Download Excretion

Excretion
•Excretion is the process by which waste
products of metabolism and other non-useful
materials are eliminated from an organism
• Organs include:
– Lungs
– Liver
– Sweat Glands
– Kidneys
– Bladder
Lungs
• CO2 diffuses from the capillaries into the
alveoli of the lungs
• Excess water from AEROBIC respiration is also
brought to the lungs
• Both are removed from the body by the
process of exhalation
Liver
• Disposal of Hemoglobin
– Old Red Blood Cells are destroyed
– Hemoglobin is released which is then turned into
bile pigments
– These pigments are stored in the gall bladder and
are later released into the small intestine where
they can be removed from the body through feces
• Disposal of Nitrogenous wastes
– Nitrogenous compounds are broken down and
turned into UREA
– Urea is then absorbed into the blood system and
transported to the kidneys
– Removed through URINARY SYSTEM
Sweat Glands
• Structure
– Small, coiled tubular glands in DERMIS of skin
– Ducts lead to openings in the epidermis called
PORES
• Function
– Water, salts, and urea diffuse into glands from
blood
– Eliminated from body, SWEAT
– PERSPIRATION: The formation of sweat
• Temperature Regulation
– Acts as a way of controlling our body temps
– Sweat absorbs heat and carries the heat to the
outside of our bodies
– Sweat evaporates into the air, thereby cooling the
body
– Used in maintenance of homeostasis
Kidneys
• Function
– Remove UREA from blood
– Excrete nitrogenous wastes
– Regulate concentration of substances in the blood
Nephron
• Functional unit of the kidney
• Arteries turn into small balls of capillaries
–GLOMERULUS
• Glomerulus enclosed in cup like structure
known as the BOWMAN’S CAPSULE
• Extending from Bowman’s Capsule is a long,
coiled tubule surrounded by capillaries
• Filtration
– Water, Salts, Urea, Amino Acids, and Glucose
diffuse out of blood in the Glomerulus and into
Bowman’s Capsule
• Re-absorption
– After leaving Bowman’s Capsule, some of the
water, salts, etc. enter back into the bloodstream
through ACTIVE TRANSPORT
• URINE , made up of water, salts, and urea, is
left over and travels to the URETER
• The Urine travels through the Ureter into the
BLADDER
– Stores urine
• Sphincter muscle leads to URETHRA
– Leads outside the body
Diseases of the Excretory System
• Kidney Disease
– Variety of conditions where kidneys and nephrons
are unable to do their jobs effectively
– Unable to remove nitrogenous wastes
– Can be caused by a high protein diet
• Gout
– Form of arthritis
– Uric Acid crystals form and float in bloodstream
– Get deposited in joints (Big Toe)
– Cause pain and stiffness