Transcript Glencoe Biology

Chapter 34 Circulatory, Respiratory, and Excretory Systems
34.3 Excretory System
Functions of the Excretory System
 The excretory system removes toxins and
wastes from the body.
 Regulates the amount of fluid and salts in
the body
 Maintains the pH of the blood
Chapter 34 Circulatory, Respiratory, and Excretory Systems
34.3 Excretory System
Parts of the Excretory
System
 The components
that make up the
excretory system
include the lungs,
skin, and kidneys.
Chapter 34 Circulatory, Respiratory, and Excretory Systems
34.3 Excretory System
The Kidneys
 Bean shaped organs
that filter out wastes,
water, and salts from
the blood
 Renal cortex
 Renal medulla
 Renal pelvis
How it works
• http://glencoe.mcgrawhill.com/olcweb/cgi/pluginpop.cgi?it=swf::550
::400::/sites/dl/free/0078695104/383960/Kidn
ey_Filtration.swf::Kidney%20Filtration
Chapter 34 Circulatory, Respiratory, and Excretory Systems
34.3 Excretory System
Nephron Filtration
 Each kidney contains
approximately one
million filtering units
called nephrons.
 The renal artery
transports nutrients and
wastes to the kidney.
Chapter 34 Circulatory, Respiratory, and Excretory Systems
34.3 Excretory System
Reabsorption and the Formation of Urine
 After the blood is filtered, the “filtrate” flows
through the loop of Henle and the collecting
tubule.
• Glucose and minerals are reabsorbed back
into the capillaries surrounding the renal
tubule.
• Urine (urea and water), which is excess
fluids and wastes, leaves the kidneys
through ducts called the ureters.
animation
• http://www.biologymad.com/resources/kidne
y.swf
• Urine is stored in the urinary bladder and
exits the body through the urethra.
Chapter 34 Circulatory, Respiratory, and Excretory Systems
34.3 Excretory System
Kidney Disorders
Diabetes
Type 1
(children / no
insulin)
Type 2 (adults
/ unresponsive
to insulin)