Transcript EXCRETION - St. Dominic High School

EXCRETION
 The
removal of the metabolic waste
products produced by cells
 CO2
 H20
 Nitrogen
compounds/proteins
– (ammonia, urea, uric acid)
 Salts – NaCl
 Regulated
by nerves and hormones
Structures

Urinary System

Skin
1. Urinary System:
Homeostasis

maintaining a stable
internal environment:
Fluid inside and
around cells  the
regulation of
chemicals in the blood
is done by the kidney
Human Urinary System

2 Kidneys  filter blood – remove wastes

1 artery brings blood to kidney
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2 Ureters  carries urine to bladder

1 Bladder  urine storage

1 Urethra  takes urine out of the body
Kidney
maintain H20, maintains salt, maintain
blood pH, maintain blood volume, rids
nitrogen waste
 Nephron = function unit of the kidney
(filters)

Feed back mechanism
= blood volume and H20 levels
increase  urine production
will increase

Ex: if you sweat  lose H20  blood
volume decreases  stimulates brain 
sends signal to kidney to keep more H20
 less urine is made
Reabsorption

kidneys filter all the blood
in the body approx. Every
45 minutes

99% of the water that
enters the bowman’s
capsule is reabsorbed
into the blood
Urine formation
All material that remains
after filtration and
reabsorption is called
urine

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made up of urea, excess
salts, and water
stored in the bladder until
released from the body
through the urethra
2. Integumentary System
Skin
 Largest organ in the body! – sense organ
 surrounds
 protects (water proof)
 regulates fluid, salt and urea by sweat
3. Liver
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Important in maintaining homeostasis, makes
proteins
Makes bile
Help digest fats
Stores glucose and vitamins
Detoxifies toxins: ex: alcohol
Breaks down RBC’s
Breaks down amino acids – urea
Disorders
Gout
 Nephritis
 Kidney stones
 Kidney disease
 Kidney transplant
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