Circulatory System: The heart, blood, and blood vessels that transport oxygen, nutrients, and waste products throughout the body.

Respiratory System: How the lungs work to bring oxygen into the body and expel carbon dioxide, supporting energy production at the cellular level.

Musculoskeletal System: The bones, muscles, tendons, and joints that provide structure, movement, and protection for vital organs.

Nervous System: The brain, spinal cord, and nerves that control voluntary and involuntary actions, thoughts, and emotions.

Digestive System: How food is broken down, nutrients are absorbed, and waste is eliminated, allowing the body to fuel itself.

Urinary System: The kidneys and bladder, which filter waste and maintain fluid and electrolyte balance in the body.

Endocrine System: The glands that secrete hormones to regulate metabolism, growth, stress responses, and more.

Immune System: The body’s defense system against harmful pathogens, including white blood cells and lymphatic organs.