graph TD

  subgraph Body Water Input
      A[Oral Intake (Fluids, Beverages)] --> E(Total Body Water);
      B[Food Intake (Water Content)] --> E;
      C[Metabolic Water (Oxidation of Nutrients)] --> E;
  end

  subgraph Total Body Water
      E -- Distribution --> F{Intracellular Fluid (ICF)};
      E -- Distribution --> G{Extracellular Fluid (ECF)};
      G -- Subcompartments --> H[Interstitial Fluid];
      G -- Subcompartments --> I[Plasma (Blood Water)];
      G -- Subcompartments --> J[Transcellular Fluid (e.g., CSF, Synovial Fluid)];
  end

  subgraph Body Water Output
      E --> K[Urinary System];
      K -- Urine Excretion --> L(Water Loss);
      E --> M[Respiratory System];
      M -- Water Vapor (Exhalation) --> L;
      E --> N[Integumentary System];
      N -- Sweat --> L;
      N -- Insensible Perspiration --> L;
      E --> O[Gastrointestinal System];
      O -- Feces (Water Content) --> L;
  end

  style Body Water Input fill:#ccf,stroke:#333,stroke-width:2px
  style Total Body Water fill:#9cf,stroke:#333,stroke-width:2px
  style Body Water Output fill:#fcc,stroke:#333,stroke-width:2px
  style L fill:#f9f,stroke:#333,stroke-width:2px