Dura Mater

[John Dolva]

Dura Mater.

How does an exit/entry hole, inferred small and round from how the tissue is damaged and how the hair is plastered back by blood and brain,

and

a break in the dura mater just inside the skull outside the brain, seen here side on but inferred circular from how edges are frayed.

and the major visible damage on right middle side of head.

being all in line

get caused by a bullet trajectory prerpendicular to this line of damage?

[Pat Speer]

John, one of the things that led me to my conclusion that the bullet at 313 struck Kennedy at the large defect, and that the small entrance came from an earlier shot, was reading a book on wound ballistics--perhaps the first one--written by the WW1 military surgeon Edmond De Lorme. De Lorme says that the dura mater is regularly torn at entrance but not at exit. When I thought about it it made sense. A bullet or fragment pressing the dura against the brain will cause the dura to stretch for a spell before the dura tears and the bullet or fragment enters the brain , while a bullet or fragment exploding from within will cut through the dura when it's pressed against the hard skull.

[John Dolva]

The dura is a tough flexible membrane covering the brain. The Dura Mater is the part which separates the two hemispheres of the brain.

In the top left of this image is the skull removed withoiut damaging the dura. The dura mater is seen edge on as the ridge running from top to bottom in the middle of the exposed dura.

In the image on the left, the area of Kennedy's head where the dura should be seen has had the dura superimposed to see what it would be undamaged.On the right is the damage shown.

In the top middle inset the circles show undamaged and damaged areas where the dura mater appears to have been penetrated. It seems to me that this would be impossible for a shot from the rear.

____________

Pat, the point about the dura stretching is interesting.

Another consideration is that this is a tough membrane, and skin itself is surprisingly bullet proof at low velocities which may be the case for a bullet or fragment having entered elsewhere.

What I'm getting at is that if this dura mater damage was caused by something that travelled from inside the head through the dura mater (twice as it is doubled at this point), through the skull and through the skalp to cause a small circular hole that thing would have to be at very high velocity and uniform in shape and heavy, in other words an intact bullet would do nicely,

which is ridiculous

More likely, is a bullet entering at this point.

[John Dolva]

As a further visual aid, here is an inside view of the top of the skull showing the dura mater

[John Dolva]

The mater appears to be a bit more complex:

In this image:

The dura mater is made up of two layers, the Periosteal, and Meningeal.

Between the dura mater and the brain is the Arachnoid mater.

And covering the convolutions of the brain proper is the Pia mater.

Between the Dural and the Arachnoid mater is a subdural space, and between the Arachnoid and the Pia mater is a subarachnoid space.

Down the midline of the head between the Periosteal and the Meningeal (which makes up the Dura Mater) is a space called the Superior sagittal sinus.

Above the Periosteal comes the skull bone, and above this the scalp, made up of the Periosteum and the Skin and hair.

The Meningeal part of the Dura Mater that dips down to form the divider between the hemispheres of the brain is called the Falx cerebri.

So, technically this topic should be called the 'Falx Cerebri'.

No matter, it becomes clearer over time.

__________________

So the object that punched a hole through the Skin and the fringe of the Falx cerebri, passed through

skin

periosteum

bone of skull

periosteal

meningeal

sinus

space

arachnoid

space

pia

and brain

with the meningeal,arachnoid,and pia layers probably twice.

These are not insubstantial materials, they have hardness, strenth, toughness and flexibility.

It seems to me far easier to assume a relatively heavy intact bullet at high velocity, rather than a slow velocity fragment achieving this apparently neat round small puncture. Therefore, the bullet that struck kennedy at this point came from his front left.

[John Dolva]

The top of the head photo used here has been colorised at high res using the smaller color photo as base.

Here is attempt at separating blood:

full size: http://i27.photobucket.com/albums/c168/yan.../Untitled-8.jpg