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and from the contraction of the arteries, very many vapors pass out through the porousness of the skin. The organs of the nutritive part are the mouth and the esophagus and the stomach and the liver, and all the veins, and the intestines and both biles, and the kidneys. For the mouth first prepares the food for the stomach, cutting it into small pieces by means of the teeth and the tongue. For the tongue also provides a very great service in mastication, gathering the food and placing it under the teeth, just as grinding-women put the grain into the mills with their hand. For in a way, the tongue is also the hand of mastication. And so the food, having been worked upon, is sent along to the belly through the esophagus; for the esophagus is not only the organ for sensing want but also a passage for foods. For it runs up in swallowing and draws in the food and sends it along to the belly. And the belly, having received it, separates the useful and nutritious from the stony and woody and non-nutritious; and changing the useful part into chymes, it sends it up to the liver through the veins that draw from it and channel it to the liver, which veins are like the roots of the liver, drawing the nourishment from the stomach, as the roots of plants draw it from the earth. For the belly is like the earth that provides nourishment to plants; and the veins that lead the chyme up to the gates and the hollows of the liver from the stomach and the intestines through the mesentery are like roots; and the liver itself is like the trunk; and the veins that are split off from the vena cava that grows out of the convex parts of the liver are like branches and boughs; for the liver, having received the chyme from the belly, both digests it and makes it like itself. And since its flesh is most like blood, it reasonably changes the chyme into blood. But the blood is purified through the spleen and the gall-bladder and the kidneys: the spleen drawing off the dreggy part and making it its own nourishment; the gall-bladder drawing off the acrid part that remained in the chymes from the food; and the kidneys drawing off the serous part with the remaining acrid part, so that the blood, having thus become pure and useful, is distributed as nourishment to all the other parts of the body through the veins that are sown into them; and thus each of the parts, drawing the blood and holding it and changing it into its own nature, sends the surplus on to the neighboring parts, having become suitable nourishment for them. And in this way, all the parts are nourished from blood and grow and persist, the liver supplying it. And this part of the irrational soul is said not to obey reason since it accomplishes its own work not according to our judgment nor according to choice, but naturally. 23 Concerning Pulses The pulsative motion is also called the vital faculty. And having the heart as its origin, and especially its left ventricle, which is called the pneumatic, it distributes the innate and vital heat to every part of the body through the arteries, just as the liver distributes nourishment through the veins. Accordingly, when the heart is heated contrary to nature, at once the whole animal is also heated contrary to nature, and when it is cooled, it is cooled. For the vital pneuma is sown from it through the arteries into the whole body. And for the most part these three are branched together with one another—vein, artery, nerve—from the three principles that govern the animal: from the brain, which is the origin of motion and sensation, comes the nerve; from the liver, which is the origin of blood and the nutritive faculty, comes the vein, the vessel of the blood; and from the heart, which is the origin of the vital faculty, comes the artery, the vessel of the pneuma; and being together with one another, they reap benefits from one another. For the vein supplies nourishment to the nerve and the artery, while the artery imparts to the vein natural heat and vital pneuma; whence it is not possible to find an artery without fine blood, nor a vein without vaporous pneuma. And the artery dilates and contracts forcefully according to a certain harmony and ratio, having the origin of its motion from the heart; but when dilating

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καὶ τῆς συστολῆς τῶν ἀρτηριῶν ἀτμοὶ πλεῖστοι διὰ τῆς μανότητος τοῦ δέρματος διεξέρχονται. ὄργανα δὲ τοῦ θρεπτικοῦ τό τε στόμα καὶ ὁ στόμαχος καὶ ἡ γαστὴρ καὶ τὸ ἧπαρ, αἵ τε φλέβες πᾶσαι, τά τε ἔντερα καὶ αἱ χολαὶ ἀμφότεραι, καὶ οἱ νεφροί. τὸ γὰρ στόμα πρῶτον προκατασκευάζει τῇ γαστρὶ τὴν τροφὴν εἰς λεπτὰ κατατέμνον αὐτὴν διὰ τῶν ὀδόντων καὶ τῆς γλώττης. μεγίστην γὰρ καὶ ἡ γλῶττα χρείαν παρέχεται τῇ διαμασήσει, συνάγουσα τὴν τροφὴν καὶ τοῖς ὀδοῦσιν ὑποβάλλουσα, καθάπερ αἱ ἀλετρίδες διὰ τῆς χειρὸς τὸν σῖτον ταῖς μύλαις. τρόπον γάρ τινα καὶ ἡ γλῶττα χείρ ἐστι τῆς διαμασήσεως. οὕτω δὲ κατεργασθεῖσα ἡ τροφὴ παραπέμπεται τῇ κοιλίᾳ διὰ τοῦ στομάχου· ὁ γὰρ στόμαχος οὐ μόνον αἰσθητήριόν ἐστι τῆς ἐνδείας ἀλλὰ καὶ δίοδος τῶν σιτίων. ἀνατρέχει γὰρ ἐν τῇ καταπόσει καὶ ἐπισπᾶται τὴν τροφὴν καὶ παραπέμπει τῇ κοιλίᾳ. ἡ δὲ κοιλία παραλαβοῦσα χωρίζει τὸ χρηστὸν καὶ τὸ τρόφιμον ἀπὸ τοῦ λιθώδους καὶ ξυλώδους καὶ ἀτρόφου· καὶ τὸ μὲν χρηστὸν εἰς χυμοὺς μεταβάλλουσα ἀναπέμπει τῷ ἥπατι διὰ τῶν φλεβῶν τῶν ἑλκουσῶν ἀπ' αὐτῆς καὶ διοχετευουσῶν εἰς τὸ ἧπαρ, αἵτινες φλέβες ῥίζαις ἐοίκασι τοῦ ἥπατος, ἑλκούσαις ἀπὸ τῆς γαστρὸς τὴν τροφήν, ὡς ἀπὸ τῆς γῆς ἕλκουσιν αἱ τῶν φυτῶν ῥίζαι. ἔοικε γὰρ ἡ μὲν κοιλία τῇ γῇ τῇ παρεχούσῃ τὴν τροφὴν τοῖς φυτοῖς· ῥίζαις δὲ αἱ φλέβες αἱ ἐπὶ τὰς πύλας καὶ τὰ σιμὰ τοῦ ἥπατος ἀνάγουσαι τὸν χυμὸν ἀπό τε τῆς γαστρὸς καὶ τῶν ἐντέρων διὰ τοῦ μεσαραίου· πρέμνῳ δὲ τὸ ἧπαρ αὐτό· κλάδοις δὲ καὶ ἀκρέμοσιν αἱ φλέβες αἱ κατασχιζόμεναι τῆς κοίλης φλεβὸς τῆς ἀποφυομένης ἐκ τῶν κυρτῶν τοῦ ἥπατος· τὸ γὰρ ἧπαρ δεξάμενον ἐκ τῆς κοιλίας τὸν χυμὸν συμπέσσει τε καὶ ἐξομοιοῖ ἑαυτῷ. ὁμοιοτάτην δὲ ἔχον τὴν σάρκα τῷ αἵματι, εἰκότως εἰς αἷμα μεταβάλλει τὸν χυμόν. τὸ δὲ αἷμα καθαίρεται διά τε τοῦ σπληνὸς καὶ τῆς χοληδόχου κύστεως καὶ τῶν νεφρῶν· τοῦ μὲν σπληνὸς τὸ τρυγῶδες ἕλκοντος καὶ τροφὴν οἰκείαν ποιουμένου· τῆς δὲ χοληδόχου κύστεως τὸ δριμὺ τὸ ἐναπομεῖναν τοῖς χυμοῖς ἐκ τῆς τροφῆς· τῶν δὲ νεφρῶν τὸ ὀῤῥῶδες μετὰ τοῦ περιλειπομένου δριμέος, ὡς καθαρὸν λοιπὸν καὶ χρηστὸν τὸ αἷμα γενόμενον, εἰς τροφὴν διανέμεσθαι τοῖς ἄλλοις πᾶσι μορίοις τοῦ σώματος διὰ τῶν κατασπειρομένων εἰς αὐτὰ φλεβῶν· καὶ οὕτως ἕκαστον τῶν μορίων ἕλκον τὸ αἷμα καὶ κατέχον καὶ μεταβάλλον εἰς τὴν ἰδίαν φύσιν, τὸ περιττὸν παραπέμπει τοῖς γειτνιῶσι μορίοις τροφὴν ἐπιτήδειον ἐκείνοις γενόμενον. καὶ τοῦτον τὸν τρόπον πάντα τὰ μόρια ἐξ αἵματος τρέφεται καὶ αὔξει καὶ διαμένει, χορηγοῦντος αὐτὸ τοῦ ἥπατος. λέγεται δὲ τοῦτο τὸ μέρος τοῦ ἀλόγου μὴ πείθεσθαι λόγῳ ἐπειδήπερ οὐ κατὰ γνώμην ἡμῶν οὐδὲ κατὰ προαίρεσιν ἀλλὰ φυσικῶς τὸ ἴδιον ἔργον ἀποτελεῖ. 23 περὶ σφυγμῶν Ἡ δὲ σφυγμικὴ κίνησις καλεῖται μὲν καὶ ζωτικὴ δύναμις. ἔχουσα δὲ τὴν καρδίαν ἀρχὴν καὶ μάλιστα τὴν ἀριστερὰν αὐτῆς κοιλίαν, τὴν πνευματικὴν καλουμένην, τὴν ἔμφυτον καὶ ζωτικὴν θερμότητα διανέμει παντὶ μορίῳ τοῦ σώματος διὰ τῶν ἀρτηριῶν, καθάπερ τὸ ἧπαρ διὰ τῶν φλεβῶν τὴν τροφήν. θερμαινομένης γοῦν τῆς καρδίας παρὰ φύσιν, εὐθέως καὶ τὸ ζῷον ὅλον παρὰ φύσιν θερμαίνεται, καὶ ψυχομένης ψύχεται. τὸ γὰρ ζωτικὸν πνεῦμα παρ' αὐτῆς διὰ τῶν ἀρτηριῶν εἰς πᾶν τὸ σῶμα κατασπείρεται. συγκατασχίζεται δὲ ὡς ἐπὶ τὸ πλεῖστον ἀλλήλοις τὰ τρία ταῦτα, φλέψ, ἀρτηρία, νεῦρον, ἐκ τῶν τριῶν ἀρχῶν τῶν διοικουσῶν τὸ ζῷον· ἐξ ἐγκεφάλου μὲν ἀρχῆς ὄντος κινήσεώς τε καὶ αἰσθήσεως τὸ νεῦρον· ἐξ ἥπατος δὲ ἀρχῆς ὄντος αἵματός τε καὶ τοῦ θρεπτικοῦ ἡ φλέψ, τὸ ἀγγεῖον τοῦ αἵματος· ἐκ δὲ τῆς καρδίας ἀρχῆς οὔσης τοῦ ζωτικοῦ ἡ ἀρτηρία, τὸ ἀγγεῖον τοῦ πνεύματος· συνόντα δὲ ἀλλήλοις τὰς παρ' ἀλλήλων ὠφελείας καρποῦνται. ἡ μὲν γὰρ φλὲψ τροφὴν χορηγεῖ τῷ νεύρῳ καὶ τῇ ἀρτηρίᾳ, ἡ δὲ ἀρτηρία μεταδίδωσι τῇ φλεβὶ θερμασίας φυσικῆς καὶ πνεύματος ζωτικοῦ· ὅθεν οὔτε ἀρτηρίαν ἐστὶν εὑρεῖν χωρὶς αἵματος λεπτοῦ οὔτε φλέβα χωρὶς πνεύματος ἀτμώδους. διαστέλλεται δὲ σφοδρῶς καὶ συστέλλεται ἡ ἀρτηρία κατὰ ἁρμονίαν τινὰ καὶ λόγον, τὴν ἀρχὴν ἔχουσα τῆς κινήσεως ἐκ τῆς καρδίας· ἀλλὰ διαστελλομένη μὲν