Download The Excretory System - Field Local Schools

The
Excretory
System
Excretion
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The process by which the body
collects and removes wastes
Several organs involved in excretion
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Minor Role
■ Liver
■ Lungs
■ Skin
Major Role
■ Kidneys
■ Large Intestine
■ Bladder
■ Urethra
Liver
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Converts impurities and
poisons in the body to less
harmful substances
Makes urea
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Substance formed from a waste
product of protein breakdown
Some of these substances
become a part of bile
After aiding fat digestion in
the small intestine, bile is
eliminated from the body
during stool
Lungs and Skin
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Lungs
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When you exhale lungs remove
■ Carbon Dioxide
■ Some water
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Why can you see your breathe
when it's cold outside?
Skin
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Sweat glands
■ Water
■ Urea
Kidneys
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2 kidneys, about the size of your fist
Major organ of urinary system
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Filter urea and other wastes from blood
Wastes are eliminated through urine
Maintain water balance
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Urine- Watery fluid produced by kidneys
Hot day (sweating) and little water consumption
■ Kidneys do not release much water
Cool day (no sweat) and drink plenty of water
■ Kidneys release more water
Homeostasis
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Stable internal environment
The Urinary System
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Kidney
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Ureter
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One ureter extends from each kidney. The ureters
carry urine from the kidneys to the bladder.
Bladder
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The kidneys produce urine by filtering urea and
other wastes from the blood.
The bladder is a saclike muscular organ that stores
urine.
Urethra
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Urine travels through the urethra as it exits the
body.
Filtration of Wastes
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Nephrons
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Tiny filtering units that remove
wastes and produce urine
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First both needed
materials and wastes are
filtered from the blood
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Then, the needed materials
are returned to the blood,
and wastes are eliminated
Nephron
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Blood flows from an artery into a
nephron
In the glomerulus, urea, water, glucose
and other materials are filtered from
the blood.
Materials pass through the long
twisting tube, surrounded by blood
vessels.
In the tube, the water and glucose are
reabsorbed into your blood.
Most of the urea and other waste stay
in the tube.
Liquid remaining in the tube is urine.
Keeping Healthy
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Drinking plenty of water
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Medical Checkups
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Can dilute harmful substances
Urine Tests
■ Glucose - diabetes
■ Protein - High blood pressure
Urinary Tract Infections (UTI)
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Bacterial infection of the urethra or bladder
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Bacteria from digestive system come in
contact with the urethra
■ Frequent painful urination
■ Blood in urine
Prompt treatment with antibiotics
Can lead to kidney damage
Kidney Disease
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Kidney Stones
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Pebble like masses that form in the kidney
Very painful
Most pass through excretory system on own
May have to have stone shattered
Low-sodium diet to reduce risk
Kidney Failure
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Result of injury, diabetes, or high blood pressure
Kidneys unable to remove excess waste and fluid
■ Kidney Dialysis
● Machine is used to filter waste and excess fluid from blood
● Tubes carry blood from the body through the machine
● Performed 3 times a week for 3-5 hours
■ Kidney Transplant
● Patients damaged kidney is replaced with a healthy kidney from another person