Olfaction and the limbic system Flashcards
How many different odours are there?
2000-4000
What are the different types of cells of olfactory epithelium?
Bipolar olfactory neurons
Sustentacular cells
Basal cells
Label the following diagram:
What are the key landmarks of the olfactory system?
Olfactory bulb (mitral cells)
Olfactory tract
Olfactory stria (medial and lateral)
Piriform cortex and orbitofrontal cortex
Connections to brainstem promote autonomic responses
What is a clinical deficit of the olfactory system?
Anosmia
Prodromal auras- temporal lobe epilepsy pre-seizure.
Label the following diagram:
What is the limbic system responsible for?
Processes aimed at survival of the individual.
Maintenance of homeostasis via activation of visceral effector mechanisms, modulation of pituitary hormone release and initiation of feeding and drinking.
Agonistic (defence and attack) behaviour.
Sexual and reproductive behaviour.
Memory.
What is the limbic system?
Rim or limbus of cortex adjacent to corpus callosum and diencephalon.
Structurally and functionally interrelated areas considered as a single functional complex.
System responsible for processes aimed at survival of the individual.
Complete the following flow chart of the Papez circuit:
What is the main output pathway of the hippocampus?
Fornix.
Travels out of the inferior horn of the lateral ventrical (in ventrical floor), up and forward and down to the hypothalamus- specifically to mammillary bodies.
What connects the hypothalamus to the anterior nucleus of the thalamus?
MTT- mammillothalamic tract
Emotional expression
In the Papez circuit, what does the anterior nucleus of the thalamus project to?
Cingulate cortex- just above corpus callosum.
Emotional experience.
In the Papez circuit, what does the cingulate cortex project to?
Hippocampus via cingulum bundles.
What are the three levels of emotional interaction in the Papez circuit?
Emotional colouring- neocortex
Emotional experience- cingulate cortex
Emotional expression- hypothalamus
What are the main connections of the hippocampus?
Afferent- perforant pathway
Efferent- fimbria/ fornix