A középkori arab orvoslás alapjai: A vérrendszerek Avicenna leírásában a Kánon első könyvéből egy részlet fordításával

Based on the knowledge of ancient Greek philosophers, medieval Arabic theoretical anatomy describes the organs, their roles and function as well as their mutual relationships on a philosophical basis wherever there are organs with higher and subordinate roles. According to Ibn Sīnā Abū ‘Alī al-Ḥusayn b. ‘Alī (Avicenna) (370-428 AH or 980-1037 AD), everything in nature is connected with everything else, and the main operator of the body is the immortal divine soul (rūḥ). While breathing, a part of the divine soul enters the lungs, and then the heart as its mixture with blood where 'pneuma' is formed, which spreads out along the arteries throughout the body. The soul part of the inhaled air (al-hawāʼ) regulates the heat of the heart and nourishes it. According to Ibn Sīna, the heart has three cavities: one on the right side, one on the left side, and the third in the middle, which serves as a kind of blood store. The liver governs the right side, the spleen governs the left one. The heart is located in the middle of the chest maintaining a kind of balance between the two vascular systems. The left side has been exalted by the fact that the divine soul comes from the air to the left side of the heart, and from here it floods the whole body through the arteries. The right side of the body is dedicated to bodily functions like turning food into blood, nourishing the organs, and removing the excess. The right half of the body is operated by the left half through nerves originating from the brain. In the brain, the two sides merge. The source of the veins in the liver, while the arteries originate from the heart. As part of a close reading of the text, I created a diagram of branches of the blood vessels to facilitate their identification. In many passages of the anatomical description, we only learn that the vessel in question branches in three, four or five directions and travels in a certain direction or towards certain parts of the body. There is always a branch among them, indeed the largest one, and by connecting these largest branches, we get the full path of a given blood vessel from the beginning to the end. Such as the route v. cava superior from the right ventricle (branches in two directions) - v. brachiocephalica (branches to five) - v. subclavia (branches towards 4) - v. axillaris (branches towards 3) - v. basilica (2 branches branch to 4 at the forearm) - v. mediana cubiti (branches towards 2) - v. salvatella from the heart to fingers. In some cases, erroneous conclusions can be identified in Ibn Sīna's description wherever he connects blood vessels with different origins. Sometimes Ibn Sīna begins to describe a route of a blood vessel and then continues to describe another blood vessel as if it were a continuation of the previous one. Alternatively, he also assigns branches belonging to one blood vessel to branches belonging to another one, such as the v. jugularis interna in the description of branches of the v. jugularis externa.