A systeme of anatomy, treating of the body of man, beasts, birds, fish, insects, and plants illustrated with many schemes, consisting of variety of elegant figures, drawn from the life, and engraven in seventy four folio copper-plates. And after every part of man's body hath been anatomically described, its diseases, cases, and cures are concisely exhibited. The first volume containing the parts of the lowest apartiments of the body of man and other animals, etc. / by Samuel Collins ...

CHAP. XLIV. Of the Aspera Arteria, or Wind-pipe.

THE Windpipe is so styled from its use, as being made by Nature for the reception and transpiration of Air into the substance of the Lungs, and hath the appellative of Aspera Arteria from the antient Anatomists, by reason of many unevennesses, as encircled with numerous prominent Carti∣lages, seated above its Membranes.

This fine Tube of Air hath its situation in the fore part of the Neck, lean∣ing in its hinder region upon the superior part of the Gulet, lodged between the Vertebres and Windpipe; and hath one continued Duct, like a Trunk, reaching from the Fauces, or hinder part of the Mouth to the Lungs, and is connected above to the Muscles of the Os Hyoides; and when the Wind∣pipe enters into the upper region of the Thorax, the Origens of the Muscu∣li Mastoeidei do border upon this Tube, to secure it from any violence in the motion of the neighbouring parts.

This Pipe of Air is a Cylinder, as endued with an oblong round Figure, in some parts more depressed, in others more orbicular; so that the anteri∣or part of it when distended, is more round, and the posterior region, when rendred more lank, as empty of Breath, groweth more flattish, and tend∣eth toward a plain; the top of this Tube hath more large Dimensions, and afterward hath its bore somewhat lessened.

The Aspera Arteria in its upper part, before it arriveth the Lungs, doth somewhat resemble a Trunk of a Tree (in its outward shape) as free from all Limbs, and when the Aspera Arteria cometh over against the Fourth Verte∣bre of the Back, is divided into Two Branches, which being propagated in∣to the Lobes of the Left and Right Side of the Lungs, do sprout into fruitful Ramulets (like so many roots of a Tree) implanted into the sub∣stance of the Lungs.

The Wind-pipe consisteth of many parts, the head of it is called Larynx, the middle or single Tube may be called Bronchus, which is seated between

the Larynx and Lungs, and afterward it may be named Bronchia, from their Plurality as being many Branches, and Ramulets of the Bronchus, when they enter into the body of the Lungs, in most numerous sprouts.

The Larynx, or top of the Aspera Arteria, is composed of divers substances, which are Membranous, Cartilaginous, and Muscular, beset with many dif∣ferent Tubes, Importing and Exporting various Liquors, of which I intend a particular discourse in the next Chapter.

The middle of the Aspera Arteria, called the Bronchus, is also Membranous, and Cartilaginous (but not Muscular) inclosed too with various Vessels; and hath one continued single Duct, reaching from the Mouth to the Fourth Vertebre of the Back.

The Bronchia or Branches of the Wind-pipe, are integrated of divers sub∣stances, some part is membranous, and another Cartilaginous, and a Third wholly Membranous, as ministerial to different ends.

The Bronchia, when they are entred into the Body of the Lungs, alter the Figure of their Cartilages, and grow in some places perfectly orbicular; in others triangular and quadrangular; and when the Bronchia, associate with the Sanguiferous Vessels, they quit their Cartilages, and turn wholly Membranous, lest they should discompose the whole tender frame of the Vessels, by gauling them with their hard Compage, and when dilated, should too much narrow the small bones of the Sanguiducts, and hinder the motion of the Blood through the substance of the Lungs.

So that this curious Tube of Air hath a rare Mechanisme, as being a Compage made up of divers Integrals, Membranes, Cartilages, Arteries, Veins, Nerves, and Muscles, guarding the Heads of it, and are so many Machines ministerial to various motions of the Cartilages, productive of Speech.

The outward surface of the Wind-pipe, beside that of the Larynx, is en∣dued with divers Asperities, so that it seemeth unequal in many regular ranks of prominencies, and for the most part circular Cartilages; as with so many Ribs, and when this Cylinder is distended with Air, it is smooth in its hin∣der Region, as being a continued Membrane, destitute of Cartilages; but this Wind-Tube is full of unevennesses in its lateral and anterior Region, as the Membranes are interspersed with many protuberant Cavities, rising above them.

This surface of the outward Coat, being Membranous (as lodged be∣tween the numerous rows of Grisles) hath a connexion by the interposition of many thin Ligaments, to the upper part of the Aesophagus, and the Larynx is tied to the top of the Gulet, by the mediation of many small Muscles, which embracing the top of the Gulet, as in some part im∣planted into the buckler Cartilage, and the fore part and sides of the Wind∣pipe are affixed to the Blood-vessels, and chiefly to the recurrent Nerves, which are adjoyned to the Aspera Arteria.

The inward surface of the Wind-pipe (bating the unevennesses of the Car∣tilages, giving strength to the tender membranous structure) is very smooth and slippery, as anointed with an unctuous Matter.

The Wind-pipe is composed of many Membranes, of which the out∣ward is very thin (made up of many minute Fibres, running in different Positions, and curiously interwoven) by which it is tied to the annular Cartilages; This Coat is derived, as I conceive, from the Pleura, (the com∣mon reputed Parent of all the outward Membranes in the Thorax,) encom∣passing the Viscera.

The inward Membrane (investing the inside of the Aspera Arteria) is more thick then the former, and much contributeth to the Connexion of the Membranes with the annular Cartilages.

This inward Coat of the Wind-pipe is lined with a Mucilaginous hu∣mor, to soften the voice which is rendred hoarse, when this humor is mix∣ed with thin, or salt Catarrhs, or exsiccated by immoderate heat.

This unctuous humor, with which the inward Coat of the Aspera Arteria, is embrochated, is transmitted from the terminations of the Bronchial Arte∣ry; or when it doth abound, or is mixed with Saline Recrements, is the cause of a Cough, caused by discomposing the inward Coat of the Aspera Arteria.

The inward Coat is surnished with many Right and annular fleshy Fibres, which by contracting themselves, do give it a power to narrow the Cavity of the Wind-pipe, and by brisk Contractions, to throw up the offensive Matter, either lining the inward Coat of the Aspera Arteria, or thrown out the Bronchia of the Lungs into the greater Trunk, and afterward into the Mouth.

Between the outward and inward Membrane, is lodged an intermedial proper Coat of a divers substance from the other, partly Cartilaginous, and solid to form the sound of the voice; and partly ligamentous, whereupon it is capable to be expanded and contracted in successive Motions in the re∣ception and return of Air in respiration.

The use of this rough Artery is to receive and transmit Air by Inspiration, into the Lungs, through many small Pipes, branched every way through the substance of them; And also the Lungs when they have received the more volatil, nitrous, and elastick parts of Air into the mass of Blood, they throw out the more effaete and sluggish Atomes, with the fuliginous steams of the Blood, First, through the minute Pipes into a greater Trunk, and afterward into the Mouth.

Whereupon the Grand Architect hath most wisely contrived this fine Cylinder to be made for the greatest part of a membranous substance, to ren∣der it capable of Dilatation in the reception of the elastick Particles of Air in Inspiration, and to be able to contract it self in Expiration, when the Lungs do subside for the exclusion of Air, and the smoaky reeky vapours of the Blood.

This fine Tube is not only framed of a Membranous, but of a Cartila∣ginous substance too, as consisting of many grizly Rings, besetting the mem∣btanous Compage, to keep it constantly open for the free Ingress and Egress of Air, and the gross effaete steams of the Blood; and I humbly conceive that this choice Cylinder was furnished with numerous, almost circular Carti∣lages, to render it Rigid and Tense, in order to the formation of the voice, by making brisk verberations, or appulses of expired Air, against the inside of numerous Cartilages.

The Bronchia are furnished with an Artery (imparting many Branches to the Wind-pipe) First discovered by Ingenious Frederick Ruisch Hanc Ar∣teriam, inquit, Bronchialem appellare visum fuit, supra Bronchia enim Ser∣pens, ea concomitatur ad finem us{que} Ortum sumit ab Arteriae magnae descen∣dentis postica parte, digiti latitudine plus minus, supra supremas arteriolarum intercostalium, ex Aorta descendenti exortarum; aliquando etiam Duorum Di∣gitorum latitudine supra Arterias modo dictas; nonnunquam etiam infra eas, originem habere Comperio: placet enim naturae aliquando varietate frui. Nunc unica assurgit, nunc gemina, ita ut saepius, Arteria magnâ cadavere exemptâ,

intercostalibus & Bronchialibus abscissis, Trunculi Bronchialium remanentes, ex∣ortum Intercostalium mentiantur. Hinc pulmones oblique subit, Bronchia{que} sub Arteria venosa ad extremum us{que} Comitetur, donec Capillaris facta visus aciem effugiat. In pulmonibus humanis observavi, hanc Arteriam saepius anticam Bronchiorum perrepere partem, quod in brutorum pulmonibus raro vidi.

The Bronchial Artery branched over the Bronchia, is attended with nume∣rous Divarications of Branches of Veins, as the Associates of the Bronchial Artery, the one importing Blood to the Bronchia, and the other exporting it from them.

The Bronchia of the Lungs are not only beset with Arteries and Veins, but with Nerves too, as both their associates, which being derived from the Par Vagum, do transmit many Fibres into the Membranes of the Bronchia.