1. The Urinary System Waste Removal System

2. The Urinary System The major function of the urinary system is to remove metabolic waste from blood and direct them out of the blood. The major function of the urinary system is to remove metabolic waste from blood and direct them out of the blood. The major organs of the urinary system are the kidneys, ureters, urinary bladder and urethera. The major organs of the urinary system are the kidneys, ureters, urinary bladder and urethera.

3. Urinary Organs

4. The kidneys are located high on the posterior abdominal wall. The kidneys are located high on the posterior abdominal wall. The right kidney lies just below the left. The right kidney lies just below the left.

5. Urinary Organs The structure of the kidney is divided into the: The structure of the kidney is divided into the: –Renal capsule, tough outer shell of the kidney –Renal cortex, outer portion of the kidney –Renal medulla, inner portion of the kidney –Renal pyramids, cone shaped masses of tissue in renal medulla

6. Urinary Organs Kidney structure (cont.) Kidney structure (cont.) –Ureter, the tube leading away from the kidneys –Renal pelvis, superior end of the ureter which is expanded to form a funnel shape –Major calyces, division of renal pelvis –Minor calyces, division of major calyces

7. Urinary Organs The function of the kidneys is to remove metabolic waste from the blood. The function of the kidneys is to remove metabolic waste from the blood. They also regulate RBC formation with the hormone erythropoietin. They also regulate RBC formation with the hormone erythropoietin. They regulate blood pressure with the hormone renin. They regulate blood pressure with the hormone renin. They regulate blood volume with the hormone ADH. They regulate blood volume with the hormone ADH. They also control blood composition and blood pH. They also control blood composition and blood pH.

8. Urinary Organs The functional unit of the kidney is called the nephron. The functional unit of the kidney is called the nephron. –A nephron is made up of a renal corpuscle and a renal tubule

9. Urinary Organs A renal corpuscle is a glomerulus within a Bowman’s capsule. A renal corpuscle is a glomerulus within a Bowman’s capsule. –The glomerulus is the filtration unit. –The Bowman’s capsule sac of tissue surrounding the glomerulus.

10. Urinary Organs The renal tubule is tube made up of the loop of Henle. The renal tubule is tube made up of the loop of Henle. –The loop of Henle is a tube in which water and solute flow to regulate blood levels.

11. Urinary Organs There are three major steps in the process of urine formation: There are three major steps in the process of urine formation: 1.) Glomerular filtration 2.) Tubular reabsorption 3.) Tubular secretion

12. Urinary Organs Glomerular filtration is when water and dissolved particles are filtered out of the blood into the Bowman’s capsules. Glomerular filtration is when water and dissolved particles are filtered out of the blood into the Bowman’s capsules. This filtration is due to the force of hydrostatic pressure. This filtration is due to the force of hydrostatic pressure. –Hydrostatic pressure is the pressure felt by the fluid because of the weight of the fluid above it. –The magnitude of the hydrostatic pressure is determined by the bodies blood pressure and blood volume.

13. Urinary Organs Tubular reabsorption is the process by which substances are transported from the glomerular filtrate to blood in the peritubular caps. Tubular reabsorption is the process by which substances are transported from the glomerular filtrate to blood in the peritubular caps. Most of this reabsorption takes place by active transport. Most of this reabsorption takes place by active transport. The reabsorbed substances include glucose, amino acids, water, ions and other minor substances. The reabsorbed substances include glucose, amino acids, water, ions and other minor substances.

14. Urinary Organs Tubular secretion is the process by which substances are transported from the blood in the peritubular caps. Tubular secretion is the process by which substances are transported from the blood in the peritubular caps. This process maintains ion concentrations in the blood. This process maintains ion concentrations in the blood.

15. Urinary Organs The hormone anti-diuretic hormone (ADH) promotes the reabsorption of water. The hormone anti-diuretic hormone (ADH) promotes the reabsorption of water. This negative feedback loop is responsible for preventing dehydration. This negative feedback loop is responsible for preventing dehydration.

16. Urinary Organs The wastes that make up urine are: The wastes that make up urine are: –Urea, which is formed during amino acid metabolism –Uric acid, which is formed during nucleotide metabolism

17. Urinary Organs Urine is composed of 95% water and 5% other components including: Urine is composed of 95% water and 5% other components including: –Urea –Uric acid –Trace amino acids –Electrolytes

18. Urinary Organs The ureters are small tubes that carry urine from each kidney to the urinary bladder for storage. The ureters are small tubes that carry urine from each kidney to the urinary bladder for storage. They are 25 – 39cm in length. They are 25 – 39cm in length. They are made up of three layers: They are made up of three layers: 1.) Mucosa layer, inner 2.) Muscularis layer, middle layer of smooth muscle 3.) Serosa layer, outer

19. Urinary Organs The urinary bladder is located in the pelvic cavity. The urinary bladder is located in the pelvic cavity. It is a hollow, distensible and muscular organ. It is a hollow, distensible and muscular organ. It is made up of three layers of smooth muscle. It is made up of three layers of smooth muscle. It functions in the storage of urine. It functions in the storage of urine.

20. Urinary Organs The urethra is a tube that carries urine from the urinary bladder to the outside. The urethra is a tube that carries urine from the urinary bladder to the outside. Length depends on sex, females have a urethra approximately 4cm long where as males on average have a 20cm long urethra. Length depends on sex, females have a urethra approximately 4cm long where as males on average have a 20cm long urethra. Micturition is the process of expelling urine from the urinary bladder. Micturition is the process of expelling urine from the urinary bladder.

21. Life Span Changes As a person ages the kidneys become grainy and scarred. As a person ages the kidneys become grainy and scarred. Reabsorption can significantly decrease causing frequent urination. Reabsorption can significantly decrease causing frequent urination. The elasticity of the urinary organs decreases also causing frequent urination. The elasticity of the urinary organs decreases also causing frequent urination.

22. Common Urinary Disorders Kidney stones are concentrations of calcium salts and uric acid. Kidney stones are concentrations of calcium salts and uric acid. They form small stones which can block the ureters. They form small stones which can block the ureters. If the ureters are blocked pressure can backup into the kidney causing swelling and severe pain. If the ureters are blocked pressure can backup into the kidney causing swelling and severe pain.

23. Common Urinary Disorders Proteinuria is excess levels of protein in the urine. Proteinuria is excess levels of protein in the urine. Proteinuria was at one time considered a sure sign of kidney damage. Proteinuria was at one time considered a sure sign of kidney damage. It has since been discovered that somewhat high protein levels among healthy active young adults is normal. It has since been discovered that somewhat high protein levels among healthy active young adults is normal.

24. Common Urinary Disorders Urinary tract infections (UTI) are an inflammatory process occurring in the kidney, ureter, bladder, or adjacent structures that occurs when microorganisms (usually Escherichia coli) enter through the urethra. Urinary tract infections (UTI) are an inflammatory process occurring in the kidney, ureter, bladder, or adjacent structures that occurs when microorganisms (usually Escherichia coli) enter through the urethra. The infection causes inflammation and in turn discomfort. The infection causes inflammation and in turn discomfort. They are usually quickly and easily treated by the use of a broad spectrum antibiotic. They are usually quickly and easily treated by the use of a broad spectrum antibiotic.