Biological Classification Chart: Alveoli Cross-Section

Biological diagram infographic titled "Alveoli Cross-Section" centered on a clean labeled diagram of the human respiratory alveolar region, shown as an editorial-grade anatomical cross-section with a cluster of alveoli connected to a terminal bronchiole and surrounded by pulmonary capillaries. Composition for a medical professional audience, with 9 labels arranged evenly around the central diagram, each connected by a thin leader line and containing a short heading in English plus a one-line function caption in English. Use biologically accurate anatomy, precise proportions, and sharp readable typography. Visual style: minimal flat scientific, forest green and earth palette, calm clinical mood, medical-textbook clarity, editorial scientific illustration, vector-clean lines, no photographic textures. Show the alveolar wall layers and gas-exchange interface clearly, with subtle depth through flat color blocking only.

Include these exact on-image labels and captions:
1. "Terminal Bronchiole" — "Conducts air into the respiratory zone."
2. "Alveolar Sac" — "Cluster of alveoli that increases gas exchange area."
3. "Alveolus" — "Primary site of oxygen and carbon dioxide exchange."
4. "Alveolar Septum" — "Thin partition separating adjacent alveoli."
5. "Type I Pneumocyte" — "Simple squamous cell forming most of the gas diffusion surface."
6. "Type II Pneumocyte" — "Secretes surfactant to reduce surface tension."
7. "Alveolar Macrophage" — "Removes inhaled particles and microbial debris."
8. "Pulmonary Capillary" — "Carries blood for respiratory gas exchange."
9. "Respiratory Membrane" — "Ultrathin barrier across which gases diffuse."

Depict oxygen and carbon dioxide movement with subtle directional arrows across the respiratory membrane, but keep the diagram primarily a labeled anatomical cross-section rather than a process flow. Add a small unobtrusive legend for gas colors if needed, using the same English-only text standard. Keep background clean and light, with balanced negative space and professional infographic layout. No gore, no blood splatter, no real patient photos, no surgical imagery, educationally tasteful human anatomy. All text MUST be written in English (array). Every heading, label, caption, legend and metric name in the image must be in English — not English. Spell each English word correctly using English characters and diacritics. Numbers stay as digits, no graphic gore, no real patient photos, no watermarks No graphic medical gore, no real patient photographs, no surgical blood. For human anatomy, keep illustrations educationally tasteful. For animal anatomy, no cruelty imagery. Scientifically accurate labeling and proportions.