Week 5: Digestive and Excretory Unit 6: Human Body Week 5: Digestive and Excretory

SC Standards Standard 7.L.3: The student will demonstrate an understanding of how the levels of organization within organisms support the essential functions of life. 7.L.3B Conceptual Understanding: Multicellular organisms (including humans) are complex systems with specialized cells that perform specific functions. Organs and organ systems are composed of cells that function to serve the needs of cells which in turn serve the needs of the organism. 7.L.3B.2: Construct explanations for how systems in the human body (including circulatory, respiratory, digestive, excretory, nervous, and musculoskeletal systems) work together to support the essential life functions of the body. S.1A.6: Construct explanations of phenomena using (1) primary or secondary scientific evidence and models, (2) conclusions from scientific investigations, (3) predictions based on observations and measurements, or (4) data communicated in graphs, tables, or diagrams

SC Objectives It is essential that students construct explanations for how systems in the human body (including circulatory, respiratory, digestive, excretory, nervous, and musculoskeletal systems) work together to support the essential life functions of the body. It is essential for the student to be able to understand the basic form and function of each of the following body systems as well as the interrelationships that occur between systems to ensure the survival of the organism.

Bell Work Monday What are 4 things that are part of the Cardiovascular System? What is the purpose of the Respiratory System? What is the difference between heart rate and blood pressure?

Review Questions (Monday) What is the function of the respiratory system? What are the major organs of the respiratory system? What is the function of the cardiovascular system?

Bell Work (Tuesday) What are the two types of blood? What is blood volume and why is it important? What are the alveoli and what are their functions?

Overview of the Digestive System The main functions of the digestive system are to break down foods into nutrients that can be used by the body absorb nutrients that are necessary for energy, growth, and maintenance rid the body of solid wastes.

Two Types of Organs The organs of the digestive system can be divided into two categories, primary and secondary. Primary organs have a direct role in digesting food and come into physical contact with the food. Secondary organs support the process of digestion by secreting digestive juices. Food does not pass through secondary organs.

Upper Primary Organs Mouth: begins to break down food into smaller pieces through mechanical digestion; saliva in the mouth starts the process of chemical digestion. Esophagus: transport tube that carries chewed food to the stomach.

Middle Primary Organs Stomach: Continues the process of mechanical digestion; and secretes gastric juices that continue the process of chemical digestion started in the mouth. Small intestines: The organ where most of the chemical digestion of food takes place Nutrients from food are also absorbed into the bloodstream through the small intestines. Large intestines The organ where water from the food is absorbed into the bloodstream Prepares the remaining undigested food for elimination from the body

Lower Primary Organs Rectum: A short tube that stores solid waste until it is eliminated from the body. Anus: Opening where solid waste is eliminated

Secondary Organs The secondary organs of the digestive system are: Liver: Produces bile Bile is used by the body to break up fat. The liver filters blood. Gallbladder: Stores bile produced by the liver. Pancreas: Produces digestive juices that help to further break down the food in the small intestine.

Organs of the Digestive System

Review Question What are the primary organs for the digestive system? Name and describe 3 of them. What are the secondary organs of the digestive system? Name and describe 3 of them.

Lesson 9: Excretory System Unit 6: Human Body Lesson 9: Excretory System

Bell Work Name and describe the function of 3 primary organs of the digestive system? Describe the function of the heart and the valves. What is the function of the lungs?

Functions of the Excretory System The main function of the excretory system is to filter cellular wastes toxins (chemicals that could be poisonous to the body) excess water that result from cellular respiration

Main Organs Kidneys: the two kidneys get rid of urea, excess water, and some other waste materials released by the cells. These are eliminated as urine. Ureters: Tubes which connect each kidney to the bladder.

Main Organs Continued Bladder: A saclike muscular organ which stores urine until it is released from the body. Urethra: Tube through which urine passes before it is removed from the body.

Diagram

Review Questions What type of muscles are found in the heart? What type of muscles are found in the stomach, small intestine, and blood vessels? What is the function of the excretory system?