Brain Pathways Flashcards
What is the rostral to caudal direction in people?
Eyes to back of head
Which three structures make up the brain stem?
Midbrain
Pons
Medulla
What does the medulla connect to inferiorly?
Spinal cord
What is the main function of the anterior nucleus of the thalamus?
Memory
What is the main function of the dorsomedial nucleus of the thalamus?
Emotional behaviour and memory
What is the main function of the ventral and ventrolateral anterior nucleus of the thalamus?
Motor behaviour
What are the main relay neurons in the thalamus?
Ventralposteromedial nucleus
Ventralposterolateral nucleus
(VPM and VPL)
The VPM and VPL of the thalamus deal with which type of information?
Somatosensory
Where to the VPM and the VPL relay information to?
Somatosensory cortex
What is the main role of the lateral posterior nucleus of the thalamus?
Integrating sensory input and associating it with cognitive function
What is the main role of the pulvinar nucleus of the thalamus?
Processing visual stimuli
What is the main function of the medial geniculate nucleus?
Auditory processing
What is the main role of the lateral geniculate nucleus?
Processing visual information
What makes up the outer covering of the thalamus?
Reticular nucleus
How many cortical layers are there?
6
Which cortical layers receive input from the thalamus?
IV
Which cortical layers receive inputs from the brainstem?
II-VI
Which cortical layers send info to the cortex?
I and II
Which cortical layers send info to the opposite hemisphere?
I-III
Which cortical layers send info to brainstem and spinal cord?
All
Which cortical layers send information to the thalamus?
IV-VI
Which broadmann’s areas are the superior temporal gyrus?
41, 42
Which Broadmann’s area is the premotor area?
6
Which Broadmann’s area is the primary motor cortex?
4
Which Broadmann’s areas is the somatosensory cortex?
3, 1, 2
Which Broadmann’s areas is the posterior parietal cortex?
5, 7
In which Broadmann’s areas is the visual cortex?
17, 18, 19
In which Broadmann’s area is the inferotemporal cortex?
20, 21, 37
Which part of the brain is responsible for object recognition?
Inferior temporal cortex
Which area of the brain is responsible for spatial recognition?
Posterior parietal cortex
Which area of the brain is responsible for semantic memory?
Anterior temporal lobe
What are the three main parts of the PFC?
Lateral PFC
Ventromedial cortex (orbitofrontal)
Anterior cingulate cortex
What is the main role of the lateral PFC?
Executive function, planning and working memory
What is the main role of the ventromedial cortex?
Social cognition and decision making
What is the main role of the anterior cingulate cortex?
Reward-based learning and social cognition
Where is the entorhinal cortex?
Medial bank of the rhinal sulcus
Where is the perirhinal cortex?
Lateral bank of rhinal sulcus
Where is the parahippocampal cortex?
Lateral to the rhinal sulcus
Which structure allows communication between the subcortical areas and the hippocampus?
Fornix
Which parts of the rhinal sulcus send information to the entorhinal cortex?
Perirhinal and parahippocampal
Where do the perirhinal and parrahippocampal send info to?
Association areas of the brain
Entorhinal cortex
Which entorhinal neurons are damaged in Alzheimer’s?
Layer II entorhinal
What is the main Input to the dentate gyrus?
Layer II entorhinal neurons
What is the main input to CA3 neurons?
Layer II entorhinal neurons
Where do CA3 neurons project to?
CA1 neurons
Which structure degenerate in Korsakoffs syndrome?
Mamillary bodies
With some damage to the anterior nucleus of the thalamus
What is the limbic system mostly associated with?
Emotion and memory
What is the amygdala mostly associated with?
Fear and stress
What are the septal nuclei of the limbic system mostly associated with?
Pleasure and reward
What is the cingulate mostly associated with?
Emotion and memory
Where do the mamillary bodies connect to?
Amygdala and hippocampus
Which two parts of the basal ganglia are considered to be the striatum?
Caudate and putamen
What is the main role of the substantia nigra?
Facilitates movement
What structure does the globus pallidus have an inhibitory effect on?
Thalamus
What does the direct pathway do?
Facilitates movement
What does the indirect pathway do?
Inhibits movement via the subthalamic nuclei
What does the hyperdirect pathway do?
Inhibits unwanted movement
Outline the direct pathway
Excites putamen Activates the inhibitory neurons in int GP Inhibition of GP Lift the inhibition of the thalamus Thalamus can be excited Movement occurs
Are the outputs of medium spiny neurons inhibitory or exhibitory?
Inhibitory
What are the two regions of the substantia nigra and which has the most neurons?
Pars compacta - most neurons
Pars reticulata
Which part of the substantia nigra has more GABA?
Pars reticulata
Which dopamine receptor type is involved in the direct pathway?
D1
Which dopamine receptor type is involved in the indirect pathway?
D2
Outline the indirect pathway
Striatum inhibits the external GP
Which inhibits the ext GP
Which excites the int GP which then inhibits action in the thalamus
What is the main function of the corticospinal tract?
Voluntary movement
The lateral corticospinal tracts control….
Distal musculature
The anterior/ventral corticospinal tracts control….
Proximal musculature
When do LMNs leave the corticospinal tract?
At the level of the spinal cord of the innervated muscle
In which layer are enterorhinal neurons damaged in alzheimers?
Layer II
What is the Papez circuit composed of?
Subcortical projections of the hippocampus
What is the fornix?
A bundle of fibres which carry information
Name the parts of the limbic system.
Fornix Cingulate cortex Parahippocampal gyrus Hippocampus Amygdala Hypothalamus Septal nuclei Mamillary body
Where do striatal medium spiny neurons receive input form?
Cortex and thalamus (excite)
SN (excitatory or inhib)
Which type of input do medium spiny neurons receive?
Glutamatergic (excitatory)
or
Inhibitory
What are D1 receptors coupled to?
Adenylyl cyclase (via G protein)
Which part of the corticospinal tract controls distal musculature?
Lateral
Which part of the corticospinal tract controls proximal musculature?
Anterior/ventral