1. Section 7.4 Effects of Aging

2. Introduction 1. The nervous system is formed during the first month of embryonic development 2. Any maternal infection can have extremely harmful effects 3. The hypothalamus is one of the last areas of the brain to develop 4. No more neurons are formed after birth, but growth and maturation continues for several years (new evidence!) 5. The brain reaches maximum weight as a young adult 6. However, we can always grow dendrites!

3. Aging 1. After age 60, the brain begins to lose thousands of neurons a day. When these cells die they are not replaced!! 2. By age 80, the brain weighs about 10% less than it did when the person was a younger adult. 3. The cerebral cortex shrinks more than any other area. Therefore, mental activities such as learning, memory, and reasoning decline. 4. Neurotransmitter production also decreases, resulting in slower synaptic transmission, slowing down thought processing and translation of a thought into action.

5. Neurological Disorders Alzheimer DiseaseParkinson Disease 1. Characterized by a gradual loss of reason that begins with memory lapses and ends with the inability to perform any type of daily activity 2. Personality changes signal the onset. 3. Genetic link exists- defect on chromosome 21 4. Abnormally structured neurons and reduction of acteylcholine 5. Drug treatment slows the progression of the disease 1. Progressive CNS disorder involving uncontrollable shaking and jerking of the body 2. Inability to control skeletal muscles, as well as coordination and balance, however cognitive functioning is not affected 3. Caused by destruction of the basal ganglia, which produce dopamine 4. New treatment= “brain pacemaker”

8. Section 7.5 Homeostasis

9. Introduction 1. The nervous system detects, interprets, and responds to changes in internal & external conditions to keep the internal environment constant. 2. Along with the endocrine system, it coordinates and regulates the functioning of all of the other systems in the body.

10. Important in Regulating… 1. The hypothalamus works closely with the endocrine system to produce hormones. 2. Controls the major movements of the body. 3. Receives and interprets sensory input from the entire body. 4. Regulates heart beat and dilation of the blood vessels. 5. Regulates breathing and breathing rate. 6. Permits and restricts digestion, defecation, and urination 7. Controls the onset of puberty