Transcript Excretory system

Alana
Skylar
Yesenia
EXCRETORY SYSTEM
HOW YOUR
EXCRETORY
SYSTEM
WORKS
As your body performs the
many functions that it needs in
order to keep itself alive , it
produces waste. These wastes
are chemicals that are toxic and
that if left alone would seriously
hurt or even kill you. For
example , as your cells brake
down amino acids , they provide
a dangerous toxic known as urea.
The cells of your body excrete
this urea into your blood.
YOUR KIDNEYS
As your blood travels along within your body, it becomes more and more
polluted with urea and other wastes. Eventually the blood enters a special
filter, an organ known as your kidneys. As the blood enters your kidneys it is
cleansed. Your kidneys remove the urea from the blood, sending it to your
bladder for storage in the form of urine, commonly known as pee. It takes
about 45 minutes for your kidneys to completely filter all of the blood in your
body.
YOUR BLADDER
Slowly your bladder fills up with the urine being produced by your kidneys.
Eventually as it becomes full, you will feel a sensation telling your brain that
you need to remove it from your body. Urine leaves your body through the
process of urination, commonly known as peeing.
INTERACTING WITH OTHER
SYSTEMS
The excretory system is a close partner with both the circulatory and
endocrine system. The circulatory system connection is obvious. Blood that
circulates through the body passes through one of the two kidneys. Urea, uric
acid, and water are removed from the blood and most of the water is put back
into the system.
The endocrine system is the major controller of the excretory system. As levels of
compounds and fluids are monitored, kidney function must be constantly altered to
provide the best internal environment for your cells. If you drink too much water,
hormones are released that allow for more urine production. If you are dehydrated,
less urine will be produced. The kidneys are also tied to the endocrine system with the
adrenal gland position on the top of each kidney. The adrenals release adrenaline into
your body.
NASTY DISEASES
While there are many diseases of the excretory system, even more problems can be
created by a malfunctioning set of kidneys. Blood pressure is closely tied to the
amount of fluid in your body. If a kidney does not work and filter properly, blood
pressure can increase to dangerous levels. If that weren't bad enough, urea would
accumulate in your tissues and would slowly poison the cells of your body.
People with malfunctioning kidneys often have to go through a process called dialysis
where they are hooked up to a machine that filters their blood. The machine acts as an
artificial kidney and tries to re-establish normal levels of ions and water in their bodies.
Many people on dialysis are waiting for kidney transplants.
REGULATION OF
EXTRACELLULAR FLUIDS
Excretory systems regulate the chemical composition of body fluids by
removing metabolic wastes and retaining the proper amounts of water, salts,
and nutrients. Components of this system in vertebrates include the kidneys,
liver, lungs, and skin.
Not all animals use the same routes or excrete their wastes the same way
humans do. Excretion applies to metabolic waste products that cross a plasma
membrane. Elimination is the removal of feces.
NITROGEN WASTES
Nitrogen wastes are a by product of protein metabolism. Amino groups are
removed from amino acids prior to energy conversion. The NH2 (amino
group) combines with a hydrogen ion (proton) to form ammonia (NH3).
Ammonia is very toxic and usually is excreted directly by marine animals.
Terrestrial animals usually need to conserve water. Ammonia is converted to
urea, a compound the body can tolerate at higher concentrations than
ammonia. Birds and insects secrete uric acid that they make through large
energy expenditure but little water loss. Amphibians and mammals secrete
urea that they form in their liver. Amino groups are turned into ammonia,
which in turn is converted to urea, dumped into the blood and concentrated
by the kidneys.
WHAT DOES THIS SYSTEM DO?
What do those kidneys do? The regulation process of body fluids and salt
levels is also called osmoregulation. The kidneys act as a filter. Eventually all
of the blood in your body passes through the kidneys and they are able to do
their filtering magic. The kidneys pull harmful molecules out of your blood
.The kidneys are also key players in the hydration (water) levels for your body.
Let's say you are in the desert and you haven't been drinking much water.
Chemical signals are sent to your kidneys to reabsorb as much water as
possible. The result is less urine creation and your body loses less water. A
normal day has you creating about one and a half liters of fluid.bloodstream
and leave the ones that are good for you.
EXCRETION IS NOT
ELIMINATION
The excretory system is very important to your body and only has a few parts.
In a similar way to removing solid waste from your body, you must also get rid
of fluids. You know the results of the excretory system as urine. Urine is the
result of the excretory system balancing the amount of water and salts in your
body. We said the system is small. Your kidneys are the core organs involved
in the excretory system. Related body parts include the ureters, bladder, and
urethra. Once the urine passes through your urethra, that's it, it's out of your
body.
WATER AND SALT BALANCE
The excretory system is responsible for regulating water balance in various body fluids.
Osmoregulation refers to the state aquatic animals are in: they are surrounded by freshwater
and must constantly deal with the influx of water. Animals, such as crabs, have an internal
salt concentration very similar to that of the surrounding ocean. Such animals are known as
osmoconformers, as there is little water transport between the inside of the animal and the
isotonic outside environment.
Marine vertebrates, however, have internal concentrations of salt that are about one-third
of the surrounding seawater. They are said to be osmoregulators. Osmoregulators face two
problems: prevention of water loss from the body and prevention of salts diffusing into the
body. Fish deal with this by passing water out of their tissues through their gills by osmosis
and salt through their gills by active transport. Cartilaginous fish have a greater salt
concentration than seawater, causing water to move into the shark by osmosis; this water is
used for excretion. Freshwater fish must prevent water gain and salt loss. They do not drink
water, and have their skin covered by a thin mucus. Water enters and leaves through the gills
and the fish excretory system produces large amounts of dilute urine
EXCRETORY SYSTEM FUNCTIONS
1.collect water and filter body fluids.
2.Remove and concentrate waste products from body fluids and return other
substances to body fluids as necessary for homeostasis.
3.Eliminate excretory products from the body.
INVERTEBRATE EXCRETORY
ORGANS
Many invertebrates such as flatworms use a nephridium as their excretory
organ. At the end of each blind tubule of the nephridium is a ciliated flame
cell. As fluid passes down the tubule, solutes are reabsorbed and returned to
the body fluids.
VERTEBRATES HAVE PAIRED
KIDNEYS
ALL vertebrates have paired kidneys. Excretion is not the primary function of
kidneys. Kidneys regulate body fluid levels as a primary duty, and remove
wastes as a secondary one
THE HUMAN EXCRETORY
SYSTEM
The urinary system is made-up of the kidneys, ureters, bladder, and urethra.
The nephron, an evolutionary modification of the nephridium, is the kidney's
functional unit. Waste is filtered from the blood and collected as urine in each
kidney. Urine leaves the kidneys by ureters, and collects in the bladder. The
bladder can distend to store urine that eventually leaves through the urethra
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