Case 7 anatomy Flashcards
what are the four pairs of nuclei in the cerebellum?
fasitigial, globose, emboliform (em’s body form), dentate
where do these cerebellar nuclei receive information from?
- spinal cord
- olives
- vestibular nuclei
- pons
- reticular formation
where do efferent fibres from the cerebellar nuclei project to
- reticular and vestibular nuclei of the pons and medulla
- red nucleus of the midbrain
- ventral lateral nucleus of the thalamus
what are the subdivisions of the cerebellum?
- vestibulocerebellum (archicerebellum)
- spinocerebellum (paleocerebellum)
- cerebrocerebellum (neocerebellum)
what does the vestibulocerebellum consist of?
flocculonodular node and fastigial nucleus
what does the spinocerebellum consist of?
vermis, paravermis, globose and emboliform nuclei
what does the cerebrocerebellum consist of?
anterior and posterior cerebellar hemispheres and the dentate nucleus
what does the superior cerebellar peduncle contain?
- efferent fibres which arise in the dentate nucleus (largest single structure linking the cerebellum to the rest of the brain) and project to the red nucleus, thalamus and cortex
- afferent tectocerebellar fibres and afferent fibres from the anterior spinocerebellar tract
what does the middle cerebellar peduncle contain?
afferent fibres from the opposite pontine nucleus
what does the inferior cerebellar peduncle contain?
- afferent fibres from the posterior spinocerebellar tract and from the olivocerebellar tracts
- both afferent and efferent fibres which originate or terminate in the vestibular nucleus
what are the names for collections of different nuclei in the basal ganglia?
- Corpus striatum = caudate nucleus, putamen and globus pallidus
- Lentiform nucleus = putamen and globus pallidus
what is the limbic system involved in?
- memory
- behaviour
- emotion
- olfaction
- The main purpose of the limbic system is in the preservation of the species and in order to achieve this it has to ensure the safety of the individual and the passing on of his/her genes
- It prepares the individual to deal with hostile circumstances by developing the short-term memory and allowing stimulation of its various parts to produce pleasure or aversion
- It affects motivation, controls sexual behaviour and promotes caring of offspring
what does the limbic system consist of? where is afferent information received from and where do efferent fibres project to?
- The functioning of the limbic system is complex and not fully understood
- The limbic system consists of a collection of cortical and subcortical neurons and their interconnections
- Afferent information is received from the association cortex and fibres leaving the limbic system project to the hypothalamus
where is the limbic lobe? what does it consist of?
- border around the corpus callosum and rostral brain stem (limbic means border)
- consists of cingulate gyrus, parahippocampal gyrus and subcallosal gyrus
what does the hippocampal formation consist of?
- hippocampus
- dentate gyrus
- parahippocampal gyrus
what does the hippocampal formation play a major part in?
memory, learning and spatial navigation
where does the hippocampal formation receive input from?
the entorhinal area of the parahippocampal gyrus
where does the hippocampus lie?
along the floor of the inferior horn of the lateral ventricle
where is the dentate gyrus?
dentate gyrus extends between the hippocampus on a coronal brain slice; it is a C-shaped structure on the inferomedial aspect of the temporal lobe
what is the amygdaloid body involved in?
- formation and storage of memories
- associated with acquisition and expression of fear conditioning
- sense of smell
where does the amygdala receive input from?
- association cortices
- cingulate gryrus
- olfactory bulb
- brain stem visceral pathways
where is the amygdala?
lies in the temporal lobe close to the uncus, overlying the anterior part of the inferior horn of the lateral ventricle
what are the connecting pathways in the limbic system?
number of structures connect the various parts of the limbic system to each other and to the hypothalamus:
- fornix = posterior part of hippocampus with mamillary bodies of hypothalamus (can be divided up into anterior columns, body, commissure and crus)
- stria terminalis = amygdaloid body with anterior hypothalamus and septal nuclei
- mamillothalamic tract = mamillary bodies of hypothalamus with anterior nuclei of thalamus
what is anosmia?
loss of sense of smell
what’s covered in the olfactory mucosa?
superior nasal conchae and the upper part of the nasal septum
describe the primary olfactory neurons
- Primary olfactory neurons are bipolar neurons which posses a peripheral and a central process
- The peripheral process possesses ciliated receptors that are dispersed throughout the olfactory mucosa
- The central processes unit to form olfactory nerves
describe the olfactory pathway
- Olfactory nerves enter the skull by passing through the cribriform plate of the ethmoid bone
- Olfactory nerves terminate in the olfactory bulb by synapsing with mitral and tufted cells
- Axons of the mitral and tufted cells enter the olfactory tract
- The fibres of the olfactory tract divide into the medial and lateral striae
- Fibres in the medial stria pass through the anterior commissure to the contralateral olfactory bulb
- Most fibres enter the lateral stria and project to the primary olfactory cortex
what does the primary olfactory cortex consist of?
- uncus
- amygdala
where is the thalamus situated? what connects the two?
- contributes to the lateral wall of the third ventricle and extends anteriorly to the interventricular foramen
- it lies medial to the posterior limb of the internal capsule and is connected to the opposite side by the massa intermedia (interthalamic adhesion)
where is the hypothalamus situated? what does it contribute to?
contributes to the lateral wall of the third ventricle, located inferior to the thalamus – it is attached by the pituitary stalk to the pituitary gland
where are the epithalamus and subthalamus located?
- Epithalamus = the most posterior structure of the diencephalon, located rostral to the superior colliculus
- Subthalamus = located inferior to the thalamus, dorsolateral to the hypothalamus and superior to the tegmentum of the midbrain
what are the mammillary bodies? what are they involved in?
- The mammillary bodies are two rounded elevations that overlie the mammillary nuclei of the hypothalamus
- They are involved in limbic function
what does the subthalamic nucleus have connections with?
globus pallidus and substantia nigra
what are the main components of the epithalamus? what do they do?
- habenacular nucleus - connections with the limbic system
- pineal gland - produces melatonin
