Download excretion hand outs – urinary system

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EXCRETION
Excretion is the process of removing metabolic wastes.
I. Excretion in Digestive System
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The undigested food is passed into the large intestine for temporary storage.
The undigested food contains a large amount of water and dissolved minerals like iron, calcium,
and magnesium.
Some of the water and the dissolved minerals are absorbed by the walls of the large intestine
and
The remaining solid waste after absorption is called feces. Feces contains bacteria, undigested
food, bile, and the remaining water and minerals.
It is discharged by the large intestine through the rectum. It then leaves our body through the
anus.
II. Excretion in Respiratory System
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Our lungs give off carbon dioxide and water vapor as waste products. These are picked up by
the blood from the cells and brought to the lungs. Then, the lungs give them off as we exhale or
breathe out.
III. Excretion in Integumentary System
 One body system perform this excretion of liquid wastes like water, urea and salt is our
Integumentary System .
 We call these wastes as sweat or perspiration.
 These metabolic wastes move out of the blood vessels through the capillaries into the sweat
glands.
 Each sweat gland has a sweat tube that leads to a small opening in the skin’s surface called pore.
This is where water and salt pass out of the skin.
Human homeostasis refers to the body's ability to physiologically regulate its inner environment to
ensure its stability in response to fluctuations in the outside environment and the weather. In other
words, it is the state of balance in our body.
Homeostatic imbalance will lead to diseases or even death.
Annalou L. Mercado | Handouts – Urinary System
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Our body also excretes liquid waste in the form of urine.
IV. Excretion in Urinary System
The urinary system consists of the kidneys, ureters, urinary bladder and urethra.
1. The kidneys are the major organs of the urinary system. These are two bean-shaped kidneys
found on each side of the spinal column in line with our elbows.
The main function of the kidney is to filter impurities from the blood and regulate the water level and
chemicals in the body.
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The blood, which carries waste materials and other substances, enters the kidneys through the
renal artery.
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Each kidney is composed of about a million nephrons. A nephron is the filtering unit of the
kidney. At the end, most of the water, sugar, vitamins and salts have been reabsorbed
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The substances that are useful to the body are brought back into circulation. Together with the
clean blood, they leave the kidneys through the renal veins.
Excess salts, water, and wastes remains in the tubule and become urine.
Urine enters collecting ducts (tubes) in the medulla
All the blood in the body passes through the kidneys about 20 times every hour.
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The waste material left in the kidneys after filtration is in the urine. It is made up of metabolic wastes
such as excess water, excess salts, and the nitrogenous compounds urea and uric acid. The urine leaves
the kidneys through the ureters.
Uric acid is a chemical created when the body breaks down substances called purines.
Purines are found in some foods and drinks, such as liver, anchovies, mackerel, dried beans and peas,
beer, and wine.
2. The ureters are muscular tubes 10-12 inches long that moves urine from the kidney to the
urinary bladder.
It is a hollow muscular sac organ connected from the ureters.
3. Urinary bladder temporarily store the urine that pass from the two ureters.
When the urinary bladder is full, it contracts and urine moves from the bladder through the
urethra.
Annalou L. Mercado | Handouts – Urinary System
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4. Urethra is a tube that carries urine from bladder to outside of the body.
DIAGRAM OF URINARY SYSTEM
Treatments of Kidney disorders.
Dialysis, a treatment where a machine does the job of the kidneys to filter the blood.
Kidney transplantation means replacement of the failed kidneys with a working kidney from another
person, called a donor. Kidney transplantation is not a complete cure, although many people who
receive a kidney transplant are able to live much as they did before their kidneys failed.
People who receive a transplant must take medication and be monitored by a physician who specializes
in kidney disease nephrologist for the rest of their lives.
Prevention of kidney disorders and kidney failures.
1. Do not delay urination when it is necessary
2. Drink 6-8 glasses of water everyday.
3. Eat a healthy diet. Avoid eating salty foods.
Annalou L. Mercado | Handouts – Urinary System
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4. Avoid drinking soft drinks and alcoholic drinks like beer and wine.
Annalou L. Mercado | Handouts – Urinary System