Excretory System
By Matthew Yankowitz
The function of the excretory system is the
removal of wastes from the body. The
excretory system is made up of the kidneys, urinary bladder, ureters, and a
urethra. The excretory system is illustrated
throughout this page using found diagrams and pictures taken during our
dissection.
The pig has two kidneys, each located in the dorsal region of the pig’s abdominal cavity. Their main functions are the maintenance of water and electrolyte balance, and the filtering of blood of wastes. These wastes are in the form of urine, which is excreted by the kidneys to the bladder.
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A pair of
kidneys |
A pair of
kidneys |
A cut kidney,
with the visible medulla and cortex |
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One kidney, with
a ureter attached |
A cut kidney,
with the visible medulla and cortex, and a ureter coming out the
middle |
A cut kidney |
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A cut
kidney |
A further
dissected kidney |
A
further dissected kidney |
The pig’s urinary bladder is an elastic, muscular sac which collects urine from the kidneys for excretion. Its elasticity allows it to expand and contract. When empty, the bladder is contracted, the muscle on its inside is folded. When full, the muscle unfolds, allowing for its expansion. It can be found in dorsal region of the pig’s abdominal cavity.
The ureters are tubes leading from the kidneys to the bladder. The urethra directs urine from the bladder to outside the body.
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A bladder with
attached arteries |
A bladder
without the arteries |
An inside-out
bladder |
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A urinary
bladder |
A half-open
bladder, with stretchy muscle inside |
A completely
out-turned bladder |
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A stretchy,
out-turned bladder |
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Resources
http://library.thinkquest.org/10348/find/content/excretory.html
http://www.answers.com/kidney&r=67
Class
dissection pictures