CHAP. IV. Of Membranes in General, of the fleshy Membrane, and the Membrane which is proper to the Muscles.
UNder the fat in a Man, the Mem∣brana* 1.1 carnosa, or fleshy Mem∣brane lies, which in Apes, Dogs, and Sheep lies next the Skin. Before we treat thereof, some things are to be known concerning the Nature of a Membrane in general.
The Ancients called the Membranes Hymenas, and sometimes Chitona's Coats, also Meningas; and other∣whiles Operimenta, and Tegumenta Coverings; and with Galen and other Anatomists, speaking in a large Sense, a Coat and a Membrane, are one and the same thing. But when they speak in a strickt and proper Sense.
That is a Membrane which com∣passes some bulkie Part, as the Pe∣ritonaeum,* 1.2 the Pleura, the Periosti∣um, the Pericardium, and the pecu∣liar Membranes of the Muscles.
But the term Tunica or Coat in a strickt sense, is attributed properly to the Vessels, as Veins, Arteries, Ureters, the Womb, the Gall-blad∣der, and the Piss-bladder, the Gullet, the Stomach, the Guts, the Stones.
The term Meninx is properly given and peculiarly to the Membranes of the Brain.
Now a Membrane is a simi∣lar part broad, plane, white,* 1.3 and which may be stretched, made by a proper Membrane-making faculty, of clam∣my and watery Seed, to the end that it might by cloa∣thing defend the Parts.
The Form thereof is the equality of its Surface, Thinness, and Lightness (least it should burden) com∣pactness and strength that it might be widened and stretched.
Its Use is 1. To cloath and defend the Parts by reason of its hardness and com∣pactness;* 1.4 and to be the Instrument of feeling: For the Parts feel by help of the Membranes. And so great is the necessity of Membranes, that Na∣ture hath covered every Part with a Membrane. 2. To strengthen the parts. 3. To defend the parts from the injury of the Cold, and to keep the Natural Heat from exhaling. 4. To joyn parts with parts. So the Me∣sentery knits the Guts to the Back. 5. To shut the mouths of the Vessels, least the Humors should flow out, or flow back: As in the Bladder, where the Ure∣ters are implanted, in the Ventricles of the Heart, by the Valves.
Now a Membrane is thicker or thin∣ner.* 1.5
The thin Membrane differs in thin∣ness. For the Periostium of the Ribs is thinner then the Pleura, the Periostium of the Head, is thinner then the Pericraneum; the pia mater is thin∣ner then the dura mater.
The thick Membrane is the Membrana carnosa, which is not every where alike thick; for it is thicker in the Neck then other places. And now let us speak of the Membrana carnosa, or fleshy Membrane.
The Panniculus carnosus or Mem∣brana* 1.6 carnosa is by some termed a membranous Muscle, by others a Nervie Coat, a fattie Coat, &c. It is termed fleshy, because in some places, as about the Forehead, the compass of the Neck, and the Ears, it turns to a musculous flesh, and in such Creatures as by the help hereof can move their whole Skin, it seems to be a Muscle: It is endued with such fleshy Fibers, es∣pecially in their Necks, by the motion whereof they drive away flies. But in Man, save in his Forehead, it is immoveable; only Vesalius and Valverda report that there were some men who could move the Skin on their Chest and Back, and in other parts, just as oxen do. In whom doubtless this Membrane was made of the same constitution, which it hath in Brutes. More∣over in new-born Children, it resembles flesh, by rea∣son of plenty of blood; in grown persons it is like a Membrane, by reason of continually being dried. In a Mans Body, if exact Separation be made, it will ap∣pear to consist of four distinct Membranes. Spigelius and others do take those membranous Fibers, which are every where interwoven among the Fat, to be Pan∣niculus carnosus, or Membrana carnosa.
Its Use is 1. To defend the neighbor∣ing* 1.7 Parts, yea, and to cover and defend the whole Body, and therefore it is situate all over the bo∣dy.
2. To keep in the Fat, that it flow not out, or melt by reason of the continual motion of the Muscles.
3. To support those Vessels which are carried into the Skin (which go between* 1.8 the Skin and this Membrane) for it is knit unto the Skin by very many Veins, some fewer Ar∣teries, branches of Nerves, and membranous Fibers; and to the Membranes under the Muscles, by the smal∣ler Fibers. It is therefore false, that when the Fat is consumed by fasting, the Skin sticks to the Muscles no otherwise, then a Ball to a peice of cloth wherewith it is covered. It sticks most* 1.9 firmly to the Back, in fashion of a Mem∣brane, and therefore it is said to arise from thence. In the former part of a Mans Neck and his Forehead, it can hardly be separated from the Skin and the Muscu∣lus latus; it sticks so close, and is thought to constitute the Musculus latus.
The Surface thereof is slippery, there where it tou∣ches the Muscles, by reason of that clammy Humor, which is wont to be daubed upon the Membranes, least the motion of the Muscles should be hindred. It is of exquisite sense; and therefore if it be twitched by a sharp Humor, it causes shivering and shaking, as by Choler in Agues.
The proper Membrane of the Muscles,* 1.10 which some will have to spring from the Pericranium or Periostium, others from the nervous Fibers of the Mus∣cles, is thin, and is knit unto the Muscle, by most thin filaments.
Its Use is 1. To cloath the Muscle* 1.11 and separate them one from anothe•• 2. To impart unto them the Sense of 〈…〉〈…〉