Lecture 2- Forebrain and Limbic System Flashcards
1
Q
The forebrain includes the… which is the thalamus, hypothalamus, epithalamus and subthalamus and the…. and the …. which is the hippocampus, hypothalamus and amygdala
A
Diencephalon
Internal Capsule
Limbic System
2
Q
The pineal gland and habenula are part of the
A
epithalamus
3
Q
The thalamus is considered the gateway to the…
A
cortex
4
Q
The anterior division of the thalamus includes the… nucleus
A
anterior
5
Q
The medial division of the thalamus includes the… nucleus
A
Dorsomedial (aka medial dorsal)
6
Q
The lateral division of the thalamus is divided into
A
a dorsal and ventral tier
7
Q
The dorsal tier of the lateral division of the thalamus contains these 2 nuclei:
A
Lateral dorsal (LD) Lateral posterior (LP) pulvinar
8
Q
The ventral tier of the lateral division of the thalamus includes these 6 nuclei:
A
Ventral anterior (VA) Ventral lateral (VL) Vent post. lat (VPL) Vent post med (VPM) Lateral geniculate (LGN) Medial geniculate (MGN)
geniculate also called body
9
Q
Besides anterior, medial and lateral, the thalamus has these 3 nuclei
A
intralaminar
reticular nucleus
midline nuclei
10
Q
… subdivision of the thalamus is the largest
A
lateral
11
Q
the subdivisions of the thalamus are defined by the…
A
internal medullary lamina (IML)
12
Q
The anterior subdivision of the thalamus sits in a split in the…
A
IML
13
Q
All thalamic nuclei (except….) are based on the same general theme and have 2 different population of neurons:
A
- reticular
- projection neurons and interneurons
*proportions vary
14
Q
There are 2 basic types of thalamic inputs:
… inputs which convey info at thalamic nucleus passes on nearly directly to cortex. (example: ML to VPL or optic tract to LGN)
and … inputs where the thalamic nucleus contributes to the info it recieves before it is passed on to cortex
A
- specific
- regulatory
15
Q
there are 3 categories of thalamic nuclei based on patterns of outputs and specific inputs
A
- Relay nuclei
- Association nuclei
- Intralaminar and midline nuclei
16
Q
… nuclei recieve well defined input from a subcortical source (ex. medial lemniscus) and project to a well-defined area of cortex (ex. somatosensory cortex)
A
Relay
17
Q
…nuclei recieve specific inputs from association cortex (ex. prefrontal cortex) and project back
A
association
18
Q
…. nuclei recieve distinct set of specific inputs (basal ganglia, limbic structures) and project to cortex, BG and limbic structures
A
intralaminar and midline
19
Q
The… is an important source of regulatory input to thalamus and has no projections to cortex (unlike all other thalamic nuclei)
A
reticular nucleus
20
Q
Input to the reticular nucleus is from
A
cortex and thalamus
21
Q
Output of reticular nucleus
A
inhibitory axons to thalamus
22
Q
The… is a sheet of neurons that covers thalamus and that axons must traverse to enter/leave thalamus and send collaterals to it
A
reticular nucleus
23
Q
sensory, motor and limbic systems have… nuclei
A
relay
24
Q
relay nuclei of sensory
A
VPL and VPM
25
relay nuclei of motor
VA and VL
26
relay nuclei of limbic
Anterior and LD
27
specific inputs of anterior nucleus and cortical output
specific inputs: mammillothalamic tract, hippocampus
| output: cingulate gyrus
28
Specific inputs of Lateral Dorsal (LD) nucleus and cortical output
specific inputs: hippocampus
| output: cingulate gyrus
29
Specific inputs of VA/VL nuclei and cortical output
specific inputs:
BG (mostly VA)
cerebellum (mostly VL)
output: motor areas
30
Specific inputs of VPL nucleus and cortical output
specific inputs: Medial lemniscus, spinothalamic tract (ALP)
| output: somatosensory cortex
31
Specific inputs of VPM nucleus and cortical output
specific inputs: trigeminal system
output: somatosensory cortex
AND
input: central tegmental tract (taste)
output: insula
32
Specific inputs of MGN nucleus and cortical output
input: branchium of inferior colliculous
output: auditory cortex
33
Specific inputs of LGN nucleus and cortical output
input: optic tract
output: visual cortex
34
... and... are main association nuclei
DM and Pulvinar
35
Parietal-occipital-temporal: pulvinar-LP complex function
largely unknown; may be involved in visual perception or attention
36
Prefrontal: DM function
foresight
37
DM specific input and cortical output
input: prefrontal cortex, olfactory and limbic structures (amygdala)
output: prefrontal cortex
38
LP specific inputs and cortical output
input: parietal lobe
output: parietal cortex
39
Pulvinar specific inputs and cortical output
input: parietal, occipital and temporal lobes
output: same
40
The most lateral part of the internal capsule is the
putamen
41
The lenticular nucleus is made up of the... and...
putamen and globus papllidus of the IC
42
... and ... fibers pass through the IC.
thalamocortical and corticothalamic
*almost al fibers going to and from the cortex pass thru
43
The internal capsule collects and forms ... down which corticopontine, corticobulbar and corticospinal fibers descend
cerebral peduncle
44
Internal capsule has 5 parts based on relationship to lenticular nucleus...
1. anterior limb
2. posterior limb
3. genu
4. retrolenticular
45
The anterior limb of the IC is made up from
lenticular nucleus and caudate
46
The posterior limb of the IC is made up of
lenticular nucleus and thalamus
47
The genu of the IC is between ... limbs
anterior and posterior
48
The retrolenticular part of IC is behind the... nucleus
lenticular
49
the sublenticular is beneath the... and is only seen in coronal sections, not horizontal
lenticular nucleus
50
What limb of the IC do these pathways use?
anterior nucleus-->cingulate gyrus
DM--> prefrontal cortex
anterior limb
51
What limb of the IC do these pathways use?
VA/VL--> motor areas
Motor areas--> brainstem/sp
VPL/VPM--> somatosensory cortex
posterior limb
52
What limb of the IC does this pathway use?
MGN--> auditory cortex
sublenticular
53
What limb of the IC does this pathway use?
Pulvinar/LO--> parietal-occipital-temporal cortex
retrolenticular
54
What pathway of IC does this pathway use
LGN--> visual/occipital cortex
sublenticular- superior vision field
retrolenticular- inferior visual field
55
3 main types of connections of hypothalamus
1. interconnected with limbic system
2. output to pituitary
3. interconnects visceral/somatic nuclei
56
the hypothalamus is critical in autonomic, endocrine, emotional and somatic functions; maintains...
physiological range or homeostasis
57
The lateral aspect of the hypothalamus is the rostral continuation of the... which contains nuclei and tracts (medial forebrain bundle)
reticular formation
58
The medial aspect (middle) of the hypothalamus consists of
nuclei
59
The most medial part of the hypothalamus is the... which is a rostral continuation of the ... and this contains nuclei and tracts (dorsal longitudinal fasiculus)
paraventricular
periaqueductal
gray
60
The .... artery supplies neurohyposphysis (posterior lobe)
inferior hypophyseal artery
61
the ... artery supplies the anterior lobe (adenohypophysis)
superior hypophyseal artery
62
Capillaries of pituitary drain into.... which delivers anterior and posterior pituitary hormones
cavernous sinus
63
... cells synapse onto capillaries, and release secretions into capillaries so they are true endocrine cells
neuroendocrine
64
... area of hypothalamus contain the nuclei that have the neuroendocrine cells. And it is located in lower half of...
-hypophysiotrophic
| preoptic and tuberal regions
65
two types of neurons in hypophysiotrophic area
parvocellular
| magnocellular
66
The parvocellular type of neurons end in ...
The magnocellular type of neurons end in...
median eminence on superior hypophyseal artery
posterior lobe
67
5 nuclei of hypophysiotrophic area
1. paraventricular nucleus
2. preoptic nucleus
3. supraoptic nucleus
4. ventromedial nucleus
5. arcuate nucleus
68
Parvocellular neurons have short axons, which nuclei are these type?
preoptic
ventromedial
arcuate
69
Magnocellular neurons have long axons, which nuclei are these type?
paraventricular
| supraoptic
70
parvocellular neurons give rise to .... tract to infundibular capillary bed
tuberoinfundibular
71
2 hormones released by paraventricular and supraoptic nuclei from posterior pituitary
antidiuretic/vasopressin
| oxytocin
72
there is a loss of ADH in
diabetes insipidous
73
ADH causes
increase uptake by kidney and decrease UO
74
ADH regulation due to sensing ... also input from subfornical circumventricular organ
blood osmotic pressure
75
oxytocin is involved in
contraction of uterine and other smooth muscles
76
autonomic functions of anterior hypothalamus
parasympathetic effects- slow HR, constrict pupil, peristalsis, salivation
77
autonomic functions of posterior hypothalamus
sympathetic effects- increase HR/BP, dilate pupils, intestinal stasis
78
axons from the anterior and posterior hypothalamus have axons that project down brainstem and spinal cord in ...
dorsal longitudinal fasiculus
79
Stimulate lateral nucleus-
| lesion in lateral nucleus-
- feeding
| - refuse food
80
Stimulate ventromedial-
| lesion in ventromedial nucleus-
- refuse food
| - feeding
81
Hypothalamus has a role in feeding, it is a result of interplay between... and.... nuclei and they make a appestat (appetite set point) and it can be altered by ...
anorexics have... levels
bulimics have...levels
- lateral
- ventromedial
- serotonin
- high
- low
82
The part of the hypothalamus is also key to .. and...
rage and fear
83
Example: overweight cats due to ventromedial lesions are
mean and aggressive
84
Example: underweight cats dut to ventromedial stimulation are
extremely docile
85
How does fight or flight work in males in the hypothalamus
corticotropin RH released by paraventricular nucleus--> ACTH release pituitary--> increase in cortisol from adrenal
86
In fight or flight, males show activation in..
lateral prefrontal cortex
87
In fight or flight, females show activation of...
cingulate gyrus (a cortical emotional control center)
88
Females fight or flight response in the hypothalamus
tend and befriend- protect offspring and affiliate with social groups
89
There is a calming effect in females when... is released in capillary bed of neurohypophysis and ... counteract sympathetic over activity due to stress
oxytocin
| estrogen
90
The ... nucleus gets direct input from retina and sets normal sleep/wake cycle with pineal gland
suprachiasmatic
91
sleeping/waking, sexual arousal, memory, feeding, fight or flight are all functions of the
hypothalamus
92
Lesions in the posterior hypothalamus can cause
coma or hypersomnolence
93
The .... nucleus contains histaminergic neurons with wide projectons, arousal functions likely
tuberomammillary
94
The tuberomammillary nucleus is activated by... which is liberated by lateral nucleus. Failure of ... function leads to ...
orexin
orexin
narcolepsy
95
Sexual arousal in hypothalamus: a subset of neurons in the medial aspect of... is over twice as large in males than females. And it is rich in.... sensitive to circulating...
preoptic nucleus
adrogen receptors
testosterone
96
Females have estrogen rich neurons in... nucleus
ventromedial
97
2 general areas that provide input to hypothalamus
parts of forebrain, especially limbic system
| brainstem and sp.
98
the limbic system mostly consists of .. and..
cingulate
| parahippocampal gyri
99
The limbic cortex consists of 2 parts: .... of hippocampus and septal area and.... in parahippocampal gyrus, cingulate and insula
3-layered allocortex
| mesocortex
100
The limbic system also consists of.... nuclei: amygdala, hypothalamus, nucleus accumbens and RF
subcortical
101
Limbic system: Function of amygdala
emotional responses
102
Limbic system: Function of hippocampus
learning and memory
103
Afferents to hippocampus: ... is the main source; it gets info from olfactory (minor) and many other areas
entorhinal cortex
104
Input from.... to hippocampus is modulatory in mature: affects chances that info in hippocampus will be retained
septal nuclei
105
3 distinct zones of hippocampus
1. dentate gyrus
2. hippocampus proper (cornu ammonis)
3. subiculum (transition between hippocampus proper and adjacent parahippocampal cortex
106
8 steps of hippocampal connections (afferent)
1. afferent fibers from sensory cortex
2. entorhinal cortex prjects to dentate gyrus (.... pathway)
3. Dentate neuron projects to...
4. ... neuron projects into...and...
5. ... projects to subiculum
6. subiculum projects to fimbria (... pathway)
7. subicular neuron projects to entorhinal cortex
8. entorhinal neuron projects to sensory cortex
- perforant
- CA3
- CA3
- fimbria and CA1
- CA1
- alvear
107
important efferents of hippocampus: entorhinal to cortex and
fornix to mamillary bodies
108
the hippocampus does... memory but not ... memory
explicit
| implicit
109
Papez circuit:
1. neurons in cingulate gyrus project back
2. projection into...
3. projection into...
4. ...
5. ... tract
6. projections from anterior nucleus of thalamus to cingulate cortex
- entorhinal cortex
- hippocampus
- fornix
- mammillothalamic
110
Long term can be.... which is the recall of facts/events or episodic memory
OR
... which is performing a learned motor funtion or riding a bike (basal ganglia)
explicit
| implicit
111
Left anterior hippocampus and .... cortex: encode novel material involving..
dorsolateral prefrontal
| language
112
Right hippocampus and .... lobe engaged in spatial tasks like..
inferior parietal
| driving a car
113
Left ... more active when material is novel, as repition makes it more familiar, hippocampal activity shifts...
anterior
| posteriorly
114
The amygdala has 3 nuclear groups
medial- olfaction
central- hypothalamus, PAG; emotional responses
Basolateral: cortex; central nuclei; emotional responses
115
Kluver-bucy syndrome is.... injury involving...
- bilateral temporal lobe injury
| - amygdala, parahippocampal gyrus
116
Kluver-bucy syndrome symptoms
- hypersexual males
- sniff/eat everything and then not recognize it
- fearless, no emotional reactions, doesnt flee from threats
