Development of ischemia
Under ordinary conditions, the colon receives between 10% and 35% of the total cardiac output. If blood flow to the colon drops by more than about 50%, ischemia will develop. The arteries feeding the colon are very sensitive to vasoconstrictors; presumably this is an evolutionary adaptation to shunt blood away from the bowel and to the heart and brain in times of stress. As a result, during periods of low blood pressure, the arteries feeding the colon clamp down vigorously; a similar process can result from vasoconstricting drugs such as ergotamine, cocaine, or vasopressors. This vasoconstriction can result in non-occlusive ischemic colitis. Pathologic findings
A range of pathologic findings are seen in ischemic colitis, corresponding to the spectrum of clinical severity. In its mildest form, mucosal and submucosal hemorrhage and edema are seen, possibly with mild necrosis or ulceration. With more severe ischemia, a pathologic picture resembling inflammatory bowel disease (i.e. chronic ulcerations, crypt abscesses and pseudopolyps) may be seen. In the most severe cases, transmural infarction with resulting perforation may be seen; after recovery, the muscularis propria may be replaced by fibrous tissue, resulting in a stricture. Following restoration of normal blood flow, reperfusion injury may also contribute to the damage to the colon. Diagnosis
Ischemic colitis must be differentiated from the many other causes of abdominal pain and rectal bleeding (for example, infection, inflammatory bowel disease, diverticulosis, or colon cancer).
Cervical spinal nerve C7 controls triceps and wrist extension. Cervical spinal nerve C8 helps control the hand. The cervicocranial syndrome occurs when symptoms arise due to cervical vertebrae damage (misalignment, collapse, shift or disease, such as tumor) resulting in the improper functioning of the cervical spinal nerves. Examples of Cervicocranial Syndrome Pathophysiology
Chordoma
The craniocervical junction region comprises C1 (Atlas), C2 (Axis) and the lower part of the skull: occipital bone. In case of tumor: chordoma, in the craniocervical junction region, this leads to pressure on the cervical spinal nerves, which results in their improper functioning of the cervical spinal nerves. Hence, leading to symptoms of cervicocranial syndrome. To decompress the pressure on the nerves, the tumor is removed and the foramen through which the spinal nerve roots travel through is enlarged to allow the nerves to pass through so that symptoms of cervicocranial syndrome can be reduced and the nerves are sending signals. Atlanto-Occipital Assimilation
When the occipital bone and the atlas (C1) are fused together in a condition called atlanto-occipital assimilation, it causes improper functioning of the cervical spinal nerves due to the vascular compression. Surgical procedure can decompress the nerves and reduce symptoms. Trauma
Traumatic injuries are caused when external forces damage the cervical spine, giving rise to various symptoms. In a car accident, the vehicle jerks the neck forward and backward resulting in cervical spine damage resulting in a whiplash.