{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "schema:Vein",
  "title": "Vein",
  "description": "A type of blood vessel that specifically carries blood to the heart.",
  "type": "object",
  "allOf": [
    {
      "description": "A component of the human body circulatory system comprised of an intricate network of hollow tubes that transport blood throughout the entire body.",
      "$ref": "schema:Vessel"
    }
  ],
  "properties": {
    "drainsTo": {
      "description": "The vasculature that the vein drains into.",
      "$ref": "schema:Vessel"
    },
    "regionDrained": {
      "description": "The anatomical or organ system drained by this vessel; generally refers to a specific part of an organ.",
      "anyOf": [
        { "$ref": "schema:AnatomicalStructure" },
        { "$ref": "schema:AnatomicalSystem" }
      ]
    },
    "tributary": {
      "description": "The anatomical or organ system that the vein flows into; a larger structure that the vein connects to.",
      "$ref": "schema:AnatomicalStructure"
    }
  }
}
