Hooper, Robert [Hrsg.]: The Anatomist's Vade-Mecum: Containing The Anatomy, Physiology, Morbid Appearances, &c. Of The Human Body ; The Art of making Anatomical Preparations, &c. To which are added Anatomical, Physiological, Medical, And Surgical Examinations For Students (London, 1811)

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4. A. communicans, which proceeds backwards, aud soon

inosculates with the vertebral.

The cerebral arteries are mostly ossified, or have opaci-
ties which are progressive to ossification, in old age.
In almost every instance of apoplexy in aged people,
from extravasated blood in the brain, not produced
from external violence, this diseased state of the
arteries exists.

The subclavian artery arises on the right side, from the

artcria iunotnin&ta j and on the left, from the arch of ths

aorta.

The subclavian artery is sometimes morbidly dilated.
Aneurism arising by the side of the clavicle has been
incautiously opened, by mistaking it for a common
abscess.

Each subclavian gives off five branches :

1. The internal mammary, from which arise the A. thymic*,
A. comes phrenici, the pericardiac, and the phrenico-pericar-
diuc.

2. The inferior thyroid, or inferior guttvral, from which
arise the ramxis thyroidevs, the tracheal arteries, the ascending
thyroid, and the transversalis humeri.

3. A. vertebralis, which proceed! into the vertebral forami-
na, to ascend into the cavity of the cranium, where it unitei
upon the cuneiform process of the occipital bone with its
fellow of the other side, and forms the basilary artery,
which immediately gives off the posterior artery of the cere-
bellum ; it then proceeds, upon the tuberculum annulare, to
give off four branches, two to the right, and two to ths left,
which constitute the A. anterior ccrcbclli, which branch to the
crura cerebelli, the cerebellum, vermis, crura cerebri, corpo-
ra quadrigemina, pineal gland, and fourth ventricle ; and the
A. posterior cerebri, which being joined by the communicant.