Life Processes

1. Life Processes Class IX – Science II Chapter 4

2. What is Transport System • Transport system is an organ system in higher multi-cellular organisms with large bodies. • Transport system is used to transport materials to each and every cell of the body.

3. Transport System in Plants • Materials to transport in plant: • Carbon, hydrogen, oxygen, nitrogen and salts. All these absorbed from soil through root. • Food prepared in leaves. • Hormones secreted in certain parts of the plant. • Transportation Methods: • Ascent of SAP – The transportation of water and dissolved salts from root to other parts through xylem tissue (stem) against gravitational pull is called Ascent of SAP. • Organic translocation – The transportation of food from leaves to stem, storage regions and other parts through phloem is called organic translocation.

4. Transport System in Man • Transport system includes blood, blood vessels and heart.

5. Transport System in Man - Blood • Blood is a liquid connective tissue. • Blood contains, • Plasma. • Red Blood Corpuscles (RBC). • White Blood Corpuscles (WBC). • Platelets.

6. Transport System in Man - Blood

7. Transport System in Man - Blood • Blood Clotting means… • Fibrinogen and prothrombin in plasma are helpful in blood clotting. • When blood comes out of wound, fibrinogen comes in contact with air and forms fibrin network at the opening of the wound. • Blood cells are entangled in the network to form clot. • This process is called blood clotting.

8. Blood Vessels • There are three types of blood vessels, • Arteries. • Veins • Capillaries.

9. Blood Vessels

10. Heart • The Heart is, • Conical (shape) • Muscular • Pumping organ. • It has size of one’s own fist. • Situated in the thoracic cavity between the lungs. • It is slightly inclined to left.

11. Structure of Heart • Heart is enclosed in double layered sac called as pericardium. • Between the layers pericardial fluid is present. • The pericardial fluid protects the heart from mechanical shocks and friction.

12. SEPTUM separates right and left parts of the heart TRI-CUSPID VALVE is present between right auricle & right ventricle BI-CUSPID VALVE is present between left auricle & left ventricle The Upper 2 chambers of the heart are called AURICLES These Valves prevent backflow of blood from ventricles to auricles septum Left auricle Bicuspid valve Left ventricle right auricle Tricuspid valves right Ventricle The lower 2 chambers of the heart are called VENTRICLES

13. Vena cava carries de-oxygenated blood from the body to right auricle. Pulmonary artery carries de-oxygenated blood from right ventricles to lungs. Blood from different parts of the body open up into the Auricles. Blood is carried from Ventricles to other parts of the body. Aorta Carries oxygenated blood from left ventricles to different parts of body. The pulmonary veins carry oxygenated blood from lungs to left auricle. superior vena cava (transports blood from the head) Aorta Pulmonary veins Pulmonary artery inferior vena cava (transports blood from rest of body)

14. Functioning of Heart • When Auricles relax, De-oxygenated blood flows from the body into right auricle through inferior & superior Venacava. • When auricles contract, the right auricle pumps the de-oxygenated blood into right ventricle through tri-cuspid valve. • From there de-oxygenated blood flows into lungs through pulmonary artery. • When ventricles relax, oxygenated blood flows from lungs into left auricle through pulmonary veins. • When ventricles contract, the left auricle pumps the oxygenated blood into left ventricle through bi-cuspid valve. • From there the oxygenated blood is pumped to different parts of the body through Aorta.

15. Heart Beat • Contraction of heart muscles is called systole. • Relaxation of heart muscles is called diastole. • One systole & one diastole together form one heart beat. • Heart beat measured by stethoscope. • In a healthy individual, heart beat is about 72 per minute.

16. Blood Pressure • When left ventricle contracts the blood is pumped is pumped into aorta. • The blood exerts pressure on the walls of the arteries which is know as Blood pressure. • Blood pressure measured by sphygmomanometer. • In a healthy individual, blood pressure is in the range of 120/80 mm Hg (millimeter of mercury). sphygmomanometer

17. Pulse • The elastic wall of artery relax and then contract when blood flows forward. • This forms a wave like movement in the walls of arteries. • This movement is called pulse. • Rate of pulse is same as heart beat. • Pulse can be detected at the wrist.

18. Blood Circulation • Blood flows the heart twice to complete one circulation in the body, so this is called as Double Circulation. • Pulmonary circulation • The course taken by blood between heart and lungs is called pulmonary circulation. • It exchanges carbon-di-oxide with oxygen by diffusion. • Systematic circulation • The course taken by blood between heart and tissues of the body is called systematic circulation. • It exchanges oxygen with carbon-di-oxide by diffusion.

19. Care of Heart & Disorders of heart • Care of Heart • Yoga & Meditation to control tension. • Smoking can be avoided. • Alcohol can be avoided. • Disorders of Heart • Defects in valves – abnormal narrowing of valves. • Enlargement of heart chambers – thickening of blood chambers. • Septal holes – holes in the septum. • Blue Baby – Aorta arises from right ventricle instead of left resulting in pumping de-oxygenated blood. • Heart Attack – The deposition of fat in the coronary artery prevents getting sufficient blood and causes heart attack.

20. Excretion means … • This process eliminates metabolic wastes from the body. • Eliminates nitrogen containing waste products.

21. Waste products in plants • Metabolic waste products in plants: • Tannins, alkaloids, glycosides & anthocyanin. • Wastes from plants, • Ammonia escapes through stomata. • Nitrogen salts through roots to soil. • Wastes accumulate in cells of leaves, barks & petals as crystals. These leaves, barks & petals are shed by plants.

22. Water regulation in plants • Plant absorbs water through roots and loses through transpiration process. • Transpiration means … • Plant loses water by evaporation. • Most of the evaporation occurs through stomata. • This is called transpiration. • Benefits of transpiration: • Maintains plant’s temperature. • Helps root to take up more fresh water from ground.

23. Excretory system in Man • Excretory system of man includes kidneys. • Ureter start from kidneys opens up into urinary bladder. • Urinary bladder opens outside by urethra.

24. Kidneys • Kidneys are dark red, bean – shaped. • Located at back of abdominal cavity one on either side of backbone. • There is a depression in each kidney called hilum. • Renal artery enters and renal veins exits the kidney through hilum. • Kidney is covered with connective tissue called, renal capsule. • Kidney has outer cortex, inner medulla. • Medulla is 8 to 18 pyramid like structure. • Minute openings at the end of pyramid is called renal papillae. • Pyramid projects into hollow pelvis. • Ureter starts from pelvis. • Nephrons are functional unit of kidneys. • Functions of kidneys: • Excretes urea waste. • Excretes excess water. • Excretes excess salts

26. Nephrons – Functioning unit of kidney • Bowman’s capsule – cup shaped structure in cortex. • Coiled tubule – tube Following the capsule. • Henle’s loop – U shaped tubule in medulla. • Collecting duct – tubule joins at the collecting duct in cortex. • Renal pelvis – collecting duct opens into renal pelvis. • Glomerulus – renal artery breaks to form glomerulus in bowman’s capsule. Coiled tubule Collecting duct

27. Urine Formation • Glomerular Filtration: • blood enters nephrons. • Filtered by glomerulus. • Selective reabsorption: • Filtrate from glomerulus enters henle’s loop. • The capillaries absorb glucose, vitamins, hormones. • Through osmosis, diffusion & active transport. • Also called tubular reabsorption. • Tubular secretion: • Filtrate from henle’s loop enters convoluted tubule. • The cells of tubule secretes uric acid, ammonium salts, potassium & hydrogen ions into the filtrate. • All the above three process results in urine formation.

28. Urine • After the above three process, the filtrate with urea & other nitrogenous wastes and excess of salts is called Urine. • Straw colored. • Urine passes to the collecting duct Then to pelvis. Then to ureters. Stored in urinary bladder. Excreted through urethra.

29. Kidney Disorders & Treatments • Kidney stones – accumulation of calcium oxalate. • Kidney failure – accumulation of urea in blood. • Nephritis – Inflammation of kidney. • Kidney Treatments: • Dialysis – acts as artificial kidney. • Kidney transplantation – healthy kidney is transplanted to the patient.

30. Human Skin • Functions of Skin: • Protects inner tissues from mechanical shocks, UV rays, infections. • Perceives stimuli ( heat, touch & pain). • Excretes sweat. • Regulates body temperature. • Structure of skin • Skin has two layers • Epidermis. • Dermis.

31. Structure of the Skin

32. Epidermis & Dermis • Epidermis has three layers, • Outer most layer has dead cells. • Inner layer has living cells which move up in course of time. • Inner most layer called malpighian or germinating layer produces new living cells, melanin pigment. • Melanin gives color to skin & protects from UV rays. • Dermis has, • Blood vessels – supply food & oxygen to skin. • Sweat glands – 1. coiled tubules. 2. open out by sweat pore through sweat duct. 3. Sweat glands absorb salts, water & urea and convert to sweat • Hair follicle – present in malpighian layer. Maintains temperature. • Oil glands – secretes oil into hair follicle. Antiseptic against bacteria. • Fat globules – maintains temperature.

33. Skin: osmo-regulators • Skin maintains water level in blood. So called as osmo-regulators. • Hypothalamus in the brain dilates (make it large) blood vessels if the temperature is high. • So more blood pores in and more sweat produced. • When sweat evaporates temperature of the body decreases and becomes cool.

34. Disorders of skin • Moles • Warts • Pimples