the need for physicalexercises. All veins carry deoxygenated blood with fewer nutrientsbut more nitrogenous waste and other metabolic wastes except: a Renal vein that carries blood from the kidney wherenitrogenous waste, some water and salts has been removed. B Hepatic portal vein that carries blood rich ... |
Dissect the mammal using the procedure in the dissecting guideand conduct the following: i Display the heart, lungs, liver, kidneys and the spleen. Ii Identify the coronary, carotids, jugular, renal, hepaticarteries and veins. Iii Trace the dorsal aorta and the posterior vena cava towardsand away from the heart. Simila... |
Carefully note where these enter or leave theheart. Study Questions15. Draw and label the external structures of the heart.16. Draw and label the internal structures of the heart. Show witharrows the direction of blood flow through the heart. NAME 8To investigate pulse rate at the wristRequirementsStop watches or clock... |
Note any effects on the flow of blood when this is done. Study Questions20. What happens when a bandage or band is tied around the armof the subject?21. How is the blood flow affected after the first stroke in step 6?Give reasons for this. Diseases and Defects of Circulatory SystemThrombosisThis refers to formation of ... |
Physical exercises can also reduce chances ofarteriosclerosis since the excess fat will be broken down while theheart is kept active and strong. Varicose VeinsIt is a condition in which the superficial veins especially at the backof the legs become swollen and flabby due to failure of some valvesto function properly. T... |
These cellular components areerythrocytes red blood cells , leucocytes white blood cells andnon-nucleated thrombocytes platelets .The PlasmaPlasma is a pale yellow fluid consisting mainly of 90 per cent waterin which a variety of substances are suspended and othersdissolved. Substances in plasma include glucose, minera... |
Red bloodcells carry oxygen in the form of oxyhaemoglobin. The haemoglobin has high affinity for oxygen. It readily picksup oxygen in the lungs where the concentration is high and easilyreleases oxygen in the tissues where the concentration is low. In the tissues, oxyhaemoglobin readily breaks down dissociates into hae... |
Burning charcoalstoves, jikos in a poorly ventilated room produces carbon II oxide. Exhaust fumes from vehicles also contain carbon II oxide. Itis important therefore that charcoal stoves are not allowed to burnin poorly ventilated rooms because carbon II oxide canaccumulate to levels dangerous to life. In addition to ... |
In the tissues andblood, the granulocytes engulf pathogenic micro-organisms AUTHOR the name phagocyte. Onceingested, the micro-organism are digested. Some white blood cellsmay die in the course of phagocytosis. The dead phagocytestogether with dead micro-organisms and damaged tissues form pus. The agranulocytes assist ... |
See figure 1.24.Fig. 1.24: PlateletsA blood smear observed under a microscope reveals the variouscomponents of blood. See photomicrograph in plate 1.4.Plate 1.4: Human blood smear courtesy of KEMRI NAME ProcessThe process of clotting involves a series of complex reactions wheresoluble blood protein is converted into a ... |
There are two of these antigens, designated Aand B. Blood groups are determined AUTHOR presentin an individual s red blood cell. Thus an individual whose red bloodcells have antigen A is grouped as A. Antigen B is grouped as B.Antigen A and B is grouped as AB while that without antigens isgrouped as O type. The plasma ... |
From the above table identify the universal donor and theuniversal recipient. 23. Why is it important to screen blood before transfusion?A doctor must ensure that before one donates blood he she ishealthy and is between 18 and 65 years of age. A drop of thedonor s blood is first tested to find out what group he she bel... |
The mother s red blood cells respond AUTHOR turn pass across the placenta into the blood ofthe foetus red blood cells before the foetus birth. This reaction iscommon after the first born and affects the foetus of thesubsequent pregnancies. This is as a result of the antigen-antibodyreaction taking place on the surface ... |
It is formed as a result of ultra-filtration of blood from thenarrow blood capillaries. As blood circulates it reaches the bodytissues through the blood capillaries that form a network throughoutthe tissues. The pumping force from the heart together with thenarrow lumens of the capillaries exert a high pressure that fo... |
This meansthat a particular antibody combines with or responds only to aparticular antigen to make it harmless. Antibodies are produced AUTHOR or proteins invade the body, some lymphocytes startproducing antibodies which are complimentary to them. The bonemarrow and the thymus gland also begin to produce morepolymorphs... |
The plasma cells synthesise the antibodies whichare released into the lymph and eventually reach the blood. In theblood the antibodies destroy the invading organisms. A smallnumber of plasma cells remain in the lymph nodes for years, evenafter the antibodies have eliminated the original infection and areremoved from th... |
In somecases the artificially acquired immunity is permanent andimmunisation is done only once in a lifetime. In some cases a booster vaccination is required to maintain immunity e.g. againstcholera, since the immunity lasts for a short time. Artificial passive acquired immunity is achieved whenantibodies from another ... |
Vaccinations should be given at regular intervals see table1.7 . For example, booster injections of vaccines against polio inbabies have to be given regularly after every four weeks, for thefirst 16 weeks. It is also recommended that healthy children shouldbe exposed to chickenpox when young for the attack is severe wh... |
Histamine also causesinflammation and pain. A severe condition called anaphylaxissometimes occurs, in which blood vessels get dilated and thislowers the blood pressure to the extent of causing death. This ishow bee stings can cause death. Avoiding the allergens allergycausing substances or administration of the antihis... |
What were theblood groups of the two samples?15. People can die when they inhale gases from burning charcoal inpoorly ventilated rooms. Explain how this death comes about.16. A State two proteins in the blood which are responsible fordetermining the blood group of a person. B Give two reasons why a transport system is ... |
In morecomplex organisms, there are special organs such as lungs or gillswhich absorb oxygen and remove carbon IV oxide from the body. The importance of gaseous exchange in the living organisms isto promote oxygen intake for respiration and facilitate carbon IV oxide removal from the body as a wasted product of metabol... |
Place a cork to cover the mouth of the boiling tube as shown infigure 2.1.5. Set up a control with a boiled leaf and label B.6. Keep the apparatus on the side bench for at least one hour. Note: Bicarbonate indicator is red at the beginning of theexperiment. Study Questions1. Note the colour change of the bicarbonate in... |
The guard cells are adapted totheir function AUTHOR cell walls. Seefigure 2.3 a and b .Fig. 2.3: a Stoma closedThe Mechanisms of Opening and Closing ofStomataThis process of opening and closing of stomata has been explainedby various theories. One such theory is the photosynthetic theorybased on the sugar formation AUT... |
Carbon IV oxide, thereforeaccumulates in the guard cells resulting in the lowering of pH. Thisfavours the conservation of glucose into starch. Fig. 2.3 b Stoma openThe latter is osmotically inactive and therefore the guard cells donot gain water. Due to the resulting flaccid state of the guard cells,the stomata close. ... |
Thepartial opening during the daytime allows for gaseous exchange. The modifications mentioned above, help in water conservation inthe tissues of the plant and at the same time reduce water lossfrom the plants AUTHOR are aquatic plants or plants growing in water. Some of these aquatic plants, are not completely submerg... |
2.5: The structure of the lenticelPlate 2.1: Pneumatophores of the mangroovesPractical Activity 2To observe permanent slides of transverse sections ofleaves and stemsRequirementsPermanent slides of mesophyte, zerophyte and hydrophyte leaves,stems and light microscope. Procedure1. Place each slide in turn on the stage o... |
The amoeba is a single-celled aquaticorganism whose entire body surface is always in contact with thesurrounding water. The organism is small and has a large surfacearea exposed to its aquatic environment. It therefore does not needan elaborate gaseous exchange system since its gaseous exchangecan be adequately met AUT... |
The trachea then subdivide intofiner air tubes called tracheoles, which ramify the body tissue of theanimal for direct supply of individual cells with oxygen. Since thetracheoles lack the spiral bands of chitin, they permit gaseousexchange across their thin moist walls. See figure 2.8.Fig. 2.8: The branching of the tra... |
For example, mosquito larvae havetheir spiracles near the rectum carried on a tube called respiratorysiphon. This siphon is opened when the larva comes to the surfaceof the water to take in air and is closed AUTHOR Larvae come to the surface of water periodically tobreathe and position themselves as seen in figure 2.10... |
Draw the abdomen and show the position and shape of thespiracles. NAME in a fishFish live in water in that contains oxygen and other gases aredissolved in it. The breathing system of a bony fish consists of themouth or buccal cavity, gills, opercular cavity and the operculum. See figure 2.11 a . Fig. 2.11 a : The posit... |
2.12: Movement of water over gillsWhen all this is happening, the higher external pressurepresses the flexible free edge of each operculum against the side ofthe mouth of the fish. Each operculum in this case acts as a valve toensure that water enters only through the mouth. The mouth thencloses and muscles raise the f... |
Put the gill in water.4. Observe and draw a complete gill. 5. Examine a gill filament using a hand lens or under the lowpower of a microscope. Study Questions9. Draw the structure of the gill filament from the observations youmade in practical activity 4.10. Suggest how the total surface area of the gills in a fish can... |
The air reaches the alveoli sacs ofthe lungs that are well supplied with blood through a large networkof blood capillaries. The oxygen in the air dissolves into the moistinner lining of the alveoli. It then diffuses into the blood across thewall of the capillaries, combines with haemoglobin in the red bloodcells and is... |
The lumens of thetrachea are lined with ciliated epithelium. The cilia beat in wavesand move the mucus and foreign particles towards the pharynxaway from the lungs. As the trachea enters the lungs, it divides intotwo branches called bronchi singular bronchus .LungsLungs are found in the chest cavity. They are enclosed ... |
Connect the straw to the trachea of the animal in practicalactivity 5 and carefully blow air into the trachea, notice whathappens to the lungs. Count the number of lobes on the lungs and note the number inyour note book.13. Draw and label the respiratory system of the animal in thedissection. NAME of NAME is accomplish... |
At the same time the muscles of thediaphragm relax and it regains its original shape. These movementsdecrease the volume of the thoracic cavity and increase thepressure inside it. Thus air is forced out of the lungs through the airpassages into the atmosphere. See figure 2.17 b for the summary. Epee, tomes nt nee Diope... |
Notice what happens to the ribs and the sternum.8. Record and explain the above observation. Exchange of Gases in the AlveolusThe alveoli and the blood capillaries are made of very thin walls. The wall of the alveolus is covered AUTHOR whichdissolves oxygen in the inhaled air. Since oxygen concentration inthe blood is ... |
ExerciseDuring vigorous physical activity the rate of breathing increases soas to meet the increased oxygen demand. Faster breathing alsoeliminates the extra carbon IV oxide produced AUTHOR 2. AgeYounger people have a higher demand for oxygen. They thereforehave faster breathing rate.3. EmotionsGenerally the body emoti... |
The air that normally remains in lungsis referred to as the residual volume and is about 1 500 cm3. Seefigure 2.21 for a graphical representation. Fig. 2.21: Lung volumes in a human beingPractical Activity 7Effect of exercise on the rate of breathingRequirementsStop watch wrist watch. Procedure1. Pair up, one of you to... |
AsthmaAsthma is a common respiratory disease caused by: i Allergy to the respiratory structure due to pollen grains,atmospheric dust, animal s fur, scents from certain drugs, foodsand flowers. Fig. 2.22: Set-up for comparing amounts of carbon dioxide taken in and out ii Lung or bronchial infections AUTHOR problem comes... |
Theclinical symptoms include: headache, mild fever and coughingthat are accompanied AUTHOR The illness may clear in a few days or may persist forseveral months. B Chronic BronchitisChronic bronchitis develops after several repeated attacks of acutebronchitis. It is a fatal condition which makes the sufferer disabledand... |
This sets on when the patient s body is completelyweakened. TreatmentThe patient should use antibiotics which include penicillin andsulphonamides. Control i Avoid overcrowded places. Ii Provide good ventilation in living premises.5. Pulmonary TuberculosisTuberculosis is a respiratory disease caused AUTHOR It is airborn... |
The tumour can be benign whichaffects cells at a single point or malignant when affected cellsbreak away and spread to other parts of the body .There are no specific causes for lung cancer but it may resultfrom: i Smoking, in which the mucal walls of the bronchial tubes areblocked with deposits of tar from the cigarett... |
Explain how the following are adapted to their functions. A Guard cell. B Aerenchyma tissue.4. List the environmental factors influencing the opening andclosing of stomata.5. State the advantages and disadvantages of having stomata oneither side of the leaves.6. Samples of atmosphere and exhaled air were analysed AUTHO... |
In insects, a rare disease has been found to attack therespiratory system. Name the parts of an insect which are mostlikely to be damaged AUTHOR reason for youranswer.11. The following are events which take place during expiration in amammal. I The diaphragm and intercostal muscles relax. Ii The diaphragm returns to it... |
2.2516. In an experiment, the rate of gaseous exchange wasdetermined and recorded as shown in the table below. Usingthese figures, suggest which plant gaseous exchange structureswere responsible for these observed figures. Table 2.24StructureGaseous exchange in AApproximately 97BApproximately 2.5CApproximately 0.517. I... |
Pour a little calcium hydroxide solution into another test-tubeand support it.4. Using a delivery tube connect the two test-tubes ensuring thatthe free end of the delivery tube into the calcium hydroxide asillustrated in figure 3.1.Fig. 3.1: Set-up for investigating the gas given off when food is burnt5. Heat the test-... |
It has twomembranes, the outer and inner membranes that are separated byfluid filled spaces. The inner membrane folds into projections insidethe matrix called cristae. The cristae provide a large surface areafor respiratory activities. Enzymes are bound to the cristae. Types of NAME are two types of respiration namely ... |
What happens after pyruvic acid isformed depends on whether oxygen is available for use or not. Ifoxygen is not supplied to the cell, then pyruvic acid is then partiallybroken down to lactic acid in animals or to ethyl alcohol ethanol and carbon IV oxide in plants. See chart below. In glycolysis, one molecule of glucos... |
Record the temperature every morning and evening for a week. Fig. 3.3: Set-up for investigating production of heat AUTHOR 2. What does production of heat in the germinating beans imply?3. Explain AUTHOR in i above is produced. NAME in Plants and AnimalsAnaerobic respiration is the process AUTHOR glucose are broken down... |
Another example of anaerobic respirationin animals is when a short distance runner or diver holds his or herbreath while running or diving. The oxygen debt incurred here is paid back AUTHOR quickly and more deeplyin order to increase the supply of oxygen during the recovery periodafter the race. Figure 3.4 shows a pant... |
Boil about 20 cm3 of glucose in a tube, cool to 40 OC add someyeast.2. Pour onto the glucose and yeast suspension some kerosene oil.3. Leave this for about one hour.4. Put some calcium hydroxide in test-tube connect this test-tubeto the boiling tube using the delivery tube and rubber stopper. See figure 3.5. Fig. 3.5: ... |
Theamount of energyreleased from onemolecule of sugar is 210KJ. 2ATP molecules . Iii The substrate iscompletely broken down tocarbon IV oxide andwater. Iii The substrate is notcompletely broken downand as a result lactic acidor alcohol is produced. Iv The end products arewater and carbon IV oxide which diffuses out oft... |
Plants that are rich in fats andoils include sesame, groundnuts, sunflower, coconut, cashew nutsand castor oil seeds. Some of the animal products rich in fatsinclude fatty meat, milk, ghee, cheese and butter. Fats are not themain substrates of respiration because they are not very solubleand therefore are not easily tr... |
RQ values for carbohydrates andproteins are 1.0 and 0.9 respectively. A value of less than oneindicates higher consumption of oxygen and lower production ofcarbon IV oxide. This would represent anaerobic respiration inwhich alcohol and carbon IV oxide are produced. Respirationquotient also depends on age, temperature o... |
A What is the role of mitochondrion in respiration? B State how the mitochondrion is structurally adapted to itsfunction.4. Explain the meaning of the following terms: i NAME RQ . Ii Oxygen debt. Iii Basal metabolic rate BMR . 5. Describe what happens in the two phases of aerobic andrespiration.6. What is the economic ... |
C Suggest reasons for the shape of the graph whentemperature was maintained at 40OC. CHAPTER FOURExcretion and Homeostasis4.1 IntroductionExcretion is a process AUTHOR andeliminate waste products formed during metabolic processes, fromtheir bodies. These waste products include carbon IV oxide,nitrogenous wastes, excess... |
The waste products formed are removed from thebody AUTHOR hand, secretion is the release ofcertain useful substances produced AUTHOR , enzymes, oxalates, sebum and mucus. Plants and animals have various methods of disposing of wasteproducts and those methods involve diffusion and evaporation fromthe body. Excretion in ... |
If taken in large quantities it causes greatphysical and mental defects and addiction. Cannabis is stored in fruits, flowers and leaves of Cannabissativa bhang . It is extracted and used in the manufacture ofdrugs. Nicotine is found in leaves of tobacco plants and is used inmanufacture of insecticides and narcotic drug... |
List any other economic importance of such plants. Excretion and Homeostasis in UnicellularOrganismsMost simple organisms such as protozoa live in aquaticenvironment. Their waste products include carbon IV oxide andnitrogenous wastes. Protozoa such as amoeba and paramecium depend on diffusionas a means of excretion. Th... |
This is because their bodies arecomplex and have greater number of cells, such that simplediffusion would not suffice as a method of excretion. The excretorytissues and organs include flame cells of platyhelminthes,nephridia of annelida, malpighian tubules of insects, gills,lungs, liver and kidneys of vertebrates. Thes... |
This layer is very important because itprovides protection against mechanical damage and invasion ofbacteria. It also reduces loss of water AUTHOR are continuously lost through friction and replacedfrom beneath AUTHOR varies in the body,for example, it is thickest in areas of high friction like palms ofhands and soles ... |
Each hair is made up of a base called hair rootand hair shaft which protrudes outwards. Growth of the hair isdue to continuous addition of new dead cells at the base of thehair. Erector pili muscles are attached to the follicle at one endand on the other end to the epidermis. These muscles undergocontraction and relaxa... |
The carbon IV oxide isthen expelled from the lungs through a process of exhalation. Forthe lung structure refer to chapter 2 of this book .Structure and Function of the KidneyThe kidneys are important organs in the body whose functions areexcretion, osmoregulation, ionic balance and regulation of pH. Amammal has a pair... |
This blood is rich in nitrogenous wastes e.g. urea. It alsocontains dissolved food substances, plasma, proteins, mineral ions,hormones and oxygen. The afferent arteriole entering the glomerulus is wider than theefferent arteriole leaving it. The narrowness of the efferent arterioleproduces both resistance to blood flow... |
For efficient reabsorption the proximal convolutedtubule is adapted in the following ways:Fig. 4.6: The structure of the kidney nephron i Cells lining the tubule have numerous mitochondria whichprovide the necessary energy in form of ATP. Ii Cells of the tubule have microcilli which increases the surfacearea. Iii The t... |
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