The Nervous System

1. The Nervous System The big picture: gathers and processes information, responds to stimuli, and coordinates the workings of different cells.

3. The Central Nervous System • Consists of the brain and spinal cord, receives processes, interprets, and stores sensory information. *Nose touch • Spinal reflexes are automatic and require no conscious effort. Ex. Knee-jerk or finger on stove • The neural circuitry underlying a reflex is a reflex arc. sensory neuron >interneuron (w/in the spinal cord)>motor neuron Ex. Scottie: C-5 spinal cord injury. No way for sensory info to reach his brain.

6. The Peripheral Nervous System • Consists of all parts of the nervous system other than the brain and spinal cord. It handles the central nervous system’s input and output.*Shoulder, elbow, finger touch • Sensory nerves carry messages from receptors to the brain. • Motor nerves carry messages from the central nervous system to muscles, glands, and internal organs.*dollar drop

7. PNS con’t • 3. The peripheral nervous system is divided into the skeletal (somatic) and autonomic branches. • A. The skeletal (somatic) nervous system controls skeletal muscles and permits voluntary action. *knee/slap • B. The autonomic nervous system regulates blood vessels, glands, and internal organs. *stop your heartbeat! Like automatic pilot. • C. Although biofeedback can help people control voluntary responses, it is not clear whether they can learn to control autonomic responses directly.

8. PNS con’t • 4. The autonomic nervous system is divided into opposing sympathetic and parasympathetic branches; both are involved in emotion and stress. • A. The sympathetic nervous system mobilizes the body for action and increases energy output. *meeting a mountain lion • B. The parasympathetic nervous system conserves energy and helps the body store it. Calms/conserves. Decrease heartbeat!

11. Communication in the Nervous System: The Nuts and Bolts • Neurons, or nerve cells, are the basic units of the nervous system, which are held in place and nourished by glial cells. They specialize in communication. • A. The structure of the Neuron • 1. The neuron has three main parts: a cell body, dendrites, and an axon. • 2. The cell body keeps the neuron alive and determines whether it should send a message to other neurons; the dendrites of a neuron receive messages from other neurons and send them to the cell body; the axon transmits messages away from the cell body to other neurons, muscles, or glands.

20. Phrenology

24. B. The Cerebral Cortex: The Brain’s Thinking Cap 1. The cortex contains three-fourths of all the cells in the human brain. More cortex in humans…we aren’t on autopilot! 2. The occipital lobes contain the visual cortex, where visual processing occurs. 3. The parietal lobes contain the sensory cortex, where information about pain, touch, and temperature is processed. 4. The temporal lobes are involved in memory, perception, emotion, and language comprehension, and they contain the auditory cortex, which processes sound. 5. The frontal lobes are involved in judgment, planning, creating, and initiating, and they contain the motor cortex, which produces voluntary movement. *head pointing

25. The Motor Cortex – con’t 6. Those areas of the body requiring precise control (fingers, mouth, etc.) take up the most cortical space.

26. The Cerebral Cortex – con’t 7. Damage to the frontal lobes may dramatically alter personality. (Phinias Gage)

27. The Cerebral Cortex – con’t 8. The association cortex is the site of higher mental processes. 10% of our brain myth.

36. A Question of Dominance • Nearly all right-handed people and a majority of left-handers process language mainly in the left hemisphere, which also seems to be dominant in logical, symbolic, and sequential tasks. • The right hemisphere is superior in visual-spatial ability and facial recognition. It is also involved increasing and appreciating art and music, and seems to have some language ability. • Although some popular programs promise to enhance one or the other of your hemisphere’s abilities, in most real-life activities, the two hemispheres cooperate naturally with each contributing to our effectiveness. *which side of the brain are you accessing?

38. Left Hemisphere *Step by stem reasoning of info. Language Listening Writing Reading Mathematical calculations Right Hemisphere *Visual/Spatial information Recognize complex patterns $ drawings Aptitude for music Expression & recognition of emotion Recognizing faces Solving spatial relationship problems Symbolic reasoning Artistic activity Which is your dominate side?

39. Eavesdropping on the Brain • Progress in understanding the brain depends on studies of brain damage, investigations that stimulate brain centers, and studies in which brain activity is measured, for example by means of the … 1. Electroencephalogram (EEG)-traces electrical brainwaves. Ex how the brain responds to sound or sight.

40. Eavesdropping on the Brain – con’t 2. positron-emission tomography (PET scan) –shows consumption of sugar (glucose) as needed for brain activity.

41. In men who had ADHD, PET scans showed that they processed a memory task in visual areas in the occipital lobe of the brain, as indicated by the yellow spots in the left image. Non-ADHD men used the temporal and frontal lobes, shown at right

42. Eavesdropping on the Brain – con’t 3. Magnetic resonance imaging (MRI) – uses magnetic fields & radar waves to distinguish between different types of soft tissue. (Brain Structure)

43. MRI’S give detailed volumetric measurements of specific regions of the brain. The volumetric measurements of the caudate nucleus indicate a smaller right caudate nucleus in ADHD boys in comparison to normal boys Extensive and time consuming measurements of the head and body of the caudate nucleus and the frontal lobes have supported their role in ADHD

44. Eavesdropping on the Brain – con’t 4. Computed tomograph (CT) – takes x-ray photographs that can reveal brain damage.

45. The top picture shows a newborn with hydrocephalus prior to its treatment. The darker gray is CSF and the lighter gray rim around it is brain. The bottom picture is the same child three and a half months later, after he was shunted. Note how much smaller the fluid spaces (dark gray) are and the dramatic expansion of the brain into the space created by removing the excess CSF.

46. Eavesdropping on the Brain – con’t 5. Single Photon Emission Computed Tomography (SPECT) - Measures blood flow and brain metabolism by monitoring photons emitted by iodine-labeled monoamine and diamine tracers carried in the blood to the brain.

47. Guess what disorder these SPECT images reveal. ADHD-Attention Deficit Hyperactivity Disorder Normal When methylphenidate (Ritalin) was administered to ADHD children, its effect showed up as a redistribution of blood flow in the brain, methylphenidate appeared to increase the level of function of the under-perfused regions at the striatum, posterior periventricular region and to a lesser extent the frontal lobes. This normalization allowed the clutter of irrelevant messages to be screened out and was seen as a reduction in blood flow to the vision and hearing areas. This filtering of irrelevant distraction suppresses reflex responses and helps concentration.

48. Guess what disorder these SPECT images reveal. Normal Anxiety/panic Disorder

49. Guess what disorder these SPECT images reveal. Normal Bipolar Disorder

50. Guess what disorder these SPECT images reveal. Normal Depression