Transcript The Excretory System - ESC-2

The Excretory
System
Excretory System
Facts!
• As cells perform the chemical activities
that keep you alive, waste products
such as carbon dioxide and ammonia
are formed.
• To maintain homeostasis and keep you
healthy, they must be removed.
Functions of Excretory System
• Rids blood of wastes like urea, ammonia,
and carbon dioxide.
• Controls blood volume by removing extra
water produced by cells.
• Balances salts and water so cells can
function properly.
Excretory System
• Organs
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kidneys
ureters
urinary bladder
urethra
lungs
skin
lungs
sweat glands
Organs of Excretion
There are other organs in our body that can
excrete substances
• lungs – carbon dioxide and water vapor
are exhaled
• skin – excess salt is released when you
sweat.
Organs of the Excretory System
• kidneys –filters blood
and eliminates cellular
waste. Returns salt,
ions and glucose to
the blood.
Organs of the Excretory System
Organs of the Excretory System
• ureters – two
narrow tubes that
urine flows through
to get to the
bladder.
Organs of the Excretory System
• urinary bladder –
sac-like muscular
organ that stores
urine.
Organs of the Excretory System
• urethra – tube that urine travels to leave
the body.
The Filtering Process
• Your cells have to maintain a certain level
of water and salt to function properly.
Vocabulary
Word!
• nephrons – tiny structures
that filter blood in the
kidneys.
Filtering Out Waste
• After entering the kidneys, blood flows
through smaller and smaller arteries.
• The blood eventually reaches a cluster of
capillaries called nephrons.
• In the nephron, urea, glucose, other
chemicals, and some water move out of
the blood and into the nephron.
Filtering Out Waste
• Blood cells and proteins stay in the
capillaries.
• Glucose, water, and small amounts of
other substances are reabsorbed into the
blood stream.
• Urea and other wastes stay in the
nephrons.
Filtering Out Waste
• The liquid left in the tube is urine.
• The urine moves down the ureters and
into the bladder.
• When the bladder is full, you feel the urge
to urinate.
Filtering Summary
• 1. both wastes and needed materials are
filtered out of the blood
• 2. the needed material is returned to the
blood
• 3. the waste is eliminated in the urine
Analyzing Urine
• Some medical problems can be found by
testing urine
• Glucose – diabetes
• Protein – kidney failure
• Drug residue – drug abuse
Body systems that work
with the excretory system;
• circulatory system to carry waste
to the kidneys.
• respiratory system to remove
carbon dioxide.
• integumentary system to remove
salt.
Comparing Cells to Body
What cell organelle helps to break down
waste?
lysosomes
What cell organelle packages waste?
golgi body