Download Excretory System

EXCRETORY SYSTEM
KARA ROBBINS
FUNCTION
-
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Get rid of waste
Eliminates useless
byproducts excreted
by cells
Eradicates harmful
chemical build-up
Maintains a steady,
balanced chemical
concentration
KIDNEY
Function
• Filter blood
• Remove waste
• Control body’s fluid
balance
• Regulate balance of
electrolytes
• Create urine which
collects in kidney’s pelvis
• Urine drains down ureters
to bladder
URETERS
Function
• Moves urine from the
kidneys to the bladder
BLADDER
Functions
• Stores urine
• Allows urinating to be
infrequent and voluntary
URETHRA
Function
• Opening the allows
urine to be discharged
from the urinary
bladder
NITROGENOUS WASTE
Ammonia
• Mainly used by aquatic
animals
• Get rid of by excreting in
very dilute solutions
• In soft-body invertebrates,
diffuses across whole body
surface into surrounding
water
• In freshwater fish, helps
maintain Na+
concentrations much higher
than surrounding water
because they switch NH4+
for Na+
NITROGENOUS WASTE
Urea
• Mainly used to terrestrial
animals
• Use urea instead of
ammonia because it
conserves water
• If using ammonia would
have to urinate copiously
because the compound is
too toxic
• Made during the metabolic
by combining ammonia
with carbon dioxide
NITROGENOUS WASTE
Uric Acid
• Excreted by land snails,
birds, insects, and some
reptiles
• Can be excreted as a
precipitate after nearly all
the water has been
reabsorbed by urine
• Animals use uric acid
based on mode of
reproduction and
environmental changes
NEPHRON PROCESS
Filtration
Reabsorption
• occurs as a result of relative
high pressure inside the
capillaries and low pressure in
the Bowman's capsule
• Fine capillaries of the
glomerulus have porous walls
• Through pores flow small
molecules such as water,
glucose, amino acids and
waste products
• Red blood cells and giant
protein molecules too big to
squeeze through these pores
• form of active transport
which takes the useful
substances for the body
from the tubules and
places them back into
the blood filled capillaries
• Remain inside the blood vessels
NEPHRON PROCESS
Secretion
• Process which the
peritubular capillary
transports certain
substances directly into
the fluid of the renal
tubule
• Transported by similar
mechanism as
reabsorption but done
in reverse
Excretion
• Removes the extra
substances
• Transforms into urine
and sent to bladder
out of kidney
DISORDERS
• Urethritis
• Inflammation of the
Urethra
• Caused by infection by
bacteria that enter the
urethra through skin
around the urethra’s
opening
• Symptoms:
• Feeling the frequent or
urgent need to urinate
• Difficulty starting
urination
• Pain during sex
• Discharge from the
urethral opening or
vagina
• In men, blood in urine or
semen
• Increased prevalence in:
• Females in reproductive
years
• Males ages 20-25
• People with many
sexual partners
• High-sexual risk takers
and people with history
of STDs
• Treatment:
• Antibiotics
DISORDERS
• Cystitis
• Inflammation of the
bladder
• Caused by E. Coli or a
bacterial infection
• Symptoms:
• Strong persistent urge to
urinate
• Burning sensation when
urinating
• Blood in urine
• Passy cloudy or strongsmelling urine
• Discomfort in pelvic
area
• Low-grade fever
• Low-pressure in lower
abdomen
• Prevalence is
approximately 1 in every
43 persons
• Treatment:
• Antibiotics