Chap. XII. Of the OESO∣PHAGUS or Gullet.
THe OESOPHAGUS which some term Gula, others stomachus, and Coelius Aurelianus Via stomachi and Ventris the way of the Stomach and Belly, in Eng∣lish the Gullet, is the Pipe or Funnel of the Stomach, as the Wesand is the Pipe of the Lungs.
'Tis so Scituate, as that it begins in the Throat, where it is termed Pharynx,* 1.1 and from thence goes down right for∣ward, under the Wesand, into the Stomach. And when it is come as far as to the fift Vertebra of the Chest, giving way to the Aorta, which passes through the middle thereof, it bends to the right Hand; after∣wards it rises again to the left great Artery, and at the eleventh Vertebra, through the Diaphragma or Mid∣riff it enters the left mouth of the Stomach, accompa∣nied by two Nerves arising from the sixt pair.
It hath a few Veins from the Cava, the Azygos, Intercostal and Jugular* 1.2 Veins.
It hath Arteries from the Intercostal Arteries, and the internal Carotides.
And Nerves from the sixth pair.
Its Connexion is, at the beginning with the Jawes and Larynx, by the Coat of* 1.3 the Mouth, which is common to it and the Stomach. To the Vertebrae, the Trachea and neighbouring parts 'tis joyned by Membranes arising out of the Ligaments of the Back. And because it lies upon the Spina* 1.4 or Back-bone, therefore when it is Diseased, we apply external reme∣dies to the Back-bone.
A Glandulous Body grows to the hinder part of it, which affords* 1.5 moisture, to wet the Cavity there∣of, the better to assist the swallowing of things. And somtimes it swels so much, as to hinder the swallowing of all liquid meats and drink.
Its Substance consists of a triple Coat, that it might more easily be stretched* 1.6 long-wayes and broad-wayes.
The first is common with the Stomach. This some will have to arise from the Ligaments of the Vertebra's, others from the Pleura, who are therein both mistaken. For it hath its rise, there where the Membrane of the Stomach arises, viz. from the Peri∣tonaeum, for it is one continued Body with the Mem∣brane of the Stomach, it is exceeding thin and in a manner destitute of all Fibres.
The second is the first Proper one, the external being more fleshy, thicker and softer, then the other; being as it were a Muscle bored through, being commonly reputed to be interwoven with round and transverse Fibres. Also Hofman doth thereby prove it to be a Muscle, because it suffers Convulsions and Pal∣sies.
The third is the second Proper one, internal, more Nervous, somwhat subtile and harder, being com∣monly said to be interwoven with streight and long Fibres. It is contained with that Membrane which covers the Palate, Throat and Lips, and therefore when a Man is ready to vomit, his lower Lip trem∣bles.
Howbeit, contrary to the vulgar opinion aforesaid, our Eyes can witness, that the inner Coat is furnished with transverse and circular Fibres, the external with straight and longish ones.
The Muscles of the Gullet which other* 1.7 have passed over in silence, are four.
The first, is the same I spoke of before, trea∣ting de Larynge. It is only one like a Sphincter Mus∣cle compassing the Gullet. And therefore Riolanus, Spigelius, and Ves••ingus term it Musculus Oesophagus, being the Authors of that name.
The second, is the Sphaenopharyngaeus by them so called, arising from the internal acute process of the Sphaenoides, and being obliquely implanted into the sides of the Oesophagus, that it being drawn upwards and widened, it may be the more wide to receive in meat.
The third is Stylopharyngaeus, which arising from the Bodkin-shap'd acute process, is stretched out to the sides of Oesophagus; which both Dilates and Ampli∣fies.
The fourth, is Cephalo-pharyngaeus, commonly said to arise from the Chin, but according to late Authors, from the lowest part of the Heads-top where it is nearest the Neck; and is inserted with a various contex∣ture of Fibres into the beginning of the Oesophagus, where it is larger: and therefore because of its Latitude and Fabrick, it seems to be two.
The Action therefore of the Oeso∣phagus* 1.8 is Animal; seeing it is per∣formed by Muscles and not natural, as the vulgar opinion is of all Au∣thors, and swallowing doth doubt∣less depend upon our free will and liberty.
Now swallowing is performed after this manner: when any thing is to be swallowed, that same first Mus∣cle which Galen terms Sphincter doth every way con∣tract it self, whereupon its oblique Fibres, which reach from the Oesophagus to the Larynx, are made trans∣verse, which being done, the Larynx is lifted up, and the Gullet is depressed; and the Cavity of the Gullet so depressed, is made more narrow. Hereunto the fourth Muscle is assistant. For as the first being con∣tracted, embraces the meat which by chewing is brought into a round Mass, and so bears it down: so this fourth Muscle also contracting it self, comes out as it were to help, and that the meats received in at the Mouth may not go back, it straitens and repels them on every side, and transmits them into the Gul∣let, so that by both these Muscles contracted, and the Semicircular joyned therewith a perfect circle as it were and Sphincter is made, viz. by the fourth in the upper part of the Pharynx, and by the first in the lower.