Midterm 2 Flashcards
(239 cards)
1
Q
What are the three major functions of the brainstem?
A
Conduit, cranial nerves, and integrative functions
2
Q
Where is the attachment point for most cranial nerves?
A
The brainstem
3
Q
Which integrative functions are the brainstem responsible for?
A
Cardiovascular, respiratory, general visceral sensory and motor (autonomic reflex arcs), and the reticular formation
4
Q
What are the superior and inferior colliculi and important landmark for?
A
Where the midbrain meets the cortex
5
Q
What do we look for to know that we are viewing a dorsal image of the brain?
A
The obex and the floor of the fourth ventricle
6
Q
What are the three major divisions of the internal brainstem?
A
The tectum (area posterior to ventricular space), the tegmentum (area anterior to the ventricular space), and appended structures
7
Q
Which structures are included in the tectum?
A
The midbrain (specifically, the superior and inferior colliculi)
8
Q
Which structures are found in the tegmentum?
A
The reticular formation (contained by the pons), cranial nerves and nuclei, and spinal tracts
9
Q
Which structures are included in the ‘appended structures’ of the brainstem?
A
Cerebral peduncles, basal pons, and pyramids
10
Q
Which division of the cerebellum is involved in planning movements?
A
Lateral hemisphere
11
Q
Which region of the brain is responsible for adjusting limb movements?
A
Medial hemisphere of the cerebellum
12
Q
What functions are governed by the vermis?
A
Postural adjustments and eye movements
13
Q
Which two cerebellar regions are responsible for eye movements?
A
Flocculus and vermis
14
Q
What are the 5 main structures of the basal ganglia?
A
Caudate nucleus, putament, globus pallidus (GPe, GPi), subthalamic nucleus (STN), and substantia nigra
15
Q
Which structures make up the striatum?
A
Caudate, putamen, nucleus accumbens
16
Q
Which structures make up the lenticular nucleus?
A
Putamen, globus pallidus
17
Q
When is the lenticular nucleus referred to as such?
A
During development. After development, it is split into the putamen and globus pallidus
18
Q
What is the reticular formation?
A
A core of tissue found throughout the brainstem
19
Q
What are the functions of the reticular formation?
A
Respiratory control, cardiovascular control, sleep/wake cycles (ascending reticular activating system), sensory modulation, reflexes (i.e., coughing)
20
Q
Why do animals move more when sleeping?
A
Animals don’t have as much of an inhibitory activity of he ARAS
21
Q
Which brainstem nuclei have extremely widespread connectivity designed to modulate activity of the brain?
A
Locus coeruleus, substantia nigra (pars compacta), ventral tegmental area, raphe nuclei
22
Q
Which neurotransmitter is utilized by the locus coeruleus?
A
Noradrenaline
23
Q
Where is the locus coeruleus located?
A
Floor of 4th ventricle in rostral pons
24
Q
Where does the locus coeruleus project to?
A
Thalamus, hypothalamus, hippocampus, and cerebral cortex (somatosensory)
25
What are the roles of the locus coeruleus?
Maintaining attention and vigilance
26
What is the main neurotransmitter in the substantia nigra pars compacta?
Dopamine
27
Where is the SNc located?
Rostral midbrain
28
Where are the projections from the SNc?
Striatum and putamen (nigrostriatal pathway)
29
What is the main neurotransmitter in the ventral tegmental area?
Dopamine
30
Where is the VTA located?
Rostral midbrain
31
Where does the VTA project to?
Cerebral cortex (mesocortical) and amygdala (mesolimbic)
32
What are the roles of the VTA?
Initiation of movement, motivation, and cognition
33
What is the main neurotransmitter used by the raphe nuclei?
Serotonin
34
What are the raphe nuclei and where are they found?
A unilateral series of nuclei found along the midline of the brainstem reticular formation
35
Where do the raphe nuclei project to?
All parts of the CNS
Higher density in sensory and limbic cortical regions
Cerebellum, brainstem, and spinal cord
36
What are the roles of the raphe nuclei?
Overall level of arousal and descending pain control system
37
Which pathway is the spinal lemniscus associated with?
The Anterolateral pathway
38
What is the anterolateral system responsible for?
Pain
39
Where do the facial and abducens nerves exit?
At the pontomedullary junction
40
Where does the cerebral aqueduct begin?
Caudal midbrain
41
What is the role of the periaqueductal gray?
Modulation of pain
42
Where does the medial longitudinal fasciculus (MLF) run?
The entire length of the brainstem
43
How is the MLF unique?
The composition of fibres changes at different levels
44
What are the roles of the MLF?
```
Eye movements (coordination of oculomotor, trochlear, and abducens nuclei)
Vestibular compensations (gait adjustments)
```
45
Describe layer I of the neocortex contents
Cell-poor
46
Describe the contents of layer II of the neocortex
Granular cells
47
Describe the contents of layer III of the neocortex
Small pyramidal cells
48
Describe the contents of layer IV of the neocortex
Granular cells
49
Describe the contents of layer V of the neocortex
Large pyramidal cells
50
Describe the contents of layer VI of the neocortex
Fusi/multiform (spindle-like) pyramidal cells
51
Which neocortical layers are involved in subcortical inputs? What nuclei are involved?
Middle layers, particularly layer IV
Thalamic relay nuclei (VPL/VPM)
Other thalamic nuclei (LGN/MGN)
52
Which neocortical layers are involved in corticocortical inputs?
Mostly layers II and III
53
Which neocortical layers are involved in subcortical outputs? Which areas are these corresponding to?
Layer V (basal ganglia, brainstem, and spinal cord)
Layer VI (thalamic regulatory projections)
54
Which neocortical layers are involved in corticocortical outputs?
Layer III
55
Describe the commissural pathway
Corpus callosum and anterior commissure to contalateral hemisphere
Corticocortical efferents
56
Describe the association pathway
Short and long projections to ipsilateral hemisphere
Corticocortical efferents
57
What kinds of projection fibres arise from the cerebral cortex?
Subcortical and corticothalamic
58
Describe the short association fibres
"U fibres"
| Connect adjacent gyri
59
Describe the long association fibres
Connect different lobes
Superior longitudinal fasciculus (arcuate fasciculus)
Cingulum
Uncinate fasciculus
60
What are the Brodmann's areas?
Division of the cerebral cortex in 46 areas based upon cytoarchitectural characteristics
61
What are the primary sensory/motor areas?
Input of sensory information from outside world/output to body to respond to outside world
62
What are the unimodal associative areas?
Allow for more complex responses to sensory information
63
What are the multimodal associative areas?
Respond to multiple sensory inputs
| Increased proportion of association cortices in humans compared to other species
64
How are primary sensory/motor areas organized?
Exhibit topographical organizations, often distorted to emphasize highly discriminating/fine motor control areas
65
How are the primary motor and somatosensory cortices organized?
By body surface (homunculus)
66
How are the primary auditory areas organized?
By tonal frequencies
67
How are the primary visual areas organized?
Retinotopically
68
Where are unimodal association areas found?
Adjacent to primary sensory/motor areas
69
Where do unimodal association areas receive input from?
Appropriate primary cortex (via U fibres) and limited direct projections
70
How do multimodal association areas differ from unimodal association areas?
They respond to multiple sensory modalities, and are associated with high-level intellectual functions such as speech or executive function. They receive projections from long association fibres
71
What are the 5 primary sensory/motor areas?
Motor, somatosensory, auditory, visual, olfactory
72
What are the 7 unimodal association areas?
Premotor, supplementary motor, visual association (x3), auditory association, somatosensory association
73
What are the 2 multimodal association areas?
Prefrontal and parietal-occipital-temporal
74
Which type of sensory information is processed in the parietal lobe?
Somatosensation
75
Describe the inputs to the somatosensory areas?
From the thalamus via 2 routes.
1 - VPL via Medial lemniscus (DCML Pathway)
2 - VPL/VPM via spinothalamic (AL pathway)
76
Where is the primary somatosensory area?
Postcentral gyrus
77
Which Brodmann area is the primary somatosensory area?
BA 5
78
Which Brodmann area is the secondary somatosensory area?
BA 7
79
Where is the secondary somatosensory area in relation to the primary?
Caudal
80
Which type of sensory info does the occipital lobe process?
Vision
81
Where does the occipital lobe receive input from?
LGN of the thalamus via optic radiation
82
Which Brodmann area is the primary visual cortex?
17
83
What happens when there are lesions to Brodmann area 17?
Total/near total loss of conscious awareness of visual stimuli
84
Which Brodmann Areas are contained in the visual association cortex?
17, 18, 19, and others
85
Which sensation is the temporal lobe responsible for?
Hearing
86
Where does the temporal lobe receive input from?
Medial geniculate nucleus
87
Which Brodmann area is the primary auditory cortex?
41
88
What happens when there is a lesion to BA 41?
Little effect, auditory information travels bilaterally, some difficulty localizing sounds
89
Which BA is the secondary auditory cortex?
42
90
Which BAs are the auditory association cortex?
22, 44, 45
91
What happens with a lesion to BA 22?
Language problems, difficulty understanding prosody (Wernicke's area)
92
What happens with a lesion to BA 44/45?
Inability to produce speech (Broca's area)
93
Which information does the frontal cortex contain?
Motor
94
Which BA is the primary motor cortex?
4
95
Which BA is the premotor cortex?
Lateral portion of 6
96
Which BA is the supplementary motor area?
Medial portion of 6
97
Which tract is the output from the motor cortex?
Corticospinal tract
98
Where is the posterior parietal cortex?
Posterior to S1
99
What is agnosia?
Inability to recognize the identity or some other property of objects when using a given sense
100
What happens as a result of right posterior parietal damage?
Contralateral neglect (you ignore one side of your body entirely)
101
What is apraxia?
The inability to perform some actions, even though the muscles required are perfectly sound and able to perform the same action in a different context
102
Where is the prefrontal cortex?
Frontal lobe areas anterior to Brodmann areas 4 and 6
103
What is the role of the prefrontal cortex?
```
Controlling the activities of other cortical areas
Executive functions (planning, insight, foresight, and personality)
```
104
What does the connectivity of the dorsolateral PFC look like?
Extensive interconnectivity with dorsomedial nucleus of thalamus
105
What is the role of the dorsolateral PFC?
Working memory
106
What is the ventromedial PFC connected to?
Limbic structures (amygdala)
107
What is the result of damage to the ventromedial PFC?
Inability to suppress inappropriate responses (hypersexuality) and emotional reactions
108
What are the longitudinal divisions of the cerebellum?
Vermis and cerebellar hemispheres
109
What are the 3 lobes of the cerebellum?
Anterior, posterior (2) and flocculonodular
110
What are the functions of the cerebellum?
Coordination of trunk and limb movements, eye movements, equilibrium, postural control, coordination of voluntary movements
111
Which landmark divides the body of the cerebellum into anterior and posterior lobes?
Primary fissure
112
Which landmark of the cerebellum separates the flocculonodular lobe?
Posterolateral fissure
113
How is the cerebellum divided functionally?
Into longitudinal strips containing cerebellar cortex and deep internal structures
114
What is contained in the spinocerebellum?
Vermis and medial hemisphere
115
What is the ponto/neocerebellum?
Lateral hemisphere
116
Which lobe is considered the vestibulocerebellum?
Flocculonodular
117
Which functional division of the cerebellum is associated with the fastigial nucleus?
Spinocerebellum
118
Which functional division of the cerebellum is associated with the interposed nucleus?
Spinocerebellum
119
Which deep cerebellar nucleus is associated with the pontocerebellum?
Dentate nucleus
120
What are the cerebellar peduncles?
Fibre tracts
121
What is the role of the superior cerebellar peduncle?
Primary output route
122
What inputs does the middle cerebellar peduncle receive?
Inputs from the contralateral cerebral cortex via pontine nuclei
123
Which types of fibres are contained in the inferior cerebellar peduncle?
Mix of afferents and efferents
124
How does the cerebellum communicate with the body?
Ipsilaterally
125
How does the cerebellum communicate with the cortex?
Contralaterally
126
How many layers does the cerebellum have?
3
127
What does the outer molecular layer of the cerebellar cortex contain?
Axons and dendrites
128
What does the middle Purkinje cell layer of the cerebellar cortex contain?
Largest, most intricate dendritic tree in the nervous system. It is a single layer.
129
What does the inner granule cell layer of the cerebellar cortex contain?
Mostly small granule cells (some interneurons)
130
What are the 2 types of cerebellar inputs?
Mossy fibres and climbing fibres
131
Describe mossy fibres
Projections from widespread areas. Synapse with granule cells. Granule cells give rise to parallel fibres to synapse with Purkinje cells
132
Describe climbing fibres
They arise from the contralateral inferior olivary nucleus. Synapse directly with Purkinje cells.
Each Purkinje cell receives a single climbing fibre. Single climbing fibre makes 1000s of connections with Purkinje cell.
133
Describe parallel fibres
1 granule cell parallel fibre makes 1 or 2 contacts with multiple Purkinje cells. Need many parallel fibres to get Purkinje cells to fire.
134
Describe the output of the cerebellar cortex
Axons of Purkinje cells are the only axons to emerge from the cerebellar cortex. They project to deep nuclei. Output is GABAergic
135
What is feline leukopenia?
A viral infection in utero that destroys purkinje cells (cerebellar hypoplasia)
136
Where are the vestibular nuclei found?
Flocculonodular lobe
137
Where is the fastigial nucleus found?
The Vermis
138
Where is the interposed nucleus found?
Medial hemisphere
139
Where is the dentate nucleus found?
Lateral hemisphere
140
Where does the fastigial nucleus output to?
Vestibular nuclei and reticular formation
141
Where does the interposed nucleus project to?
Red nucleus of the thalamus and thalamus on way to contralateral cerebral cortex
142
Where does the dentate nucleus project to?
Thalamus on the way to contralateral cerebral cortex
143
Which cerebellar area is responsible for planning movements?
Lateral hemispheres
144
Where do the lateral hemispheres of the cerebellum receive input from?
Cerebral cortex via pontine nuclei (all contralateral)
145
Where do the lateral hemispheres of the cerebellum project to?
Motor and premotor cortex via red nucleus of thalamus
146
Which functions are the lateral hemispheres important for?
Learned movement that becomes more rapid and precise over time (i.e., piano playing)
147
Which area of the cerebellum is responsible for adjusting limb movements?
Medial hemispheres
148
Where do the medial hemispheres of the cerebellum receive input from?
Spinal cord and motor cortical information about limbs
149
Where do the medial hemispheres of the cerebellum project to?
Red nucleus and to the cortex
150
What, specifically, do the medial hemispheres of the cerebellum do?
Compare intended movement and actual movements and allowing for corrections to be made
151
Which area of the cerebellum is responsible for postural adjustments?
Vermis
152
Where does the vermis receive input from?
Vestibular nuclei and spinocerebellar fibres from trunk areas
Visual and auditory cortex
153
Where does the vermis project to?
Vestibular nuclei and reticular formation to affect vestibulospinal and reticulospinal tracts
154
What, specifically, does the vermis do?
Anti-gravity, adjusts posture to allow for movement (i.e. walking), eye movements and gaze shift
155
Which areas of the cerebellum are responsible for eye movements?
Flocculus and vermis
156
Where does the flocculus receive input from?
Vestibular nuclei
157
What are the outputs of the flocculus and vermis?
Vestibular nuclei and brainstem gaze centres
158
What is the flocculus responsible for?
Eye movements and gaze shift (saccades)
159
What is the basal ganglia?
A group of nuclei in the basal forebrain and midbrain that consists of 5 major structures. This region is important for granting/denying position for voluntary movement
160
What are the 5 main structures of the basal ganglia?
```
Caudate
Putamen
Globus Pallidus (GPi and GPe)
Substantia Nigra (pars compacta)
Subthalamic nucleus (STN(
```
161
Which structures are in the striatum?
Caudate, putamen, and (sometimes) NAcc
162
Which structures, during development, form the lenticular nucleus?
Putamen and globus pallidus
163
What is a landmark that lets us know we are more rostral?
Optic chiasm, no hippocampus visible, no 3rd ventricle
164
Describe basal ganglia afferents from the cortex
Corticostriatal fibres
| Glutamatergic
165
Describe basal ganglia afferents from the thalamus
Thalamostriatal fibres
| Glutamatergic
166
Describe basal ganglia afferents from the SNc
Nigrostriatal
| Dopaminergic
167
Describe basal ganglia efferents from the GPi
Pallidothalamic
| GABAergic
168
Describe basal ganglia efferents from the SNr
Nigrothalamic
| GABAergic
169
What are the 4 basic circuits in which the basal ganglia participates?
Motor loop (learned movements), cognitive loop (planning and motor intentions), limbic loop (emotional aspects of movement), and oculomotor loop (voluntary eye movements)
170
Describe the motor loop that the basal ganglia plays a role in
Sensorimotor cortex -> Striatum -> Thalamus -> Motor cortex and supplementary motor area
171
What are the 5 sets of neurons in the direct pathway?
Corticostriate (Glu), Striatopallidal (GABA), Pallidothalamic (GABA), Thalamocortical (Glu), Corticocortical (Glu)
172
What does the direct pathway do?
Disinhibits the thalamus and promotes movement
173
Describe the steps of the direct pathway.
1. Cortex excites striatum via Glu
2. Striatum inhibits GPi via GABA
3. Thalamus disinhibited (less GABA release)
4. Cortical activity facilitated via Glu
174
What are the 7 sets of neurons in the indirect pathway?
Corticostriate (Glu), Striatopallidal (GABA), Pallidosubthalamic (GABA), Subthalmopallidal (Glu), Pallidothalamic (GABA), Thalamocortical (glu) Corticocortical (Glu)
175
What does the indirect pathway do?
Inhibits movement
176
Describe the steps of the indirect pathway.
1. Cortex excites striatum via Glu
2. Striatum inhibits GPe via GABA
3. Subthalamic nucleus disinhibited
4. Thalamus inhibited via GABA from GPi
5. Cortical activity suppressed (less Glu)
177
Which 2 systems are striatal neurons modulated by?
Dopaminergic (via SNc) and cholinergic (via interneurons)
178
Which dopaminergic receptors are on direct pathway neurons?
D1
179
Which dopaminergic receptors are on indirect pathway neurons?
D2
180
Overall, what effect does dopamine have on motor activity?
Increase
181
What can be involved in hyperkinetic disorders? What is an example?
Tremors, Chorea, Athetosis, Ballimus
| Ex. Huntington's Disease
182
What is chorea?
"Dance"
| Rapid movements of face, tongue, or limbs
183
What is athetosis?
"Without position"
| Slow, writhing movements constantly
184
What is ballimus?
"Jumping about"
| Wild, flailing movements of one limb
185
What is seen in hypokinetic disorders? What is an example?
Rigidity, slow and reduced movements, stooped posture and resting tremor
Ex. Parkinson's disease
186
What can cause dementia?
A neurodegenerative basal ganglia disorder
187
What are the symptoms of PD?
Bradykinesia, hypertonia, dyskinesia, tremor, akinesia
188
What causes PD?
Progressive degeneration of dopaminergic neurons in SNc
189
Which structures are included in the epithalamus?
Pineal gland and habenula
190
Which 4 parts make up the diencephalon?
Epithalamus, thalamus, subthalamus, and hypothalamus
191
Describe the pineal gland
Midline, unpaired structure, shaped like a pinecone.
| Secretion of melatonin in response to darkness (reproductive cycles, circadian rhythms)
192
What is the role of the habenula?
Aversion
193
What is included in the subthalamus?
Rostral portions of the red nucleus and substantia nigra, STN, zona incerta
194
What is the zona incerta?
Small area of grey matter between thalamus and STN. Continuation of the midbrain reticular formation
195
Describe the thalamus
Large, egg-shaped nuclear mass with a posterior appendage
80% of diencephalon
All sensory pathways relay through thalamus
Also a part of basal ganglia, cerebellar, and limbic system circuits
Gateway to cortex
196
Describe the specific input of the thalamus. What is an example?
Convey information that a given nuclei may pass on accurately to the cerebral cortex
Ex. Medial lemniscus is the specific input to the VPL
197
What is regulatory input of the thalamus? What is an example?
Contributes to the decision about whether information leaves a given nucleus
Ex. Cerebral cortex
198
How is the thalamus divided?
The internal medullary lamina (a thin sheet of myelinated fibres) subdivides the thalamus into nuclear groups (anterior, lateral, medial)
199
Which principle thalamic nuclei are contained the the anterior nuclear group?
Anterior nucleus (A)
200
Which principle thalamic nuclei are contained in the medial nuclear group?
Dorsomedial nucleus (DM)
201
Which principle thalamic nuclei are contained in the lateral nuclear group?
Ventral anterior nucleus (VA), Ventrolateral nucleus (VL), Ventroposterolateral nucleus (VPL), Ventroposteromedial nucleus (VPM), Pulvinar nucleus (Pul), Lateral geniculate nucleus (LG), Medial geniculate nucleus (MG)
202
What are the intralaminar nuclei? What are 2 examples? Where do they project to?
Collections of cells embedded within the internal medullary lamina.
Ex: Centromedian (CM) and parafascicular (PF) nuclei.
Projections to the cerebral cortex and basal ganglia
203
What is the thalamic reticular nucleus?
Found between the external medullary lamina and the internal capuse. No projections to cerebral cortex. Regulatory GABAergic projections to other thalamic nuclei
204
What is the function of a specific/relay nucleus? Give an example.
Receive their specific input from subcortical areas, send their output to the cerebral cortex.
E.g. Medial geniculate nucleus
205
What is the function of an association nucleus? What is an example?
Receive most of their specific input from cortical regions and then distribute it to other cortical regions.
Ex. Dorsomedial nucleus
206
What is the function of a non-specific nucleus? Give an example.
Not specific to any one sensory modality.
| Ex. Intralaminar nuclei
207
What are the inputs and outputs of the VA/VL nuclei?
Basal ganglia, cerebellum -> VA/VL -> Motor areas (precentral gyrus, adjacent frontal areas)
208
What are the inputs and outputs of the VPL nucleus?
Medial lemniscus, spinothalamic tract (spinal components) -> VPL -> Somatosensory cortex (postcentral gyrus)
209
What are the inputs and outputs of the VPM nucleus?
Medial lemniscus, spinothalamic tract (trigeminal components) -> VPM -> Somatosensory cortex (postcentral gyrus)
210
What are the inputs and outputs of the MGN?
Brachium of the inferior colliculus -> MGN -> Auditory cortex (transverse temporal gyri)
211
What are the inputs and outputs of the LGN?
Optic tract -> LGN -> Visual cortex (occipital lobe)
212
What are the inputs and outputs of the anterior nucleus?
Mammillothalamic tract -> Anterior Nucleus -> Cingulate gyrus
213
What is the corona radiata? What does it become caudally?
A bundle of white fibre tracts that fans out throughout the cerebral cortex. Narrows to pass through the internal capsule on the way to brainstem and spinal cord
214
What is the internal capsule?
A compact bundle of fibres found between the lenticular nucleus (lateral) and the thalamus and head of the caudate nucleus (medial).
Almost all neural traffic to and from the cerebral cortex passes through the internal capsule
215
What are some examples of pathways that pass through the internal capsule?
Thalamocortical and corticothalamic fibres
Corticospinal, corticobulbar, and corticopontine fibres
216
The hypothalamus is an important nodal point for which types of pathways?
Autonomic, endocrine, emotional, somatic that are generally designed to maintain our internal environment within a defined range -- Homeostasis
217
What functions other than homeostasis is the hypothalamus involved in?
"Drive-related" functions like hunger, rage, sleep, and sexual behaviour
218
What are the longitudinal divisions of the hypothalamus?
Anterior, tuberal, posterior
219
What are the medial-lateral divisions of the hypothalamus?
Periventricular zone, medial zone, lateral zone
220
Which nuclei are in the periventricular zone of the hypothalamus?
Suprachiasmatic nucleus (SCN), Arcuate nucleus
221
Which nuclei are in the medial zone of the hypothalamus?
(Medial) Preoptic nucleus, Paraventricular (PVN), Supraoptic, Dorsomedial (DMN), Ventromedial (VMN), Posterior (PN), Mammillary bodies (MB)
222
Which nucleus is in the lateral zone of the hypothalamus?
Tuberomammillary (TN)
223
What are the 2 major input areas of the hypothalamus?
Brainstem/spinal cord and limbic system
224
What are the outputs of the hypothalamus?
Outputs are mostly reciprocal plus widespread cortical projections
(E.g., limbic structures, thalamus, visceral nuclei, pituitary gland, cortical areas)
225
Which two neuroendocrine cells control pituitary gland secretions?
Magnocellular (large) cells and parvocellular (small) cells
226
Describe magnocellular cells
Axons from the hypothalamo-hypophyseal tract which descends to the posterior pituitary (neurohypophysis)
227
Describe parvocellular cells
Axons travel to median eminence, release hormones into portal system. Stimulate/inhibit cells of the anterior pituitary (adenohypophysis). Hypothalamic-pituitary-adrenal axis (HPA)
228
Which hormones do magnocellular cells produce and secrete?
ADH (antidiuretic hormone)
- AKA vasopressin
- Stimulation of water uptake in kidneys, regulated by changes in blood osmotic pressure
Oxytocin
- Uterine contractions and milk ejection
Both thought to be involved in learning, anxiety, and stress as well
229
Which hormones do parvocellular cells release?
Trophic hormones into the portal circulation to reach the anterior pituitary and either stimulate or inhibit endocrine cells.
E.g. Corticotropin RH, thyrotropin RH, GH RH, GH IH (somatostatin), Prolactin RH, Prolactin IH (dopamine), Gonadotropic hormone RH
230
Describe the function of the anterior hypothalamus.
Autonomic control
Parasympathetic effects
Slowing of heart, pupil constriction, salivary secretion, intestinal peristalsis
231
Describe the function of the posterior hypothalamus.
Autonomic control
Sympathetic effects
Increase heart rate and blood pressure, pupillary dilation, intestinal stasis
Temperature regulation
Control of heat generating mechanisms (i.e., vasoconstriction, shivering)
232
What is the role of the preoptic nucleus?
Contains thermosensitive neurons.
| Maintenance of core body temperature.
233
What is the role of the SON/PVN?
"Osmoreceptors"
Detection of changes in blood volume and pressure, angiotensin levels, and blood osmolality
Send signals to cerebral cortex to initiate necessary corrections (i.e., sensation fo thirst)
234
What is the role of the arcuate nucleus?
Integration point within hypothalamus
| Sensitive to glucose levels
235
What is the role of the lateral nucleus of the hypothalamus?
"Feeding centre"
| Damage leads to refusal to eat
236
What is the role of the ventromedial nucleus?
"Satiety centre"
| Damage causes overeating and obesity
237
How is the hypothalamus involved in stress response?
HPA axis
PVN secretes CRH, anterior pituitary secretes ACTH, stimulates glucocorticoid (cortisol, adrenaline) release from adrenal gland
Sex differences in stress responsivity
238
Which parts of the hypothalamus are involved in rage and fear?
Role for lateral and ventromedial nuclei
239
Which part of the hypothalamus is responsible for sleeping and waking?
Suprachiasmatic nucleus
| Circadian rhythms and normal sleep/wake cycles
