1. The Nervous System and the Endocrine System Module 04

2. Module Overview Neurons: The Building Blocks of the Nervous SystemNeurons: The Building Blocks of the Nervous System How Neurons Communicate The Structure of the Nervous System The Endocrine System Click on the any of the above hyperlinks to go to that section in the presentation.

3. Neurons: The Building Blocks of the Nervous System Module 04: The Nervous System and the Endocrine System

4. Nervous System The electrochemical communication system of the body Sends messages from the brain to the body for movement Brings information to the brain from the senses

5. Neuron A nerve cell; the basic building block of the nervous system. Neurons perform three basic tasks –Receive information –Carry the information –Pass the information on to the next neuron

6. Parts of the Neuron

7. Parts of the Neuron - Dendrites Dendrite – The branching extensions of a neuron that receive information and conduct impulses toward the cell body (soma).

8. Parts of the Neuron - Soma Soma – The cell body of a neuron, which contains the nucleus and other parts that keep the cell healthy

9. Parts of the Neuron - Axon Axon – The extension of a neuron through which neural impulses are sent.

10. Parts of the Neuron – Myelin Sheath Myelin Sheath – protects the axon and influences the speed of the neural impulse.

11. Parts of the Neuron - Terminals Axon terminals – The endpoint of a neuron where neurotransmitters are stored.

12. How Neurons Communicate Module 04: The Nervous System and the Endocrine System

13. How Neurons Communicate: The Neural Impulse Module 04: The Nervous System and the Endocrine System

14. Action Potential A neural impulse; a brief electrical charge that travels down the axon of a neuron. Considered an “on” condition of the neuron

15. Action Potential

16. Refractory Period The “recharging phase” during which a a neuron, after firing, cannot generate another action potential Once the refractory period is complete the neuron can fire again

17. Refractory Period

18. Resting Potential The state of a neuron when it is at rest and capable of generating an action potential. The neuron is set and ready to fire

19. Resting Potential

20. All-or-None Principle The principle stating that if a neuron fires, then it always fires at the same intensity; all action potentials have the same strength. A neuron does NOT fire at 30%, 45% or 90% but at 100% each time it fires.

21. How Neurons Communicate: Communication Between Neurons Module 04: The Nervous System and the Endocrine System

22. Synapse The tiny, fluid-filled gap between the axon terminal of one neuron and the dendrite of another. The action potential cannot jump the gap

23. Neurotransmitters A chemical messenger that travels across the synapse from one neuron to the next and influences whether a neuron will generate an action potential.

24. Neurotransmitters

28. Excitatory Effect A neurotransmitter effect that makes it more likely that the receiving neuron will generate an action potential or “fire.” The second neuron is more likely to fire.

29. Inhibitory Effect A neurotransmitter effect that makes it less likely that the receiving neuron will generate an action potential or “fire.” The second neuron is less likely to fire.

30. How Neurons Communicate: The Neural Chain Module 04: The Nervous System and the Endocrine System

31. Receptor Cells Specialized cells in the sensory systems of the body that can turn other kinds of energy into action potentials (neural impulses) that the brain can process. Receptor cells in the eye turn light into a neural impulse the brain understands.

32. Sensory Nerves Nerves that carry information from the sensory receptors to the spinal cord and brain. Connect the sense organs to the brain and spinal cord

33. Interneurons Nerve cells in the brain and spinal cord responsible for processing information. Related to sensory input and motor output

34. Motor Nerves Nerves that carry information from the brain and spinal cord to the muscles and glands. Carries messages from the brain and spinal cord to other parts of your body

35. A Neural Chain

40. The Structure of the Nervous System Module 04: The Nervous System and the Endocrine System

41. The Nervous System

42. Central Nervous System (CNS) The brain and spinal cord. The brain is the location of most information processing. The spinal cord is the main pathway to and from the brain.

43. Divisions of the Nervous System

44. Peripheral Nervous System (PNS) The sensory and motor nerves that connect the brain and the spinal cord to the rest of the body. Peripheral means “outer region” The system is subdivided into the somatic and autonomic nervous systems.

45. Divisions of the Nervous System

46. Somatic Nervous System The division of the peripheral nervous system that controls the body’s skeletal muscles. Contains the motor nerves needed for the voluntary muscles

47. Divisions of the Nervous System

48. Autonomic Nervous System The division of the peripheral nervous system that controls the glands and muscles of the internal organs; its subdivisions are the sympathetic (arousing) division and the parasympathetic (calming) division. Monitors the autonomic functions Controls breathing, blood pressure, and digestive processes

49. Divisions of the Nervous System

50. Sympathetic Nervous System The part of the autonomic nervous system that arouses the body to deal with perceived threats. Fight or flight response

51. Divisions of the Nervous System

52. Parasympathetic Nervous System The part of the autonomic nervous system that calms the body. Brings the body back down to a relaxed state

53. Divisions of the Nervous System

54. The Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

61. The Endocrine System Module 04: The Nervous System and the Endocrine System

62. Endocrine System One of the body’s two communication systems; a set of glands that produce hormones, chemical messengers that circulate in the blood.

63. Hormone A chemical messengers produced by the endocrine glands and circulated in the blood. Similar to neurotransmitters in that they are also messengers Slower communication system, but with longer lasting effects

64. Pituitary Gland The endocrine system’s “master gland” that, in conjunction with adjacent the brain area, controls the other endocrine glands. Called the “master gland” Located at the base of the brain and connects to the hypothalamus

65. Endocrine System – Pituitary Gland

66. Hypothalamus the brain region controlling the pituitary.

67. Endocrine System – Pituitary Gland

68. Thyroid Gland Endocrine gland that helps regulate the energy level in the body Located in the neck

69. Endocrine System – Thyroid Gland

70. Adrenal Gland Endocrine glands that help to arouse the body in times of stress Located just above the kidneys Release epinephrine (adrenaline) and norepinephrine (noradrenaline)

71. Endocrine System – Adrenal Gland

72. Pancreatic Gland Regulates the level of blood sugar in the blood

73. Endocrine System – Pancreatic Gland

74. Sex Glands Ovaries (females) and testes (males) are the glands that influence emotion and physical development. Testosterone – primary males hormone Estrogen – primary female hormone Males and females have both estrogen and testosterone in their systems.

75. Endocrine System – Sex Glands

76. The End