Pyogenic infective diseases of the brain and spinal cord : meningitis abscess of brain, infective sinus thrombosis.

  • MacEwen, William, Sir.
Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: Pyogenic infective diseases of the brain and spinal cord : meningitis abscess of brain, infective sinus thrombosis. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    extra speed of the blood from the inferior petrosal sinus ensures the continuity of the flow from the sigmoid sinus into the jugular vein. It is also possible that the flow of blood through the inferior petrosals may be further hastened by the pulsations of the two internal carotids, acting on either side of the cavernous sinus like a hand pressing gently on an india-rubbber ball. The various positions which the head may assume affect the mechanism, but they are met by the multiplicity of curves which serve in their turn the above function, and the principle of the mechanism is preserved.1 It is also interesting to note that the foetal distribution of the vessels is different from that just described. At an early period of foetal life the lateral sinus pours its blood into the petro-squamosal sinus, which in turn empties itself into the external jugular vein. In the foetus there is no lung breathing, and consequently no aspiration. Therefore the special mechanism which would guard against aspiration is not required, and the passage of blood into the heart takes a less tortuous and more direct course. Here, therefore, is a beautiful mechanism for retarding the flow of blood, and shutting it off from the aspiratory influence to which it would otherwise be subjected, so that the brain is guarded against the sudden loss of functional activity and faint- ness, which would otherwise be brought about by the sudden withdrawal from, and the constant variation of, the quantity of blood within it. At the same time, a strong aspiratory force is applied, which quickly withdraws the blood discharged from the sinuses, once it has escaped from the jugular fossa, and so prevents any impediment to the flow. Lymphatics.—The lymphatics from the scalp pass into the occipital, the mastoid, and the parotid lymphatic glands, while those from the forehead join the facial lymphatic vessels. The lymphatics of the face are divided into two sets, a superficial and a deep. The former, following the course of the facial vein, terminate in the submaxillary and parotid lymphatic glands; the latter, including those of the orbit and nasal cavity, end in the internal maxillary glands. The intracranial lymphatics have their origin in the cerebral pia mater and in the choroid plexuses 1 Mr. Blyth of Anderson's College, Glasgow, suggested the need of increased speed in the flow of the inferior petrosal in order to make the mechanism hydraulically perfect. Dr. Thomson thoughtthe pulsations of the carotids might facilitate the flow through the cavernous sinus into the inferior petrosals.