Ch 23, 25, 26 Flashcards
1
Q
neural tube
A
primitive brain/sheet of cells rolls up to form this structure, will develop into the brain and spinal cord
2
Q
apoptosis
A
genetically programmed cell death
3
Q
what are the 7 stages of brain development?
A
- cell birth (neurogenesis; gliogenesis)
- cell migration
- cell differentiation
- cell maturation (dendrite and axon growth)
- synaptogenesis (formation of synapses)
- cell death and synaptic pruning
- myelogenesis (formation of myelin)
4
Q
anencephaly
A
cerebral hemispheres, diencephalon, and midbrain are absent
5
Q
holoprosencephaly
A
cortex forms as a single undifferentiated hemisphere
6
Q
lissencephaly
A
brain fails to form sulci and gyri and corresponds to that of a 12-week embryo
7
Q
micropolygyria
A
gyri are more numerous, smaller, and more poorly developed than typical
8
Q
macrogyria
A
gyri are broader and less numerous than typical
9
Q
microencephaly
A
development of the brain is rudimentary and the person has low-grade intelligence
10
Q
porencephaly
A
cortex has symmetrical cavities where cortex and white matter should be
11
Q
hetertopia
A
displaced islands of gray matter appear in the ventricular walls or white matter, caused by aborted cell migration
12
Q
callosal agenesis
A
entire corpus callosum or a part of it is absent
13
Q
cerebellar agenesis
A
parts of the cerebellum, basal ganglia, or spinal cord are absent or malformed
14
Q
neural stem cells
A
multipotential, have an extensive capacity for self-renewal
15
Q
subventricular zone
A
consists of neural stem cells that line the ventricles
16
Q
progenitor (precursor cells)
A
formed from neural stem cells, can also divide but eventually produce nondividing cells (neuroblasts/glioblasts)
17
Q
neuroblasts/glioblasts
A
nondividing cells formed from progenitor cells that mature into specialized neurons/glial cells
18
Q
radial glial cells
A
fibre extends from the subventricular zone to the cortical surface along which neurons migrate to the corresponding function
19
Q
athetosis
A
slow, involuntary movement
20
Q
dystonia
A
imbalances in muscle tone
21
Q
growth spurts
A
irregularly occurring periods during which the brain increases in mass suddenly
22
Q
outline Piaget’s stages of cognitive development
A
- sensorimotor (birth to 18-24 months): experiences the world through senses and actions, object permanence, stranger anxiety
- preoperational (2-6 years): represents things with words and images but lacks logical reasoning, pretend play, egocentrism, language development
- concrete operational (7-11 years)” thinks logically about concrete events, grasps concrete analogies and performs arithmetical oeprations, conservation, mathematical transformations
- formal operational (more than 12 years): reasons abstractly, abstract logic, potential for mature moral reasoning
23
Q
brain plasticity
A
the nervous system’s potential for physical or chemical change that enhances its adaptability to environmental change and its ability to compensate for injury
24
Q
amblyopia
A
deficits of vision without obvious impairment of the eye
25
what are 3 ways that the brain could show plastic changes that support recovery after injury?
1. changes in the organization of the remaining intact circuits in the brain
2. generation of new circuitry
3. generation of neurons and glia to replace at least some lost neurons
26
neurotrophic factors
chemical compounds that support growth and differentiation in developing neurons and may act to keep neurons alive in adulthood
27
chronic traumatic encephalopathy (CTE)
a progressive degenerative disease found in individuals with a history of multiple concussions and other closed head injuries
28
long term potentiation (LTP)
long term change in the efficiency of synapses (can be achieved by high frequency electrical stimulation)
29
kindling
the development of persistent seizure activity after repeated exposure to an initially subconvulsant stimulus
30
what are the 10 principles of brain plasticity?
1) plasticity is common to all nervous systems, and the principles are conserved
2) plasticity can be analyzed at many levels
3) the two general types of plasticity derive from experience
4) similar behavioural changes can correlate with different plastic changes
5) experience-dependent changes interact
6) plasticity is age-dependent
7) plastic changes are time-dependent
8) plasticity is related to an experience's relevance to the animal
9) plasticity is related to the intensity or frequency of experiences
10) plasticity can be maladaptive
31
experience-expectant plasticity
occurs largely during development, for different brain systems to develop requires specific types of experience
32
experience-dependent plasticity
reflects brain changes necessary to modify neuronal ensembles that are already present
33
what are 4 conclusions of functional imaging studies after cerebral injury?
1) if the primary sensorimotor cortex survives a stroke, some functional improvement is likely with the passage of time
2) activation of motor areas during limb movements recruits cortical areas along the rim of cortical injury
3) the motion of stroke patients activate much larger cortical areas, especially parietal and premotor areas, than do similar movements by controls
4) reorganization is not restricted to one hemisphere: similar changes take place bilaterally
5) capacity for reorganization declines with increasing size of stroke and increasing age
6) variability among stroke victims is considerable
34
what are 5 major experimental therapeutic approaches to recovery after brain damage?
1) rehabilitation procedures consisting of a variety of experiential, behavioural, and psychological therapies
2) pharmacological therapies intended to promote recovery in the immediate postsurgery period
3) brain stimulation increases brain activity
4) brain-tissue transplants and stem-cell induction techniques are being developed in the hope of restoring healthy brain function
5) diet provides the building blocks for plastic changes
35
constraint-induced movement therapy
place the unaffected limb in a sling and force the patient to perform daily activities with the impaired limb, goal is to stimulate plastic changes in the brain that lead to an enlargement of the motor representation of the affected arm and hand.
36
neurologist
a physician specializing in the treatment of brain injury or dysfunction
37
cerebral vascular accident (CVA) / stroke
the sudden appearance of neurological symptoms as a result of interrupted blood flow
38
infarct
an area of dead or dying tissue resulting from an obstruction of blood vessels supplying the area
39
ischemia
any group of disorder in which the symptoms are caused by vessel blockage preventing a sufficient supply of blood to the brain
40
thrombosis
some of the blood in the vessel has coagulated to form a plug or clot that has remained at the place of its formation
41
embolism
a clot or plug brought through the blood from a larger vessel into a smaller one, where it obstructs circulation
42
cerebral arteriosclerosis
thickening and hardening of the arteries
43
cerebral vascular insufficiency/transient ischemia
temporary ischemia
44
migraine strokes
experienced as a transient ischemic attack with a variety of neurological symptoms
45
cerebral hemorrhage
massive bleeding into the substance of the brain
46
angiomas
congenital collections of abnormal blood vessels that divert the normal flow of blood
47
arteriovenous malformations (AVM)
masses of enlarged cortical vessels that are supplied by one or more large arteries and are drained by one or more veins
48
aneurysms
vascular dilation resulting from localized defects in a vessel's elasticity
49
metabolic syndrome
a combination of metabolic disorders, including obesity and diabetes, which collectively increases the risk of developing cardiovascular diseases and diabetes
50
coup
bruise that develops at the site of damage
51
countrecoup
bruise that forms opposite to site of blow
52
hematoma
growing mass from blood trapped within the skull, exerts pressure on surrounding structures
53
coma
loss of consciousness
54
epilepsy
brain disorder caused by seizure (abnormal, spontaneous discharges of brain neurons as a result of scarring from injury, infections, or tumours)
55
symptomatic seizures
can be identified with a specific cause
56
idiopathic seizure
appears to arise spontaneously and in the absence of other CNS diseases
57
what are the 3 particular symptoms in epilepsy?
1) onset of aura (a subjective sensation, perceptual experience, or motor phenomenon that precedes and marks the onset of an epileptic seizure or migraine)
2) loss of consciousness
3) movement
58
focal seizures
begins in one place and then spreads
59
generalized seizures
bilaterally symmetrical, without focal onset, can be characterized by loss of consciousness and stereotyped motor behaviour
60
what are the 3 stages of generalized seizures?
1) tonic stage - body stiffens and stops breathing
2) clonic stage - rhythmic shaking occurs
3) postseizure - postictal depression; patient loses affect and is confused
61
akinetic seizures
usually seen in children, very brief duration
62
myoclonic spasms
massive seizure that basically consists of a sudden flexion/extension of the body
63
tumour/neoplasm
mass of new tissue that persists and grows independently of its surrounding structures and has no physiological use
64
glioma
arise from glial cells and infiltrate the brain substance
65
meningiomas
growths attached to meninges, grow outside the brain
66
metastatic tumour
established from a transfer of tumour cells from some other region of the body
67
what are 3 types of brain tumours?
1) glioma
2) meningioma
3) metastatic tumour
68
migraine
familial disorder characterized by recurrent attacks of headache in variable intensity, frequency, and duration
69
classic migraine
begins with an aura
70
common migraine
no clear aura but gastrointestinal or other "signal" may presage an attack
71
cluster headache
unilateral pain in the head or face, rarely lasts longer than 2 hours but recurs repeatedly before disappearing
72
hemiplegic migraine
loss of movement on one side of the body
73
ophthalmologic migraine
loss of movement of the eyes
74
muscle-contraction headaches (tension/nervous headaches)
result from sustained contractions in the muscles of the scalp and neck caused by constant stress and tension
75
nonmigrainous vascular headaches
associated with dilation of cranial arteries
76
ergotamine
compounds can be useful for treating heache; constrict cerebral arteries, reduces dilation/source of pain
77
infection
the invasion of the body by disease - produced by (pathogenic) microorganisms and the reaction of the tissues to their presence and to the toxins they generate
78
how do infections kill neural cells?
1) interfering with blood supply
2) disturbing glucose/oxygen metabolism
3) altering cell-membrane properties
4) formation of pus
5) causing edema
79
what are 4 types of CNS infections?
1) viral infection
2) bacterial infection
3) mycotic infection (fungus)
4) parasitic infections
80
viral meningitis
inflammation of meninges caused by infection
81
bacterium
any micro-organism that has no chlorophyll and multiplies by cell division
82
bacterial meningitis
meninges infected by bacteria and becomes inflamed
83
brain abscesses
begins as a small focus of purulent (pus-producing) bacteria that cause necrosis of cells in the affected region, produced by a variety of bacteria, secondary to infection elsewhere in the body
84
parasite
an organism that lives on or within another living organism, at the host's expense
85
amebiasis
caused by infestation of a protozoan, results in encephalitis and brain abscesses
86
malaria
caused by protozoa transmitted by bites of infected mosquitoes, infects brain capillaries, produces local hemorrhages & subsequent neuronal degeneration
87
myasthenia gravis
severe muscle weakness as a result of muscle receptor dysfunction
88
poliomyelitis
infectious disease caused by a virus with special affinity for spinal cord motor neurons and sometimes for the motor neurons of the cranial nerves
89
multiple sclerosis
a disorder of myelinated motor fibres, characterized by a loss of myelin, mostly in motor tracts but also in sensory tracts
90
paraplegia
caused by complete transection of the spinal cord, both lower limbs are paralyzed
91
quadriplegia
paralysis of all four limb
92
Brown-Sequard syndrome
refers to the consequences of a unilateral transection through the spinal cord
- loss of pain and temperature on contralateral side
- loss of fine touch, pressure sensation, voluntary movement of distal structures on ipsilateral side
93
hemiplegia
loss of voluntary movements on one side of the body resulting from damage to the neocortex and basal ganglia contralateral to the motor symptoms
94
Babinski sign/extensor planar response
scratching sole of foot causes downward flexion of all toes
95
abdominal reflex
stroking causes abdominal muscles to retract
96
cremasteric reflex
in males, stroking of the inner thigh causes testicle retraction
97
narcolepsy
excessive sleep/brief sleep episodes including REM sleep
- sleep attacks
- cataplexy
- sleep paralysis
- hypnagogic hallucination
98
sleep attacks
brief, irresistible sleep episodes that last about 15 minutes and can occur at any time
99
cataplexy
complete loss of muscle tone or sudden paralysis that results in buckling of the knees/complete collapse
100
sleep paralysis
occurs in transition between wakefulness and sleep
101
hypnagogic hallucination
episodes of auditory, visual, or tactile hallucination during sleep paralysis as an affected person is falling asleep or waking up
102
insomnia
inadequate sleep or inability to fall asleep/frequent arousal from sleep
- sleep apnea
- obstructive sleep apnea
- central sleep apnea
103
sleep apnea
inability to breathe during sleep
104
obstructive sleep apnea
occurs mainly in the course of dreaming, collapse of the oropharynx during sleep paralysis
105
central sleep apnea
CNS disorder, failure of the diaphragm and accessory muscles to move
