Transcript The Excretory System - Doral Academy High School

The Excretory
System
By: Joseph Martinez
Function of the Excretory System
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Removes harmful substances and waste materials that collect
in the body.
Major Excretory Organs: Skin, Lungs, Liver, Large Intestines,
and Kidney.
Skin Layers and Function
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The Skin is the largest organ and covers the entire body.
Three major layers:
Epidermis, Dermis, and Subcutaneous.
Excretory functionRemoves waste materials absorbed
by the sweat glands through the
process of sweating or perspiration.
Helps to cool down the body.
Excretory Organ of Skin
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Sweat Glands
Found in the Reticular Layer of the Dermis.
Two types of sweat glandsApocrine and Eccrine sweat glands.
Sweat glands function and structureStore and release sweat through the excretory duct on the
surface of the skin during perspiration.
Perspiration increases when exercising, fighting a fever and
when the weather is warm.
Ducts are made up of simple and stratified cuboidal
epithelium.
Sweat glands are made up of columnar epithelium.
Connective tissue surrounds the sweat glands.
Type of Sweat Glands
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Eccrine Sweat glandsStore sweat and release sweat through the excretory duct on to
the surface of the skin from the sweat pore.
Found on most of body.
Greater in thick skin -Palms of the hands and soles of the feet.
Type of Sweat Glands
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Apocrine Sweat GlandsFound under the armpits, and private areas of your body.
Less apocrine glands than eccrine glands.
Apocrine gland stores sweat and releases it out the excretory
duct which opens into the hair follicle.
Secretes a thick substance which has an odor due to the
breakdown of bacteria.
Lungs
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Pair of organs found in the chest.
Remove the waste material carbon
dioxide from the body,
during exhalation.
Process of Breathing
Respiratory center in brain receives message from nerves in
aorta and carotids that oxygen is low in the blood.
Brain signals diaphragm, a muscle below the lungs, and
respiratory muscles to tighten which causes inhalation to occur
when the muscles relax.
Inhalation- Oxygen is breathed in through upper airways
into the lower airways, and then into the gas exchange
airways.
Exhalation – Carbon dioxide is breathed out.
Liver Anatomy
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Largest Gland organ in the body.
Found in chest under right
diaphragm.
Covered by Glisson’s capsule.
Divided into two lobes:
Right lobe and Left lobe.
Excretory function
The liver filters waste from the blood and it is taken to the
large intestine for removal from the body from the anal canal.
Ammonia is broken down by the liver and made into urea
which is taken to the kidney for removal from the body
through the urethra.
Liver – Excretory Function
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Blood supply from the intestines is brought to the liver through
the mesenteric vein, into the portal vein of the liver and into
the sinusoids.
The blood supply includes Amino acids, sugars, small fatty
acids, and harmful substances.
Hepatocytes help breakdown the substances through process
called metabolic detoxification.
Large Intestine
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Cecum, appendix, colon, rectum, and anal canal.
Colon: ascending, transverse, descending, and sigmoid.
Chyme or undigested food is received from the small intestine
into the large intestine which becomes feces.
Feces is made by removing water and adding mucous and is
released from the body through the anal canal or anus.
Kidneys
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Two bean shaped organs located on the back wall of the
abdomen space.
Renal capsule covers both kidneys.
Covered by fat and connective tissue.
Removes waste materials from the body such as urea,
minerals, and excess water called urine.
Nephron
Part of the Kidney that makes urine.
 1.2 million nephrons in each kidney.
Three types of Nephrons
Superficial cortical nephron- Majority of the nephrons goes
into a small portion of the medulla.
Midcorticol nephrons- Have short or long loops.
Juxtamedullary nephrons- Extend into the medulla and
they are responsible for making the urine more
concentrated.
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Urine formation
Blood enters the glomerulus through the afferent arteriole
and leaves through the efferent arteriole.
Urine is formed when the blood is filtered through the clefts
or filtration membranes of the glomerulus.
Urine Excretion
Urine flows from Bowman’s
space into:
 Proximal tubule
 Loop of Henle
 Distal convoluted tubule
 Collecting ducts
The collecting ducts flow into :
 Calyxes- Minor and Major
 Renal pelvis
 Ureter
 Bladder
 Urethra and out of body
Disease of Excretory System
Liver Cirrhosis- A disease that causes the liver to become
tough, hard, and scarred.
 Damage can not be reversed.
 It occurs over a period of years.
 Leading cause of death in United States.
Symptoms Yellowing of the skin and eyes
 Abdomen swelling
 Abdomen pain
 Weight loss
 Weakness.
Causes- Hepatitis, liver obstruction,
and excessive alcohol or drug use.
Liver Cirrhosis
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Treatment- Steroids, drugs to slow the hardening of the
liver, stopping the drug or alcohol use, removing the
obstruction, good nutrition, and rest.
Liver failure- Liver has failed, toxins build up in body,
and the person would require a liver transplantation.
Prevention- Avoid drinking alcohol and taking drugs.
Quiz
1. What are the two types of sweat glands?
2. What waste product does the lungs release?
3. The liver converts ammonia into what waste product?
4. Urine is formed after it is filtered through what part of the
kidney?
5. What is the major cell type found in the liver that is
responsible for breaking down waste?
Answers
1. Apocrine and Eccrine
2. Carbon Dioxide
3. Urea
4.Glomerulus
5.Hepatocyte
Bibliography
Eroschenko, V. P. (2000). Atlas Of Histology (9th Ed.).
Baltimore, MD: Lippincott Williams and Wilkins.
Huether, S. E, &McCance, K. L. (2006).
Pathophysiology: The Basis for Disease in Adults and
Children (5th Ed.). Philadelphia, PA: Elsevier Mosby.
Paulsen, Douglas F. (2000). Histology and Cell Biology (4th Ed.).
New York, NY : McGraw-Hill.
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