Carotid artery dissection Carotid artery dissection Carotid artery dissection is a separation of the layers of the artery wall supplying oxygen-bearing blood to the head and brain and is the most common cause of stroke in young adults. (In vascular medicine, dissection is a blister-like de-lamination between the outer and inner walls of a blood vessel, generally originating with a partial leak in the inner lining.) The signs and symptoms of carotid artery dissection may be divided into ischemic and non-ischemic categories: "Non-ischemic signs and symptoms" "Ischemic signs and symptoms" The causes of internal carotid artery dissection can be broadly categorised into two
Composition of the human body viewed on an atomic and molecular scale as shown in this article. The estimated gross molecular contents of a typical 20-micrometre human cell is as follows: Body composition can also be expressed in terms of various types of material, such as: There are many species of bacteria and other microorganisms that live on or inside the healthy human body. In fact, 90% of the cells in (or on) a human body are microbes, by number (much less by mass or volume). Some of these symbionts are necessary for our health. Those that neither help nor harm humans are called commensal