Intro to NBB (Glendinning) Flashcards
Explain the concept of localization.
Specific brain regions have specific functions (i.e. motor, vision, language, emotion)
*Localization does NOT mean hard-wiring (i.e. sensations on tongue can pass through visual cortex - use tongue to “see” objects)
Localization = basis for MRI
Define and describe neuroplasticity.
Changes in neurons and pathways in response to experience -> Potential that brain has to reorganize by creating new neural pathways to adapt
Example: London taxi drivers have measurably larger hippocampus size than that of bus drivers (who drive the same route every day) - cabbies rely on hippocampus constantly for navigation
Explain the difference between a focal and a diffuse lesion.
Focal lesion: infection, tumor, or injury that develops at restricted area of neural tissue
Diffuse lesion: neurodegenerative diseases, psychiatric disorders, inflammatory disorders, infections, malnutrition, genetic disorders, compression of the brain
*Diagnosis depends on SYMPTOMS and PATTERNS OF SYMPTOMS
Discuss the relevance of temporal characteristics of neurological symptoms to making a diagnosis.
- Episodic - migraine, seizures
- Recent-onset and episode (headache, pain) - expanding brain tumor
- Relapsing, remitting - MS
- Sudden onset, lasting deficits - stroke (cerebrovascular accident)
- Slow, progressive (Neurodegenerative diseases: PD, Alzheimer’s disease)
- Progressive over short time period (Expanding tumor, expanding pressure)
Explain the various forms of neuronal branching and neuron-to-neuron communication.
Neuronal Branching:
- Unipolar (pseudo-): only one process that leaves cell body (axons and dendrites arise from single process, i.e. sensory neurons in dorsal root ganglia)
- Bipolar (often sensory neuron neurons - vision/olfaction - single axon and dendrite arising from cell body)
- Multipolar
Neuron-to-neuron communication occurs at synapses:
Divergence vs. Convergence
- Divergence: enabled by axon collaterals (info can be sent to multiple parts of the nervous system… pathway 1 vs pathway 2)
- Convergence: Integration of inhibitory and excitatory information/Comparisons / examples: sensory systems, motor systems, associative learning
CNS neuron types:
- Interneurons - neurons that form connections within the CNS
- Local interneurons - neurons that connect to cells in the immediate region
- Projection interneurons - neurons that project to more distant areas of the CNS (make up TRACTS which are components of PATHWAYS)
Define basic terms related to neuroanatomical groups of cell bodies and axons.
Cluster of nuclei - cell bodies = “nucleus” or “ganglia” in PNS
Cluster of axons: “tract”, “nerve”, “fascicles”, “commissure” (R-L)
Describe the basic functions of neurons and glial cells.
Nervous system composed of neurons + glial cells
Neurons = basic units of signaling (10%)
Glial cells = support (non-neuronal) cells (90%)
- Schwann cells: myelin production (PNS)
- Astrocytes (CNS):
- > component of BBB (control K+ and cerebral blood flow)
- > remove K+ from ECF at nodes of Ranvier during AP and neurotransmitters from synaptic clefts (i.e. glutamate regulation prevents excitotoxicity)
- > communicate through GLIOTRANSMITTERS (D-serine, glutamate, ATP) in response to adjacent synaptic activity
- > produce neurotrophic factors
- > produce scar tissue in response to CNS injury
- Oligodendrocytes: myelin production (CNS)
- Microglia: scavenger cells of the CNS, produce growth factors
- Ependymal cells (CNS) - line ventricles and central canal of spinal cord
List the types of cellular changes that can underlie neuroplasticity.
Axon sprouting
Dendritic branching synaptogenesis
Neurogenesis
Angiogenesis
What (6) things does the neurological exam assess?
- Mental Status (cognition, alertness, language)
- Cranial Nerves
- Motor function
- Reflexes
- Coordination and gait
- Sensory function
