Body system

2. System The digestive system houses a large portion of the body's immune cells and plays a crucial role in immune function, as the gut microbiota help protect against pathogens and regulate immune responses.
7. System Hormones released by the endocrine system influence the function of neurons and neurotransmitters, regulating mood, stress responses, and other neurological processes.
8. System Muscles attached to bones allow for movement and support, working together to facilitate locomotion and maintain posture.
10. System The digestive system breaks down food into nutrients that are absorbed into the bloodstream and transported to cells for energy and repair.

1. System Hormones produced by the endocrine system regulate reproductive functions such as puberty, menstruation, and fertility.
3. System The immune system defends the body against pathogens and foreign invaders, with lymphatic vessels aiding in the circulation of immune cells and fluids.
4. System The nervous system sends signals to the muscles to initiate movement.
5. System The circulatory system transports oxygen from the lungs to cells via the bloodstream, while the respiratory system provides oxygen and removes carbon dioxide from the body.
6. System The urinary system removes waste products and excess fluids from the bloodstream, helping to maintain proper electrolyte balance and blood pressure.
9. System and Cardiovascular System The respiratory system supplies oxygen to the bloodstream, which is then circulated throughout the body by the cardiovascular system.