Mindblown: a blog about philosophy.

The superior vena cava is the large vein which returns blood to the heart from the head, neck and both upper limbs. The inferior vena cava returns blood to the heart from the lower part of the body. The return of blood via the vena cava can be compromised and cause disease. For example, in the superior vena cava…

Medical term for a hangover. From the Norwegian kveis (uneasiness following debauchery) + the Greek algia (pain).

A blood vessel that carries blood that is low in oxygen content from the body back to the heart. The deoxygenated form of hemoglobin (deoxy-hemoglobin) in venous blood makes it appear dark. Veins are part of the afferent wing of the circulatory system, which returns blood to the heart. In contrast, an artery is a vessel that carries blood that…

In medicine, a carrier of disease or of medication. For example, in malaria a mosquito is the vector that carries and transfers the infectious agent. In molecular biology, a vector may be a virus or a plasmid that carries a piece of foreign DNA to a host cell.

A blood test for syphilis (VDRL stands for Venereal Disease Research Laboratory) that detects an antibody that is present in the bloodstream when a patient has syphilis. A negative (nonreactive) VDRL is compatible with a person not having syphilis, but in the early stages of the disease, the VDRL often gives false negative results. Conversely, a false positive VDRL…

A reflex of the involuntary nervous system that causes the heart to slow down (bradycardia) and that, at the same time, affects the nerves to the blood vessels in the legs permitting those vessels to dilate (widen). As a result the heart puts out less blood, the blood pressure drops, and what blood is circulating tends to go into…

A reflex of the involuntary nervous system that causes the heart to slow down (bradycardia) and that, at the same time, affects the nerves to the blood vessels in the legs permitting those vessels to dilate (widen). As a result the heart puts out less blood, the blood pressure drops, and what blood is circulating tends to go into…

Relating to the nerves and muscles that cause blood vessels to constrict or dilate.

Agents that act as blood vessel dilators (vasodilators) and open vessels by relaxing their muscular walls. For example, nitroglycerin is a vasodilator. So are the ACE (angiotensin converting enzyme) inhibitors.

Widening of blood vessels that results from relaxation of the muscular walls of the vessels. What widens in vasodilation is actually the diameter of the interior (lumen) of the vessel. The opposite of vasodilation is vasoconstriction.