Midterm Flashcards
1
Q
Brain
A
(encephalon) is part of the CNS encapsulated within the cranium
2
Q
Spinal cord
A
part of the CNS that lies within the spinal canal (within the vertebral column) and terminates at the level of the second lumbar vertebra
3
Q
Cranial nerves
A
series of nerves emerging from the brain, part of the PNS
4
Q
Spinal nerves
A
series of nerves emerging from the brain, part of the PNS
5
Q
Somatic nervous system
A
part of the PNS, conveys and processes sensory information, provides motor control for voluntary muscles
6
Q
Autonomic nervous system
A
part of the PNS, conveys and processes sensory information, provides motor control for voluntary muscles
7
Q
Sympathetic system
A
part of the ANS, responsible for general arousal, activation, and fight-or-flight
8
Q
Parasympathetic system
A
part of the ANS, responsible for relaxation and long-term body homeostasis
9
Q
Maintained activity of one system will produce a…
A
compensatory overshoot when the stimulation ceases or fatigues from prolonged stimulation
10
Q
Enteric nervous system
A
Contains 500 million neurons that reside along the gastrointestinal tract, it does not receive direct CNS input and is thought to function independently
11
Q
Brain volume
A
1300 cubic cm
12
Q
Cerebrum
A
part of the brain split into two cerebral hemispheres separated from each other by a longitudinal fissure
13
Q
Brain stem
A
comprises the midbrain, pons, and medulla oblongata
14
Q
Forebrain
A
largest part of the CNS in humans, divided into the telencephalon and dienchephalon
15
Q
Telencephalon
A
“end brain” this is the two cerebral hemispheres, the cerebral cortex, and a number of subcortical structures
16
Q
Diencephalon
A
“between brain” includes the thalamus and hypothalamus
17
Q
Mesencephalon
A
“middle brain” is a short narrow region connecting the forebrain and the hindbrain
18
Q
Metencephalon
A
“hind brain” composed of the pons and cerebellum
19
Q
Myelencephalon
A
“marrow brain” medulla
20
Q
Mesencephalon and myelencephalon
A
form a connection between the forebrain and spinal cord
21
Q
Neuraxis
A
the long, t-shaped axis through the brain
22
Q
Ontogenic
A
time-related
23
Q
Saggital plane
A
divides the brain into two symmetrical halves
24
Q
Coronal plane
A
a vertical place passing through both ears
25
Axial plane
divides the brain into a top and bottom half
26
Rostral-caudal
front-to-back
27
Dorsal-ventral
top-to-bottom
28
Medial-lateral
middle-to-side
29
Cephalic flexure
causes a bending in the midbrain-diencephalic junction
30
Anterior, posterior, superior, inferior
in front of, behind, above, below
31
How much of the brain is extracellular?
15 to 25 percent
32
Neurons
10x10^-6m in diameter, the basic unit of signalling in the nervous system
33
Dendrite
Receives most inputs to the cell
34
Purkinje cells
in the cerebellum, can have as many as 10,000 dendrites
35
Soma
cell body
36
Axon
carries most outputs
37
Action potentials
The patterns of pulses between neurons
38
Most mammalian neurons are-
multipolar, meaning they have several axons and dendrites arising from the cell body
39
Synapses
carry information from the axon terminal of one neuron to the dendrites of the next neuron
40
Neurotransmitters
chemicals that mediate rapid inter cellular communication
41
Glutamate and GABA
the most common neurotransmitters, they comprise 30% of the brains neurotransmitters
42
Serotonin, dopamine, and noradrenaline
each less than 5% of total synapses
43
Acetylcholine
5-10% of synapses, is mostly obtained through diet, important part of myelin
44
Neuropeptides
long sequences of assembled amino acids
45
Gray matter
consists of neuronal cell bodies, dendrites, axon terminals, synapses, glial cells, and is highly vascularized
46
White matter
consists of bundles of axons, many of which contain myelin, no cell bodies so it's less vascularized
47
Nuclei
groupings of neuronal cell bodies within the gray matter of the CNS
48
Cerebral cortex
a layer of gray matter on the surface of the cerebral hemispheres
49
Ganglia
groups of neuronal cell bodies within the PNS
50
Tracts
bundles of axon fibres in the CNS
51
Nerves
bundles of axon fibres in the PNS
52
Contralateral
refers to the opposite side (usually in reference to a lesion)
53
Ipsilateral
refers to the same side (usually in reference to a legion)
54
Afferent
pathways toward a structure
55
Efferent
pathways away from a structure
56
Neural tube
a specialized sheet comprised of cells that fold over to form the neural tube, from which the CNS arises
57
Congenital malformation
caused by a flaw in the process by which the brain is formed
58
Craniorachischisis totalis
"cleft skull and spine", in which the brain and spinal cord appears externalized on the back surface of the head and body
59
Spina bifida
in which the caudal spinal cord is uncovered and open to the outside, can cause anencephaly
60
Anencephaly
"without brain", in which most if not most of the cerebral hemispheres fail to develop, caused by spina bifidi
61
Specific gravity is higher for the-
left hemisphere, it contains more gray matter
62
Left planum temporale
5 time larger on the left in most people, plays a critical role in language
63
Individuals with perfect pitch-
have larger leftward symmetry and smaller right absolute size of their left planum temporale
64
Patients with scizophrenia often have-
enlarged right planum temporale and no leftward asymmetry, these differences might reflect the odd language patterns and symptoms of paranoia because of the right hemisphere's involvement in emotion
65
The region of the temporal cortex lying ventral to the lateral fissure is larger on the right-
possible base for spatial visualizing during mathematical problem solving
66
Broca's area
"frontal operculum", organized differently on left and right side. More area visible on the cortical surface on the right. More in the sulci on the left
67
Broca's area is more visible on the cortical surface on the right and more buried in sulci on the left, this corresponds with-
the left side affecting the production of grammar and the right side influencing the tone (timbre) of voice
68
Left cerebral hemisphere
organization & categorization of info into discrete temporal units, sequential control of finger, hand, arm, and articulatory movements, perception & labelling of material that can be coded linguistically
69
Right cerebral hemisphere
nonverbal awareness, perception of musical stimuli, identification of environmental and nonverbal sounds, analysis of geometric and visual space, facial and gesture recognition, visual imagery, emotion
70
Frontal lobe primary function?
motor, inhibition, language (expression), and antici... pation
71
During depression there is predominantly-
left hypofrontal activity, this means the person would have less emphasized ability to initiate activity and control thoughts
72
Parietal lobe
integration and awareness of body image and body boundary (touch, proprioception, and pain)
73
Occipital lobe
visual recognition and visual processing
74
Temporal lobe
language (reception), hearing , vestibular functions
75
Insular lobe
autonomic and visceral experiences
76
Cingulate-limbic lobes
sense of self, meaningfulness, emotion, memory, species-bonding behaviour
77
Basal ganglia
conscious/unconscious motor movements, includes caudate, putamen, globus palcidus
78
Hippocampus
gateway to memory
79
Amygdala
affect and meaningfulness
80
Meninges
A succession of the connective tissue membranes that envelop the brain and spinal cord
81
Dura mater, arachnoid mater, and pia mater
the three layers of the meninges from most dorsal to ventral
82
Falx cerebri
the dural partition between the two cerebral hemispheres, composed of the thickened and folded meningeal dura
83
Subdural hematoma
collection of blood in the arachnoid as a result of skull injury
84
Meningitis
inflammation of the meninges
85
Ventricles
fluid-filled cavities, through which cerebrospinal fluid (CSF) flows, within the brain
86
Lateral ventricles
a pair of horn-shaped caverns inside the cerebral hemispheres, running from the front of the brain to the back and curving around into the temporal lobe
87
Cerebral aqueduct
connects the third and fourth ventricle in the midbrain
88
Choroid plexus
Produces CSF at a total volume of about 70 to 160ml, lines ventricular walls
89
CSF composition can be affected-
during the course of disease, usually clear and colourless, but will turn cloudy when it contains too many white blood cells
90
Classical diseases
enlargement of lateral ventricles occurs in chronic schizophrenia and hydrocephalus
91
Chronic schizophrenia
associated with flat affect (poor emotional responses and withdrawal, not very responsive to medication
92
The vertebral arteries transform into-
basilar arteries (along the surface of the medulla)
93
The anterior region of the basilar artery bifurcates into the two-
posterior cerebral arteries (PCA)
94
The posterior cerebral arteries (PCA)-
supply the caudal medial surface of the hemispheres. the occipital, and ventral temporal lobes
95
Interference with the PCA produces-
visual anomalies (without unilateral loss of motor control), memory difficulties, and sudden falling without loss of consciousness
96
Stenosis
reduction in the size of a supplying vessel (can cause brain damage)
97
Occlusion
blocking vessel (can cause brain damage)
98
Haemorrhage
loss of blood from a damaged vessel (can cause brain damage)
99
Transient ischemic attack (TIA)
weakness or sensations on the side of body opposite to hemisphere where ischemia is occurring
100
If TIA symptoms last longer than 24 hours its called a-
cerebral infarction
101
Stroke
usually rapid onset of symptoms, experience psychological depression post-stroke
102
Hematosis
collection of blood due to vascular leakage
103
Parenchyma
brain proper, the neurons
104
Arteriousvenous malformations (AVM)
anomalous occurrences of anastomoses
105
Anastomoses
where arterioles are fused with other arterioles or venules
106
Most common place for AVMs
Parietal lobe
107
Basic premise of Neuroscience (fMRI) research
that portion of the brain that displays metabolic activity that is greater than the expected average will dominate the behavioural output of the organism
108
Physiological redundancy
more neurons are present than are required to maintain normal function
109
Overactivity of serotonin pathways within frontal-basal ganglia system is associated with-
obsessive compulsive disorder
110
Individual neurons or nerve cells are-
the basic units of the nervous system
111
How many neurons in the human brain?
100 to 200 billion
112
The neuron is composed of-
4 morphologically defined regions
113
Cell body (soma) (ch2)
average diameter is about 10 microns (10x10^-6m), which is the metabolic and genomic hub of the neuron
114
Dendrites (ch2)
branching processes that receive info from other neurons
115
Axon (ch2)
long cylindrical process that propagates info away from the cell body
116
Presynaptic terminals
end of the axon, specialized enlarged regions often terminating in vicinity of the dentries of another neuron
117
Presynaptic cell
neuron transmitting a signal
118
Postsynaptic cell
neuron receiving a signal
119
Synaptic cleft (synapse)
narrow space between the presynaptic and postsynaptic cells
120
Mitochondria
chief source of energy production in the cell through the generation of ATP
121
ATP-bound energy is essential for all cellular processes and is-
critical for maintaining the high levels of activity of nerve cells
122
Nissl bodies/substance
stacked ribosomes which synthesize large quantities of proteins, high concentration on the rough endoplasmic reticulum of neurons
123
The dominance of Nissl substance in neurons emphasizes-
the importance of protein synthessis to neuronal function
124
The entirety of the dendritic branches is called the-
dendritic tree or dendritic arbor
125
Since microstructure dictates microfunction-
the structural organization of the dendritic tree reflects the function of the neuron
126
Spines
tiny protuberances on the dendrites of neurons that increase the surface area of the receptive membrane of the neuron and is the site where axon terminals interface
127
Dendritic spines are-
dynamic and can be induced to growth with only 1 second of 400Hz stimulation
128
Spines swell and change in response to-
neurotransmitters, especially primary exitatory neurotransmitter glutamate
129
Changes in the numbers or shapes of spines-
are the microstructural correlates of learning and thinking
130
Action potentials-
transmissions of coded info in the form of electrical perturbations
131
The larger the diameter of the axon-
the faster the propagation of the action potential
132
Cytoskeleton
complex mesh of filamentous polymers within the interior of the cell
133
Myelin
covers most axons, enables rapid axonal conduction of action potentials along the axon
134
Oligodendrocytes
synthesize myelin in the CNS
135
Node of Ranvier
Separation between individual segments of myelin wrapping
136
Demyelinating diseases affect the-
myelinated axons in the PNS or CNS, but not both
137
Loss of myelin in the CNS can lead to-
multiples sclerosis
138
Multiple sclerosis
myelin produced by oligodendrocytes is disrupted as a result of autoimmune reaction resulting in multiple plaques of demyelinated white matter
139
Charcot-Marie-Tooth Disease
damage is restricted to peripheral myelination only, leaving central myelin intact
140
The most typical synapse interface is-
axodendritic synapse, between the axon of neuron I and the dendrite of neuron II
141
Synaptic vessel
an organelle in the presynaptic membrane that contains and releases neurotransmitters into the synaptic cleft in response to electrical activity
142
Most drugs that influence the brain have chemical structures similar to the-
neurotransmitters, these drugs compete with them at the synapse
143
Gap junctions
intercellular channels that allow direct diffusion of ions and small molecules between adjacent cells
144
There are 5 to 10 times more-
glial cells than neurons
145
Glial cell processes are connected in a-
vast syncytium, composed primarily of gap junctions
146
Glial cells act as a-
potassium buffer within the extracellular fluid
147
Electrical or epileptogenic focus-
area with chronic disruption in the levels of extracellular fluid
148
Astrocytes
a type of glial cell, interface between neuron and blood supply, part of the blood-brain-barrier
149
Oligodendrocytes
a type of glial cell, smaller than astrocytes, related to myelin formation
150
Microglia
type of glial cell, phagocytosis of deteriorating myelin, immune-related function
151
Most tumors are derived from-
astrocytes
152
Chance of tumors occurring-
2 to 20 per 100,000
153
Epilepsy is a dynamic process that-
can manifest itself in varying degrees of intensity at different times, rather than as one or more seizures of fixed origin
154
Why does epilepsy exist?
it's a natural consequence of the operation of the brain, experience is coded by cells that are very electrically labile and unstable
155
Paroxysmal discharge
repeated, synchronous high amplitude changes in electrical activity that result in seizure
156
If the seizure remains confined subcortically-
there may be no anomalous EEG pattern, only 50% of people with temporal lobe epilepsy show abnormal EEGs
157
Sometimes the actual focus of the seizure may start in one part of the brain then-
generalize to other parts of the brain that can provoke the convulsion
158
Generalized seizures
may be preceded by an aura and EEG recordings show a diffuse origin of electrical discharges in both hemispheres, includes absence and tonic clonic seizures
159
Absence seizure
sudden onset, interruption of activites, blank stare, 1 to 30s, originates in the thalamus (usually)
160
Tonic clonic seizure
"cry" or moan, patient lies rigid (tonic stage), small gusts of respiration (clonic stage), muscles relax, patient may enter a deep sleep
161
Simple symptomology
without impairment of consciousness
162
Complex symptomology
with impairment of consciousness
163
If a seizure impairs consciousness, you are more likely to experience-
automatisms, coordinated involuntary movements
164
Contusion
bruising
165
Force distribution: damage can occur at the impact site or (more often)-
on the opposite side of the brain due to counter-coup forces
166
Neuropsychiatric sequelae
symptoms that appear to be related to shaking injuries of the brain
167
Postconcussional syndrome
a neuropsychiatric sequelae. symptoms: headache, dizziness, poor concentration, easily fatigues, alcohol intolerance, and attentional deficits
168
Demyelinating disorders occur in-
the white matter
169
Multiple sclerosis is the demyelinating-
in the cerebrum and spinal cord
170
In females, multiple sclerosis symptoms-
decrease during the first part of pregnancy
171
How many functions does the brain stem have?
four
172
Brainstem provides transit for-
ascending pathways travelling to the thalamus and hypothalamus
173
Cranial nerves III to XII are attached to the surface of the brainstem and-
convey specialized sensory, motor, and visceral information
174
Brainstem supports integrative activities such as-
consciousness, the sleep-wake cycle, perception of pain, respiration and cardiovascular control (much of this is accomplished by the reticular core)
175
The brainstem is the origin of several-
monoaminergic (serotonin, dopamine, noradrenaline/norepinephrine) neurons
176
Corticospinal tract-
major pathway in the basilar portion, motor cortex, to spinal cord, responsible for voluntary motor control and movement
177
How much of the corticospinal tract is crossed?
85-90%
178
The pyramid-
(motor decussation) made of crossing fibres on the corticospinal tract
179
Because of the decussation of the motor fibres at the pyramids-
one side of the brain is said to control the opposite side of the body for voluntary movements
180
Inferior olive
lateral to the pyramids
181
Obex
the point at which the fourth ventricle narrows into the central canal
182
Area postrema
one of the periventricular organs (composed of special glial-like cells) it mediates nausea
183
Mast-cells
contain histamine, make up the area postrema
184
The inferior olive gives rise to-
climbing fibres that innervate the cerebellum. They provide a strong excitation signal when activated and it is believed they contribute to learning the timing of movements
185
The primary function of the reticular core is to-
modulate levels of arousal with information ascending to the cortex and descending to the spinal cord
186
Raphe nuclei
a series of different aggregates of serotonin (5HT) containing neurons that occupy the midline portion of the midbrain, pons, and adjacent medulla
187
Destruction of the raphe nuclei can produce-
insomnia
188
Tryptophan
sometimes used to ease sleep disorders
189
Reticular activating system (RAS)
ascending projections to specific thalamic neurons that mediate arousal and wakefulness
190
Bilateral damage of RAS projections can produce-
a state of coma!
191
The descending projections (reticulospinal tracts) influence-
spinal reflexes, muscle tone, and motor activity
192
Reticulospinal tracts may serve as an alternative to-
corticospinal (pyramind) tract that sends voluntary motor commands from the cerebral cortex to spinal motor neurons
193
Parabrachial nucleus
in the pons and midbrain, carries info involved with the taste pathway, and it's dense projections to the amygdala are thought to mediate the "liking" response to pleasurable flavours
194
Pedunculopontine (PPN) nucleus
(in the pons) plays a role in motor function (planning of movement)
195
Some of these neurons in the RAS contain acetylcholine (Ach) and control-
the generation of REM sleep!
196
Locus coeruleus
major source of noradrenaline to the brain
197
The only input from the prefrontal cortex to the locus coeruleus is-
from the prefrontal cortex (allows for self-evoking activation and monitoring of self and environment)
198
Locus coeruleus has multiple functions-
dreams, and monitoring external and internal events and prepare the organism to cope with emergencies
199
Cerebral peduncle
tegmentum and basilar portion of the midbrain
200
Superior colliculus
"upper hill" complex multimodal (multi-sensory) integration center, controls saccadic eye movements (rapid movements of the eyes that dart from one region of interest to another)
201
Inferior colliculus
"lower hill" major component of the auditory ascending relay
202
Periaqueductal gray
nuclear region that contains a high density of opioid producing neurons that aid in pain suppresion
203
Ventral Tegmental Area
plays an important role in the thought disorder component of schizophrenia
204
Dopamine projections from the VTA to the nucleus accumbens is part of-
the natural reward/motivation circuit and is strongly linked to addiction
205
Red nucleus
Lesions produce and intention tremor, low frequency tremor that is only present with voluntary movement
206
Substantia nigra
comprised of the pars compacta (source of dopamine transmitted via nigrostriatal pathways to the striatum) and the pars reticulata
207
Parkinsons disorder
fixed expression, pill-rolling tremor, resting tremor
208
At least 80% of the SN pars compacta neurons must die before-
the clinical symptoms of Parkinsonism become apparent
209
What are the specific nuclei of the midbrain?
superior colliculus, inferior colliculus, periaqueductal gray, ventral tegmental area, red nucleus, substantia nigra
210
Dopamine receptors are modulated by-
female hormones
211
Lesions of cranial nerves generally produce ipsilateral deficits with the exception of-
CNs II, CN III, and some components of CN VII, which produce contralateral deficits
212
Hypoglossal complex (CN XII)
lesion results in unilateral tongue paralysis, the tongue deviates to the paralyzed side
213
Vagal complex (CNX)
contains the cardiac-inhibitory center, nucleus ambiguous, and nucleus solitarius (nucleus of the solitary tract)
214
Cardiac-inhibiting center
source of parasympathetic innervation, contributes to vasovagal syncope (painting). Lesions can cause tachycardia (increased heart rate)
215
Nucleus solitarius
nucleus of the solitary tract, major source of the afferent taste pathway, innervation of taste buds of the epiglottis. Lesions can cause uncontrollable hiccups
216
Lesions of the Vagus Nerve
Messed up voice, swallowing, breathing, heartrate
217
Spinal accessory nerve (CN XII)
permits rotation and tilting of head, shrugging of shoulders
218
Lesion of the accessory nerve
makes it hard to rotate your head and shrug your shoulders
219
Glossopharyngeal complex (CN IX)
mediates taste sensation from the posterior one third of the tongue
220
Lesions of the glossopharyngeal nerve
no taste in back of tongue, no gag reflex, no carotid sinus reflex
221
Cochlear nuclei (VIII)
auditory processing
222
Vestibular nuclei (VIII)
medial longitudinal fasciculus, visual image on retina despite body movement
223
Nystagmus
to and fro eye movements, occurs with cerebellar problems, ethanol abuse, or labyrinthitis
224
Facial complex (CN VII)
innervates muscles of facials expression and mediates taste sensation on anterior 2/3 of the tongue
225
Lesions of facial nerve
Bell's palsy, paralyzes facial expression, also possibly crocodile tear syndrome
226
Trigeminal (CN V)
largest cranial nerve, provides major sensory innervation to part of the scalp, most of the dura mater, and the orofacial structures
227
Trigeminal sensory pathway-
transits information related to touch, pain, and dermal sensation of the face
228
Mastication
chewing
229
Bruxism
teeth grinding
230
Herpes zoster virus
shingles, results in sever pain (trigeminal neuralgia)
231
Lesions of the trigeminal nerve
may develop sharp, agonizing pain over the distributions of one of the branches of the trigeminal nerve known as trigeminal neuralgia or tic doulourex
232
The trochlear nerve (IV) innervates the-
superior oblique muscle
233
The abducens nerve (VI) innervates the-
lateral rectus muscle
234
The oculomotor nerve (CN III) innervates-
all remaining extraocular muscles
235
The medial rectus and lateral rectus-
collectively move the eyeball in a horizontal place
236
The superior rectus
elevates the eye (pupil up)
237
The inferior rectus-
depresses the eye (pupil down)
238
Diplopia
double vision caused by the paralysis of one or more extraocular muscles
239
Lesion of the oculomotor nerve-
drooping eyelid, dilated pupil, unequal-sized pupils, pupil stuck at temple (external strabismus)
240
Lesions of the abducens nerve-
horizontal diplopia (double vision)
241
Lesions of the trochlear nerve-
vertical diplopia, eye moves down and out
242
The trochlear nerve has the-
longest intracranial route
243
Homeostasis
a set of physiological processes and behavioural actions that keep internal composition of the body steady or sufficiently so to support normal health
244
Hypothalamus
promotes homeostasis, can be seen as the great integrator of emotional experience through modulating visceral and somatic outputs
245
The pituitary connects with the-
infundibulum or pituitary stalk
246
Medial forebrain bundle
sends information to control centers in the brainstem
247
Hypothalamus controls-
temperature, blood pressure, daily rhythms, energy metabolism, reproduction, emergency
248
Hypothalamus is a major correlate of-
instinctual behaviours (feeding, feeling, fighting, mating)
249
The release of hormones into both the hypothalamus and general circulation allows for-
coordinate hormonal regulation of motor, autonomic, emotional, and cognitive processes in service of complex goals such as hydration or maternal care
250
Although the hypothalamus occupies a very small volume, control of the body is completed through a-
cascading principle: hypothalamus to pituitary to blood to organs
251
Preoptic divisions
includes the anterior nucleus, medial preoptic area, and lateral preoptic nucleus
252
Anterior nucleus
act to prevent a rise in body temperature by activating processes that favour heat loss
253
Damage to the anterior nucleus causes-
hyperthermia (elevation in body temperature)
254
Medial preoptic area
contain gonadotropin-releasing hormones, which regulate reproductive behaviour. Sexually dimorphic in rats
255
The third intersititial nuclei of the anterior hypothalamus-
smaller in homosexual men
256
Lateral preotic nucleus
important sleep-promoting area! lesions produce insomnia :(
257
Anterior or Supraoptic Division
contains suprachiasmatic nucleus, paraventricular nucleus, and supraoptic nucleus
258
Supraoptic nucleus
internal master clock of the circadian timing system
259
Paraventricular nucleus
synthesize and release oxytocin
260
Supraoptic nucleus
synthesizes vasopressin (for water conservation). lesions produce diabetes insipidus
261
Tuberal division
contains ventromedial hypothalamus and lateral hypothalamus
262
Hyperphagic
eating excessively
263
Mammillary body
controls memory
264
Wernicke-Korsakoff encephalopathy
a condition involving marked anterograde and retrograde amnesia
265
Pituitary gland is connected to the hypothalamus by the-
infundibulum
266
Pituitary consists of-
two parts
267
Adenohypophysis
releases anti-inflammation and immunosuppressive chemicals like cortisol
268
ACTH (adrenocorticotrophic hormone)
an important neuropeptide that stimulates the adrenal cortex to release glucocorticoids
269
Cortisol
glucocorticoid, anti-inflammatory and immunosuppressive
270
Limbic system
several large agregates of brain nuclei within the depths of the cerebrum, crucial for normal human behaviour: memories, personality, thoughts, and emotions
271
The limbic system (or limbic lobe of Broca) includes-
the cingulate and parahippocampal gyri, the amygdala, and the hippocampus
272
James Papez proposed-
that the limbic lobe was organized as an anatomical substitute for drive-related and affective (emotional) behaviours
273
Papez circuit
the cingulate gyrus and its widespread cortical connections are responsible for internal emotion, whereas the hypothalamus is responsible for outward emotions, this is basically correct but other structures are involved
274
More recent conceptions of the limbic system include-
the cingulate gyrus, orbitofrontal and medial prefrontal cortex, perirhinal entorhinal, parahippocampal gyrus, and the hippocampus, and the amygdala
275
Anterior cingulate
part of the limbic system, allows for mammals to engage in peer play and tactile contact, separates animals from lizards
276
Septal nuclei or septum
part of the limbic system, electrical stimulation counters and inhibits aggressive behaviour and suppresses the expression of rage reactions following hypothalamic stimulation
277
Lesions of the septal nuclei can produce-
a temporary and dramatic increase in aggressive behaviour
278
Ventral Striatum
includes the nucleus accumbens and the substantia innominata (which includes the basal nucleus of Meynert)
279
Nucleus Accumbens
part of the ventral striatum, associated with substance abuse and addiction, such as alcoholism
280
Substantia Innominata/The Basal Nucleus of Meynert
part of the ventral striatum, massive death in cells here occurs in Alzheimer's disease
281
Uncinate fits
Seizures precuded by olfactory auras (like smelling burnt toast), fits occur in the uncus
282
Unicinate fasciculus
An association bundle that connects the orbitofrontal cortex with the anterior temporal lobes and amygdala
283
Parahippocampal oculus
involved with vigilance and is one of the central sources of panic attacks
284
Indusium griseum
passes through the cingulate and entorhinal area, gateway to the hippocampus, plays a functional role in the developing fetus, embryonic equivalent of the adult hippocampus
285
Anterograde amnesia
The person cannot remember events/details since the time of the damage
286
Retrograde amnesia
Person cannot recall memory before the incident
287
The hippocampus is considered the gateway to declarative memory (which is-
the ability to remember when, what, and where you learned
288
Besides memory, the hippocampus is involved with-
dreaming and seizures
289
Hippocampal neurons exhibit a-
slow-wave theta (4-7 Hz) activity during arousal, or when presented with noxious or novel stimuli
290
Near-death experiences involve-
hypoxic-induced electrical alterations of the hippocampus
291
The amygdala attaches-
meaningfulness and affect to experience
292
Among humans, fear and rage responses are the most common manifestations of-
amygdala electrical stimulation
293
According to Paul Maclean, the amygdala is involved with-
self-preservation
294
The amygdala modulates-
hypothalamic activity, including immune function
295
The amygdala is prone to kindling (which is-
brief 1-second electrical stimulation when applied once a day for several days produces a seizures (drugs like cocaine can stimulate this process)
296
Kluver-Bucy Syndrome or social-emotional agnosia-
ablation of the amygdala resulting in hyperphagia, hypermetamorphosis, reduced aggressiveness and fearfulness, low social interest, hyperorality, and hypersexuality
297
"cosmic wow"
intense meaningfulness evoked by stimulating the amygdala
298
Electrical stimulation of the mesiobasal temporal lobe
produces very meaningful hallucinations and out-of-body experiences
299
Temporal lobe pattern of personality
sensitivity to smells, hyperreligiosity, delusions with no evidence of a thought disorder, memory blanks
300
There is no single component of mystical, parapsychological, or religious experience that cannot be evoked by-
Mesial temporal lobe stimulation
301
Cortical expression
conscious awareness of one's self, both internal and in relation to the environment
302
How many neurons does the cerebral cortex contain?
Roughly 25 billion
303
How thick are the cerebral cortices?
1.5 to 4.5mm thick
304
What is the isocortex?
6 layered neocortex, part of the cerebral cortex
305
Cytoarchitecture differences
Differences in cell shape
306
Brodmann numbers or areas
areas within which cell shapes are similar
307
The neocortex is organized in-
six horizontal laminae (layers) oriented parallel to the cortical surface
308
Collumns/modules extending from the pia surface to the white matter-
long 3D slabs up to 0.5mm in width
309
Superior longitudinal fasciculus
largest of the association bundles, connects the cortex of the frontal, parietal, occipital, and temporal lobes, it is involved in language processing
310
The inferior longitudinal fasciculus
connects the temporal and occipital lobes
311
Uncinate fasciculus
runs deep to the Sylvian fissure to connect the orbitofrontal lobe with the rostral part of the temporal lobe (amygdala/hippocampal regions)
312
Cingulum
runs within the cingulate and parahippocampal gyri, connects the cingulate gyrus with the hippocampus
313
Functional callosectomies
where the person cannot detect facial gestures, visuospatial patterns, emotional meanings, and innuendos
314
Neocortical lobes
frontal, parietal, occipital, and temporal lobes, all part of the cerebral cortex
315
Primary or receptive cortex
directly receives thalamic input, damage to these areas produce a loss of modality (blindness/deafness), information from here travels to the secondary (association) cortices
316
secondary (association) cortices
daage to these areas usually produces agnosia
317
Agnosia
person still detects the stimuli but does not recognize it, or the meaning of the stimulus
318
Information from the secondary cortices travel to the-
tertiary (polymodal) cortices
319
tertiary (polymodal) cortices
multimodal (multisensory) and involved with higher-order functions related to reasoning, thought, and language
320
Occipital lobe primary function:
vision
321
Input from the upper visual field terminates-
below the fissure and terminates near the temporal lobe
322
Lesions in the temporal lobe that extend into the occipital cortex produce-
visual deficits along the upper visual field
323
Input from the lower visual field
enters above the cacarine fissure (near the parietal lobe)
324
Lesions in the parietal lobe that extend into the occipital cortex often produce-
visual deficits along the lower visual field
325
Area 17 (primary visual cortex)
involves awareness of what is being seen
326
Lesions of area 17
produce blindness
327
Area 18, 19 (peristrate or extrastriate area, secondary association cortex)
involved with recognition of movement, depth, color
328
Lesions of area 18, 19
produce visual agnosia (one can see an object but cannot recognize it)
329
Stimulation of area 18, 19
Produces coloured images, stars, wheels, crosses
330
Some lesions evoke hallucinations that involve-
perception of the mirror image of the self (much like OOBEs)
331
Areas 1, 2, 3 (primary somatosensory cortex)
primary projection area for touch, proprioception, and pain; posterior (caudal) to the central sulcus
332
Lesion of area 1, 2, 3
loss of ability to recognize position of body, estimate, weight, appreciate differences in temperature
333
Input from body is represented as a
homunculus
334
Areas 5, 7 (secondary association area)
allow recognition and understanding of body
335
Lesions of areas 5, 7
Corticoasterognosis, loss of two-point discrimination, failure of body scheme
336
Corticoasterognosis
can still feel an object with eyes closed but can't recognize it, can't recognize letter "written on skin"
337
Area 39 (angular gyrus)
a tertiary cortex, involved with complex language function
338
Alexia
inability to read
339
Agraphia
inability to copy
340
Finger agnosia
cannot identify which finger is being touched when eyes are closed
341
Lesions of area 39 (angular gyrus)
produce alexia, agraphia, left-right confusion, and finger agnosia
342
Area 40 (supramarginal gyrus)
tertiary cortex, involved with language and symbolic processing capacity
343
Lesions of area 40
produce aphasia (deficits in understanding and expression by symbols and language)
344
Lesions to areas 39 and 40 produce
Gertsmann syndrome
