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The Nervous System. Don’t get nervous about the nervous system. Functions of the Nervous System. 1. Communication and coordination Adapt and respond to changes from both inside and outside the body 2. Site of reasoning- your brain 3. Two main divisions
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The Nervous System Don’t get nervous about the nervous system
Functions of the Nervous System • 1. Communication and coordination • Adapt and respond to changes from both inside and outside the body • 2. Site of reasoning- your brain • 3. Two main divisions • Central nervous system (CNS): brain and spinal cord • Peripheral nervous system- the nerves
Neuron- basic structural unit of the nervous system • Dendrites- carry impulses towards the cell • Axon-carry impulses away from the cell • Myelin sheath • Synaptic terminal • Epinephrine • Norepinephrine • Acetylcholine
Nerves are made of many nerve cells • Afferent-sensory nerves carry message to brain • Efferent-motor neurons carry message from brain to muscle • Associate- do both • Heads up
Central nervous system • Brain and spinal cord
Cerebrum-largest part of brain. Responsible for reasoning, thought, memory, speech, sensation, etc. • Divided into two halves. • Further divided into lobes; occipital, parietal, temporal and frontal
Cerebellum-responsible for muscle coordination • Brain stem- most basic functions; respiration, swallowing, blood pressure. Lower part (medulla oblongata) is continuous with spinal cord
Spinal cord- begins at foramen magnum and ends at second lumbar vertebrae • Contains both afferent (to the brain) and efferent (motor neurons- away from the brain)
Both the brain and spinal cord are covered by a membrane system called the meninges • In addition, the brain has four hollow areas called ventricles. Cerebrospinal fluid is produced in the ventricles and baths the brain and spinal column
Peripheral nervous system • Somatic system • 12 pairs cranial nerves • 31 pairs spinal nerves • Autonomic • Sympathetic • Fight or flight • Parasympathetic
Disorders of the nervous system • Meningitis- inflammation of the linings of the brain and spinal cord • Encephalitis- inflammation of the brain • Epilepsy-seizure disorder. Excessive discharge from neurons. 1 in 200 suffer. Grand mal or petit mal seizures • Cerebral palsy- disturbance in voluntary muscular action • Parkinson’s –decreased neurotransmitter • MS multiple sclerosis- autoimmune