Download the excretory system

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HIDDEN THROUGHOUT YOUR BODY ARE
DANGEROUS POISONS THAT MUST BE
REMOVED IN ORDER FOR YOU TO
SURVIVE. THE PROCESS OF EXCRETION
INVOLVES FINDING AND REMOVING
WASTE MATERIALS PRODUCED BY THE
BODY.
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THERE ARE SEVERAL ORGANS THAT WORK
TOGETHER IN THE EXCRETORY SYSTEM INCLUDING
THE KIDNEYS, URETER, BLADDER, AND URETHA.
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BLOOD IS SUPPLIED TO THE KIDNEYS BY THE
RENAL ARTERY. ONCE THE BLOOD ENTERS
THE KIDNEYS, THE FILTERING PROCESS
BEGINS. WATER AND OTHER WASTE
PRODUCTS ARE REMOVED FROM THE
BLOOD BY MICROSCOPIC STRUCTURES
WITHIN THE KIDNEYS CALLED NEPHRONS.
EACH KIDNEY CONTAINS OVER ONE
MILLION NEPHRONS. THIS ORGAN IS ABOUT
THE SIZE OF A HUMAN FIST.
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THE WASTE FILTERED FROM THE BLOOD
FORMS A LIQUID CALLED URINE. THE
KIDNEYS FUNNEL THE URINE INTO THE
BLADDER ALONG TWO SEPARATE TUBES
CALLED URETERS. URETERS ARE TUBES
MADE OF SMOOTH MUSCLE FIBERS THAT
PROPEL URINE FROM THE KIDNEYS TO THE
BLADDER. IN ADULTS, URETERS ARE
USUALLY 25-30 CM LONG AND 3-4 MM IN
DIAMETER.
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FROM THE URETERS, THE URINE IS FUNNELED
INTO THE BLADDER. THE BLADDER STORES
THE URINE UNTIL MUSCULAR CONTRACTIONS
FORCE THE URINE OUT OF THE BODY
THROUGH THE URETHA. EACH DAY, YOUR
KIDNEYS PRODUCE ABOUT 1.5 LITERS OF
URINE. ALL OF IT NEEDS TO BE REMOVED
FROM YOUR SYSTEM. WHEN EMPTY, THE
BLADDER IS ABOUT THE SIZE AND SHAPE OF
A PEAR.
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THE RENAL VEINS DRAIN THE KIDNEYS
AND CARRY THE FILTERED BLOOD
TOWARDS THE HEART. THEY CONNECT
THE KIDNEY TO THE INFERIOR VENA
CAVA. BECAUSE THE INFERIOR VENA
CAVA IS ON THE RIGHT HALF OF THE
BODY, THE LEFT RENAL VEIN IS GENERALLY
THE LONGER OF THE TWO.
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ALL BLOOD THAT CIRCULATES
THROUGHOUT THE BODY PASSES
THROUGH ONE OF THE TWO KIDNEYS. THE
EXCRETORY SYSTEM CLEANS THE BLOOD
OF WASTE PRODUCTS PRODUCED BY THE
SKELETAL, MUSCULAR, DIGESTIVE,
RESPIRATORY, CIRCULATORY, AND
NERVOUS SYSTEMS.
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http://www.biology4kids/files/systems
excretory.html
http://www.cic-carcas.org/departments
http://www.fi.edu./learn/heart/systems
http://www.teachnet.com/lessonplans/scie
nce/biology/theexcretorysystem
http://www.webmd.com/urinary/bladder
http://www.wikipedia.org/wiki/renalartery