Section 3: Excretory System
The kidneys maintain homeostasis by removing wastes and
excess water from the body and by maintaining the pH of blood.
K
What I Know
W
What I Want to Find Out
L
What I Learned
Essential Questions
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What is the function of the kidney in the body?
What are the steps of the excretion of wastes from the Bowman’s capsule to
the urethra?
What is the difference between filtration and reabsorption in the kidneys?
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Excretory System
Vocabulary
Review
New
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pH
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kidney
urea
Excretory System
17-1-23
CH-34.3-EXCRETORY SYSTEM
• L.O- To analyse the structure and function of
human excretory system and nephron
[Pg.1005-1006]
Parts of the Excretory
System
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The excretory system removes
toxins and wastes from the body.
Regulates the amount of fluid and
salts in the body.[osmoregulation]
Maintains the pH of the blood
The components that make up the
excretory system include the lungs,
skin, and kidneys.
Tim Fuller
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Excretory System
The Kidneys
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Bean shaped organs that
filter out wastes, water,
and salts from the blood
Renal cortex
Renal medulla
Renal pelvis
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Excretory System
The Kidneys
Nephron Filtration
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Each kidney contains
approximately one million
filtering units called
nephrons.
The renal artery
transports nutrients and
wastes to the kidney.
Urea is nitrogenous
waste product.
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Excretory System
Kidney Filtration
Go to your ConnectEd resources to play Animation: Kidney
Filtration.
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Excretory System
21-9-21
CH-34.3-EXCRETORY SYSTEM
• L.O- To describe steps in urine formation and
kidney disorders [ Pg. 1006-1007]
The Kidneys
Nephron Filtration
•
•
•
Each kidney contains
approximately one million
filtering units called
nephrons.
The renal artery
transports nutrients and
wastes to the kidney.
Urea is nitrogenous
waste product.
Copyright © McGraw-Hill Education
Excretory System
The Kidneys1.Ultrafiltration-Blood is filtered through the glomerulus into Bowman’s capsule,
due to high blood pressure in glomerulus. [Ultrafiltration]
The filtrate moves through convoluted tubules, loop of Henle and collecting tubule[
called together as renal tubule]
2.Reabsorption and the Formation of Urine
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Glucose, some water and minerals are reabsorbed back into the
capillaries surrounding the renal tubule.
Urine, which is excess fluids and wastes[like urea and excess salts],
leaves the kidneys through ducts called the ureters.
Urine is stored in the urinary bladder and exits the body through the
urethra.
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Excretory System
Kidney Disorders
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Infections
Nephritis-inflammation of the glomeruli
Kidney stones-crystallized solid that forms in the kidney
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Excretory System
Common Excretory Disorders
Copyright © McGraw-Hill Education
Excretory System
Review
Essential Questions
•
•
•
What is the function of the kidney in the body?
What are the steps of the excretion of wastes from the Bowman’s capsule to
the urethra?
What is the difference between filtration and reabsorption in the kidneys?
Vocabulary
• kidney
• urea
Copyright © McGraw-Hill Education
Excretory System