Cerebral arteriovenous malformation locations may stop the circulation of the cerebrospinal fluid, causing accumulation of the fluid within the skull and giving rise to a clinical condition called hydrocephalus. A stiff neck can occur as the result of increased pressure within the skull and irritation of the meninges. AVMs are an abnormal connection between the arteries and veins in the human brain. Arteriovenous malformations are most commonly of prenatal origin. In a normal brain oxygen enriched blood from the heart travels in sequence through smaller blood vessels going from arteries, to arterioles and then capillaries. Oxygen is removed in the latter vessel to
Internal elastic lamina Internal elastic lamina The internal elastic lamina or internal elastic lamella is a layer of elastic tissue that forms the outermost part of the tunica intima of blood vessels. It separates tunica intima from tunica media. It is readily visualized with light microscopy in sections of muscular arteries, where it is thick and prominent, and arterioles, where it is slightly less prominent and often incomplete. It is very thin in veins and venules. In elastic arteries such as the aorta, which have very regular elastic laminae between layers of smooth muscle cells in their tunica media, the internal elastic lamina