The Nervous System

1. The Nervous System

2. Nervous System • Nervous system is the chief controlling and coordinating system of the body. • It controls and regulates all voluntary and involuntary activities of human body. • There are three characteristic properties of nervous system of human body; Sensitivity, Conductivity and Responsiveness • Composed of brain, spinal cord, nerves, and nerve endings • Divided into two sections • Central Nervous system (CNS): brain and spinal cord • Peripheral Nervous system (PNS): Cranial nerves, Spinal nerves and Ganglia

6. Neuron • Neuron is also called a nerve cell • Basic structural unit of the nervous system • Parts of neuron • Cell body • Nucleus • Nerve fibers (dendrites, axon)

7. Nerves • Combination of nerve fibers • Located outside the brain and spinal cord • Afferent—sensory nerves • Efferent—motor nerves • Associative—internuncial nerves

8. Central Nervous System • Brain • The brain plays a central role in the control of most bodily functions, including awareness, movements, sensations, thoughts, speech, and memory.  • Spinal Cord • connected to a section of the brain called the brainstem and runs through the spinal canal. Nerve roots exit the spinal cord to both sides of the body. The spinal cord carries signals (messages) back and forth between the brain and the peripheral nerves. • Cerebrospinal fluid (CSF) surrounds the brain and spinal cord

9. Central Nervous System - The Brain • Cerebrum • Cerebellum • Diencephalon • Midbrain • Pons • Medulla oblongata

10. Central Nervous System - The Spinal Cord • Continues down from medulla oblongata • Surrounded and protected by the vertebrae • Responsible for many reflex actions • Carries sensory (afferent) messages to the brain • Carries motor (efferent) message from the brain

12. Peripheral Nervous System • All other nerves in the body • Subdivided into 2 section • Somatic nervous system • Autonomic nervous system • Sympathetic • Parasympathetic

13. PNS- Somatic Nervous System • The primary role of the somatic nervous system is to connect the central nervous system to the organs, muscles, and skin. • This allows you to perform complex movements and behaviors. • The somatic neurons carry messages from the outer areas of the body having to do with the senses. • It is like a passageway from the environment to the central nervous system. 

14. PNS- Somatic Nervous System • Cranial Nerves • 12 pairs • Responsible for senses • Can be tested individually • Hearing, smell, taste, vision, eye movement, reflexes

15. PNS- Somatic Nervous System • Spinal Nerves • Mixed Nerve • Carries both sensory and motor signals • 31 pairs • Connected in some way to all other nerves in the body

16. PNS- Autonomic Nervous System • It is responsible for monitoring conditions in the internal environment and bringing about appropriate changes in them. • Further divided into two sub parts • Sympathetic Nervous system • Excitability • Parasympathetic Nervous System • Relaxation

17. Sympathetic Nervous System • “Fight or flight” • Acts in response to any stressor (mild to severe) • Releases adrenaline • Pupils dilate • Increased sweating • Increased heart rate, breathing, BP • Decreased GI motility and urinary production

18. Parasympathetic Nervous System • Responsible for returning body back to normal function after sympathetic response • Causes • Slowing down of the heartbeat lowering of blood pressure • constriction of the pupils • increased blood flow to the skin and viscera • peristalsis of the GI tract

19. Aging effects on the nervous system • Your brain and spinal cord lose nerve cells and weight (atrophy). • Nerve cells may begin to pass messages more slowly than in the past. • Waste products can collect in the brain tissue as nerve cells break down. This can cause abnormal changes in the brain called plaques and tangles to form. • Slowing of thought, memory, and thinking is a normal part of aging • Breakdown of nerves can affect the senses. Aging can cause reduced or lost reflexes or sensation. This leads to problems with movement and safety.

20. Dementia and Alzheimer’s Disease • Dementia is a broad category of brain diseases that causes a long term and often gradual decrease in the ability to think and remember such that a person's daily functioning is affected • Alzheimer's is the most common form of dementia. Alzheimer's disease accounts for 60 to 80 percent of dementia cases. • Alzheimer's is not a normal part of aging, although the greatest known risk factor is increasing age, and the majority of people with Alzheimer's are 65 and older https://www.youtube.com/watch?v=7_kO6c2NfmE

21. Dementia and Alzheimer's Disease • Though most people develop some plaques and tangles as they age, those with Alzheimer's tend to develop far more. They also tend to develop them in a predictable pattern, beginning in areas important for memory before spreading to other regions • The destruction and death of nerve cells that causes memory failure, personality changes, problems carrying out daily activities and other symptoms of Alzheimer's disease.

22. Dementia and Alzheimer’s • Sx: Increasing forgetfulness, mild to severe confusion, disorientation, difficulty speaking and writing, difficulty with concentrating, thinking, and reasoning, poor judgment, change in personality and behavior • Dx: Physical and neurological exam, lab tests (gene mapping), brain imaging • Tx: medications to slow progress not cure, exercise, nutrition, creating a safe and supportive environment

24. Putting Knowledge Into Action • You are caring for a patient in the advancing stages of Alzheimer’s Disease. • What symptoms do you feel like your patient might be experiencing? • What special actions might you need to take to ensure the patient’s needs are met and to keep them safe? • What challenges might the family face? What could you do to help them?

25. Think.Pair.Share • Using your phone research current treatments for Alzheimer’s. • Share my findings with your partner. • Be prepared to share them with the class

26. Parkinson’s disease • Affects the way you move. • Symptoms generally begin to appear in 50-60’s • Normally nerve cells make dopamine. Dopamine sends signals to the part of your brain that controls movement. • Parkinson’s causes the nerve cells to break down leading to trouble moving due to loss of production of dopamine • It’s progressive and no cure • Cause of nerve cell destruction is unknown

27. Parkinson's Disease • SX: tremors, stiff muscles, slow movement, problems with balance or walking, “shuffle walking”, problems speaking and swallowing, depression, dementia • Dx: brain imaging, improvement of symptoms with Parkinson’s medications • Tx for symptom management: medications, exercise, surgery, speech therapy, physical therapy

29. https://www.youtube.com/watch?v=hu4eTijdIv0

30. Have we met our standard? Standard 11) Outline the gross normal structure and function of all body systems and summarize appropriate medical text(s) in order to relate signs and symptoms of common diseases and disorders associated with each.