Kidneys Urinary System

This lesson will increase your knowledge of concepts covered in the following TEKS for biology: 4.b – Investigate and identify cellular processes including homeostasis, permeability, energy production, transportation of molecules, disposal of wastes, function of cellular parts, and synthesis of new molecules 5.c – Sequence the level of organization in multicellular organisms to relate the parts to each other and to the whole 9.a – Compare the structures and functions of different types of biomolecules 10.a – Interpret the functions of systems in organisms 10.b – Compare the interrelationships of organ systems to each other and to the body as a whole 11.a – Identify and describe the relationships between internal feedback mechanisms in the maintenance of homeostasis 11.b – Investigate and identify how organisms respond to external stimuli

Previous Lesson

Diseases of the Endocrine System

Question: Would a person that is somewhat lethargic and overweight be suffering hyperthyroidism (high thyroid production) or hypothyroidism (low thyroid production)? Why?

Negative Feedback (inhibits hormone release)

Hypothyroidism: Low Thyroxine Pituitary Thyroid Stimulating Hormone Thyroid

Treatment: Synthetic thyroid pills

Low Thyroxine Low Metabolism and High Weight

Question: If a person is in an area where a nuclear reactor has released radioactive iodine, why would authorities recommend they take iodine pills? From Harvard Health Letter

Nuclear Reactor Accident Destruction of nuclear reactor Release of radioactive iodine

Taking iodine in pills would Uptake of radioactive iodine by thyroid block uptake of radioactive iodine by thyroid, thereby Radioactive iodine causes preventing mutations ofcancer DNA in thyroid cells Thyroid cancer

Question: Why does a person with Type II diabetes have high blood sugar, and why is this so dangerous to a person’s health?

Type II Diabetes

Based on: Time, November 5, 1990

•Cells of body become resistant to the effects of insulin •Sugar cannot enter cells •Concentrations of sugar in blood become too high

Effects of Uncontrolled Diabetes and High Blood Sugar

Based on: Newsweek, September 4, 2000

Today’s Lesson

Kidneys and the Urinary System

Major Parts of the Machine food, water intake

oxygen intake

Digestive System nutrients, water, salts

Based on: Starr, C., Biology: Concepts and Applications, Brooks/Cole

Respiratory System oxygen

elimination of carbon dioxide

carbon dioxide

Circulatory System

Urinary System water solutes

elimination of food residues

rapid transport to and from all living cells

elimination of excess water salts, wastes

Overview of Lesson • • • •

Formation of urine Urinary system Water balance and alcohol Problems of the urinary tract

When protein is broken down in the body, it results in nitrogenous waste that must be eliminated from the body

Protein

Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Examples of Amino Acids

Based on: Mader, S., Inquiry Into Life, McGraw-Hill

All 20 amino acids have a nitrogen group (NH2). When broken down for energy, the nitrogen group is converted to ammonia (NH3).

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. Based on: Mader, S., Inquiry Into Life

Urea is less toxic than ammonia and can be transported in the blood to the kidney

O H2N - C - NH2 urea

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

Overview of Lesson • Amino acids, ammonia and urea • Urinary system • Water balance and alcohol • Problems of the urinary tract

Urinary System

Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Anatomy of the Kidney

Based on: Mader, S., Inquiry Into Life, McGraw-Hill

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

Nephron

Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Urine moves from the collecting ducts through the kidney pelvis to the ureter

Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Urine moves from the kidneys, through the ureters to the bladder and finally through the urethra

Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Overview of Lesson • Amino acids, ammonia and urea • Urinary system • Water balance and alcohol • Problems of the urinary tract

Regulation of Water Balance Brain monitors water content of blood If low water content, pituitary releases ADH ADH travels in blood to nephron ADH causes more water to move from urine back into blood

Nephron

Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Alcohol consumption suppresses the production of ADH by the pituitary. Why would this result in dehydration and a hangover?

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

Overview of Lesson • Amino acids, ammonia and urea • Urinary system • Water balance and alcohol • Problems of the urinary tract

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

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

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

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

Based on Mayo Clinic Health Letter

Kidney stones cause pain when they pass down the ureters to the bladder and urethra

Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Treatments for Kidney Stones Small stones may pass with no pain Larger stones may pass but cause extreme of pain, requiring a lot pain medication • Stones that are too large to pass may require 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 • •

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

Women may have more UTIs than men because: 1) they have a shorter urethra, allowing quicker access to the bladder 2) the urethral opening is nearer the anus 3) intercourse may result in UTIs in women

Based on: Harvard Medical School Family Health Guide

Symptoms of UTIs • Urge to urinate but only small amount of urine produced • Pain and burning sensation in bladder • Fever • Blood in urine

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

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

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Exam II (Lessons and Labs)