Discuss in detail about the Close Head Injuries

Closed-head injuries result from a blow to the head, which can subject the brain to a variety of mechanical forces:

• Damage at the site of the blow, a bruise (contusion) called a coup, is incurred where the rain has been compacted by the bone's pushing inward, even when the skull is not fractured.
• The pressure that produces the coup may push the brain against the opposite side or end of the skull, producing an additional bruise, known as a countercoup.
• The movement of the brain may cause a twisting or shearing of nerve fibers, producing microscopic lesions. In addition, twisting and shearing may damage the major fiber tracts of the brain, especially those crossing the midline, such as the corpus callosum and anterior commissure. As a result, connection between the two sides of the brain may be disrupted, leading to a disconnection syndrome.
• Bruises and strains caused by the impact may produce bleeding (hemorrhage). Because the blood is trapped within the skull, it acts as a growing mass (hematoma), exerting pressure on surrounding structures.
• As with blows to other parts of the body, blows to the brain produce edema, another source of pressure on the brain tissue.