The anatomy of human bodies, comprehending the most modern discoveries and curiosities in that art to which is added a particular treatise of the small-pox & measles : together with several practical observations and experienced cures ... / written in Latin by Ijsbrand de Diemerbroeck ... ; translated from the last and most correct and full edition of the same, by William Salmon ...

CHAP. II. Of the Fibres.

FIbres are white similar Parts, so∣lid, oblong, like little Strings, designed for the Motion of some, and the Preservation of other Parts.

I. They are Parts which are not derived from others, but existing of themselves, for the Complement of those Parts where they are required. And therefore they mistake, who be∣lieve them to be produced from the Brain, or from the Spinal Marrow, as are also they who think them the Pro∣ductions of the Nerves, it being impos∣sible that the Nerves should be expand∣ed into so many Strings. For Example, a small Nerve, which shall consist of twenty fibrous Strings, is inserted into some larger Muscle, consisting of a hundred fibrous Strings, much bigger and stronger than those in the Nerve. Thus the whole Body of the Heart is fibrous, whereas it has very few, and those very small Nerves. The Fibres indeed communicate with the Nerves, so far as they receive Animal Spirits from them, yet they are no more Pro∣ductions from them, then the Veins are Productions of the Arteries, from whence they receive Blood.

Therefore they are Parts existing of themselves, united to others for com∣mon use.

II. Their Action is, to be contract∣ed into one another. Though Riola∣nus believes, that rather Use than Acti∣on is to be attributed to them.

All the Muscles are moved by Fibres, which being cut or wounded, their Mo∣tion ceases. Therefore the wonderful Contexture of the Fibres of the Heart, is the reason that it is able to endure such a continual Motion. The Sto∣mach, Intestines, Womb, Bladder, and the like Parts are furnished with Fibres, the more to strengthen them in Retention and Expulsion. Lastly, all the Parts that are appointed for actual Perfor∣mance, are full of Fibres. However, some do question whether there be any such things as the little Fibres of the Brain, Lungs and Liver, and Fallopius positively denies them; but now adays there is no Body doubts of them, more than that the Arteries and Veins are not without Fibres; though Fallopius and Vesalius will hardly admit them,

because they are so very small: howe∣ver Fernelius Brisot, Fuchsius, and other eminent Men allow them, for the Strength and Preservation of the Vein, and teach us that their streightness is to be observed in Blood-letting. And this Experience teaches us in Warts, when the orbicular and oblique Fibres being broken, the Tunicle of the Veins will be extended after a strange manner, nor can ever be again contracted or reduc'd to its first Condition.

III. Vulgarly there is a threefold difference observed from their Situati∣on. Some are streight, which are ex∣tended at full length; some are trans∣verse, which intercut the streight ones; others oblique, which mutually cut both. But to these three differences we must add orbicular Fibres, as in the Sphincter Muscle, unless you will reckon them among the transverse ones. The streight ones, are vulgar∣ly said to attract, the Oblique to retain, the Transverse to expel; which three Distinctions, Fallopius, not unde∣servedly derides, and teaches us how that all the Fibres expel, but that none in re∣spect of themselves either attract or re∣tain.

But the Parts that perform one single Action, have single Fibres, as several Muscles whose Action is single, that is to say, Contraction. But they that perform many Actions, are furnished with various Fibers, as the Intestines which retain and expel, to which the streight ones are added to strengthen and corroborate. But the Membranes which ought to be every way fitted and prepared for Action, have Fibres so in∣termixed, that their whole Substance seems to be but a Contexture of Fibres joyned together.

Notes

• Their Ori∣ginal.
• Their Ac∣tion.
• Diffe∣rence.