The Excretory System
Adapted from
Perry Glickman
IS THIS A GOOD IDEA?
Organs of the Human Excretory
System
1. Lungs
2. Liver
3. Kidneys
Organs of the Human Excretory
System
1. Lungs – excrete carbon dioxide.
2. Liver – produces urea and bile.
3. Kidneys – Filter blood (remove urea,
adjust salt and water content of urine)
Lungs
Pathway

CO2 from cells
(Respiration)

Carried by blood to
alveoli/lungs

Excreted through
exhalation
Liver
Pathway

Excess amino acids

Carried by blood to liver

Liver forms urea

Sends urea to kidneys
Kidneys
Big Picture!

Blood travels by Aorta to the Renal Artery
Renal Artery takes blood into Kidney
Blood travels through arteries in Medulla
Blood enters capillaries in the Cortex
Blood by capillary enters
Nephron (Filtered)
Blood returns by veins through
Cortex and Medulla
Blood travels back to Vena
Cava to heart
The Finer Details - Nephron
1. Glomerulus – Filtration of waste
2. Bowman’s Capsule – Collects Filtrate
3. Proximal Tubule – Reabsorption of water,
glucose and other non-wastes
4. Loop of Henle – Reabsorption of water
5. Distal Tubule – Secretion of added wastes
Filtrate enters collecting duct for final Excretion
Nephron
Filtering Unit of Kidney

4 Functions
– Filtration (Glomerulus/Bowman’s Capsule)
– Reabsorption (Proximal Tubule/Loop of Henle)
– Secretion (Distal Tubule)
– Excretion (Collecting Duct)
Quiz - Questions
1. What organ filters out nitrogenous waste from the
blood?
2. Where are the kidneys located?
3. What is the filtering unit of the kidney called?
4. Where are the four functions of the nephron?
Quiz
1. The kidney filters out nitrogenous waste from the
blood.
2. The kidneys located in the the lower back.
3. The filtering unit of the kidney is called the
nephron.
4. The filtrate is colleted in the Bowman’s capsule.
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the answer