The brain and spinal cord form the human body's central nervous system. The spinal cord is the primary pathway by which the body conducts sensory information from the peripheral nervous system to the brain. The brain processes sensory input and initiates the execution of coordinated motor output from the brain to effector muscles, which include skeletal, cardiac and smooth muscles. Diseases such as multiple sclerosis, amyotrophic lateral sclerosis and acute bacterial meningitis affect and deteriorate the brain and central nervous system.
Multiple Sclerosis
Multiple sclerosis is an inflammatory disease that results in the primary demyelination of myelin sheaths in the white matter of the brain. The nerve fibers of the brain and spinal cord are covered with myelin sheaths, a fatty substance that insulates neural cells and increases the speed by which nerve impulses are transmitted between the brain and spinal cord. According to the Nationalalmsociety.org, the destruction of the myelin sheath in multiple sclerosis results in the distortion or interruption of neurotransmission thereby resulting involuntary movements and involuntary contraction of muscles.
Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis, also known as Lou Gehrig's disease, is a progressive, neurodegenerative diseases of the motor neurons, notes Alsa.org. Motor neurons initiate voluntary muscle contractions in the brain. This sensory input extends from the brain to the spinal cord and finally ends in muscle fibers throughout the body. The progressive degeneration of motor neurons results in an inability of the brain to send neural impulses to muscle fibers and initiate muscle movement, thereby resulting in muscle atrophy or death. Initial symptoms of amyotrophic lateral sclerosis include muscle weakness, especially in the arms and legs, as well as problems with speaking, breathing and swallowing. As amyotrophic lateral sclerosis progresses, the muscles in the chest atrophy as well, resulting in respiratory failure and, eventually, death.
Acute Bacterial Meningitis
Acute bacterial meningitis is a rapidly developing inflammation of the meninges, the membrane that covers the brain and spinal cord, as well as the cerebrospinal fluid. Bacterial meningitis is most commonly caused by Neisseria meningitidis and Streptococcus pneumoniae. According to the National Institute of Neurological Disorders and Strokes, a bacterial infection of the meninges causes the immune system to react and defend the body against the foreign invaders, resulting in inflammation of the brain and spinal cord. Inflammation of the meninges causes blood clots resulting in a stroke as well swelling and bleeding in small areas of the brain. Severe swelling of the brain increase the pressure within the skull, causing the brain to shift other parts of skull. This shifting of the skull can cause parts of the brain to be pressed through small openings in the brain tissue, resulting in brain herniation.
