Choroid plexuses

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A Moment in History

William S. Halsted, MD
(1852 – 1922)

American anatomist, teacher, and surgeon, William Stewart Halsted was born in New York City, USA to a wealthy family of English origin. His father was involved in charitable work and Governor and trustee to a city hospital. Not a brilliant student initially, Halsted took an undergraduate in Liberal Arts in Yale, CT., after which he entered the Medical College of Physicians at the Columbia College, where he excelled.

As a second-year medical student Halsted applied and obtained a position in surgery at a local hospital. In here he learned about Lister’s antiseptic technique and became an adamant proponent of it to reduce infection. In 1877 Halsted obtained his MD. After a short time as House Physician at the New York Hospital, Halsted traveled to Europe to further his education studying for two years at the Universities of Vienna, Leipzig, and W?rzburg.

Besides being at the forefront of surgical and antiseptic techniques (introducing the use of rubber gloves in surgery), Halsted was extremely concerned with the way medical students were taught in the US. He pioneered bedside clinical round discussions with the medical students after two years of basic sciences studies. Halsted developed the idea of a patient chart; he also developed the residency program for medical students in use today.

Halsted is probably the most influential researcher and surgeon at the turn of the century. He dedicated time to the study of intestinal anastomoses and the use of silk as a suture material. His experimental work in 1887 proved that the inclusion of the submucosa layer in an anastomosis was mandatory, as well that a single layered anastomosis was enough to attain closure. Perhaps Halsted’s most important contribution was the application and use of the scientific method to surgical questions. Halsted’s principles, also known as "Halsted's Rules of Surgery", set the standards used today in surgical suturing and surgical stapling.

He also pioneered the development and surgical techniques for radical mastectomy as a treatment for breast cancer.

As a side effect of this studied in anesthesia and the use of cocaine for anesthesia, Halsted became addicted to this substance, a problem that followed him through the years. Without impairing his capacity as a researcher and a surgeon, Halsted eventually recovered. He died in Baltimore in 1922 as a complication to surgery.

Sources:
1. Dubay, A. D., & Franz, G. M. (2003). Acute Wound Healing: The Biology of Acute Wound Failure. Surg Clin NA, 83, 463-481.
2. Halsted, W. S. (1887). Circular Suture of the Intestine - An Experimental Study. Am J Med Sci, 436-461.
3. “William Stewart Halsted: his life and contributions to surgery” Osborne, P. Lancet Oncol 2007; 8: 256–65
4. “William Stewart Halsted: Surgical pioneer” Burress, P Endoc Today (2010), 8: (2) 22
5. “William Stewart Halsted (1852–1922) Neurological stamp” Haas, LF J Neurol Neurosurg Psych 2000;69:641
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Details: Published: June 05, 2015

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UPDATED: The choroid plexuses are highly vascular structures situated in the ventricular system of the brain. They are formed by convoluted capillaries surrounded by modified ependymal cells. The choroid plexuses are responsible for the constant formation of the cerebrospinal fluid (CSF), as well as part of the blood-brain barrier, which in this case should probably be called the blood-CSF barrier.

The choroid plexuses are found in each ventricle of the brain. The accompanying image shows a dissection of a human brain where the frontal, parietal, and occipital lobes, as well as the corpus callosum have been removed to expose the lateral ventricles. The trigone has been transected and reflected posteriorly and the choroid plexuses can be seen as a cluster of grape-like longitudinal masses in each lateral ventricle.

Choroid plexuses form when three elements come in contact within the brain: pia mater, ependymal epithelium, and blood vessels. This only happens in the ventricular system of the brain.

The etymology (word origin) of the term [choroid] is a bit complicated. The suffix [-oid] means "similar to", while the root term [chor-] derives from the Greek word [χορίου] pronounced (joríu), meaning "dermis", "skin", or "membrane". The reason for the use of this term is that the Greek used the term "membrane" referring to the highly vascularized membranes that invest a fetus.

The term "plexus" means a "mesh", so the term [choroid plexuses] means "similar to the vascular membranes that invest a fetus"

Sources:
1. "Medical Meanings, A Glossary of Word Origins" Haubrich, W.S. 1997. American College of Physicians, Philadelphia, PA.
2. "Elementos de Neuroanatomia" Fernandez, J.; Miranda, EA.

Choroid plexuses

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