Body Systems Demonstrations

See also: Dissections

Body systems are groups of organs that work together to perform specific functions in living organisms. This category introduces the main systems such as circulatory, respiratory, digestive, and nervous, and shows how they interact to maintain life. Understanding body systems helps explain health, disease, and the interconnected nature of biological processes.

Demonstration	Materials	Difficulty	Safety	Summary
Bell Jar Breathing Model	★★☆	★★☆	★☆☆	A bell jar model can be used to demonstrate how breathing works by showing how changes in chest cavity volume and pressure cause air to move in and out of the lungs. Pulling on a rubber sheet represents diaphragm contraction (inhalation), while pushing it up represents diaphragm relaxation (exhalation).
Blood Flow and Artery Constriction	★☆☆	★★☆	★☆☆	This demonstration models how artery size affects blood flow. Water dyed red to represent blood flows through tubes of different diameters, showing that narrower arteries restrict flow and increase resistance, similar to what happens in the human body when vessels are constricted.
Blood Model in a Bottle	★☆☆	★☆☆	★☆☆	This activity creates a model of blood inside a bottle using food coloring, cereals, marshmallows, and pom poms to represent plasma, red blood cells, white blood cells, and platelets. It helps students visualize the different components of blood and their functions.
Build a Model Lung	★☆☆	★☆☆	★☆☆	This demonstration uses balloons, straws, and a plastic bottle to create a working model of the lungs and diaphragm. Pulling on the bottom balloon increases the chest cavity volume, causing the lung balloons to inflate, while releasing it decreases the volume, causing them to deflate.
Carbon Dioxide in Breath	★★☆	★★☆	★★☆	This experiment compares the carbon dioxide content of inhaled and exhaled air by passing a person’s breath through tubes into test solutions. Limewater is used to detect carbon dioxide, showing the difference between inhaled and exhaled air.
DIY Robot Hand	★☆☆	★☆☆	★☆☆	This activity demonstrates how tendons work in the human hand by creating a cardboard model where strings act like tendons and beads simulate finger control. Pulling the strings bends the cardboard fingers, showing how muscles and tendons work together to create movement.
Easy Heart Pump Model	★☆☆	★☆☆	★☆☆	This demonstration uses a balloon, jar, and straws to create a simple model that mimics how the heart pumps blood through the body. The balloon acts as the heart muscle, and the straws represent blood vessels, showing one-way flow similar to valves in the heart.
Fetal Pig Dissection	★★★	★★☆	★★☆	Students explore a fetal pig to identify major external features and dissect internal systems (respiratory, cardiovascular, digestive, urinary, and reproductive). Colored latex in vessels and stepwise incisions help reveal organ relationships and fetal circulatory adaptations.
Frog Dissection	★★★	★★☆	★★☆	Students examine a preserved frog to identify major external features and internal organs of the digestive, respiratory, circulatory, and excretory systems. The activity builds skill with dissection tools while linking structure to function across body systems.
Heart Rate Recovery	★☆☆	★☆☆	★☆☆	Heart rate recovery (HRR) is the decrease in heart rate after stopping exercise, typically measured one minute post-exercise. It reflects how quickly the heart and autonomic nervous system return to baseline and is used to assess cardiovascular health and risk of future heart disease.
Human Reflexes	★☆☆	★★☆	★★☆	These demonstrations show how the nervous system controls involuntary reflexes such as the knee-jerk, pupil response, and blinking.
Kidney Dissection	★★★	★★☆	★★☆	Students examine a preserved mammalian kidney to identify external landmarks and internal structures that move urine from nephrons to the ureter. The dissection links organ anatomy to functions in filtration, fluid balance, and waste removal.
Making Poo: Modeling the Digestive System	★☆☆	★☆☆	★☆☆	Students create a hands-on model of the digestive system using everyday materials to show how food is broken down, nutrients are absorbed, and waste is excreted as poo. This activity helps students visualize and understand the stages of digestion and the role of each organ.
Mouse Trap Muscle Contraction	★☆☆	★☆☆	★★☆	A mousetrap is used to demonstrate the all-or-none principle of muscle contraction. Just like a muscle fiber, the trap either snaps fully or not at all when triggered by a stimulus.
Pig Heart Dissection	★★★	★★☆	★★☆	Use a preserved pig heart to identify external landmarks and internal chambers, valves, and vessels. Trace the path of blood through the right and left sides to connect structure with one-way flow and double circulation.
Rubber Chicken Bones	★☆☆	★☆☆	★☆☆	Clean chicken bones are soaked in vinegar so the acid reacts with calcium carbonate in the bone, removing minerals and leaving the collagen matrix flexible. After drying, the bones can harden in their new shape.
Shark Dissection	★★★	★★☆	★★☆	Students dissect a preserved dogfish shark to examine external features, muscular organization, and the major systems of a cartilaginous fish. The investigation includes identifying fins and sensory structures, exposing trunk and head muscles, opening the body cavity to trace digestive and circulatory organs, locating urogenital features, and optionally revealing the brain.
Simulated Blood Typing	★★★	★☆☆	★☆☆	Students use a simulated blood typing kit to identify the ABO and Rh blood groups of synthetic blood samples. The activity demonstrates how agglutination reactions work in real blood typing while remaining completely safe.

Materials
★☆☆ Easy to get from supermarket or hardware store
★★☆ Available in most school laboratories or specialist stores
★★★ Requires materials not commonly found in school laboratories

Difficulty
★☆☆ Can be easily done by most teenagers
★★☆ Available in most school laboratories or specialist stores
★★★ Requires a more experienced teacher

Safety
★☆☆ Minimal safety procedures required
★★☆ Some safety precautions required to perform safely
★★★ Only to be attempted with adequate safety procedures and trained staff