The partially digested food arriving from the stomach stimulates the duodenum to produce hormones. These hormones tell the pancreas to release digestive enzymes, and the gallbladder to release bile. Much of the food digestion takes place in the duodenum.
Vertebral artery dissection (abbreviated VAD, often vertebral dissection) is a dissection (a flap-like tear) of the inner lining of the vertebral artery, which is located in the neck and supplies blood to the brain.fter the tear, blood enters the arterial wall and forms a blood clot, thickening the artery wall and often impeding blood flow. The symptoms of vertebral artery dissection include head and neck pain and intermittent or permanent stroke symptoms such as difficulty speaking, impaired coordination and visual loss.
The vertebral and basilar arteries supply blood to several structures in the brain including: the occipital cortex, the brainstem consisting of the midbrain, pons and medulla, the cerebellum and the thalamus. Atherosclerosis or hardening of the arteries is the primary cause of vertebrobasilar disease. The narrowing of the vertebral or basilar arteries caused by atherosclerosis creates vertebrobasilar insufficiency (VBI), or an insufficient delivery of blood flow to the posterior structures of the brain.