1. Kidneys and the Urinary System
Contemporary Issue – Kidneys and Hangovers
Lesson Goals
To learn how urine is formed in the body.
To learn how the urinary system rids the body of wastes in urine.
To understand how alcohol disrupts the body’s ability to maintain proper water balance and can cause “hangovers”
To learn about the more common problems associated with the urinary system.
Key Terms;
Nitrogenous waste protein amino acid peptide bond nitrogen group ammonia NH2 NH3 urea kidneys ureters urinary bladder urethra renal artery renal vein renal cortex renal medulla nephron collecting duct renal pelvis pituitary gland antidiuretic hormone (ADH) incontinence stress incontinence urge incontinence overflow incontinence Kegel exercises urinary sphincter prostate gland kidney stone calcium stone uric acid stone cystein stone ureteroscope nephroscope lithotripsy urinary tract infection (UTI) E. coli

2. Major Parts of the Machine
food, water intake
oxygen intake
Based on: Starr, C., Biology: Concepts and Applications, Brooks/Cole
elimination of carbon dioxide
Digestive System
Respiratory System
nutrients,
water,
salts
oxygen
carbon
dioxide
Main Idea(s) of This Slide -
This slide outlines the major components of the human “machine”. Each system will be addressed individually in separate lessons, but it is important to realize that all are interconnected.
This lesson deals with the digestive system.
The major functions of the digestive system include;
Taking organic food molecules into the body.
Mechanically breaking the food into smaller parts.
Chemically breaking down the food into units small enough to cross the epithelium and enter into the body.
Ridding the body of undigested waste products.
Circulatory System
Urinary System
water
solutes
elimination
of food
residues
rapid transport
to and from all
living cells
elimination of
excess water
salts, wastes

3. Overview of Lesson Formation of urine Urinary system
Water balance and alcohol
Problems of the urinary tract
Advance Organizer
The first portion of the lesson will describe where the components of urine come from.
The second portion of the lesson will describe how the urinary system takes the waste materials from the blood to form urine.
The third portion of the lesson will describe how the consumption of alcohol disrupts the urinary systems ability to regulate proper water balance in the body and how this can lead to “hangovers”
The fourth portion of the lesson will describe the more common problems associated with the urinary system.

4. When protein is broken down in the body, it results in nitrogenous waste that must be eliminated from the body
Main Idea(s) of This Slide -
One of the primary waste products found in urine is from the metabolism of proteins. Anytime a protein is broken down, it results in nitrogenous waste which is toxic and must be eliminated from the body.

5. Protein Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Main Idea(s) of This Slide -
It is good to remind students at this time that proteins are large organic molecules made of many amino acids bonded together with peptide bonds. Remind the students that proteins are the end result of transcription and translation of DNA in the cell and that proteins have many functions in the body (I.e. structural, enzymes, hormones).
Based on: Mader, S., Inquiry Into Life, McGraw-Hill

6. Examples of Amino Acids
Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Main Idea(s) of This Slide -
Each amino acid (of the 20 different amino acids found in proteins) have a nitrogen group as part of their structure. When a protein is broken down for energy, the nitrogen groups are converted into ammonia (NH3) which is toxic to the body.
All 20 amino acids have a nitrogen group (NH2). When broken down for energy, the nitrogen group is converted to ammonia (NH3).

7. Circulatory System
Ammonia is converted into urea by the liver. Urea is then transported in the blood to the kidneys where the urea is removed from the blood.
Main Idea(s) of This Slide -
This slide illustrates many parts of the circulatory system that are not necessary for this lesson. Use this illustration to emphasize that nitrogenous waste (ammonia) travels through the bloodstream to the liver where it is converted to urea and then is transported to the kidneys where it may be eliminated from the body.
Since ammonia is produced by all of the cells of the body and ammonia is toxic to body cells, it is important that it gets broken down into a less toxic form. The liver converts ammonia into urea which is less toxic to the body. The urea is then transported through the bloodstream to the kidneys where it can be excreted from the body.
Based on: Mader, S., Inquiry Into Life

8. Urea is less toxic than ammonia and can be transported in the blood to the kidney
H2N - C - NH2
Main Idea(s) of This Slide -
While urea is less toxic to the body than ammonia, it can convert to uric acid and cause pH shifts in the body. Because of this, it is important that the urea gets excreted from the body by the kidneys.
urea

9. Formation of Urine
Amino acids in protein are broken down, resulting in production of ammonia Ammonia is converted to urea in liver Urea travels in blood to kidneys, where removed from blood and incorporated into urine
Main Idea(s) of This Slide -
The formation of urine begins when proteins are broken down by cells throughout the body resulting in ammonia being produced. The ammonia is converted to urea by the liver. The urea is then transported to the kidneys where it is removed from the blood and incorporated into urine.

10. Overview of Lesson Amino acids, ammonia and urea Urinary system
Water balance and alcohol
Problems of the urinary tract
Advance Organizer
This portion of the lesson will discuss the way in which the urinary system removes waste products from the bloodstream and eliminates it from the body.

11. Urinary System Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Main Idea(s) of This Slide -
This slide identifies the major components of the urinary system. The kidneys are located within the muscular wall of the middle back (just below the ribcage). The kidneys are the site of urine formation. The urine formed in the two kidney then travels down the two ureters towards the urinary bladder where it is stored. Urine exits the body by way of the single urethra.
Based on: Mader, S., Inquiry Into Life, McGraw-Hill

12. Anatomy of the Kidney
Main Idea(s) of This Slide -
Blood that is rich in waste products travels towards the kidneys by way of the aorta. The right and left renal artery branches off of the aorta and enters each of the kidneys. Once inside the kidneys, the renal arteries branch many times into smaller and smaller vessels until they finally form millions of capillary beds that are closely associated with microscopic tubes within the kidney called nephrons. The nephron is the small tubule that receives the components of the blood that will ultimately form urine.
Based on: Mader, S., Inquiry Into Life, McGraw-Hill

13. Urine Formation by Nephron
Blood pressure forces water, glucose, amino acids and urea from capillaries into nephron Glucose and amino acids are reabsorbed into blood from nephron Some water is reabsorbed into blood Urine is urea and salt concentrated in water
Main Idea(s) of This Slide -
This slide simplifies the steps in urine formation.
Step 1 - Blood pressure forces materials out of the bloodstream into the nephron. This “filtrate” includes waste materials as well as nutrients, water, hormones, and other valuable materials.
Step 2 - The valuable components of the filtrate such as glucose, amino acids, and water are then reabsorbed back into the bloodstream.
Step 3 - The waste components of the filtrate such as urea and salt remain in the nephron and become concentrated as urine.
Since the waste products are left in the nephron, they ultimately drain from the body.

14. Nephron Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Main Idea(s) of This Slide -
This slide shows a close-up view of a nephron where urine is formed. Waste-filled blood arrives at the nephron and blood pressure forces water, salt, nutrients, and waste products (filtrate) from the blood capillary into the glomerular capsule of the nephron. The blood components that entered the nephron tubule are on a pathway out of the body as they will ultimately travel down the nephron tubule, to the collecting duct, down to the renal pelvis, out of the kidney down the ureter, to the urinary bladder and out of the body by way of the urethra.
Before this happens, it is important to re-absorb the nutrients, water, and other filtrate materials back into the bloodstream. This is accomplished by the capillary network that is wrapped around the nephron tubule. By this process, waste materials are left in the nephron to be drained from the body while valuable components of the filtrate are returned to the bloodstream.
Based on: Mader, S., Inquiry Into Life, McGraw-Hill

15. Urine moves from the collecting ducts through the kidney pelvis to the ureter
Main Idea(s) of This Slide -
After leaving the collecting ducts and traveling into the renal pelvis, the urine then flows out of the kidneys by way of the right and left ureters. The ureters will transport the urine to the urinary bladder.
Based on: Mader, S., Inquiry Into Life, McGraw-Hill

16. Urine moves from the kidneys, through the ureters to the bladder and finally through the urethra
Main Idea(s) of This Slide -
Once the urine has left the kidneys and traveled to the urinary bladder, it can then drain from the bladder out of the body by way of the urethra.
Based on: Mader, S., Inquiry Into Life, McGraw-Hill

17. Overview of Lesson Amino acids, ammonia and urea Urinary system
Water balance and alcohol
Problems of the urinary tract
Advance Organizer
This portion of the lesson will describe how the urinary system maintains water balance in the body and how alcohol can disrupt this function of the kidneys.

18. Regulation of Water Balance
Brain monitors water content of blood If low water content, pituitary releases ADH (antidiuretic hormone) ADH travels in blood to nephron ADH causes more water to move from urine back into blood
Main Idea(s) of This Slide -
The brain constantly monitors water concentration in the bloodstream. If the water concentration drops (dehydration), the pituitary gland releases a hormone called anti-diuretic hormone (ADH). ADH travels through the bloodstream towards the nephron where it elicits a response to combat the dehydration. ADH causes excess water to be reabsorbed from the nephron back into the bloodstream to rehydrate the body.

19. Nephron Based on: Mader, S., Inquiry Into Life, McGraw-Hill
Main Idea(s) of This Slide -
This is an opportunity to remind the students of the parts of the nephron and review each step in the process of urine formation.
Based on: Mader, S., Inquiry Into Life, McGraw-Hill

20. Alcohol consumption suppresses the production of ADH by the pituitary
Alcohol consumption suppresses the production of ADH by the pituitary. Why would this result in dehydration and a hangover?
Main Idea(s) of This Slide -
Alcohol disrupts the ability of the kidneys to maintain water balance by blocking the production of ADH by the pituitary gland. As a reminder, ADH increases the reabsorption of water from the nephron. Without ADH, the nephron retains more water and urine production increases. With excess water being excreted in the urine (rather than being reabsorbed) the body becomes dehydrated. Dehydration is primarily responsible for the feelings associated with “hangovers” after drinking an excess of alcohol.

21. Alcohol Effects
Alcohol suppresses ADH production by the pituitary Without ADH, higher amounts of water stay in the urine Urine with high concentrations of water leaves the body
Main Idea(s) of This Slide -
Again, alcohol suppresses ADH production from the pituitary.
Less ADH means more urine produced.
Excess water leaving the body leads to dehydration.

22. Write on back of sheet
Describe how the following chemicals and/or cells affect the production of urine:
Osmoreceptors- cells in hypothalamus responsible for sensing water pressure in plasma (blood) = control urine output
Aldosterone- hormone in adrenal cortex that reabsorbs sodium ions (salt); this causes water to be reabsorbed as well = decreases urine output
Renin- hormone in kidneys that simulates aldosterone (see above) = decreases urine output

23. ADH- in nephron causes water to be reabsorbed into bloodstream = decreases urine output
Salt- causes cells to retain water = decreases urine output
Water- increases water output (under normal conditions)
Caffeine- acts as a diuretic = increases urine output
Alcohol- surprreses ADH = increases urine output

24. Overview of Lesson Amino acids, ammonia and urea Urinary system
Water balance and alcohol
Problems of the urinary tract
Advance Organizer
This portion of the lesson will discuss the more common problems associated with the urinary system.

25. Incontinence (urine leakage)
More than 10 million Americans experience incontinence
Most do not seek treatment
Treatment can improve or eliminate the problem 90% of the time
Main Idea(s) of This Slide -
Although over 10 million Americans suffer from some sort of incontinence, and 90% of these cases can be improved with treatment, most do not seek treatment.

26. Causes of Incontinence
Stress incontinence: leaking small amounts of urine when coughing, lifting, or exercising
Urge incontinence: the bladder suddenly and unexpectedly contracts and expels urine
Overflow incontinence: bladder cannot completely empty so urine dribbles
Main Idea(s) of This Slide -
There are many causes for incontinence. This slide describes three common reasons for incontinence.
Stress incontinence is when small amounts of urine leak from the urethra when pressure is on the bladder as during coughing, sneezing, or lifting.
Urge incontinence results when the bladder spastically contracts uncontrollably resulting in leakage.
Overflow incontinence occurs when the bladder cannot completely empty at one time and so urine continues to “dribble” from the body.

27. Treatments for Incontinence
Kegel exercises to strengthen the urinary sphincter
Medicines that increase the sphincter’s ability to contract
Surgery to strengthen the pelvic muscles or to lift the bladder
Retrain the bladder to increase its storage capacity (allowing 3-4 hours between urinating)
Drugs to prevent urge incontinence
Surgery to remove part of prostate gland if responsible for overflow incontinence
Main Idea(s) of This Slide -
As stated on the previous slide, 90% of cases of incontinence can be improved with some sort of treatment.
Kegel exercises can strengthen the urinary sphincter which is the circular muscle that holds urine in the urinary bladder.
Medications can increase the ability of the urinary sphincter to contract.
Surgery that lifts the bladder can reduce pressure on the bladder, and thereby, decrease stress incontinence.
Simply resisting the urge to urinate for increasing periods of time can “retrain” the bladder decreasing urge incontinence.
Drugs can relax the urinary bladder’s muscle further reducing urge incontinence.
Surgery can widen the prostatic urethra which often cures overflow incontinence by allowing the bladder to empty completely.
Sphincter may be a new term for students. Make sure students understand that a sphincter is a circular band of muscle that encircles a tube. When the sphincter is contracted it prevents movement through the tube, and when it relaxes, it allows substances to pass. Other notable sphincters are found at either end of the stomach and at the anus.

28. Kidney stones form in the kidney pelvis. There are 4 types of stones.
Calcium stones
(most common)
Uric acid stones
Bacteria caused stones
Cystein stones
Main Idea(s) of This Slide -
Kidney stones are a common problem with the urinary system. Four different types of stones can form due to various causes. Calcium stones, uric acid stones, bacterial caused stones, and cystein stones all form in the pelvis of the kidney and then must travel down the ureters to the bladder and out the urethra.
This is a good opportunity to remind students that perimenopausal and post menopausal women may take calcium supplements to offset risk of osteoporosis, but that this preventative method may increase their risk of kidney stones.
Based on Mayo Clinic Health Letter

29. Kidney stones cause pain when they pass down the ureters to the bladder and urethra
Main Idea(s) of This Slide -
Extreme pain is common as the kidney stones travel down the ureters to the bladder.
Based on: Mader, S., Inquiry Into Life, McGraw-Hill

30. Treatments for Kidney Stones
Small stones may pass with no pain
Larger stones may pass but cause extreme of pain, requiring a lot of pain medication
Stones that are too large to pass may require surgical treatment
Main Idea(s) of This Slide -
Although smaller stones can pass with relatively little or no pain, larger stones often require medical attention. If the stone is small enough to pass, but large enough to cause sever pain, strong pain medication is prescribed. Stones that are too large to pass down the ureters must be handled differently. A ureteroscope can go up into the ureter and remove the stone mechanically. A nephroscope can go up into the kidney and crush the stone into smaller pieces that can pass out of the body. Lastly, shock wave lithotripsy is a treatment that involves submerging the patient in a bath of water that has strong shock waves moving through it. The shock waves pulverize the stones from outside of the body allowing the smaller pieces to pass out of the body.

31. Surgical treatment including:
using a ureteroscope to go up and snare the stone
using a nephroscope to crush the stone and retrieve it
using shock wave lithotripsy where a person is submerged in water containing shock waves to pulverize the stones

32. Urinary Tract Infection (UTI)
Second most common infection following respiratory infections
UTI occur when bacteria (E. coli) from the digestive tract get into the opening of the urinary tract and multiply
Bacteria first infect the urethra, then move to the bladder and finally to the kidneys
UTI tend to occur more in women than men
Main Idea(s) of This Slide -
Urinary tract infections (UTI) are one of the most common type of infections in humans (second only to respiratory infections). UTI can occur when bacteria (commonly E. coli from the digestive tract) gets into the urethral opening and travels up the urethra towards the bladder. If the infection progresses, the bacteria can reach up into the kidneys causing damage to the nephrons.
UTI are much more common in women due to the proximity of the urethral opening to the anus and the much shorter urethra found in women. This is a good time to remind students of male and female anatomy that was presented during the early lessons.

33. Women may have more UTIs than men because:
they have a shorter urethra, allowing quicker access to the bladder
the urethral opening is nearer the anus
intercourse may result in UTIs in women
Main Idea(s) of This Slide -
Women experience UTI’s much more commonly than men for several reasons.
Women have much shorter urethras than do men so the bacteria have a much shorter distance to travel in order to reach the bladder or kidneys.
Their urethral opening is much closer to the anus (where the infectious bacteria often come from).
Sexual intercourse often introduces bacteria into the urethral opening.
It is important for women to pay close attention to preventing bacteria from entering the external urethral opening. Several preventative steps include regular bathing, requiring sex partners to bathe before sexual intercourse, and urinating after sexual intercourse (in order to “flush out” any bacteria that may have been introduced into the urethra).
Based on: Harvard Medical School Family Health Guide

34. Symptoms of UTIs
Urge to urinate but only small amount of urine produced
Pain and burning sensation in bladder
Fever
Blood in urine
Main Idea(s) of This Slide -
The common symptoms of a UTI are;
Urge to urinate, but only a small amount released
Pain and burning in the bladder and during urination
Fever
Blood in urine

35. Diagnosis and Treatment
Doctors check urine for white and red blood cells and bacteria
Bacteria grown in culture to determine which antibiotic will work the best
UTIs are treated with antibiotics and are often cured within 1 or 2 days
Main Idea(s) of This Slide -
If the symptoms of a UTI are felt, a doctor will take a urine sample and test for red and white blood cells as well as bacteria. After growing the bacteria in a culture, the doctor will then choose which antibiotic will most effectively treat the infection. Usually, symptoms of UTI’s are relieved very quickly and the infections are cured within a few days.

36. Kidney Disease and Ethnicity
Kidney disease 26 million Americans
African Americans five times likely to require dialysis or kidney transplant
Possible reasons
Lack of health care
Genetic component
Diabetes
Hypertension
Main Idea(s) of This Slide -
Kidney disease occurs when the kidneys fail to remove wastes from the body. Waste products build up in the blood and can complicate high blood pressure and result in anemia, poor nutritional healthy and nerve damage. Risks for heart disease and disease of the blood vessels are also increased.
Chronic kidney disease are linked to diabetes, high blood pressure and other disorders.
More than 26 million Americans have kidney disease. Persistent proteinuria- protein in the urine means Chronic Kidney Disease is present.
Health: Kidney Troubles in Black and White
African Americans five times more likely to require dialysis or transplantation
Kidneys are not more prone, rates of early kidney disease are similar.
African Americans are far more likely to progress to severe disease.
Reasons?
Health care
Genetic component
Complications of diabetes
Complications of hypertension