Studying the nervous system Flashcards
What is the distribution of genes
- Expressed in nervous system =
6000 genes - Ubiquitous, expressed in all
cell and tissue types = 8000
genes - Not expressed in nervous
system = 6000 genes
What is the function of the sensory systems
To report information about state of organism and its environment
What is the function of the motor systems
To organize and generate actions
What does the associational systems provide
Higher order brain functions:
perception, attention, memory, emotions, language and thinking
What are the two main parts of the central nervous system
Brain and spinal cord
What ae the two main parts of the peripheral nervous system
Cranial nerves and spinal nerves
What does the central nervous system contain
Cerebral hemispheres, diencephalon, cerebellum, brainstem and spinal cord
What are the sensory components of the peripheral nervous system
Sensory ganglia, sensory nerves, sensory receptors (at surface and within the body
What are the two divisions of the motor components of the PNS
Visceral motor system and somatic motor system
What composes the visceral motor system
sympathetic, parasympathetic, enteric divisions, autonomic ganglia and autonomic nerves
What composes the somatic motor system
Motor nerves
What stimulates the sensory components
Internal and external environment
What are the effectors of the motor components for the visceral and somatic systems
Visceral: smooth muscles, cardiac muscles and glands
Somatic: Skeletal (striated) muscles
What are the primary components of neural systems
Neural circuits
What are neurons specialized for
electrical signaling, mostly over long distances
What does the glia support
Signaling functions of nerve cells
T/F more dendrites = more information reception
True
What is a gap junction
Intercellular continuities between neurons that allow direct transfer of electrical and chemical signals
What is a location that receives electrical signals
The heart
What is a chemical synapse
Contacts with no continuity between neurons
What do ions flow through in order to cross the post synaptic membrane
gap junction channels
What is the axon hillock
Where the cell body transitions into the axon
What is the conduction component of the neuron
The axon
What are the 4 phases of an action potential
resting potential, depolarization, repolarization and hyperpolarization
Where can the output of the neuron alter activities of other cells
At the presynaptic axon terminals
Define convergence
Number of inputs to neuron
Define divergence
Number of targets innervated by neuron
T/F Glial cells participate directly in synaptic transmission or electrical signaling
False, they do not participate
What is the function of an astrocyte
To maintain the chemical environment for neuronal signaling and secrete substances that influence the formation of new synaptic connections
What is the function of oligodendrocytes
They form the myelin sheaths around axons in the CNS
What is the equivalent to oligodendrocytes in the PNS
Schwann cells
What do microglia do
They are scavenger cells that remove cellular debris from injury sites or normal cell turnover
What is the afferent neural circuit
Afferent neurons send electrical signals to the brain and spinal cord
What are interneurons neural circuits
Local circuitry located between sensory and motor neurons
What is the efferent neuron circuit
Sends electrical signal to the muscle or gland
What is a neurophil
A tangle of axonal and dendritic branches
Where do neurophils synapse
Between the axonal and dendritic brances
What is grey matter
region of cell bodies and neurophil in the brain and spinal cord
What is white matter
Axon tracts and commisures
What is the nucleus
Gray matter where there us concentration of neurons with similar connections and functions
What is the cortex
Sheetlike arrays of nerve cells
What are tracts
Bundles of central axons
What are columns
subdivisions of white and gray matter
What are nerves
Bundle of peripheral axons
What are ganglia
Local accumulation of nerve cell bodies supporting cells in the PNS
what is the first step of a knee jerk response
Hammer tap stretches tendon, which in turn stretches sensory receptors in the leg extensor muscle
2A 2B 2C knee jerk response
2A: Sensory neurons synapses with and excites motor neuron in the spinal cord
2B: Sensory neuron also excites spinal interneuron
2C: Interneuron synapse inhibits motor neuron to flexor muscles
3A 3B knee jerk
3A: Motor neuron conducts action potential to synapses on extensor muscle fibers, causing contraction
3B: Flexor muscle relaxes because the activity of its motor neurons has been inhibited
Step 4 in knee jerk
Leg extends
What are the three locations in the electrophysiological recording
Receptive field (center), receptive field (surrounding), outside receptive field
What causes changes in fluorescence intensity
Electrical activity or calcium transients in the cells’ cytoplasm
Explain post mortem studies
Inferences of functional localization by correlating behavioral deficits to damaged brain structures
Explain animal studies
Purposefully damaging a brain region, nerve or tract and observing subsequent loss of function
Explain a pneumoencephalogram
Injecting the ventricles with air makes them more translucent than the surrounding tissue. This allows the ventricular space to be seen clearly
Explain an angiogram
Injecting contrast agent into the circulation reveals the blood vessels within the brain.
What limits use for a pneumoencephalogram and angiogram
Risks and discomfort
What two methods are used for indirect imaging of functional localization and maps
ElectroEncephalography and Transcranial magnetic stimulation
In an EEG what is detected, amplified and mapped with reference to each electrode’s position on the head.
The net electrical activity from each point in the scalp electrode array
In a TMG what is briefly disrupted by the magnetic pulses leading into the transient change in behavioral performance
Activity in the underlying cortical tissue
What does a computerized tomography use
An arrow x-ray beam and a row of very sensitive detectors to probe small portions of tissue with limited radiation exposure
What rotates around the head in a CT scan
X-ray tube and detectors to collect information form every orientation around a narrow slice
What is the MRI based of off
Atomic motion
What does CT stand for
Computerized tomography
What does MRI stand for
Magnetic resonance imaging
Explain steps of functional MRI
Brain area activated by a specific task, it uses more oxygen, brain vasculature responds by increasing the flow of oxygen-rich blood to the active area
T/F FMRI is usually the favored approach
true
What does the MEG record
Magnetic consequences of brain electrical activity rather than electrical signals
