Downloaded 30 times
Uploaded byXu Jia Xian
Topic 11 Excretion
The document provides instructions for comparing urine samples from two subjects and identifying which sample belongs to each subject. It discusses observing the color, volume, smell, temperature, and texture/taste of solutions A and B. Subject X's urine was collected one hour after drinking water, while subject Y's urine was not collected for 5 hours without drinking water. The document also contains information about the structure and functions of the urinary system.
More Related Content
Similar to Topic 11 Excretion
Topic 11 Excretion
- 1. Observe the solutionsA & B! Compare the colour! Compare the volume! Compare the smell! Compare the temperature! (optional) Compare the texture! (optional) Compare the taste!
- 2. Subject X Urine collectfrom this boy an hour after he drank 1 litre of water.
- 3. Subject Y Urine collected fromthis energetic boy who did not drink any water for the past 5 hours.
- 4. Which sample belongsto subject X? Which sample belongs to subject Y? Why???
- 5. Chapter 11 Part 1Excretionin Humans
- 6. define excretion andexplain the importance of removing wastes from the body. to identify and state the functions of different parts of the urinary system.
- 7. • Removal ofmetabolic wastes & toxic materials • Metabolism = all the chemical activities in living cells Metabolism = Catabolism + Anabolism
- 8. Chemical processesthat cause the breakdown of complex substances into simpler ones Examples: 1) Aerobic or anaerobic respiration 2) Deamination of proteins and excess amino acids in the liver to form urea. 3) Digestion of food substances
- 9. Chemical processesthat form complex substances from simpler ones Examples: 1) Photosynthesis 2) Conversion of glucose into glycogen or starch 3) Synthesis of new cells
- 10. Excreted substancesare: Carbon dioxide? Can change the pH level of blood plasma Water? Can change the water potential in the blood plasma Urea? Can be toxic if accumulated to high amounts Not useful to the body, excrete!
- 11. Excretory product Excretoryorgan Carbon dioxide Lungs excreted during exhalation Urea Kidneys excreted in the form of urineExcess water
- 13.
- 14. A pairof dark red, bean- shaped organs They are attached to the dorsal body wall, one on each side of the spinal cord The left kidney is slightly higher than the right one (Why ley?)
- 16. a) Ureter: – Anarrow tube carrying urine from the kidneys to the bladder – By peristalsis b) Renal Pelvis: – The enlarged portion of the ureter inside the kidney
- 17. c) Urinary Bladder: Ahollow muscular bag used to store urine temporarily d) Sphincter muscles: Relaxes to allow urine to flow from the bladder to the urethra e) Urethra: A tube which carries urine out of body
- 18. Each kidneyis covered by an outer layer of protective cells called the capsule It has 2 main regions: Medulla Cortex
- 19. Medulla theinner region In man, it is split into 12 -16 conical structures, called the pyramids Cortex the outer region
- 20. The functionalunit of the kidney Part of it is located in the medulla, part of it is located in the cortex Urine is formed in the nephron About 1 million in each kidney Each is about 3 cm in length Total length: about 60 km
- 22. • The renalartery brings blood from the body into the kidneys. • It branches into numerous afferent arterioles. • Each arteriole branches into a mass of blood capillaries in the renal capsule Blood from the body
- 23. • This massof blood capillaries is called the glomerulus. Glomerulus + Renal Capsule Malpighian (Renal) Corpuscle
- 24. • Blood leavesthe glomerulus through the efferent arteriole and enters blood capillaries surrounding the tubule. • These blood capillaries then unite to form the renal vein Blood leaves the kidneys
- 25. Small substances are forcedunder high pressure from the glomerulus into the renal capsule Ultrafiltration occurs here
- 26. The renalcapsule leads into the Proximal Convoluted Tubule Selective reabsorption occurs here
- 27. The proximal convolutedtubule straightens out as it passes into the medulla, makes a U-turn & passes back into the cortex Selective reabsorption continues here
- 28. Distal Convoluted Tubule:The tubule then becomes coiled again Selective reabsorption continues here
- 29. It thenleads into a Collecting Duct and eventually leads into the renal pelvis Selective reabsorption continues here
- 30.
- 31. Different in diameter Afferenthas a bigger diameter than efferent So what???
- 32. Topic 8: Chapter11 Part 2 Excretion
- 33. Excretion Waste Products removedby the Kidneys Excess Mineral Salts Nitrogenous waste • Mainly urea • Creatinine • Uric acid Excess H2O
- 34. Right Kidney Left Kidney Sphincter Muscle InferiorVena Cava Dorsal Aorta Renal Artery Renal Vein Ureter Ureter Urinary Bladder Urethra
- 35. Role of theKidney Carry out High Pressure Filtration of the blood to achieve 2 functions Removal of Urea and toxins from the blood Osmoregulation Maintain a constant blood plasma concentration
- 36.
- 37. The Nephron Proximal Convoluted Tubule DescendingLimb of Loop of Henle Ascending Limb of Loop of Henle Distal Convoluted Tubule Bowman’s Capsule Glomerulus Collecting Duct Blood Capillaries
- 38. Ultrafiltration Forced out ofblood into kidney tubules Remains in the blood Water RBC Platelets Blood Proteins (e.g Fibrinogen) Small Solute Molecules • Glucose • Amino Acids • Nitrogenous waste products (especially Urea) • Mineral Salts 2 conditions required: 1) High Blood Pressure – Afferent arteriole has a larger diameter than the efferent arteriole 2) Partially permeable membrane – Basement membrane of glomerulus has small pores that allows only water and small molecules to pass through
- 39. Diffusion and Active transportof •Ions (Na+, Cl-) •Amino Acids •Glucose Back into the bloodstream 1 Water potential gradient created H2O flows out of tubule into the blood capillaries by Osmosis 2 * Descending Limb is impermeable to Na+ and Cl- ions As the filtrate moves through the Distal tubule and down the Collecting Duct, more H2O is reabsorbed from the filtrate by Osmosis * Ascending Limb is impermeable H2O 4 Na+ and Cl- ions leaves the Ascending Limb into the interstitial fluid and is reabsorbed into the bloodstream by Diffusion & Active Transport Proximal Convoluted Tubule Proximal Convoluted Tubule + Descending Loop of Henle Distal convoluted Tubule + Collecting Duct Ascending Limb + Distal Convoluted Tubule Selective Reabsorption 3 Interstitial Fluid 2 1 H2O H2O H2O H2O Na+ Cl- 3 H2O H2O H2O H2O H2O H2O 4 Urine to Ureter H2O Na+ Cl-
- 40. Flows through Ureter Urinary Bladder Bladderwall is stretched Bladder muscle will contract Urine from the urinary bladder flows into the urethra To the Urine flows out of the body Urine Urea + Other nitrogenous waste (Creatinine, uric acid) + Excess Salts and ions + Excess water
- 41. Topic 8: Chapter11 Part 3 Excretion
- 42. • Maintenance ofa constant water potential in the body • by regulating the water and solute levels in the blood • This is an example of homeostasis (the maintenance of a constant internal environment)
- 43. Absence of osmoregulation- Effects • Blood plasma water potential will be higher than the surrounding cells and tissues • Water will enter the blood cells and surrounding tissue cells by osmosis • Cells will swell and burst Blood plasma too dilute Blood plasma too concentrated • Blood plasma water potential will be lower than the surrounding cells and tissues • Water will leave the blood cells and surrounding tissue cells by osmosis • Cells will shrink and crenate and be unable to perform its metabolic functions
- 44. Kidneys as osmoregulators 1)Hypothalamus • Control centre in the brain which controls body activities (e.g temperature regulation, blood plasma regulation and other involuntary responses in the body) 2) Pituitary gland • Releases hormones (e.g Antidiuretic Hormone) which are transported in the bloodstream to target organs to carry out its effect 3) Antidiuretic Hormones (ADH) • Increases water reabsorption by the kidney tubules back to the bloodstream • Causes vasoconstriction of arterioles Organs/Glands/Hormones involved in osmoregulation
- 45.
- 46. Negative feedback mechanis m 1) Blood Plasma•volume drops • water potential decreases • volume increases • water potential increases Stimulus 2) Receptors in the Hypothalamus Are triggered Are triggered Receptor 3) Pituitary Gland Releases more ADH Releases less ADH Corrective mechanisms which brings about a response 4) Distal Convoluted Tubule and Collecting Duct More permeable to water Less permeable to water 5) Effect: More water reabsorbed back to the bloodstream Less water reabsorbed back to the bloodstream 6) Urine •Becomes more concentrated • Volume decreases • Becomes more dilute • Volume increases Effect 7) Blood Plasma • Volume increases • Water potential increases • Volume decreases • Water potential decreases Water potential returns to normal • Hypothalamus detects the normal blood plasma water potential and decreases the release of ADH by the pituitary gland. • Hypothalamus detects the normal blood plasma water potential and increases the release of ADH by the pituitary gland back to the normal level. Negative feedback to resume normal activity of pituitary gland Water lost through sweat Water gained through drinking
- 47. • Sodium chlorideconcentration in the blood plasma also has an effect on the water potential of the blood plasma. • If sodium chloride content in the blood plasma is high, • Sodium and chloride ion re-absorption from the glomerular filtrate back to the bloodstream will be reduced.
- 48. Kidneys controlling blood pressure BloodVolume Diameter of blood vessels High blood pressure High Narrow Low blood pressure Low Wide How are the kidneys involved in the treatment of high blood pressure? • By the prescription of “Diuretics” • Reduces the reabsorption of water from the distal convoluted tubule and collecting duct back to the blood capillaries • Blood volume decreases, Urine volume increases • Blood pressure decreases
- 49. Topic 8: Chapter11 Part 4Excretion
- 50. - Partially -Permeable -Allows small molecules to pass: • Water • Sugars • Salts • Amino acids • Urea - Long and coiled to increase SA to VR for exchange of substances Consists of: Purpose: • H2O at a preset temperature To maintain an environment as close to the body as possible •Normal concentrations of essential substances as blood: (1)Glucose, (2)Mineral Ions, (3)Amino Acids - To ensure similar osmotic concentrations on both sides of tubing. (Minimize loss of water and essential substances from blood) •Blood and Dialysis Fluid flow in opposite directions - To create and maintain a diffusion gradient •Anti Coagulant Prevent blood from clotting The Dialysis Machine Pump Dialysis Tube Dialysis Fluid Pum p • Smoothen the blood flow • Maintain blood pressure • Maintain speed of blood flow
- 51. Difference in theconcentration between the blood and dialysis fluid Results in Blood is purified Therefore Blood is drawn from an artery in the patient’s arm • Diffusion of urea and waste products down a concentration gradient • Diffusion of excess mineral down a concentration gradient • Movement of excess water out of blood by osmosis • Diffusion of essential mineral salts if lacking in blood Blood to Dialysate Dialysate to Blood Blood is returned to a vein in the patient’s arm
- 52. Difference between theDialysis Machine and the Nephron Dialysis Machine Nephron Filtration does not take place Ultrafiltration occurs at the Bowman’s Capsule The pump keeps the blood pressure constant throughout the tubing Blood is under great pressure No active transport of solutes Active transport of solutes at the proximal and distal convoluted tubule, and loop of Henle. Depends largely on diffusion Depends largely on active transport and osmosis. Minimal diffusion
- 53. Name: …………………………… () Class: ……… Date: ……….……… Diagram of a Kidney
- 54. Diagram of aKidney Tubule (Nephron)
- 55.
Editor's Notes
- #3 4 beakers of urine:Normal urine – white, slight odorDehydrated urine – yellow, stronger odor
- #4 4 beakers of urine:Normal urine – white, slight odorDehydrated urine – yellow, stronger odor
- #9 Hint for eg.1 - One of the chemical processes you have learnt in the previous chapterHint for eg.2 – one of the chemical processes happening in the liver after you have taken a high-protein mealHint for eg.3 – one of the more common processes whereby complex food substances are broken down into simpler food substances