The Nervous System

1. The Nervous System Central Nervous System Peripheral Nervous System

2. Procedure • A starting person will be chosen and will be given an object. • Once the teacher gives the signal, the start person will pass the object to their right. • Each student will take the object and pass it to their right until it makes it back to the starting person.

3. Procedure • DO NOT THROW THE OBJECT! • A time will be recorded for each trial • Repeat the process 2 more times and record the times in your spiral.

4. Questions • In your spiral, answer the following questions about the demonstration.

5. Functions of the Nervous System • Your nervous system controls the actions and reactions of the body in response to stimuli. • receives information • responds to stimuli • maintains homeostasis

6. Maintaining Homeostasis • The nervous system maintains homeostasis by directing the body to respond correctly to the information it receives. • When you are hungry, your brain tells you to eat

7. Central Nervous System Vocabulary Word! • central nervous system – composed of the brain and spinal cord. • brain – receives and processes information from inside and outside your body. • spinal cord – thick column of nerve tissue that links the brain to nerves in the rest of your body.

8. Peripheral Nervous System Vocabulary Word! • peripheral nervous system - network of nerves that connects your rain to the rest of your body. • Made up of 43 pairs of nerves • 12 begin in the brain • 31 begin in the spinal cord • One nerve in each pair goes to the right side and one to the left

9. Organs of the Nervous System • The nervous system consists of: • brain • spinal cord • nerves • neurons • sense organs

10. brain Vocabulary Word! • brain – receives and processes information from inside and outside your body. • The skull, layers of connective tissue, and fluid protect the brain from injury

12. cerebrum Vocabulary Word! • cerebrum – largest part of the brain that controls thinking, problem solving, the senses and memories. • reads input from the senses • controls skeletal muscles • In charge of learning, remembering and making judgments

13. Cerebrum • Right side • controls left side of body • controls creativity and artistic ability • Left side • controls right side of body • Controls math, speech, writing, and logic

14. cerebellum Vocabulary Word! • cerebellum - second largest part of your brain that coordinates your muscles and controls your balance.

15. brain stem Vocabulary Word! • brain stem – connects your brain to your spinal cord and controls involuntary actions like breathing, digesting and heartbeat.

16. spinal cord Vocabulary Word! • spinal cord – a bundle of nerves that links your brain and peripheral nervous system. • Protected by bone, connective tissue and fluid

17. Receiving Information • Because of your nervous system, you are aware of what is happening in the environment around you. • Your brain is also aware of your internal conditions like temperature and glucose level.

18. Responding to Stimuli • After receiving information, your nervous system analyzes the data and causes a response. • Putting your hand in front of your face if a ball is coming at you. • Increasing your heart rate when exercising.

19. Responding to Stimuli • Your nervous system works by receiving information from inside or outside the body and turning that info into an electrical signal. • The messages are sent out along special cells called neurons.

20. Vocabulary Word! neuron - a cell that moves messages in the form of fast-moving electrical energy called impulses.

21. The Neuron • Neurons are cells that carry information around your body. • Nerve impulse - The message a neuron carries

22. The Neuron • The cell body of the neuron has two extensions • dendrite– carries impulses to the cell body. A neuron can have lots of dendrites. • axon– carries impulses away from the cell body. A neuron only has one axon. • The nerve impulse begins in the dendrite, moves to the cell body then moves down the axon.

23. The Neuron signal goes from axon to dendrite

24. Kinds of Neurons • Different kinds of neurons perform different functions • sensory neurons • motor neurons

25. Sensory Neuron • sensory neuron – gathers information from the internal or external environment and converts each stimulus into a nerve impulse. • The impulse travels along the sensory neuron until it reaches an interneuron in the brain or spinal cord • sensory impulse travels at 76.2 m/s

26. Motor Neuron • motor neuron – moves nerve impulses from the brain and spinal cord to the rest of the body. • Motor impulse travels at 119 m/s

27. How a Nerve Impulse Travels • Millions of nerve impulses travel your body each day. • The nerve impulse travels along the neuron in the form of electrical and chemical signals.

28. How a Nerve Impulse Travels • synapse - tiny space between a the axon of one neuron and the dendrites of the next. • A nerve impulse must jump this gap. • Axon tips release a neurotransmitter that allows the impulse to travel the gap.

29. How a Nerve Impulse Travels • Drugs and alcohol can affect the neurotransmitters • depressants, like alcohol and • marijuana slow reaction time • stimulants, like meth, speed up • reaction time

30. The Path of a Nerve Impulse https://www.youtube.com/watch?v=dSkxlpNs3tU

31. Reflex • reflex - is an automatic response that occurs very rapidly and without conscious control. • Reflexes protect us from pain and injury.

32. Reflexes

33. the senses • The senses gather information for the nervous system. • sight • touch • hearing • taste • smell

34. Body systems that work with the nervous system; • The nervous system works with every system in the body.

35. Comparing Cells to the Body • The cell part that controls the cell is the nucleus