I. The Nervous System chapter 4

Nervous System [p116] Gathers and processes information Gathers and processes information Produces responses to stimuli Produces responses to stimuli Coordinates workings of different cells Coordinates workings of different cells Consists of 2 parts: Consists of 2 parts: –Central nervous system (CNS) –Peripheral nervous system (PNS)

Organization of the nervous system [pp ] chapter 4

The Central Nervous System [pp ] Brain Housed in the skull Housed in the skull Approx. 3 lbs Approx. 3 lbs Mostly comprised of neurons Mostly comprised of neurons Spinal cord Comprised of neurons and Comprised of neurons and supportive tissue supportive tissue Runs from base of brain down Runs from base of brain down center of back center of back Protected by spinal column Protected by spinal column chapter 4

The Peripheral Nervous System [pp ] Somatic Nervous System *Controls skeletal muscles *Allows for voluntary movement Autonomic Nervous System *Controls muscles of internal organs *Regulates blood vessels, glands, internal organs internal organs *Divided into 2 systems: Sympathetic Nervous SystemSympathetic Nervous System Parasympathetic Nervous SysParasympathetic Nervous Sys chapter 4

The Autonomic Nervous System [p118] Sympathetic Nervous System *Arouses the body *Uses energy *”Fight or flight” response Parasympathetic Nervous System *Calms the body *Conserves energy chapter 4

Sympathetic nervous system:

Parasympathetic nervous system: chapter 4

Biofeedback [p118] A method for gaining control over the autonomic nervous system A method for gaining control over the autonomic nervous system One learns using feedback from equipment that measures biological functions (e.g., body temperature, blood pressure, sweat response, muscle tension, brain activity) One learns using feedback from equipment that measures biological functions (e.g., body temperature, blood pressure, sweat response, muscle tension, brain activity)

II. Neural Communication

Nervous system [p119] The body’s electrochemical communication circuitry The body’s electrochemical communication circuitry Made up of: Made up of: –nerve cells (neurons)—conduct impulses –and glial cells (glia)—support cells

Structure of a neuron— 3 main parts [p120] Cell body: Keeps neuron alive and determines whether it will fire Dendrites: Receive information from other neurons and transmit toward the cell body Axon: Extending fiber that conducts impulses away from the cell body to other cells chapter 4

How neurons communicate Axon terminals release neurotransmitter Neurotransmitter enters synapse (gap between neurons) [p122] Neurotransmitter binds to receptors that it fits chapter 4

Neurotransmitter [p125] Chemical released by a transmitting neuron at the synapse and capable of affecting the activity of a receiving neuron chapter 4

III. A tour through the brain

The brain stem Medulla Responsible for certain automatic functions such as breathing and heart rate [p130] Pons Involved in sleeping, waking, and dreaming [p130] Reticular activating system Arouses cortex and screens incoming information [p131] chapter 4

The cerebellum [p131] Regulates movement and balance Involved in remembering simple skills and acquired reflexes Plays a part in: Analyzing sensory info Analyzing sensory info Solving problems Solving problems Understanding words Understanding words chapter 4

The thalamus Relays sensory messages to the cerebral cortex Includes all sensory messages except those from olfactory bulb [p131] chapter 4

The limbic system [p132] A group of brain areas involved in emotional reactions and motivated behavior chapter 4

The amygdala [p132] Responsible for Arousal Arousal Regulation of emotion Regulation of emotion Initial emotional Initial emotional response to sensory response to sensory information information chapter 4

Hypothalamus [p131] Involved in: Involved in: EmotionsEmotions Drives vital to survivalDrives vital to survival Fear Fear Hunger Hunger Thirst Thirst Reproduction Reproduction Feeling rewardedFeeling rewarded Regulating autonomic nervousRegulating autonomic nervous system system chapter 4

Pituitary gland [p132] Small endocrine gland which releases hormones and regulates other endocrine glands Small endocrine gland which releases hormones and regulates other endocrine glands Works in conjunction with hypothalamus Works in conjunction with hypothalamus

The endocrine system [p126] Endocrine glands release hormones into the bloodstream… chapter 4 …Hormones regulate growth, metabolism, sexual development and behavior, and other functions.

The hippocampus [pp ]  Responsible for storage of new information in memory  Compares sensory information with what the brain expects about the world  Enables us to form spatial memories for navigating the environment chapter 4

The cerebrum [p133] Largest brain structure Largest brain structure In charge of most sensory, motor, and cognitive processes In charge of most sensory, motor, and cognitive processes Divided into two halves, called hemispheres Divided into two halves, called hemispheres chapter 4

Lobes of the cerebral cortex (cerebrum) [p134] Occipital lobes Vision (visual cortex) Parietal lobes Body sensation (somatosensory cortex) Temporal lobes Memory, perception, emotion, hearing (auditory cortex) Frontal lobes Emotion, planning, creative thinking, personality, and movement (motor cortex) chapter 4

Phineas Gage’s frontal lobe damage [pp ] Gage was a railroad construction foreman An 1848 explosion forced a steel tamping rod through his head Others said he was “no longer Gage” Lost his job, worked as a sideshow exhibit chapter 4

The corpus callosum [p133] Millions of myelinated axons connecting the brain’s hemispheres Provides a pathway for communication If surgically severed to treat epilepsy, resulting in a “split-brain” condition, the hemispheres cannot communicate directly [p137] chapter 4

Lateralization [ p133] Specialization of the two cerebral hemispheres for particular operations chapter 4

Motor control and the hemispheres Left hemisphere controls right side of body Left hemisphere controls right side of body Right hemisphere controls left side of body Right hemisphere controls left side of body

Broca’s area Left hemisphere controls speech production (in Broca’s area) [p134]

What is the object in your left hand? If someone with a split brain is blindfolded and asked what they are holding in their left hand, can they do it? If someone with a split brain is blindfolded and asked what they are holding in their left hand, can they do it?

Plasticity [p123] The brain’s ability to change and adapt in response to experience The brain’s ability to change and adapt in response to experience Reorganizing or growing new neural connections Reorganizing or growing new neural connections chapter 4

IV. Techniques for looking into the brain

Neurosurgery chapter 4

Electroencephalogram (EEG) [p128] A recording of neural activity detected by electrodes chapter 4

Positron Emission Tomography (PET Scan) [p129] Active areas have increased blood flow. Sensors detect radioactivity. Different tasks show distinct activity patterns. A method for analyzing biochemical activity in the brain, using injections of a glucose-like substance containing a radioactive element chapter 4

Magnetic Resonance Imaging (MRI) [p129] Magnetic fields align certain ions and compounds. When field is removed, these molecules release energy as radio waves. Computer calculates tissue density from radio waves. Provides clear 3D images Method for studying body and brain tissue chapter 4

Your turn Jenny bumps her head and is suddenly unable to see, although the doctor says there is nothing wrong with her eyes? Which part of her brain did Jenny damage? 1. The amygdala 2. The hippocampus 3. The occipital lobe of the cerebral cortex 4. The parietal lobe of the cerebral cortex chapter 4

Your turn Jenny bumps her head and is suddenly unable to see, although the doctor says there is nothing wrong with her eyes? Which part of her brain did Jenny damage? 1. The amygdala 2. The hippocampus 3. The occipital lobe of the cerebral cortex 4. The parietal lobe of the cerebral cortex chapter 4