Excretion Study Guide
What is Excretion?
Excretion is the process of removing waste products and harmful substances from the body.
Organs Involved in Excretion
- Kidneys: They filter the blood to remove waste products and excess substances, producing urine as a result.
- Lungs: They remove carbon dioxide, a waste product of cellular respiration, during exhalation.
- Skin: Sweat glands in the skin excrete water, salts, and small amounts of urea in the form of sweat.
- Intestines: They excrete solid waste in the form of feces, which contains undigested food and other waste products.
Importance of Excretion
Excretion is essential for maintaining the body's internal balance by eliminating waste products and regulating the levels of substances such as water, salts, and gases.
Common Waste Products
Waste products excreted from the body include urea, carbon dioxide, water, salts, and other metabolic by-products.
Disorders Related to Excretion
Disorders such as kidney stones, urinary tract infections, and kidney failure can affect the excretory system and lead to imbalances in the body.
.◂Science Worksheets and Study Guides Third Grade. Science in our world - 3rd gr.
Study Guide
Science in our world - 3rd gr. 
Worksheet/Answer key
Science in our world - 3rd gr. Worksheet/Answer key
Science in our world - 3rd gr. Worksheet/Answer key
Science in our world - 3rd gr. Worksheet/Answer key
Documenting Data
Worksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyThe resources above cover the following skills:
History and Nature of Science: A student should understand the history and nature of science. A student who meets the content standard should:
Develop an understanding that historical perspectives of scientific explanations demonstrate that scientific knowledge changes over time, building on prior knowledge.
Develop an understanding that scientific knowledge is ongoing and subject to change as new evidence becomes available through experimental and/or observational confirmation(s).