Neurological Function Flashcards
Describe the structure and function of the three parts of a neuron: the cell body, the dendrites, and the axons
the cell body: contains a large, vesicular nucleus. equipped for a high level of metabolic activity.
the dendrites: the dentries are multiple, short, branched extension of the nerve cell body. They are CONDUCTORS, conducting information TOWARDS the cell body–main source of information for the neuron.
the axons: long efferent (exiting) processes that project from the cell body, usually only one axon, but axons can branch off. the axon of a neuron conducts nerve impulses from the cell body to it’s synapse.
Describe the importance of Myelin and its relationship with White Matter
The main function of myelin is to protect and insulate these axons and enhance the transmission of electrical impulses. If myelin is damaged, the transmission of these impulses is slowed down, which is seen in severe neurological conditions such as multiple sclerosis (MS).
the name white matter is given to the masses of myelinated fibers in the spinal cord and brain.
Explain the significance of metabolic requirements of nervous tissue: blood flow, glucose usage, & oxygen consumption
any interruption in blood or o2 supply to the brain can lead to huge problems because the brain uses blood and oxygen to power itself. (think strokes and other TBIs)
glucose: the major fuel source, although neurons can’t store it. so people need to keep blood glucose at a healthy level. can be complicated with diabetic’s.
Describe the function(s) of the CNS glial cells: Astrocytes, Oligodendrocytes, Microglia & Ependymal.
astrocytes: maintain an important link between neurons (esp. synapses), and capillary blood flow. help maintain the right potassium ion concentration in the space between the neurons.
oligodendrocytes: form the myelin in the CNS>
microglia: little eaters–phagocytotic, clean up debris after cellular damage, infection, or cell death.
ependymal: forms the lining of the neural tube cavity, the ventricular system.
Explain the process of synaptic transmission (See Understanding, Pg.355-356).
synaptic transmission:
neurotransmitters synthesized in the presynaptic neuron
neurotransmitters stored in presynaptic vesicles
nerve impulse stimulates the presynaptic neuron
synaptic vesicles move to the cell membrane
neurotransmitter released into synaptic cleft
neurotransmitter moves across the synaptic cleft
neurotransmitter binds to receptors on the postsynaptic neuron
removal of neurotransmitter from receptor site (reuptake or broken down by enzymes)
**action of neurotransmitter determined by what type it is: excitatory will often open a sodium channel.
Define Neurotransmitters & provide an example of an excitatory vs inhibitory neurotransmitter
neurotransmitters are chemical that excite, inhibit, or modify the response of cerebral cells. they include amino acids, neuropeptides, and monoamines.
excitatory neurotransmitters are: glutamate, epi, etc.
inhibitory neurotransmitters are: GABA
Recall Spinal Nerve locations (Cervical, Thoracic, Lumbar, Sacral, Coccygeal) & differentiate its innervation versus plexus
cervical– C1-C7
thoracic: T1-T12
Lumbar: L1-L5
Sacral: S1-S5
Coccygeal: coccyx
spinal nerves are the ones that go straight to the brain.
the peripheral nerves are the ones that go through the plexuses.
Identify region for lumbar puncture for cerebral spinal fluid & why this area is preferred (see: Pg.367-368)
Since the spinal cord ends as a solid structure around the level of the second lumbar vertebra (L2) the insertion of a needle must be below this point, usually between L3 and L4. The spinal cord continues below L2 down into the sacrum as many separate strands of nerve pathways, the cordae equina, bathed in CSF.
Identify the structures found in the brain stem & forebrain and be able to briefly recognize their functions
Forebrain
diencephalon: thalamus: coordination and integration of peripheral sensory stimuli, crude remembrance of highly emotionally laden auditory experiences (remembering what was said while they were in a coma)
cerebral hemispheres: processing of olfactory information
basal ganglia: supply axial an proximal unlearned and learn postures and movements, arm swinging during walking and running, follow-through movements with throwing a ball or swinging a bat. damage: parkinsons, cerebral palsy, etc.
frontal lobe: anticipation and prediction of the consequences of behavior
parietal lobe: somesthetic perception (appreciation of the meaningfulness of integrated sensory information from various sensory systems). Perception of “where” the stimulus is in relation to space and body parts.
temporal lobe: primary auditory cortex, some long term memory recall
occipital lobe: primary visual cortex
Identify the structures found in the brain stem & forebrain and be able to briefly recognize their functions
brain stem: The three components of the brainstem are the medulla oblongata, midbrain, and pons.
medulla: The medulla oblongata is the lower half of the brainstem. It controls autonomic functions and connects the higher levels of the brain to the spinal cord.
The medulla oblongata is responsible for regulating several basic functions of the autonomic nervous system, including respiration, cardiac function, vasodilation, and reflexes like vomiting, coughing, sneezing, and swallowing.
midbrain: the midbrain plays a major role in both wakefulness and regulation of homeostasis.
pons: The pons is a relay station between the forebrain and cerebellum that passes sensory information from the periphery to the thalamus. The pons contains nuclei that relay signals from the forebrain to the cerebellum, along with nuclei that deal primarily with sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture.
Describe the function of the blood brain barrier
the function of the blood brain barrier is to provide the means for maintaining a chemically stable environment of the brain. Only water, co2, and o2 enter the brain with relative ease.
The blood brain barrier permits passage of essential substances while excluding unwanted materials.
Describe the layers of the meninges (dura matter, arachnoid, & pia mater) and how they protect the brain and spinal cord.
dura mater: tough mother, the hardest layer.
The dura provides the brain and spinal cord with an extra protective layer, helps to keep the CNS from being jostled around by fastening it to the skull or vertebral column, and supplies a complex system of venous drainage through which blood can leave the brain.
Arachnoid mater: Connected to the dura mater on the side closest to the CNS, this middle layer includes a network of fibers and collagen that are part of the suspension system that helps protect the brain and spinal cord from sudden impact.
Pia mater: the innermost layer of the meninges, the pia mater closely covers the brain. It acts as a barrier and aids in the production of cerebrospinal fluid.
List aging changes expected in the nervous system (see Pg. 386)
a decrease in cell mass, overall brain weight, and reduced size of the brain and spinal cord.
reaction time slows d/t loss of nerve cells, remaining nerve cells have fewer dendrites and demyelination of the cell.
the ability of the brain to compensate for decreased blood flow decreases with age.
