Chapter 20

1. Chapter20 Human Nervous System

2. Regulation • Is achieved by both the nervous system and the endocrine system in humans *Both systems secrete chemicals and play a major role in homeostasis

3. Neurons • The nervous system is made up of nerve cells called neurons • Neurons are used for the transmission of impulses (message) • Three types of neurons: Sensory neurons Interneuron Motor neuron

4. http://psych.hanover.edu/Krantz/neurotut.html

7. Sensory neuron • Transmit impulses from the sense organs (receptors) to the spinal cord • Sense organs include eyes, ears, tongue, nose, and skin

8. Interneuron • Found in the spinal cord and brain • Transmit impulses from the sensory neuron to the motor neurons

9. Motor neuron • Transmit impulses from the brain and spinal cord to effectors (muscle or gland)

10. Reflex Arc

13. The difference between both:

14. (II) Central Nervous System • Consist of a brain and spinal cord

17. A) Brain • The most active organ in the body • Receives 20% of the blood pumped by the heart • Is a large mass of neurons located in the cranium (skull) • Three major division: Cerebrum Cerebellum Medulla Oblongata

18. The Human Brain

19. A) Brain • Note that the brain is convoluted or folded. • The convolutions of the brain allow for a greater surface area for gray matter.

21. Cerebrum • Largest part of the brain • Center of control for: a) voluntary body movements b) 5 senses c) memory (learning + thought)

22. Cerebrum • Divided into left and right hemispheres. • Outer layer of the cerebrum is the cortex (cerebral cortex). • Different areas are responsible for different functions.

23. Brain Scans PET scan on the left shows two areas of the brain (red and yellow) that become particularly active when volunteers read words on a video screen: the primary visual cortex and an additional part of the visual system, both in the back of the left hemisphere. Other brain regions become especially active when subjects hear words through ear-phones, as seen in the PET scan on the right.

25. Cerebellum • Coordinates motor activities (voluntary movement) • Aids in maintaining balance

26. Medulla • Involuntary activities like breathing and heartbeat

28. B) Spinal Cord • Extends from the brain and is protected by the vertebrae of the spinal column. • Is not the backbone or spine. • The spinal cord coordinates activities between the brain and other body structures

29. B) Spinal Cord • It is the center for reflex action a) a reflex is an involuntary, automatic response to a given stimulus b) reflex behavior involves a pathway known as the reflex arc over which impulses travel

31. C) Peripheral Nervous System • Consist of nerves extending throughout the body • Is separated into 2 parts: Autonomic Nervous System Somatic Nervous System

32. Autonomic Nervous System • Consists of nerves that regulate involuntary actions like heartbeat and gland secretions

33. Somatic Nervous System • Consist of nerves that regulate voluntary muscles of the skeleton

39. http://www.illusionworks.com/html/breathing_square.html

42. http://www.illusionworks.com/html/color_aftereffect.html http://www.illusionworks.com/html/motion_aftereffect.html http://www.illusionworks.com/html/shadow.html

43. Olfactory senses • "The VNO appears to be a much more primitive structure that uses a different set of molecular machinery than the main olfactory system ,"

46. Disordersof the Nervous System

47. Cerebral Palsy • A group of diseases caused by damage to the parts of the brain that control voluntary movement • This damage occurs during embryonic development

48. Meningitis • Inflammation of the membrane that surrounds the brain and spinal cord

49. Stroke • A disorder in which the brain is damaged as a result of cerebral hemorrhage (a broken vessel in the brain) or a blood clot in a blood vessel located in the brain

50. Polio • A viral disease of the central nervous system which may result in paralysis • It is now prevented through immunization