Melasma Causes. Melasma is usually caused by the sun, hormones in birth control pills, hormone replacement therapy, medications and pregnancy. When Melasma is caused by pregnancy it is called chloasma. In some women, when the skin is exposed to sunlight, brown blotches of excess pigment form due to the interaction with hormones or chemicals. Melasma is believed to be hereditary and woman with darker skin tones tend to be more at risk for this disorder.
Some research suggests that the hippocampus may participate only in consolidation processes lasting a few years. The entorhinal cortex, on the other hand, gives evidence of temporally graded changes extending up to 20 years, suggesting that it is this region that participates in memory consolidation over decades. The entorhinal cortex is damaged in the early stages of Alzheimerâs disease.
Brainstem. The brainstem is connected to the spinal cord at the back of the brain. The brainstem controls unconscious functions such as respiration, digestion, and pulse. Three structures comprise the brainstem: the midbrain, the pons, and the medulla oblongata.The midbrain controls eye movement and focus.uman Brain Anatomy. The human brain is the powerhouse and control center for all physiological and cognitive functions. The brain controls lower, unconscious physiological activities such as breathing, pulse, and digestion; and higher, conscious activities such as thinking, reasoning, and feeling.