Engines that do not have a water cooling system can not use a heater core; one alternative is to guide air around the (very hot) engine exhaust manifold and then into the vehicle's interior. Temperature control is achieved by mixing with unheated outside air.
1. A widening of the prevertebral soft tissue is often associated with injury to the cervical spine. Injury to the cervical spine may be accompanied by pre and/or paravertebral haematoma, which is radiographically demonstrated as an abnormal increase within the width of the prevertebral space [1] , [2] and [3] .his study was undertaken to explore the diagnostic value of prevertebral soft tissue swelling with special reference to the association of this sign with the presence and degree of cervical spine injuries.
A precapillary sphincter is a band of smooth muscle that adjusts blood flow into capillaries mainly in the mesenteric microcirculation. At the point where each of the capillaries originates from an arteriole, a smooth muscle fiber encircles the capillary. This is called the precapillary sphincter.The sphincter can open and close the entrance to the capillary, by which contraction causes blood flow in a capillary to change as vasomotion occurs.he entire capillary bed may be bypassed by blood flow through arteriovenous anastomoses or through preferential flow through metarterioles. If the sphincter is damaged or cannot contract, blood can flow into the capillary bed at high pressures.