Mikrokosmographia a description of the body of man. Together vvith the controuersies thereto belonging. Collected and translated out of all the best authors of anatomy, especially out of Gasper Bauhinus and Andreas Laurentius. By Helkiah Crooke Doctor of Physicke, physitian to His Maiestie, and his Highnesse professor in anatomy and chyrurgerie. Published by the Kings Maiesties especiall direction and warrant according to the first integrity, as it was originally written by the author.

CHAP. VII. Of the Mediastinum.

THE Mediastinum so called, because it mediateth or diuideth the Chest in the middest. Collumbus calleth it Intersepimentum and Dissepimentum, a, a hedge * 1.1 that diuideth two Pastures. It is double: The right [Tab. 3. ^GG the right, ^HH the left] and the lefte, which Galen calleth 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, because they diuide the cauitie of the Chest, which the Pleura encompasseth into two partes. For the cauitie of the Chest is not one open and continuall, but is diuided by these membranes. Wherefore in the middle of the chest there is one on either side which passe from aboue * 1.2 downeward according to his Longitude euen vnto the Midriffe, and backeward from the Breast-bone vnto the Racke-bones, so that the chest is by this meanes diuided into two cir∣cles, or if you had rather, they frame a certaine Triangle of vnequall and oblique sides, for they haue space enough to resemble this Figure: because of the deapth and length of the Breast.

These Membranes do arise from the pleura, which where it climbeth from his originall * 1.3 on either side to the sides of the breast bone, creepeth so backe againe towardes the ridge where his beginning was, that it attaineth from the middest of the breast to the very spine of the backe. These are thinner then the pleura, and softer that they may more easilie fol∣low the motion of the heart; on the outside as they looke to the Lungs (to which they som∣times * 1.4 grow) they are smooth, and oftentimes about the vesselles they appeare interlaced with much fat, so as they may bee compared to the Kall or Ome tum; on the inside rough, because of the Fibres with which the Membranes are ioyned, as also to the Pericardium; and in the hollow of the throate the Thymus so called (of which we shall heare afterwards) groweth vnto them. Heere, according to the length of the racke-bones of the backe vnto which they are ioyned by the mediation of the pleura, they euen touch together, and make but a very narrow cauity, but are after by degrees seuered and at the Breast-bone stand as wide asunder as the Breast-bone is broade, to which they cleane euen from one end of it to the other; and this distance [Tab. 3. ^LL] is intertexed or wouen between with diuers thred∣dy * 1.5 Fibres and Membranes; but they are widest asunder and make the largest distance at the Diaphragma or Midriffe, to which they are ioyned as far [Tab. 2. fig. 1; ^A] as his neruous part reacheth, insomuch that this cauity which is smooth and moist, before containeth the heart knit vp in his purse and the hollow-veine ascending vpward, and behinde the gullet with the * 1.6 stomacke Nerues.

In the fore-part of this Cauity there is oftentimes a matter conteyned, which causeth a disease resembling a Pleurisie, which matter if the breast-bone (saieth Columbus) bee verie cunning he perforated may bee safely drawne out. In Dogges this Cauitie is more large * 1.7 but hath no such webbe of Fibres as in a man. The Veynes and Arteries that it hath are

[illustration]

Table 3. sheweth the middle belly before and at the sides, bared from the skinne to the Muscles, wher∣in also the brest-bone with the gristles of the ribs are separated from the Mediastinum and reflec∣ted backewarde, that those thinges vvhich are conteyned in the Chest may better bee percey∣ued.

[illustration]

TABVLA III.

• A A A. The middle A. is the inside of the brest-bone; the other two shew the inside of the gristles and the ribs ioyned together.
• B, C. The Mammary veines descending vnder the brest-bone vnto the right Muscles.
• D, E. the Mammary arteries descending
• F. Certaine glandules or kernels about the Coller bone, apointed to secure the distribution of the vessels.
• G G, H H. The right and the left place of the Mediastinum, which before the diuision of it did grow vnto the brest-bone.
• I, K. The right & left superficies of the same Mediastinū, which is next to the lungs.
• L L. The distance betwixt the Mem∣branes of the Mediastinum.
• M M. This swelling place sheweth the scite of the left part of the heart.
• N. The vpper part of the right Lobe of the Lungs.
• O. The lower part of the right Lobe of the Lungs.
• P. The vpper part of the lefte Lobe of the Lungs.
• Q. The lower part of the lefte Lobe of the Lungs.
• R R. The Midriffe separated from the brest-bone, and from the tops of the gristles which cleaue vnto it.
• S. The Gristle called the brest-blade.
• T, V. The skin drawn downward from the foreside of the Chest.

very small from the Mammary [Tab. 3. ^BCDE] which passe from the hole of the throat down∣ward vnder the brest-bone, from which in their passage as also from the vein Non-paril they borrow a surcle. [Tab. 2. fig. 1. ^OO, from the Mammary vessels.] Moreouer in a man it recei∣ueth a good large veine out of the hollow of the throate, which descendeth accompanyed with a Nerue [Tab. 2. fig. 1, ^Q] by the whol length of both the Membranes to the Midriffe, but groweth onely to their outside; sometimes also it receiueth small branches from those Vessels which we haue before named Phrenicae that is the vessels of the Midriffe.

The vse of this Mediastinū or bound hedge is first to hold the hart vp suspended (for being * 1.8 tyed to the purse of the heart it must needs do that office) lest if it had no such tye, but hung downe at liberty, in the diuerse position of the body it might fal to the sides, to the brest, to the spine, or else downward. Secondly, this serues to strengthen and secure the passage of the vessels. Moreouer, it incompasseth the parts conteyned in the Chest that they should not hurt the Lunges in his motion. And finally, it diuideth the Chest into two partes or * 1.9 cauities which is their chiefe profit saith Galen in the 3. chapter of his 6. Booke de vsu part. so that if one part be hurt, yet the other may be safe: as wee haue knowne a theefe Anato∣mized who was a strong and stout fellon, but had one side, that is, the right side of his lungs * 1.10 withered almost all away and dryed vp into a very small quantity, but the other remained faire and fresh as any other mans. So in wounds, if one part bee very sorely wounded, so

that because of the entrance of the outward aer the motion of the Lungs do cease; yet the other part will not be wanting to susteine life by performing his part of the worke. For, if both parts of the Lungs be wounded any thing wide through, the voice and respiration to must needs perish: although I saw when I was a Boy a Knight wounded quite thorough * 1.11 the backe on both sides the bone, and so deepe that on both sides in his dressing his breath would at the mouth of the wound blow out a Candle, and yet the Patient hath perfectlye recouered. And this shall suffice to haue spoken of the Conteyning parts of the Chest, e∣specially of those that are soft, for the hard parts which are the bones and the gristles, will fall out better to be handled afterward. Now wee will pursue our Historie vnto the partes conteyned.

Notes

• * 1.1

  The Media∣stinum. His Names.
• * 1.2

  His scituation
• * 1.3

  His originall.
• * 1.4

  His substance
• * 1.5

  Their distāce.
• * 1.6

  Wher the di∣stāce is widest
• * 1.7

  A disease re∣sembling a Pleurifie.
• * 1.8

  The vses of this Mediasti∣num.
• * 1.9

  Their cheefe vse.
• * 1.10

  A strong and stout mā with one Lung.
• * 1.11

  〈…〉〈…〉 Euers.