85 to 180 billion neurons in the human brain How does anything get done CENTRAL NERVOUS SYSTEM Brain and spinal cord PERIPHERAL NERVOUS SYSTEM PNS Def all nerves that lie outside the brain and spinal cord ID: 1033491
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1. ORGANIZATION OF THE NERVOUS SYSTEM85 to 180 billion neurons in the human brain?! How does anything get done?
2. CENTRAL NERVOUS SYSTEMBrain and spinal cord.
3. PERIPHERAL NERVOUS SYSTEM (PNS)Def: all nerves that lie outside the brain and spinal cordNerves: bundles of neuron fibersPNS is subdivided into the Somatic Nervous System and Autonomic Nervous System
4. SOMATIC NERVOUS SYSTEMDef: nerves that connect to voluntary skeletal muscles and to sensory receptorsCarry info to and from Central Nervous System2 types of nerve fibers…
5. AFFERENT AND EFFERENT NERVE FIBERSAfferent nerve fibers: axons that carry info. inward to the central nervous system from the periphery of the bodyEfferent nerve fibers: axons that carry info. outward from the central nervous system to the periphery of the body
6. AUTONOMIC NERVOUS SYSTEMDef: nerves that connect to the heart, blood vessels, smooth muscles, and glandsControls involuntary functionsSubdivided into 2 branches…
7. SYMPATHETIC AND PARASYMPATHETIC DIVISIONSSympathetic division: mobilizes body’s resources for emergenciesParasympathetic division: conserves bodily resources
8. CENTRAL NERVOUS SYSTEMDef: brain and the spinal cordSurrounded by Cerebrospinal Fluid: nourishes the brain and provides a protective cushionCSF comes from bloodSubstances must pass the Blood-brain barrier: semipermeable membrane-like mechanism that controls which substances pass btwn the blood and brain
9. SPINAL CORDConnects the brain to the rest of the body through the PNSAn extension of the brainRuns from brain to just below the waist
10. THE BRAINIn the skullWeighs c. 3 lbsContains billions of interacting cellsNumerous ways to study…
11. RESEARCH METHODS FOR THE BRAINBrain function is difficult to examine…Unless someone wants to volunteer to have their brain dissected while they are still living. Technology has helped…
12. ELECTRICAL RECORDINGSElectroencephalograph (EEG): a device that monitors electrical activity of the brain over time by means of electrodes attached to the scalpInvented by Hans Berger in 1929Translates info. into brain waves
13. LESIONINGDef: destroying a piece of the brainUsed to study cause-and-effect relations btwn brain damage and behaviorAttach an electrode to a specific area and burn the tissue
14. ELECTRICAL STIMULATION OF THE BRAIN (ESB)Def: ESB involves sending a weak electrical current into a brain structure to activate itUsed mostly on animalsUsed in brain surgery for humans
15. BRAIN-IMAGING PROCEDURESComputerized Tomography (CT) scan: X-ray of brain structureCreates a horizontal “slice” of the brainLeast expensive and widely used
16. BRAIN-IMAGING PROCEDURESPositron Emission Tomography (PET) scanningUsed to examine brain functionMaps actual activityProvides color coded map of brain
17. BRAIN-IMAGING PROCEDURESMagnetic Resonance Imaging (MRI) scanUses magnetic fields, radio waves, and computerized enhancement to map brain structureProduces 3-D image of brainFunctional Magnetic Resonance Imaging (fMRI) monitors blood and oxygen flow in the brain