Reticular Formation And Cerebellum Flashcards
(34 cards)
What does the reticular formation consist of?
A substantial part of the dorsal part of the brain stem in which the groups of neurons and intersecting bundles of fibres present in netlike appearance in transverse sections.
What functions does the reticular formation contribute to?
Sleep-arousal cycle
Perception of pain
Control of movement
Regulation of visceral activity
How do parts of the reticular formation differ from one another?
Cytoarchitecture, connections and physiological functions
What are an aggregation of neurons in the reticular formation called?
Nuclei
What are the nuclei of the reticular formation?
Precerebellar nuclei
Raphe nuclei
Central group of nuclei
Cholinergic and catecholamine cell groups
Lateral parvocellular reticular area
Parabrachial area
Superficial medullary neurons.
What paracerebellar reticular nuclei project to the cerebellum?
Lateral reticular nucleus
Paramedical reticular nucleus
Pontine reticulotegmental nucleus
Where are the raphe nuclei located?
Groups of neurons either in or adjacent to the midline of the brain stem, interspersed among bundles of decussating axons.
What do raphe neurons synthesise?
Serotonin
These serotonergic raphe neurons are thin, unmyelinated and greatly branched and are distributed to gray matter through the CNS.
Which pathway in the raphe nuclei suppress the conscious awareness of pain.
Medullary raphe nuclei connects with the periaqueductal gray matter and the spinal dorsal horn
Where does the pontine and mesencephalic raphe nuclei project to?
The cerebellum and all parts of the cerebrum, including the cerebral cortex, basal ganglia and lambic system
Where are the central group of reticular nuclei located.
Medically located nuclei in the medulla and pons and the cuneiform and subcuneiform nuclei in the midbrain.
What do central nuclei of the reticular formation receive?
Afferents from all the general and special sensory systems and from the reticular formation of the midbrain, the cholinergic reticular nuclei, the hypothalamus, and the pre motor area of the cerebral cortex.
Where do ascending axons of the central romp of reticular nuclei travel in?
In the central tegmental tract
What are the two groups of neurons that use acetylcholine as their synaptic transmitter in the reticular formation?
- Pedunculopontine nucleus
- Lateral dorsal tegmental nucleus
What do the cholinergic neurons in the reticular formation receive?
Afferents from the nearby noradrenergic (locus coeruleus) and serotinergic (raphe) nuclei, from histominergic neurons in the hypothalamus and inhibitory GABA descending fibres from the pallidum and the pre optic area.
Name the catecholamines
Dopamine
Noradrenaline
Adrenaline
Where are the dopaminergic neurons located in the reticular formation?
Pars compacta of the substantia nigra and in the hypothalamus
where is the largest group of central noradrenergic neurons?
Locus coeruleus or nucleus pigmentosus at the pontomesencephalic junction
How do noradrenergic neurons function?
Fire spontaneously but are modulated by neurons in other parts of the reticular formation, the hypothalamus and the cortex of the orbital surface of the frontal lobe and the anterior part of the cingulate GYRUS.
Where do efferent axons of noradrenergic neurons travel?
Efferent axons of the locus coeruleus travel rostrally in the central tegmental tract and the medial forebrain bundle.
Where do descending noradrenergic axons arise?
Predominantly from the lateral medullary catecholamine nuclei.
Where is the parvocellular reticular area located?
Medulla and pons, lateral to the central group and medial to the trigeminal nuclei.
Where do neuron send their axons from the parvocellular reticular area?
To the motor nuclei of the Hypoglossal, facial, and trigeminal nerves.
Indicate involvement in feeding,
Where are the parabrachial area located?
Lateral part of the reticular formation of the caudal midbrain, close to the superior cerebellar peduncle.
