Chapter 6 part D Flashcards
(117 cards)
1
Q
What are the two parts of the nervous system?
A
the peripheral nervous system (PNS)
the central nervous system (CNS)
2
Q
What makes up the central nervous system?
A
the brain
the spinal cord
3
Q
What makes up the peripheral nervous system?
A
all of the nerves in the body not including the brain and the spinal cord.
4
Q
What is the afferent division of the peripheral nervous system?
A
the division that carries signals to the CNS.
5
Q
What is the efferent division of the peripheral nervous system?
A
the division that carries signals to the target or effector organ.
6
Q
What kinds of neurons make up the efferent division of the PNS
A
somatic neurons and autonomic neurons.
7
Q
What two systems make up the autonomic neurons?
A
the sympathetic
the parasympathetic
8
Q
What is the enteric nervous system?
A
lies within the wall of the gastrointestinal tract.
9
Q
Describe afferent neurons.
A
have sensory receptors.
cell bodies are in the dorsal root ganglion (DRG).
10
Q
Describe efferent neurons.
A
cell bodies are generally located in the CNS.
efferent axons or nerve fibers leave the CNS and travel to the target organ.
11
Q
Describe the location of the autonomic efferent fibers.
A
have 2 neurons between the CNS and target organ, the cell body of the first neuron is in the CNS, and the cell body of the second neuron is a ganglion.
12
Q
Describe interneurons.
A
lie entirely within the CNS.
make up 99% of all neurons.
coordinate information between the afferent and efferent fibers and also, in the brain, provide signal processing for higher cognitive function.
13
Q
What are tracts?
A
bundles of axons in the CNS
14
Q
What are nerves?
A
bundles of axons in the PNS.
15
Q
What are nuclei?
A
clusters of cell bodies in the CNS.
16
Q
What are ganglia?
A
clusters of cell bodies in the PNS.
17
Q
What are glial cells?
A
make up 90% of cells in the CNS.
Make up 50% of the volume of the brain.
do not conduct nerve impulses.
are able to divide.
18
Q
What are astrocytes?
A
glial cells in in the CNS that are star-shaped and hold neurons together in proper spatial relationships.
serve as scaffolding for neuronal migration in brain development.
19
Q
What do astrocytes accomplish by retracting their processes?
A
allow new synapes to form.
20
Q
What do astrocytes establish?
A
the blood brain barrier by working with small blood vessels.
21
Q
What do astrocytes maintain?
A
the proper relationship between sodium and potassium in the brain by taking up potassium.
high potassium concentrations in the extracellular fluid are correlated with epileptic seizure episodes.
22
Q
What are the lesser functions of astrocytes?
A
repair injuries and form neural scar tissue.
provide metabolic support for the neurons by taking up and degrading glutamate and GABA.
communicate with other astrocytes and neurons via gap junctions and chemical messages.
23
Q
What are oligodendrocytes?
A
glial cells that myelinate the axons in the CNS.
24
Q
What are ependymal cells?
A
glial cells in the CNS that line the ventricles of the brain and central canal of the spinal cord and play a role in the production of CSF.
have cilia to help with flow of CSF.
can act as stem cells for neurons and glia.
25
What are microglia?
glial cells in the CNS that are phagocytic and remove invading organisms.
develop from the same lineage as monocytes, but these cells have migrated to the brain and differentiate into microglia
26
What do microglia release?
reactive oxygen species and may be the cause of cell death in ALS.
27
What are the glial cells of the PNS?
schwann cells and satellite cells.
28
What are schwann cells?
glial cells in the PNS that myelinate axons
29
What are satellite cells?
glial cells in the PNS that support cell bodies of neurons in ganglia.
30
What are gliomas?
cancer of the brain of glial cells.
31
How much of the bodies oxygen does the brain use?
20%
32
How much of the body's glucose does the brain use?
50%
33
What is neuroglobin?
a protein like hemoglobin and myoglobin, specialized to bind oxygen.
34
Does the brain store glucose?
no, during starvation, the brain can use ketones for energy.
35
How long does it take brain tissue to begin to die after blood supply has been blocked?
4-5 minutes.
36
What provides nutrients to the brain?
blood and CSF.
37
What are the three protective structures of the brain?
skull, vertebral column, and meninges.
38
What are the meninges?
membranes that wrap around the CNS.
| Contains dura matter, dural sinuses, and arachnoid mater.
39
What are the dura mater and dura sinuses?
the outer layer of the meninges that are very tough.
| In the sinuses, the blood and CSF recombine.
40
What is arachnoid mater?
the middle layer of the meninges that is filled with CSF.
41
What are arachnoid villi?
villi that project into the dural sinuses and provide structure for passage of CSF into the blood.
42
What is the pia mater?
the highly vascular inner layer of the meninges.
| lies next to the nervous tissue.
43
What is the function of cerebral spinal fluid?
cushions the brain and provides it with nutrients.
44
Where is the cerebral spinal fluid?
Inside the four ventricles within the interior of the brain and a central canal within the spinal cord.
45
Describe the flow of CSF
1. CSF is produced by the choroid plexus
2. CSF circulates in the ventricles
3. CSF flows out of the 4th ventricle into the subarachnoid space
4. CSF enters the venous system via the dural sinuses, CSF is therefore reabsorbed into the blood at the dural sinuses.
46
How is CSF formed?
by the choroid plexuses (special clusters of ependymal cells) found within the ventricles of the brain.
47
What is the total volume of CSF?
125 to 150 mls.
| Replaced three times daily.
48
What does excess CSF lead to?
hydrocephalus.
49
How do CSF and plasma differ?
the CSF has a lower potassium and higher sodium concentration than plasma because this supports the ion gradient needs of neurons (high sodium in ECF, low potassium in ECF).
CSF lacks plasma proteins and blood cells.
50
Describe the capillaries in the brain. (BBB).
capillaries have tight junctions between the endothelial cells.
51
What does the capillary structure in the brain mean? (BBB).
the tight junctions provide that all material that crosses into the brain must be lipid soluble or be transported by specific carrier proteins.
52
What are some examples of lipid soluble substances that can cross the blood brain barrier?
oxygen, carbon dioxide, alcohol, and steroid hormones.
53
What do membrane-bound carrier protein transport?
glucose, ions, and amino acids.
54
What do astrocytes do to help the BBB?
surround the capillaries and induce them to form tight junctions, also participate in ion transport.
55
Why is the hypothalamus excluded from the BBB?
has capillaries that are more freely permeable because it must sample from the bloodstream.
56
What is gray matter?
predominantly cell bodies and dendrites; any non-myelinated tissue.
57
What is white matter?
bundles or tracts of myelinated fibers.
58
Describe the location and function of occipital lobe.
located in the back of the head.
| contains the visual cortex and visual processing area.
59
Describe the location and function of temporal lobe.
located on the sides of the brain.
handles hearing.
inferior medial portion deals with memory, motivation and behavior.
60
Describe the location and function of parietal lobes.
located on the top, back of the brain.
receives and processes sensory input for touch, pressure, heat, cold and pain
also handles proprioception (body position).
somatosensory homunculus.
61
Describe the location and function of the frontal lobes.
front of the brain.
reasoning and initiating voluntary motor control.
motor homunculus.
62
Describe the location and function of the insular lobes.
internal to frontal and temporal lobes.
| cortex for gustation and olfaction
63
Describe Broca's area.
responsible for controlling muscles for articulation.
64
Describe Wernicke's area.
responsible for recognition of language (conprehension.
also responsible for forming coherent patterns of speech, then sending information to Broca's area for execution.
receives input from occipital lobes and temporal lobes.
This allows reading and conversation to be possible.
65
What are the three association areas of the brain?
1. prefontal association cortex.
2. parietal-temporal-occipital association cortex.
3. limbic association cortex.
66
What is the prefontal association cortex?
plans for voluntary activity
weighs the consequences of future actions
personality traits
67
What is the parietal-temporal-occipital association cortex?
integrates somatic, auditory, and visual information for comprehension.
involved in the language pathway.
68
What is the limbic association cortex.
motivation and emotion
memry
direct link with olfactory neuron
69
What is the specialization of the right hemisphere?
spatial relationships
| music and art
70
What is the specialization of the left hemisphere?
language
fine motor control
logic, analytical, sequential tasks
71
Describe the basal nuclei and midbrain.
regulates muscle tone throughout the body.
maintains purposeful motor activity and inhibits unnecessary activity .
helps maintain postural muscles
72
What is the substantia Nigra?
located in the midbrain.
gets its name from the dark pigment that it contains.
release dopamine from their axon terminals.
73
How does the substantia Nigra contribute to the development of Parkinson's disease?
the neurons degenerate and the amount of dopamine they deliver to the basal nuclei is reduced. This decreases the subsequent activation of the sensorimotor cortex.
74
Describe the thalamus.
located in the diencephalon.
collection of several large nuclei that serve as synaptic relay stations.
coordinates sensory input from the body and filters out unnecessary input.
neurons carrying different sensory info make a synapse in the thalamus, before another neuron takes the info to the appropriate cortical lobe.
75
Describe the hypothalamus.
Most important control area for homeostatic regulation of the internal environment.
body temperature
thirst and urine output.
satiety centers
production of posterior pituitary hormones.
secretion of anterior pituitary hormones.
coordinates ANS
emotional and behavioral patterns.
sleep/wake cycle
some regions are sexually dimorphic.
76
Describe the limbic system.
emotion and motivation
momory
direct link with olfactory neurons.
77
What is learning?
the acquisition of knowledge or skills via experience and or instruction.
Influenced by environment and early nutrition.
has a strong genetic component.
78
Describe reinforcement in learning.
rewards-positive reinforcement (Study well=good grades)
| punishment-negative reinforcement (bad behavior=punishment).
79
What is memory?
the storage and retrieval of information.
laid down in stages
initially concepts are stored as a memory trace.
80
What is short-term memory?
the initial storage point for newly acquired memory traces. lasts for seconds to hours.
81
What is consolidation?
memory traces can be transferred from short-term to long-term.
involves the practicing or rehearsal of the information.
usually it involves further personalization of the information.
82
What is long-term memory?
lasts from days to years.
| storage capacity is much greater than short-term.
83
Describe the retrieval of memory.
takes longer for long-term memories than short term.
84
How are memories segregated?
based upon input.
| Ex. visual memories are stored separately stored from auditory or olfactory memories.
85
What is amnesia?
loss of memory.
86
What is retrograde amnesia?
the inability to recall past events
87
What is anterograde amnesia?
the inability to create long-term memories.
88
What could anterograde amnesia be caused by?
lesions in the medial portion of the temporal lobes.
89
Where are memories stored?
throught the cortical and subcortical regions.
90
What is consolidation accomplished by?
the hippocampus.
91
What is memory access accomplished by?
the prefrontal region of the cerebrum.
92
What are declarative memories?
fact-based memories.
| associated with the hippocampus and surrounding regions.
93
What are procedural memories?
memories involving steps (tying shoes).
| stored in the cerebrum.
94
What is habituation?
involved in formation of short-term memory.
becoming used to a particular stimulus.
involves closing of calcium channels which decreases amount of neurotransmitter released.
95
What is sensitization?
involved in formation of short-term memory.
responding strongly to a mild stimulus in anticipation of a stronger one.
calcium channels are maintained open for a slightly longer period of time thus leading to an increase in neurotransmitter release.
96
What is long-term potentiation?
an increase in strength of existing synaptic connections following stimulation.
plays an important role in declarative memories.
changes are induced in both the presynaptic and postcsynaptic neurons.
changes make neural pathway more ready to be used.
a messenger is released by postsynaptic neuron and influences both pre- and postsynaptic neurons to increase responses to synaptic events.
occurs in the hippocampus.
97
What does formation of long-term memory involve?
permanent physical changes in the brain including formation of new synapses, rearrangement of synapses, and increase or decrease in neurotransmitter production.
protein synthesis is also important.
Genetic regulation also plays a role.
98
What is CREB
cAMP response element binding protein.
| has been demonstrated to activate genes used in long-term memory storage.
99
Describe the cerebellum.
balance, muscle tone, skilled voluntary movements, alters movements based on changes in body position, and procedural memories.
100
What is nystagmus?
rhythmic oscillation of the eye.
| cerebellum
101
what is intention tremor?
back and forth movement resulting from faulty start stop commands.
cerebellum.
102
What are the functions of the brain stem?
breathing, heart rate, alerness.
103
Describe the medulla.
located in the brain stem.
houses centers for controlling respiration, blood pressure and heart rate.
contains center for swallowing.
contains chemoreceptor trigger zone which is important in vomiting.
plays a role in salivation.
104
Describe the pons.
located in the brain stem.
plays a role in respiration (apneustic center) and blood pressure regulation.
plays a significant role in analgesic system.
105
Describe the midbrain.
houses the corpora quadrigemina and red nucleus.
106
What is the corpora quadrigemina?
functions in visual and auditory reflexes for orientation.
| Located in the midbrain.
107
What is the red nucleus?
functions in gross motor movement.
| Located in the midbrain.
108
What is the reticular formation?
Located in the brain stem and is part of the thalamus.
contains reticular activating system which controls over all degrees of alertness.
wake v sleep v coma v brain dead
109
What is the dorsal horn?
the region of the spinal cord that receives afferent fibers.
110
What is the dorsal root?
the afferent spinal nerve.
111
What is the dorsal root ganglion?
contains afferent/sensory nerve cell bodies.
located outside of the spinal cord on the dorsal surface. Also contains a central axon that passes into the spinal cord.
the terminals from the central axon synapse with orther neurons in the spinal cord.
112
What is the ventral horn?
the region of the spinal cord that transmits efferent fibers.
There is no ventral root ganglion.
cell boiese of efferent/ motor neurons.
113
What is the ventral root?
the efferent spinal nerve.
114
What are ascending tracts?
tracts that carry sensory information to the brain.
115
What are descending tracts?
tracts that carry information from the brain via efferent neurons to muscles or glands.
116
What are the five parts of the reflex arc?
1. receptor
2. afferent pathway
3. integrating center in the CNS
4. Efferent pathway
5 Effector organ.
117
What can reflexes be overriden by?
IPSPs
