Lecture 2 - The Nervous System: Structure & Function Flashcards
Neuropsychology
The study of the relationship between brain function and behavior, with particular emphasis on assessment after brain trauma.
EEG
Electroencephalography; a tool that provides a temporal record of brain activity (an electroencephalogram) by measuring the graded potentials of many thousands of neurons from the scalp.
PET
Positron Emission Tomography; a tool that produces a spatial image of the brain by detecting changes in blood flow, which itself is accomplished by the administration of radioactive tracers.
fMRI
Functional Magnetic Resonance Imaging; a tool that measures changes in brain activity by measuring changes in iron and oxygen levels in the flow of blood to active neurons.
MEG
Magnetoencephalography; a tool that produces a temporospatial rendering of the brain through the detection of magnetic potentials produced by the electrical fields of neurons.
TMS
Transcranial Magnetic Stimulation; a spatial tool that creates its own magnetic field in order to stimulate certain areas of the brain. TMS is able to inhibit or excite brain activity in this way.
Neuron & Structure
The neuron is the basic unit of information-processing, providing for sensing, thinking, remembering, controlling, and regulating.
Its essential structure consists of a cell body (soma), dendrites, and an axon.
Neuron Doctrine
A conceptual doctrine that espouses neurons to be the functional units of the nervous system, where interaction between them enables behavior. This communication between neurons, an informational transaction, takes place at the synaptic cleft.
Axon
The main conduit for the cascade of action potentials; conducts impulses toward other neurons, muscle cells, or glands.
Dendrite
Furcating offshoots resembling branch coral, dendrites, along with the soma, are considered the input in the communication networks between neurons.
Synapse & Components
A neuron-neuron or neuron-effector junction is referred to as the synapse.
At the axon terminal, a swollen structure called the synaptic end bulb emerges. Here, the presynaptic neuron meets with a postsynaptic neuron or the postsynaptic membrane of an effector.
In the case of neuron-neuron connectivity, the end bulb meets an extension of the dendrites called a dendritic spine. The transmission of information occurs when vesicles from the end bulb are released, carrying neurotransmitters across the synaptic cleft to the dendritic spine.
Types of Neurons
Organized by function: sensory, motor, and interneurons.
Organized by shape: multipolar, bipolar, and unipolar.
Glial Cells & Types
Glia (or neuroglia) support, nourish, and protect neurons.
There are four majorly important types of glial cells:
- Astrocytes, which link neurons to blood vessels
- Microglia, which remove debris from damaged or dead cells
- Oligodendrocytes, which provide for myelination in the CNS
- Schwann Cells, which provide for myelination in the PNS
PNS & Structure
The Peripheral Nervous System consists of all nervous tissue outside of the Central nervous system and is divvied into three parts: the ANS (autonomic), SNS (somatic), and ENS (enteric).
SNS: Structure & Functions
The Somatic Nervous System serves as a conduit for stimuli acting on sensory receptors and transfers action potentials to the CNS and response signals through motor neurons in the PNS.
It is constituted by two functionally significant classes of neurons: afferent (incoming) and efferent (outgoing).
