Biopsychology Exam 1 Study Guide PDF

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Biopsychology Exam 1 Study Guide Chapter One: What Is Biopsychology? Donald Hebb  1949; proposed that psychological phenomena might be produced by brain activity; he developed the first theory of how our perception, emotion, memory, and thought process might be produced from brain activity Biopsychology  scientific study of the biology of behavior; utilizes the knowledge and tools of other disciplines of neuroscience; study how the brain and the rest of the NS determine what we do, think, feel, perceive, etc. Brain function  depends on communication among neurons (the building blocks of behavior) and glial cells Neuroplasticity  neurons change in response to experience and learning; brain is not a static network of neurons Human/Nonhuman Subjects in Research Nonhumans  used due to simpler brains which make it more likely that brain-behavior interactions will be revealed; advantages of studying— brains are simpler, fewer ethical constraints, comparative approach Humans  can follow instructions, make subjective reports, often less expensive; disadvantages of studying— very complex, some research is deemed unethical on human subjects Comparative approach  insight from comparisons with other species Experiments/Non-experiments in Research Experiments  used by scientists to study causation (find out what causes what); single-handedly responsible for the knowledge that is the basis for our lives Between-subjects design  different group of subjects tested under each condition Within-subjects design  same group of subjects under each condition Independent variable  difference between the conditions Dependent variable  effect of the IV on the DV is assessed Confounded variable  affects the DV, but not controlled for Quasi-experimental studies  studies of groups of subjects exposed to conditions in the real world; not real experiments Case studies  studies that focus on a single case/subject; disadvantage— generalizability (the degree to which their results can be applied to other cases) Jimmie G  case study in which he believe him being in the Navy was present tense (actually in the past) Korsakoff’s Syndrome  Jimmie G; primary symptom is severe memory loss; largely caused by brain damage associated with thiamine deficiency

Chapter Three: Anatomy of the Nervous System General layout  consists of the Central Nervous System (CNS) and the Peripheral Nervous System (PNS) Central Nervous System  division of the NS that is located within the skull and the spine; brain/spinal cord Peripheral Nervous System  located outside the skull and spine; consists of somatic and autonomic nervous systems; serves to bring information into the CNS and carry signals out of the CNS Peripheral Nervous System Somatic Nervous System  part of the PNS that reacts with external environment; composed of afferent (sensory) and efferent (motor) nerves Autonomic Nervous System  part of the PNS that regulates the body’s internal environment; both types of nerves are efferent; sympathetic and parasympathetic nerves (generally have opposite effects)— two stage neural paths (project from the CNS and only go part of the way to the target organs before they synapse on other neurons, 2 nd stage neurons, which carry the signals the rest of the way) Sympathetic Nerves  thoracic (chest) and lumbar (small of the back); “fight or flight”; 2nd stage neurons are far from target organ Parasympathetic Nerves  cranial (brain) and sacral (lower back); “rest and restore”; 2nd stage neurons

Protective Mechanisms of the CNS Meninges  dura mater—tough outer membrane; arachnoid membrane—web-like; pia mater—adheres to the CNS surface Meningitis  infection of meninges Cerebrospinal fluid  fills the subarachnoid space, the central canal of the spinal cord, and the cerebral ventricles of the brain; cushion against mechanical shock; delivery of hormones and nutrients Hydrocephalus  buildup of cerebrospinal fluid Central canal  small central channel that runs the length of the spinal cord Cerebral ventricles  4 large internal chambers of the brain Blood-brain barrier  or the cerebral vascular system; delivery of nutrients (glucose, thiamine, other); delivery of hormones (communication); thermoregulation (maintain temperature); hormones travel thru blood Cells of the Nervous System Neurons  transmit electrical and chemical signals; different types of neurons; many shapes/sizes Structure & Function  components of structure relate to what specific functions the neurons need to carry out (i.e. cerebellum interneurons—long axons with many dendrites in order to receive many signals) Semi-permeable membranes  uncharged molecules (oxygen, carbon dioxide) move freely across the membrane; a few charged molecules (Na+, K+, Cl⁻) move through channels; lipids are key components of the membrane; protein molecules are key components of ion channels Nuclei  clusters of cell bodies in the CNS (tracts—bundles of axons in CNS) Ganglia  clusters of cell bodies in the PNS (nerves—bundles of axons in PNS) Glial cells  support neurons; recent evidence for glial communication and modulatory effects of glia on neural communication; several different types of glia (oligodendrocytes, Schwann cells, etc.) Oligodendrocytes  glial cells with extensions that wrap around the axons of some neurons of the CNS; extensions are rich in myelin which create myelin sheaths (increase the speed/efficiency of axonal conduction); do NOT promote regeneration; several myelin segments Schwann cells  similar to function of oligodendrocytes, but in PNS; can guide axonal regeneration (one myelin sheath per cell) Microglia  smaller than other glia; respond to injury and disease (by multiplying, engulfing cellular debris, triggering inflammatory responses) Astrocytes  largest glial cells; star-shaped; extensions cover the outer surfaces of blood vessels that course through the brain; also make contact with neuron cell bodies (passage of chemicals into the blood) Radial glia  form temporary network to facilitate neural migration Neuroanatomical Techniques and Directions Golgi stain  visualization of individual neurons and general shapes Nissl stain  selectively stains cell bodies; permits quantification of cell bodies Electron microscopy  details of neuronal structure Anterograde (forward)  tracing to where axons project away from an area Retrograde (backward)  tracing from where axons are projecting into an area Contralateral  opposite side Ipsilateral  same side Medial  toward the middle Proximal  close Lateral  toward the side Distal  far

The Spinal Cord

Gray matter  inner component, primarily cell bodies White matter  outer area, mainly myelinated axons; sensory signals (afferent) in via dorsal root; motor signals (efferent) out via ventral root Spinal nerves  62 spinal nerves; pairs of spinal nerves are attached to the spinal cord (one on each side) at 31 different levels Organization of the Brain Major structures of the Forebrain  cerebral hemispheres/cortex, thalamus, hypothalamus, pituitary gland, hippocampus, basal ganglia Major structures of the Midbrain  tectum, tegmentum, superior colliculus, inferior colliculus, substantia nigra Major structures of the Hindbrain  medulla, pons, cerebellum Hindbrain Myelencephalon  or medulla; composed largely of tracts carrying signals between the rest of the brain and the body; key for vital functioning (heart rate, respiration); origin of the reticular formation (complex network associated with sleep, wake, attention, movement, maintenance of muscle tone, cardiac/circulatory reflexes) Metencephalon  houses many ascending/descending tracts; 2 major divisions (pons and cerebellum) Pons  located on the brain stem’s ventral surface; exchange information Cerebellum  large, convoluted structure on the brain stem’s dorsal surface; coordination, complex movement, learning; important sensorimotor structure Midbrain (Mesencephalon) Tectum  roof of the midbrain; composed of two pairs of bumps called the colluculi; inferior colliculi—auditory; superior colliculi—vision Tegmentum  important to the sensorimotor system (movement ++); contains reticular formation (sleep/wake); contains periaqueductal gray, cerebral aqueduct, and substantia nigra Periaqueductal gray  gray matter situated around the cerebral aqueduct (duct connecting the third and fourth ventricles); role in mediating the analgesic effects of opiate drugs Raphe  sleep/wake and attention Substantia Nigra  black substance; significant for movement; dopamine and Parkinson’s Forebrain (Diencephalon) Hypothalamus  homeostasis; motivated behavior (feeding, thirst, sexual, fear) Pituitary gland  release of hormones Thalamus  large, two-lobed structure at the top of the brain stem; sensory relay; lateral geniculate nuclei; medial geniculate nuclei; ventral posterior nuclei (all 3 areas important for visual, auditory, and somatosensory systems) Cortex  “bark-like” covering of the cerebrum, cerebellum, and limbic areas; different types of cells; columns and laminae vary by brain area; convolutions serve to increase surface area; longitudinal fissure—a groove that seperates right and left hemispheres; often referred to as “gray matter” Cerebral cortex  interprets sensory input; initiates voluntary movement; mediates complex cognitive processes such as learning, speaking, and problem solving Corpus callosum  largest hemisphere-connecting tract Lobes of the Cerebral cortex Frontal  primary motor cortex (fine motor); prefrontal cortex (integration) Parietal  primary somatosensory cortex (sensory) Temporal  auditory cortex Occipital  visual cortex

Telencephalon (Subcortical structures)

Limbic system  regulation of motivated behaviors (mammillary bodies, hippocampus, amygdala, fornix, cingulate, septum) Amygdala  almond-shaped nucleus in the anterior temporal lobe Basal ganglia motor system  Amygdala, striatum (caudate nucleus + putamen), globus pallidus

Chapter Four: Neural Conduction and Synaptic Transmission Resting Membrane Potential Membrane potential  difference in electrical charge (charged particles or ions0 between inside and outside of cells Resting potential…  is about -70mV; potential inside the neuron is 70 mV less than that outside of the neuron; when the difference in the potential exists, the membrane is said to be polarized (carries a charge) Microelectrodes  intracellular electrodes; recording the membrane potential Ionic Basis of the Resting Potential Ions  positively and negatively charged ions Factors contributing to even distribution of ions  random motion—particles tend to move down their concentration gradient; electrostatic pressure—like repels like, opposites attract Factors contributing to uneven distribution of ions  selectively permeable; sodium-potassium pumps (require energy) Ions and the Neuron at Rest Ions…  move in and out through ion-specific channels; Potassium (K+) and Chloride (Cl⁻) pass readily Sodium (Na+)  little free movement across membrane Negatively charged proteins  synthesized within the neurons; found primarily within the neuron; A⁻ don’t move at all (trapped inside) Sodium (Na+)  is driven IN by BOTH electrostatic forces and its concentration gradient Potassium (K+)  is driven IN by electrostatic forces and OUT by its concentration gradient Chloride (Cl⁻)  is at equilibrium Sodium-potassium pump  active (uses ATP) force that exchanges 3 Na+ ions inside for 2 K+ outside Postsynaptic Potentials Excitatory postsynaptic potentials (EPSPs)  postsynaptic depolarization; increase the likelihood that the neuron will fire Inhibitory postsynaptic potentials (IPSPs)  postsynaptic hyperpolarization; decrease the likelihood that the neuron will fire Depolarize  decrease the resting membrane potential (ex. From -70 to -67 mV); LESS polar; more likely to have action potential; EPSPs Hyperpolarize  increase the resting membrane potential (ex. From -70 to -72 mV); MORE negative; IPSPs PSPs…  occur primarily on the cell body, dendrites, and dendritic spines; travel passively from their site of origination Decremental  they get smaller as they travel PSPs: What Can Cause Ion Channels to Open? Neurotransmitters…  bind at postsynaptic receptors (ligand-gated receptors); binding to receptors causes ion channels to open and changes in the electrical charge (membrane potential) Integration of PSP’s: Spatial Summation/Temporal Summation Spatial summation  adding or combining individual signals (PSPs) happening at different places into one overall signal Temporal summation  adding or combining individual signals (PSPs) happening at different times into one overall signal Threshold of excitation  usually about -65mV Axon hillock  conical structure at the junction between the cell body and the axon

The Action Potential Voltage-gated ion channels  opened when threshold of excitation (-65mV) is reached at the axon hillock Nodes of Ranvier  the gaps between adjacent myelin segments; regeneration of AP at each Node of Ranvier (steady signals without degradation) Frequency of AP  message about intensity of signal; release of neurotransmitters at axon terminal...