---
title: Homeostasis Explorer
emoji: 🫀
colorFrom: red
colorTo: blue
sdk: streamlit
app_file: app.py
pinned: false
license: mit
---

# Homeostasis Explorer

Interactive teaching app for visualizing how changes in **PaCO₂** affect **respiratory rate (RR)**, **pH**, and **cerebral blood flow (CBF)**. Designed for an online, asynchronous 300-level physiology course.

> **Student link (share this):**  
> `https://<owner>-<space-name>.hf.space`  
> Replace `<owner>-<space-name>` with your actual Space URL (e.g., `rick-hes-homeostasis-explorer.hf.space`).

---

## How to use (students)
1. Open the link above.
2. Move the **PaCO₂** slider (20–80 mmHg).
3. Observe real-time updates to RR, pH, and CBF plus trend graphs.
4. Use the display to answer guided questions in your worksheet or quiz.

---

## Instructor notes
- Coefficients are **illustrative** for teaching. Tweak them in `app.py` to match your model:
  - RR: `RR = RR_base + 0.6 * (PaCO2 - 40)`
  - pH: `pH = 7.40 - 0.01 * (PaCO2 - 40)`
  - CBF (relative): `CBF = 1.0 * (1 + 0.015 * (PaCO2 - 40))`
- Suggested activities:
  - Have students capture screenshots at PaCO₂ = 30, 40, 50, 60 mmHg and explain trends.
  - Ask them to predict values before moving the slider, then verify and reflect on any mismatch.

---

## Files in this Space
- `app.py` — Streamlit app (main entry point).
- `requirements.txt` — minimal Python deps.
- `README.md` — this file.

If you see **“Welcome to Streamlit”** instead of the app:
- Ensure **Settings → SDK** is **Streamlit** and **App file** is exactly `app.py`.
- Confirm `app.py` exists at the repo root (or update **App file** to the correct path).

---

## Run locally (optional)
```bash
python -m venv .venv && source .venv/bin/activate  # Windows: .venv\Scripts\activate
pip install -r requirements.txt
streamlit run app.py