Sciatica causes pain that begins in the lower back and spreads through the buttock, leg, calf and, occasionally, the foot. The pain generally will feel dull, aching or burning. Sometimes, it starts gradually, worsens during the night, and is aggravated by motion. Sciatica also can cause tingling, numbness or muscle weakness in the affected leg.
A callus (or callosity) is a toughened area of skin which has become relatively thick and hard in response to repeated friction, pressure, or other irritation.Rubbing that is too frequent or forceful will cause blisters rather than allow calluses to form.oo much friction occurring too fast for the skin to develop a protective callus will cause a blister or abrasion instead. Biologically, calluses are formed by the accumulation of terminally undifferentiated keratinocytes in the outermost layer of skin.
The corpus callosum is made of nerve fibers, deep in the brain, that connect the two halves of the cerebral hemispheres. Brain Stem. The brain stem is the bottom-most portion of the brain, connecting the cerebrum with the spinal cord.The midbrain, pons, medulla oblongata, and reticular formation are all part of the brain stem. Midbrain. The midbrain is the short portion of the brain stem between the pons and the cerebral hemispheres.he corpus callosum is made of nerve fibers, deep in the brain, that connect the two halves of the cerebral hemispheres. Brain Stem. The brain stem is the bottom-most portion of the brain, connecting the cerebrum with the spinal cord.