The Nervous System …

1. The Nervous System… Terine’ Campbell Angela Durham Anatomy & Physiology 1st Period “Life is in the eye of the beholder”

2. What is the function of the nervous system? • The function of the nervous system is to receive information from a sensory neuron, • process information by the brain and spinal cord • respond by an effectors (muscle/gland).

3. From the brain Stem to the Cerebrum…

4. What is the basic unit of the nervous system? A neuron. Basic Components: 1. Soma- the cell body 2. Dendrites- receives neural stimuli, shorter and more numerous projections of the nerve cell 3. Synapse - is a juncture point at which electrical impulses are transmitted from nerve to muscle, gland, or another neuron. 4. Axons - conducts nerve impulses away from the neuron to other parts, longer single fiber 5. Myelin - is composed of Schwann cells., which enhances rapid transmission of electrical impulse along the nerve fiber. On the average, a myelinated transmission along fiber is roughly 50 times as fast as one along an unmyelinated fiber.

5. What is a synapse ? • Junction of two neurons • Neurotransmitters convert the electrical impulse into a chemical message

6. Myelin Sheath The myelin sheath is a fatty layer that covers and protects the axon and helps the nerve signal to travel down the nerve.

7. Stimulus • A changing condition that comes from thee inside of your body that causes you to react to situations. For example: when you're sad you cry, when you're hungry you eat and when you're scared you might run from the situation. Etc..

8. Sensory neurons or" receptors” receive a stimulus from: • eyes - sight • ears - hearing • nose - smell • skin - touch • mouth - taste

9. The five types of receptors • Are highly specialized • Receive only one type of stimuli • Can be “overloaded” when over stimulated

10. The Central Nervous System: 1. Spinal Cord 2. Brain • The medulla is for breathing. • The cerebellum is for balance. • The cerebrum is for higher thinking.

11. Cerebral Cortex= higher thinking

12. Parts of the Cerebrum

13. Cerebellum & “old brain” controls basic body functions.

14. The real thing (Cerebrum)…

15. Any blow to the head does brain damage. Example of amnesia & processing skills

16. The Autonomic Nervous System... Two parts: Parasympathetic & Sympathetic…

17. The 2 types of nervous responses? a. Voluntary that use • the brain & • spinal cord b. Involuntary or Autonomic System • Sympathetic • Parasympathetic

18. The effectors that do actions are: • The Muscles: -voluntary use thesomatic system -involuntaryuse autonomic system • The Glands: -endocrine organs that make hormone messengers

19. Involuntary Reflex Arcs... • Use only spinal cord • Do not go to the brain • Follow the R-SIM pathway • Examples: knee jerk, eye blink, hot stove pull back

20. Voluntary Reflex Arcs… • A voluntary action is basically an action which you yourself initiate by your own conscious. • This is done by your brain by sending impulses from it to the effectors or in this case, your biceps and triceps muscles and also your larynx, via relaying neurons, the spinal cord, synapses and motor neurons.

21. R-SIM Reflex arc pathway… • R- receptor neuron receives the stimuli • S-sensory neuron passes the impulse on • I-interneuron at the spinal cord processes • M-motor neuron acts

22. Reflex Arc!

23. Check-Ups (blood pressure, ear, eye exam, reflex, etc…)

24. Blood Pressure in Nervous System Our blood pressure is regulated from minute to minute by nerves. At specific locations in the walls of the large arteries, special sensors "measure" blood pressure by responding to the amount of stretch in the walls of the arteries. When blood pressure increases for any reason, these sensors send nerve signals to the blood pressure regulating center located in the lower portion of the brain. In response to the nerve signals, the blood pressure regulating center sends out nerve signals that slow the heart and dilate the arterioles. The lower output of blood by the heart and the lower peripheral resistance to blood flow both result in lowering the arterial blood pressure back toward normal.

25. Ears, Eyes, Nose and Mouth in nervous system. Your brain is the most complicated part of your nervous system. It receives information directly from your ears, eyes, nose and mouth, as well as from the rest of your body to the spinal cord.

26. Taste Receptors… Sweet and salty foods triggers the tip of your tongue, sour foods trigger the sides of the tongue, bitter foods trigger the back of the tongue and there aren't many taste buds in the middle of the tongue.

27. The break down of nervous system!

28. Review.. • What is the name of the nerve cell ? • Does the stimulus travel one- way or down the neuron in two directions? • Which part receives the stimuli? (The synapse, dendrites, cell body, or axon) • Which is covered by a myelin sheath ? • What is the purpose of the myelin sheath? • What are the five sensory neurons/receptors? • What are some of the functions of the central nervous system? • Name a few parts of the Cerebellum. • What are the two types of nervous responses?

29. References: • www.google.com • www.innerbody.com • kidshealth.org

30. Thanks forwatching!