diff --git a/CMakeLists.txt b/CMakeLists.txt
index fdc4907..1154bee 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,7 +5,24 @@ cmake_minimum_required(VERSION 3.10)
 project(MedicalLib)
 
 # Add the library
-add_library(MedicalLib SHARED src/MedicalLib.cpp src/Patient.cpp)
+add_library(MedicalLib SHARED
+    src/MedicalLib.cpp
+    src/Patient.cpp
+    src/Organ.cpp
+    src/Heart.cpp
+    src/Lungs.cpp
+    src/Brain.cpp
+    src/Liver.cpp
+    src/Kidneys.cpp
+    src/Bladder.cpp
+    src/Stomach.cpp
+    src/Intestines.cpp
+    src/Gallbladder.cpp
+    src/Pancreas.cpp
+    src/Esophagus.cpp
+    src/Spleen.cpp
+    src/SpinalCord.cpp
+)
 
 # Define MEDICAL_LIB_EXPORT, so that __declspec(dllexport) is used
 target_compile_definitions(MedicalLib PRIVATE MEDICAL_LIB_EXPORT)
diff --git a/examples/main.cpp b/examples/main.cpp
index 34c0ad0..92f6f6d 100644
--- a/examples/main.cpp
+++ b/examples/main.cpp
@@ -1,28 +1,51 @@
 #include <iostream>
+#include <memory>
 #include "MedicalLib/MedicalLib.h"
+#include "MedicalLib/Patient.h"
+#include "MedicalLib/Organ.h"
+#include "MedicalLib/Heart.h"
+#include "MedicalLib/Lungs.h"
+#include "MedicalLib/Brain.h"
+#include "MedicalLib/Liver.h"
+#include "MedicalLib/Kidneys.h"
+#include "MedicalLib/Stomach.h"
 
-void printPatientVitals(const Patient& patient) {
-    std::cout << "Patient ID: " << patient.patientId << std::endl;
-    std::cout << "  Blood Pressure: " << patient.bloodPressureSystolic << "/" << patient.bloodPressureDiastolic << " mmHg" << std::endl;
-    std::cout << "  Heart Rate: " << patient.heartRate << " bpm" << std::endl;
-    std::cout << "  Respiration Rate: " << patient.respirationRate << " breaths/min" << std::endl;
-    std::cout << "  Body Temperature: " << patient.bodyTemperature << " C" << std::endl;
-    std::cout << "  Oxygen Saturation: " << patient.oxygenSaturation << " %" << std::endl;
+void printPatientSummary(const Patient& patient) {
+    std::cout << "--- Patient Summary (ID: " << patient.patientId << ") ---" << std::endl;
+    for (const auto& organ_ptr : patient.organs) {
+        // Print the general summary for each organ
+        std::cout << organ_ptr->getSummary() << std::endl;
+
+        // Example of accessing specialized properties using dynamic_cast
+        if (const Heart* heart = dynamic_cast<const Heart*>(organ_ptr.get())) {
+            std::cout << "  -> Specific: Patient Heart Rate is " << heart->getHeartRate() << " bpm." << std::endl;
+        }
+        if (const Lungs* lungs = dynamic_cast<const Lungs*>(organ_ptr.get())) {
+            std::cout << "  -> Specific: Patient SpO2 is " << lungs->getOxygenSaturation() << "%." << std::endl;
+        }
+        if (const Kidneys* kidneys = dynamic_cast<const Kidneys*>(organ_ptr.get())) {
+            std::cout << "  -> Specific: Kidney Filtration Rate is " << kidneys->getFiltrationRate() << " ml/min." << std::endl;
+        }
+        if (const Stomach* stomach = dynamic_cast<const Stomach*>(organ_ptr.get())) {
+            std::cout << "  -> Specific: Stomach pH is " << stomach->getPhLevel() << "." << std::endl;
+        }
+    }
+    std::cout << "------------------------------------" << std::endl;
 }
 
 int main() {
     // Initialize a new patient
     Patient patient = initializePatient(1);
 
-    std::cout << "Initial Vitals:" << std::endl;
-    printPatientVitals(patient);
+    std::cout << "Initial State:" << std::endl;
+    printPatientSummary(patient);
 
     // Simulate a time step
     double deltaTime_s = 1.0;
     updatePatient(patient, deltaTime_s);
 
-    std::cout << "\nVitals after " << deltaTime_s << " second(s):" << std::endl;
-    printPatientVitals(patient);
+    std::cout << "\nState after " << deltaTime_s << " second(s):" << std::endl;
+    printPatientSummary(patient);
 
     return 0;
 }
diff --git a/include/MedicalLib/Bladder.h b/include/MedicalLib/Bladder.h
new file mode 100644
index 0000000..9e1eacb
--- /dev/null
+++ b/include/MedicalLib/Bladder.h
@@ -0,0 +1,24 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Bladder.
+ */
+class MEDICAL_LIB_API Bladder : public Organ {
+public:
+    Bladder(int id);
+    void update(double deltaTime_s) override;
+    std::string getSummary() const override;
+
+    // Note: A real model would get urine input from kidneys.
+    // For now, it will just fill at a constant rate.
+    void addUrine(double amount_ml);
+
+    double getCurrentVolume() const;
+    double getCapacity() const;
+
+private:
+    double currentVolume; // in ml
+    double capacity; // in ml
+};
diff --git a/include/MedicalLib/Brain.h b/include/MedicalLib/Brain.h
new file mode 100644
index 0000000..d679893
--- /dev/null
+++ b/include/MedicalLib/Brain.h
@@ -0,0 +1,35 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Brain organ.
+ */
+class MEDICAL_LIB_API Brain : public Organ {
+public:
+    /**
+     * @brief Constructor for the Brain class.
+     * @param id The ID of the organ.
+     */
+    Brain(int id);
+
+    /**
+     * @brief Updates the brain's state over time.
+     * @param deltaTime_s The time elapsed in seconds.
+     */
+    void update(double deltaTime_s) override;
+
+    /**
+     * @brief Gets a string summary of the brain's vitals.
+     * @return A string containing the brain's vital signs.
+     */
+    std::string getSummary() const override;
+
+    // Specific getters for Brain properties
+    double getConsciousnessLevel() const; // A simplified scale, e.g., 0.0 to 1.0
+    double getCerebralBloodFlow() const; // in ml/100g/min
+
+private:
+    double consciousnessLevel;
+    double cerebralBloodFlow;
+};
diff --git a/include/MedicalLib/Esophagus.h b/include/MedicalLib/Esophagus.h
new file mode 100644
index 0000000..57eeb97
--- /dev/null
+++ b/include/MedicalLib/Esophagus.h
@@ -0,0 +1,19 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Esophagus.
+ * @note This is a placeholder with minimal logic for now.
+ */
+class MEDICAL_LIB_API Esophagus : public Organ {
+public:
+    Esophagus(int id);
+    void update(double deltaTime_s) override;
+    std::string getSummary() const override;
+
+    double getMotility() const; // Peristalsis efficiency
+
+private:
+    double motility;
+};
diff --git a/include/MedicalLib/Gallbladder.h b/include/MedicalLib/Gallbladder.h
new file mode 100644
index 0000000..8e4eef2
--- /dev/null
+++ b/include/MedicalLib/Gallbladder.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Gallbladder.
+ */
+class MEDICAL_LIB_API Gallbladder : public Organ {
+public:
+    Gallbladder(int id);
+    void update(double deltaTime_s) override;
+    std::string getSummary() const override;
+
+    double getBileStored() const;
+
+private:
+    double bileStored; // in ml
+};
diff --git a/include/MedicalLib/Heart.h b/include/MedicalLib/Heart.h
new file mode 100644
index 0000000..e41708c
--- /dev/null
+++ b/include/MedicalLib/Heart.h
@@ -0,0 +1,37 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Heart organ.
+ */
+class MEDICAL_LIB_API Heart : public Organ {
+public:
+    /**
+     * @brief Constructor for the Heart class.
+     * @param id The ID of the organ.
+     */
+    Heart(int id);
+
+    /**
+     * @brief Updates the heart's state over time.
+     * @param deltaTime_s The time elapsed in seconds.
+     */
+    void update(double deltaTime_s) override;
+
+    /**
+     * @brief Gets a string summary of the heart's vitals.
+     * @return A string containing the heart's vital signs.
+     */
+    std::string getSummary() const override;
+
+    // Specific getters for Heart properties
+    double getHeartRate() const;
+    double getBloodPressureSystolic() const;
+    double getBloodPressureDiastolic() const;
+
+private:
+    double heartRate;
+    double bloodPressureSystolic;
+    double bloodPressureDiastolic;
+};
diff --git a/include/MedicalLib/Intestines.h b/include/MedicalLib/Intestines.h
new file mode 100644
index 0000000..0585017
--- /dev/null
+++ b/include/MedicalLib/Intestines.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Intestines (Small and Large combined).
+ */
+class MEDICAL_LIB_API Intestines : public Organ {
+public:
+    Intestines(int id);
+    void update(double deltaTime_s) override;
+    std::string getSummary() const override;
+
+    double getNutrientAbsorptionRate() const;
+    double getWaterAbsorptionRate() const;
+
+private:
+    double nutrientAbsorptionRate; // in arbitrary units
+    double waterAbsorptionRate; // in ml/s
+};
diff --git a/include/MedicalLib/Kidneys.h b/include/MedicalLib/Kidneys.h
new file mode 100644
index 0000000..87c1adc
--- /dev/null
+++ b/include/MedicalLib/Kidneys.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Kidneys.
+ */
+class MEDICAL_LIB_API Kidneys : public Organ {
+public:
+    Kidneys(int id);
+    void update(double deltaTime_s) override;
+    std::string getSummary() const override;
+
+    double getFiltrationRate() const;
+    double getUrineProductionRate() const;
+
+private:
+    double filtrationRate; // in ml/min
+    double urineProductionRate; // in ml/s
+};
diff --git a/include/MedicalLib/Liver.h b/include/MedicalLib/Liver.h
new file mode 100644
index 0000000..1fa483c
--- /dev/null
+++ b/include/MedicalLib/Liver.h
@@ -0,0 +1,35 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Liver organ.
+ */
+class MEDICAL_LIB_API Liver : public Organ {
+public:
+    /**
+     * @brief Constructor for the Liver class.
+     * @param id The ID of the organ.
+     */
+    Liver(int id);
+
+    /**
+     * @brief Updates the liver's state over time.
+     * @param deltaTime_s The time elapsed in seconds.
+     */
+    void update(double deltaTime_s) override;
+
+    /**
+     * @brief Gets a string summary of the liver's vitals.
+     * @return A string containing the liver's vital signs.
+     */
+    std::string getSummary() const override;
+
+    // Specific getters for Liver properties
+    double getBileProductionRate() const; // in ml/s
+    double getGlucoseProductionRate() const; // in g/s
+
+private:
+    double bileProductionRate;
+    double glucoseProductionRate;
+};
diff --git a/include/MedicalLib/Lungs.h b/include/MedicalLib/Lungs.h
new file mode 100644
index 0000000..4693fd5
--- /dev/null
+++ b/include/MedicalLib/Lungs.h
@@ -0,0 +1,35 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Lungs organ.
+ */
+class MEDICAL_LIB_API Lungs : public Organ {
+public:
+    /**
+     * @brief Constructor for the Lungs class.
+     * @param id The ID of the organ.
+     */
+    Lungs(int id);
+
+    /**
+     * @brief Updates the lungs' state over time.
+     * @param deltaTime_s The time elapsed in seconds.
+     */
+    void update(double deltaTime_s) override;
+
+    /**
+     * @brief Gets a string summary of the lungs' vitals.
+     * @return A string containing the lungs' vital signs.
+     */
+    std::string getSummary() const override;
+
+    // Specific getters for Lungs properties
+    double getRespirationRate() const;
+    double getOxygenSaturation() const;
+
+private:
+    double respirationRate;
+    double oxygenSaturation;
+};
diff --git a/include/MedicalLib/Organ.h b/include/MedicalLib/Organ.h
new file mode 100644
index 0000000..5edfeff
--- /dev/null
+++ b/include/MedicalLib/Organ.h
@@ -0,0 +1,61 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+// Define MEDICAL_LIB_EXPORT for exporting symbols from the DLL
+#if defined(_WIN32)
+    #if defined(MEDICAL_LIB_EXPORT)
+        #define MEDICAL_LIB_API __declspec(dllexport)
+    #else
+        #define MEDICAL_LIB_API __declspec(dllimport)
+    #endif
+#else
+    #define MEDICAL_LIB_API
+#endif
+
+/**
+ * @brief Abstract base class for all organ types.
+ */
+class MEDICAL_LIB_API Organ {
+public:
+    /**
+     * @brief Constructor for the Organ class.
+     * @param id The ID of the organ.
+     * @param type The type of the organ as a string.
+     */
+    Organ(int id, const std::string& type);
+
+    /**
+     * @brief Virtual destructor.
+     */
+    virtual ~Organ() = default;
+
+    /**
+     * @brief Pure virtual function to update the organ's state over time.
+     * @param deltaTime_s The time elapsed in seconds.
+     */
+    virtual void update(double deltaTime_s) = 0;
+
+    /**
+     * @brief Pure virtual function to get a string summary of the organ's vitals.
+     * @return A string containing the organ's vital signs.
+     */
+    virtual std::string getSummary() const = 0;
+
+    /**
+     * @brief Gets the organ ID.
+     * @return The organ ID.
+     */
+    int getId() const;
+
+    /**
+     * @brief Gets the organ type.
+     * @return The organ type as a string.
+     */
+    const std::string& getType() const;
+
+protected:
+    int organId;
+    std::string organType;
+};
diff --git a/include/MedicalLib/Pancreas.h b/include/MedicalLib/Pancreas.h
new file mode 100644
index 0000000..3216fc4
--- /dev/null
+++ b/include/MedicalLib/Pancreas.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Pancreas, with both endocrine and exocrine functions.
+ */
+class MEDICAL_LIB_API Pancreas : public Organ {
+public:
+    Pancreas(int id);
+    void update(double deltaTime_s) override;
+    std::string getSummary() const override;
+
+    double getInsulinProduction() const;
+    double getGlucagonProduction() const;
+
+private:
+    double insulinProduction; // in units/hr
+    double glucagonProduction; // in ng/hr
+};
diff --git a/include/MedicalLib/Patient.h b/include/MedicalLib/Patient.h
index e86d3b0..11984cc 100644
--- a/include/MedicalLib/Patient.h
+++ b/include/MedicalLib/Patient.h
@@ -1,16 +1,17 @@
 #pragma once
 
+#include <vector>
+#include <memory>
+
+// Forward-declare the Organ class to avoid circular dependencies
+class Organ;
+
 /**
  * @brief Holds all the vital signs and other medical information for a patient.
  */
 struct Patient {
     int patientId;
-    double bloodPressureSystolic;
-    double bloodPressureDiastolic;
-    double heartRate;
-    double respirationRate;
-    double bodyTemperature;
-    double oxygenSaturation;
+    std::vector<std::unique_ptr<Organ>> organs;
 };
 
 // Define MEDICAL_LIB_EXPORT for exporting symbols from the DLL
diff --git a/include/MedicalLib/SpinalCord.h b/include/MedicalLib/SpinalCord.h
new file mode 100644
index 0000000..774ab27
--- /dev/null
+++ b/include/MedicalLib/SpinalCord.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Spinal Cord.
+ */
+class MEDICAL_LIB_API SpinalCord : public Organ {
+public:
+    SpinalCord(int id);
+    void update(double deltaTime_s) override;
+    std::string getSummary() const override;
+
+    double getSignalConductionVelocity() const; // in m/s
+
+private:
+    double signalConductionVelocity;
+};
diff --git a/include/MedicalLib/Spleen.h b/include/MedicalLib/Spleen.h
new file mode 100644
index 0000000..4841bba
--- /dev/null
+++ b/include/MedicalLib/Spleen.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Spleen.
+ */
+class MEDICAL_LIB_API Spleen : public Organ {
+public:
+    Spleen(int id);
+    void update(double deltaTime_s) override;
+    std::string getSummary() const override;
+
+    double getRedBloodCellCount() const;
+    double getWhiteBloodCellCount() const;
+
+private:
+    double redBloodCellCount; // in millions/uL
+    double whiteBloodCellCount; // in thousands/uL
+};
diff --git a/include/MedicalLib/Stomach.h b/include/MedicalLib/Stomach.h
new file mode 100644
index 0000000..14886e8
--- /dev/null
+++ b/include/MedicalLib/Stomach.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#include "Organ.h"
+
+/**
+ * @brief Represents the Stomach.
+ */
+class MEDICAL_LIB_API Stomach : public Organ {
+public:
+    Stomach(int id);
+    void update(double deltaTime_s) override;
+    std::string getSummary() const override;
+
+    double getPhLevel() const;
+    double getDigestionRate() const;
+
+private:
+    double phLevel; // Acidity
+    double digestionRate; // in arbitrary units
+};
diff --git a/src/Bladder.cpp b/src/Bladder.cpp
new file mode 100644
index 0000000..3de5008
--- /dev/null
+++ b/src/Bladder.cpp
@@ -0,0 +1,29 @@
+#include "MedicalLib/Bladder.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+Bladder::Bladder(int id) : Organ(id, "Bladder"), currentVolume(50.0), capacity(500.0) {}
+
+void Bladder::update(double deltaTime_s) {
+    // In a more complex model, this would be driven by kidney output.
+    // For now, simulate a constant fill rate.
+    const double fillRate_ml_per_s = 0.02;
+    currentVolume += fillRate_ml_per_s * deltaTime_s;
+    currentVolume = std::clamp(currentVolume, 0.0, capacity);
+}
+
+void Bladder::addUrine(double amount_ml) {
+    currentVolume += amount_ml;
+    currentVolume = std::clamp(currentVolume, 0.0, capacity);
+}
+
+std::string Bladder::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Volume: " << currentVolume << " / " << capacity << " ml";
+    return ss.str();
+}
+
+double Bladder::getCurrentVolume() const { return currentVolume; }
+double Bladder::getCapacity() const { return capacity; }
diff --git a/src/Brain.cpp b/src/Brain.cpp
new file mode 100644
index 0000000..2d98dc0
--- /dev/null
+++ b/src/Brain.cpp
@@ -0,0 +1,39 @@
+#include "MedicalLib/Brain.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+// Helper function for random fluctuations
+static double getFluctuation(double stddev) {
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, stddev);
+    return d(gen);
+}
+
+Brain::Brain(int id) : Organ(id, "Brain"), consciousnessLevel(1.0), cerebralBloodFlow(50.0) {}
+
+void Brain::update(double deltaTime_s) {
+    const double baseline_consciousness = 1.0;
+    const double baseline_cbf = 50.0;
+    const double theta = 0.05; // Slower reversion for brain metrics
+    const double consciousness_stddev = 0.001;
+    const double cbf_stddev = 0.5;
+
+    consciousnessLevel += theta * (baseline_consciousness - consciousnessLevel) * deltaTime_s + getFluctuation(consciousness_stddev * deltaTime_s);
+    cerebralBloodFlow += theta * (baseline_cbf - cerebralBloodFlow) * deltaTime_s + getFluctuation(cbf_stddev * deltaTime_s);
+
+    consciousnessLevel = std::clamp(consciousnessLevel, 0.0, 1.0);
+    cerebralBloodFlow = std::clamp(cerebralBloodFlow, 40.0, 60.0);
+}
+
+std::string Brain::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Consciousness Level: " << consciousnessLevel * 100 << "%\n"
+       << "  Cerebral Blood Flow: " << cerebralBloodFlow << " ml/100g/min";
+    return ss.str();
+}
+
+double Brain::getConsciousnessLevel() const { return consciousnessLevel; }
+double Brain::getCerebralBloodFlow() const { return cerebralBloodFlow; }
diff --git a/src/Esophagus.cpp b/src/Esophagus.cpp
new file mode 100644
index 0000000..9fe8d5f
--- /dev/null
+++ b/src/Esophagus.cpp
@@ -0,0 +1,26 @@
+#include "MedicalLib/Esophagus.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+Esophagus::Esophagus(int id) : Organ(id, "Esophagus"), motility(1.0) {}
+
+void Esophagus::update(double deltaTime_s) {
+    // Placeholder, no real logic yet.
+    // Fluctuate motility slightly.
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, 0.001);
+
+    motility += d(gen) * deltaTime_s;
+    motility = std::clamp(motility, 0.95, 1.05);
+}
+
+std::string Esophagus::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Motility: " << motility * 100 << "%";
+    return ss.str();
+}
+
+double Esophagus::getMotility() const { return motility; }
diff --git a/src/Gallbladder.cpp b/src/Gallbladder.cpp
new file mode 100644
index 0000000..23dbcb6
--- /dev/null
+++ b/src/Gallbladder.cpp
@@ -0,0 +1,26 @@
+#include "MedicalLib/Gallbladder.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+Gallbladder::Gallbladder(int id) : Organ(id, "Gallbladder"), bileStored(30.0) {}
+
+void Gallbladder::update(double deltaTime_s) {
+    // A real model would be affected by liver production and digestion.
+    // For now, it just sits there with a small fluctuation.
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, 0.01);
+
+    bileStored += d(gen) * deltaTime_s;
+    bileStored = std::clamp(bileStored, 10.0, 50.0);
+}
+
+std::string Gallbladder::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Bile Stored: " << bileStored << " ml";
+    return ss.str();
+}
+
+double Gallbladder::getBileStored() const { return bileStored; }
diff --git a/src/Heart.cpp b/src/Heart.cpp
new file mode 100644
index 0000000..3c8727d
--- /dev/null
+++ b/src/Heart.cpp
@@ -0,0 +1,43 @@
+#include "MedicalLib/Heart.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+// Helper function for random fluctuations
+static double getFluctuation(double stddev) {
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, stddev);
+    return d(gen);
+}
+
+Heart::Heart(int id) : Organ(id, "Heart"), heartRate(75.0), bloodPressureSystolic(120.0), bloodPressureDiastolic(80.0) {}
+
+void Heart::update(double deltaTime_s) {
+    const double baseline_hr = 75.0;
+    const double baseline_bp_systolic = 120.0;
+    const double baseline_bp_diastolic = 80.0;
+    const double theta = 0.1; // Mean reversion speed
+    const double hr_stddev = 0.1;
+    const double bp_stddev = 0.1;
+
+    heartRate += theta * (baseline_hr - heartRate) * deltaTime_s + getFluctuation(hr_stddev * deltaTime_s);
+    bloodPressureSystolic += theta * (baseline_bp_systolic - bloodPressureSystolic) * deltaTime_s + getFluctuation(bp_stddev * deltaTime_s);
+    bloodPressureDiastolic += theta * (baseline_bp_diastolic - bloodPressureDiastolic) * deltaTime_s + getFluctuation(bp_stddev * deltaTime_s);
+
+    heartRate = std::clamp(heartRate, 60.0, 100.0);
+    bloodPressureSystolic = std::clamp(bloodPressureSystolic, 90.0, 120.0);
+    bloodPressureDiastolic = std::clamp(bloodPressureDiastolic, 60.0, 80.0);
+}
+
+std::string Heart::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Heart Rate: " << heartRate << " bpm\n"
+       << "  Blood Pressure: " << bloodPressureSystolic << "/" << bloodPressureDiastolic << " mmHg";
+    return ss.str();
+}
+
+double Heart::getHeartRate() const { return heartRate; }
+double Heart::getBloodPressureSystolic() const { return bloodPressureSystolic; }
+double Heart::getBloodPressureDiastolic() const { return bloodPressureDiastolic; }
diff --git a/src/Intestines.cpp b/src/Intestines.cpp
new file mode 100644
index 0000000..1df2ae1
--- /dev/null
+++ b/src/Intestines.cpp
@@ -0,0 +1,39 @@
+#include "MedicalLib/Intestines.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+// Helper function for random fluctuations
+static double getFluctuation(double stddev) {
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, stddev);
+    return d(gen);
+}
+
+Intestines::Intestines(int id) : Organ(id, "Intestines"), nutrientAbsorptionRate(1.0), waterAbsorptionRate(0.1) {}
+
+void Intestines::update(double deltaTime_s) {
+    const double baseline_nutrient_abs = 1.0;
+    const double baseline_water_abs = 0.1;
+    const double theta = 0.05;
+    const double nutrient_abs_stddev = 0.02;
+    const double water_abs_stddev = 0.005;
+
+    nutrientAbsorptionRate += theta * (baseline_nutrient_abs - nutrientAbsorptionRate) * deltaTime_s + getFluctuation(nutrient_abs_stddev * deltaTime_s);
+    waterAbsorptionRate += theta * (baseline_water_abs - waterAbsorptionRate) * deltaTime_s + getFluctuation(water_abs_stddev * deltaTime_s);
+
+    nutrientAbsorptionRate = std::clamp(nutrientAbsorptionRate, 0.8, 1.2);
+    waterAbsorptionRate = std::clamp(waterAbsorptionRate, 0.08, 0.12);
+}
+
+std::string Intestines::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Nutrient Absorption: " << nutrientAbsorptionRate << "\n"
+       << "  Water Absorption: " << waterAbsorptionRate << " ml/s";
+    return ss.str();
+}
+
+double Intestines::getNutrientAbsorptionRate() const { return nutrientAbsorptionRate; }
+double Intestines::getWaterAbsorptionRate() const { return waterAbsorptionRate; }
diff --git a/src/Kidneys.cpp b/src/Kidneys.cpp
new file mode 100644
index 0000000..d08d3c9
--- /dev/null
+++ b/src/Kidneys.cpp
@@ -0,0 +1,39 @@
+#include "MedicalLib/Kidneys.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+// Helper function for random fluctuations
+static double getFluctuation(double stddev) {
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, stddev);
+    return d(gen);
+}
+
+Kidneys::Kidneys(int id) : Organ(id, "Kidneys"), filtrationRate(125.0), urineProductionRate(0.02) {}
+
+void Kidneys::update(double deltaTime_s) {
+    const double baseline_filtration = 125.0;
+    const double baseline_urine_prod = 0.02;
+    const double theta = 0.03;
+    const double filtration_stddev = 1.0;
+    const double urine_prod_stddev = 0.001;
+
+    filtrationRate += theta * (baseline_filtration - filtrationRate) * deltaTime_s + getFluctuation(filtration_stddev * deltaTime_s);
+    urineProductionRate += theta * (baseline_urine_prod - urineProductionRate) * deltaTime_s + getFluctuation(urine_prod_stddev * deltaTime_s);
+
+    filtrationRate = std::clamp(filtrationRate, 100.0, 150.0);
+    urineProductionRate = std::clamp(urineProductionRate, 0.01, 0.03);
+}
+
+std::string Kidneys::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Filtration Rate: " << filtrationRate << " ml/min\n"
+       << "  Urine Production: " << urineProductionRate << " ml/s";
+    return ss.str();
+}
+
+double Kidneys::getFiltrationRate() const { return filtrationRate; }
+double Kidneys::getUrineProductionRate() const { return urineProductionRate; }
diff --git a/src/Liver.cpp b/src/Liver.cpp
new file mode 100644
index 0000000..934ac74
--- /dev/null
+++ b/src/Liver.cpp
@@ -0,0 +1,42 @@
+#include "MedicalLib/Liver.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+// Helper function for random fluctuations
+static double getFluctuation(double stddev) {
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, stddev);
+    return d(gen);
+}
+
+// Healthy baseline rates converted to per-second
+// Bile: 400-800 ml/day -> ~0.0069 ml/s
+// Glucose: ~90 g/day -> ~0.001 g/s
+Liver::Liver(int id) : Organ(id, "Liver"), bileProductionRate(0.0069), glucoseProductionRate(0.001) {}
+
+void Liver::update(double deltaTime_s) {
+    const double baseline_bile_rate = 0.0069;
+    const double baseline_glucose_rate = 0.001;
+    const double theta = 0.02; // Slow reversion for metabolic rates
+    const double bile_stddev = 0.0001;
+    const double glucose_stddev = 0.00005;
+
+    bileProductionRate += theta * (baseline_bile_rate - bileProductionRate) * deltaTime_s + getFluctuation(bile_stddev * deltaTime_s);
+    glucoseProductionRate += theta * (baseline_glucose_rate - glucoseProductionRate) * deltaTime_s + getFluctuation(glucose_stddev * deltaTime_s);
+
+    bileProductionRate = std::clamp(bileProductionRate, 0.005, 0.009);
+    glucoseProductionRate = std::clamp(glucoseProductionRate, 0.0008, 0.0012);
+}
+
+std::string Liver::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Bile Production Rate: " << bileProductionRate * 60 << " ml/min\n"
+       << "  Glucose Production Rate: " << glucoseProductionRate * 60 << " g/min";
+    return ss.str();
+}
+
+double Liver::getBileProductionRate() const { return bileProductionRate; }
+double Liver::getGlucoseProductionRate() const { return glucoseProductionRate; }
diff --git a/src/Lungs.cpp b/src/Lungs.cpp
new file mode 100644
index 0000000..1ba4046
--- /dev/null
+++ b/src/Lungs.cpp
@@ -0,0 +1,39 @@
+#include "MedicalLib/Lungs.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+// Helper function for random fluctuations
+static double getFluctuation(double stddev) {
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, stddev);
+    return d(gen);
+}
+
+Lungs::Lungs(int id) : Organ(id, "Lungs"), respirationRate(16.0), oxygenSaturation(98.0) {}
+
+void Lungs::update(double deltaTime_s) {
+    const double baseline_rr = 16.0;
+    const double baseline_spo2 = 98.0;
+    const double theta = 0.1; // Mean reversion speed
+    const double rr_stddev = 0.05;
+    const double spo2_stddev = 0.02;
+
+    respirationRate += theta * (baseline_rr - respirationRate) * deltaTime_s + getFluctuation(rr_stddev * deltaTime_s);
+    oxygenSaturation += theta * (baseline_spo2 - oxygenSaturation) * deltaTime_s + getFluctuation(spo2_stddev * deltaTime_s);
+
+    respirationRate = std::clamp(respirationRate, 12.0, 20.0);
+    oxygenSaturation = std::clamp(oxygenSaturation, 96.0, 100.0);
+}
+
+std::string Lungs::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Respiration Rate: " << respirationRate << " breaths/min\n"
+       << "  Oxygen Saturation: " << oxygenSaturation << " %";
+    return ss.str();
+}
+
+double Lungs::getRespirationRate() const { return respirationRate; }
+double Lungs::getOxygenSaturation() const { return oxygenSaturation; }
diff --git a/src/Organ.cpp b/src/Organ.cpp
new file mode 100644
index 0000000..bdad160
--- /dev/null
+++ b/src/Organ.cpp
@@ -0,0 +1,11 @@
+#include "MedicalLib/Organ.h"
+
+Organ::Organ(int id, const std::string& type) : organId(id), organType(type) {}
+
+int Organ::getId() const {
+    return organId;
+}
+
+const std::string& Organ::getType() const {
+    return organType;
+}
diff --git a/src/Pancreas.cpp b/src/Pancreas.cpp
new file mode 100644
index 0000000..cea1efe
--- /dev/null
+++ b/src/Pancreas.cpp
@@ -0,0 +1,39 @@
+#include "MedicalLib/Pancreas.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+// Helper function for random fluctuations
+static double getFluctuation(double stddev) {
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, stddev);
+    return d(gen);
+}
+
+Pancreas::Pancreas(int id) : Organ(id, "Pancreas"), insulinProduction(1.0), glucagonProduction(50.0) {}
+
+void Pancreas::update(double deltaTime_s) {
+    const double baseline_insulin = 1.0;
+    const double baseline_glucagon = 50.0;
+    const double theta = 0.05;
+    const double insulin_stddev = 0.01;
+    const double glucagon_stddev = 1.0;
+
+    insulinProduction += theta * (baseline_insulin - insulinProduction) * deltaTime_s + getFluctuation(insulin_stddev * deltaTime_s);
+    glucagonProduction += theta * (baseline_glucagon - glucagonProduction) * deltaTime_s + getFluctuation(glucagon_stddev * deltaTime_s);
+
+    insulinProduction = std::clamp(insulinProduction, 0.5, 2.0);
+    glucagonProduction = std::clamp(glucagonProduction, 40.0, 60.0);
+}
+
+std::string Pancreas::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Insulin Production: " << insulinProduction << " units/hr\n"
+       << "  Glucagon Production: " << glucagonProduction << " ng/hr";
+    return ss.str();
+}
+
+double Pancreas::getInsulinProduction() const { return insulinProduction; }
+double Pancreas::getGlucagonProduction() const { return glucagonProduction; }
diff --git a/src/Patient.cpp b/src/Patient.cpp
index 427a3b0..5deb88b 100644
--- a/src/Patient.cpp
+++ b/src/Patient.cpp
@@ -1,74 +1,54 @@
 #include "MedicalLib/Patient.h"
-#include <random>
-#include <algorithm> // For std::clamp
+#include "MedicalLib/Heart.h"
+#include "MedicalLib/Lungs.h"
+#include "MedicalLib/Brain.h"
+#include "MedicalLib/Liver.h"
+#include "MedicalLib/Kidneys.h"
+#include "MedicalLib/Bladder.h"
+#include "MedicalLib/Stomach.h"
+#include "MedicalLib/Intestines.h"
+#include "MedicalLib/Gallbladder.h"
+#include "MedicalLib/Pancreas.h"
+#include "MedicalLib/Esophagus.h"
+#include "MedicalLib/Spleen.h"
+#include "MedicalLib/SpinalCord.h"
+#include <memory>
 
 /**
- * @brief Helper function to generate random fluctuations from a normal distribution.
- * @param stddev The standard deviation of the distribution.
- * @return A random value.
- */
-double getFluctuation(double stddev) {
-    static std::random_device rd;
-    static std::mt19937 gen(rd());
-    std::normal_distribution<> d(0, stddev);
-    return d(gen);
-}
-
-/**
- * @brief Initializes a new patient with baseline vital signs.
+ * @brief Initializes a new patient with baseline vital signs and a standard set of organs.
  * @param patientId The ID for the new patient.
  * @return A Patient struct with default healthy values.
  */
 Patient initializePatient(int patientId) {
     Patient patient;
     patient.patientId = patientId;
-    patient.bloodPressureSystolic = 120.0;
-    patient.bloodPressureDiastolic = 80.0;
-    patient.heartRate = 75.0;
-    patient.respirationRate = 16.0;
-    patient.bodyTemperature = 37.0;
-    patient.oxygenSaturation = 98.0;
+
+    // Initialize default organs
+    patient.organs.push_back(std::make_unique<Heart>(1));
+    patient.organs.push_back(std::make_unique<Lungs>(2));
+    patient.organs.push_back(std::make_unique<Brain>(3));
+    patient.organs.push_back(std::make_unique<Liver>(4));
+    patient.organs.push_back(std::make_unique<Kidneys>(5));
+    patient.organs.push_back(std::make_unique<Bladder>(6));
+    patient.organs.push_back(std::make_unique<Stomach>(7));
+    patient.organs.push_back(std::make_unique<Intestines>(8));
+    patient.organs.push_back(std::make_unique<Gallbladder>(9));
+    patient.organs.push_back(std::make_unique<Pancreas>(10));
+    patient.organs.push_back(std::make_unique<Esophagus>(11));
+    patient.organs.push_back(std::make_unique<Spleen>(12));
+    patient.organs.push_back(std::make_unique<SpinalCord>(13));
+
     return patient;
 }
 
 /**
- * @brief Updates the patient's vital signs based on the time elapsed.
- * This function simulates minor, random fluctuations around a healthy baseline.
+ * @brief Updates the patient's state by updating the state of all their organs.
  * @param patient The patient to update.
  * @param deltaTime_s The time elapsed in seconds.
  */
 void updatePatient(Patient& patient, double deltaTime_s) {
-    // Baseline healthy values
-    const double baseline_hr = 75.0;
-    const double baseline_bp_systolic = 120.0;
-    const double baseline_bp_diastolic = 80.0;
-    const double baseline_rr = 16.0;
-    const double baseline_temp = 37.0;
-    const double baseline_spo2 = 98.0;
-
-    // Reversion speed (how quickly vitals return to baseline)
-    const double theta = 0.1;
-
-    // Standard deviations for random fluctuations per second
-    const double hr_stddev = 0.1;
-    const double bp_stddev = 0.1;
-    const double rr_stddev = 0.05;
-    const double temp_stddev = 0.01;
-    const double spo2_stddev = 0.02;
-
-    // Update vitals using a mean-reverting model
-    patient.heartRate += theta * (baseline_hr - patient.heartRate) * deltaTime_s + getFluctuation(hr_stddev * deltaTime_s);
-    patient.bloodPressureSystolic += theta * (baseline_bp_systolic - patient.bloodPressureSystolic) * deltaTime_s + getFluctuation(bp_stddev * deltaTime_s);
-    patient.bloodPressureDiastolic += theta * (baseline_bp_diastolic - patient.bloodPressureDiastolic) * deltaTime_s + getFluctuation(bp_stddev * deltaTime_s);
-    patient.respirationRate += theta * (baseline_rr - patient.respirationRate) * deltaTime_s + getFluctuation(rr_stddev * deltaTime_s);
-    patient.bodyTemperature += theta * (baseline_temp - patient.bodyTemperature) * deltaTime_s + getFluctuation(temp_stddev * deltaTime_s);
-    patient.oxygenSaturation += theta * (baseline_spo2 - patient.oxygenSaturation) * deltaTime_s + getFluctuation(spo2_stddev * deltaTime_s);
-
-    // Clamp values to within healthy physiological ranges
-    patient.heartRate = std::clamp(patient.heartRate, 60.0, 100.0);
-    patient.bloodPressureSystolic = std::clamp(patient.bloodPressureSystolic, 90.0, 120.0);
-    patient.bloodPressureDiastolic = std::clamp(patient.bloodPressureDiastolic, 60.0, 80.0);
-    patient.respirationRate = std::clamp(patient.respirationRate, 12.0, 20.0);
-    patient.bodyTemperature = std::clamp(patient.bodyTemperature, 36.5, 37.3);
-    patient.oxygenSaturation = std::clamp(patient.oxygenSaturation, 96.0, 100.0);
+    // Update all organs
+    for (auto& organ : patient.organs) {
+        organ->update(deltaTime_s);
+    }
 }
diff --git a/src/SpinalCord.cpp b/src/SpinalCord.cpp
new file mode 100644
index 0000000..54f6eba
--- /dev/null
+++ b/src/SpinalCord.cpp
@@ -0,0 +1,33 @@
+#include "MedicalLib/SpinalCord.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+// Helper function for random fluctuations
+static double getFluctuation(double stddev) {
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, stddev);
+    return d(gen);
+}
+
+SpinalCord::SpinalCord(int id) : Organ(id, "SpinalCord"), signalConductionVelocity(70.0) {}
+
+void SpinalCord::update(double deltaTime_s) {
+    const double baseline_velocity = 70.0;
+    const double theta = 0.01;
+    const double velocity_stddev = 0.1;
+
+    signalConductionVelocity += theta * (baseline_velocity - signalConductionVelocity) * deltaTime_s + getFluctuation(velocity_stddev * deltaTime_s);
+
+    signalConductionVelocity = std::clamp(signalConductionVelocity, 60.0, 80.0);
+}
+
+std::string SpinalCord::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  Signal Velocity: " << signalConductionVelocity << " m/s";
+    return ss.str();
+}
+
+double SpinalCord::getSignalConductionVelocity() const { return signalConductionVelocity; }
diff --git a/src/Spleen.cpp b/src/Spleen.cpp
new file mode 100644
index 0000000..9d05db0
--- /dev/null
+++ b/src/Spleen.cpp
@@ -0,0 +1,39 @@
+#include "MedicalLib/Spleen.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+// Helper function for random fluctuations
+static double getFluctuation(double stddev) {
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, stddev);
+    return d(gen);
+}
+
+Spleen::Spleen(int id) : Organ(id, "Spleen"), redBloodCellCount(4.5), whiteBloodCellCount(7.5) {}
+
+void Spleen::update(double deltaTime_s) {
+    const double baseline_rbc = 4.5;
+    const double baseline_wbc = 7.5;
+    const double theta = 0.02;
+    const double rbc_stddev = 0.01;
+    const double wbc_stddev = 0.05;
+
+    redBloodCellCount += theta * (baseline_rbc - redBloodCellCount) * deltaTime_s + getFluctuation(rbc_stddev * deltaTime_s);
+    whiteBloodCellCount += theta * (baseline_wbc - whiteBloodCellCount) * deltaTime_s + getFluctuation(wbc_stddev * deltaTime_s);
+
+    redBloodCellCount = std::clamp(redBloodCellCount, 4.0, 5.0);
+    whiteBloodCellCount = std::clamp(whiteBloodCellCount, 5.0, 10.0);
+}
+
+std::string Spleen::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  RBC Count: " << redBloodCellCount << " million/uL\n"
+       << "  WBC Count: " << whiteBloodCellCount << " thousand/uL";
+    return ss.str();
+}
+
+double Spleen::getRedBloodCellCount() const { return redBloodCellCount; }
+double Spleen::getWhiteBloodCellCount() const { return whiteBloodCellCount; }
diff --git a/src/Stomach.cpp b/src/Stomach.cpp
new file mode 100644
index 0000000..7651fb8
--- /dev/null
+++ b/src/Stomach.cpp
@@ -0,0 +1,40 @@
+#include "MedicalLib/Stomach.h"
+#include <random>
+#include <algorithm>
+#include <sstream>
+
+// Helper function for random fluctuations
+static double getFluctuation(double stddev) {
+    static std::random_device rd;
+    static std::mt19937 gen(rd());
+    std::normal_distribution<> d(0, stddev);
+    return d(gen);
+}
+
+Stomach::Stomach(int id) : Organ(id, "Stomach"), phLevel(2.0), digestionRate(1.0) {}
+
+void Stomach::update(double deltaTime_s) {
+    // For now, these values just fluctuate around a baseline.
+    const double baseline_ph = 2.0;
+    const double baseline_digestion = 1.0;
+    const double theta = 0.1;
+    const double ph_stddev = 0.05;
+    const double digestion_stddev = 0.02;
+
+    phLevel += theta * (baseline_ph - phLevel) * deltaTime_s + getFluctuation(ph_stddev * deltaTime_s);
+    digestionRate += theta * (baseline_digestion - digestionRate) * deltaTime_s + getFluctuation(digestion_stddev * deltaTime_s);
+
+    phLevel = std::clamp(phLevel, 1.5, 3.5);
+    digestionRate = std::clamp(digestionRate, 0.5, 1.5);
+}
+
+std::string Stomach::getSummary() const {
+    std::stringstream ss;
+    ss << "Type: " << organType << " (ID: " << organId << ")\n"
+       << "  pH Level: " << phLevel << "\n"
+       << "  Digestion Rate: " << digestionRate;
+    return ss.str();
+}
+
+double Stomach::getPhLevel() const { return phLevel; }
+double Stomach::getDigestionRate() const { return digestionRate; }