Limbic System & Hypothalamus Flashcards
In humans, the _____________ has a diminished importance compared to other vertebrates.
Olfactory
Olfactory receptors consist of neurons embedded in _____________ cells.
Epithelial cells
(T/F) You keep the same set of olfactory receptors throughout your entire life.
False. Olfactory receptors are replaced throughout one’s lifetime.
Around ___ fiber bundles/side enter the skull via the cribriform plate of the ethmoid bone and terminate in the olfactory bulb .
20 fiber bundles/side
_________ cells are the principal neurons of the olfactory bulb.
Mitral cells
The axons of ________ cells constitute the olfactory tract.
Mitral cells
The olfactory tract follows the ventral surface of the frontal lobe and terminates in the ________________ and ______________ of the temporal lobe.
Anterior perforated substance and pyriform
Most axons within the olfactory system follow the lateral olfactory stria to end in the ipsilateral cortex near the ___________.
Uncus
(T/F) Olfactory tracts terminate uncrossed.
True.
(T/F) The olfactory tract projects first to the thalamus and then to the cerebral cortices.
False. The olfactory system terminates directly in the cortex.
Information from one olfactory bulb may be sent to the other via the ___________________ and the _________________.
Medial olfactory stria and the anterior commissure
___________ is used to refer to the leakage of CSF from the nose, typically following a fracture to the floor of the anterior cranial fossa which involves the cribriform plate.
Rhinorrhea
___________ are tumors that may impinge upon the olfactory tracts after arising from the floor of the anterior cranial fossa. This is usually a unilateral impairment and each nostril must be tested for anosmia.
Meningiomas
Epileptic discharges termed ______________ are characterized by olfactory hallucinations, usually of a disagreeable or offensive type such as the smell of burning rubber. They may also result in involuntary movements of the lips and tongue.
Uncinate fits
Uncinate fits result from compression of the _______________.
Temporal cortex
The limbic lobe consists of the:
- Cingulate gyrus
- Parahippocampal gyrus
- Hippocampus
- Amygdala
The ______________ occupies the floor of the temporal horn of the lateral ventricle. It also bears resemblance to a C-shape in the sagittal plane and a seahorse-shape in the coronal plane.
Hippocampus
The major outflow from the hippocampal formation is via a large fiber bundle that terminates in the mammillary bodies, known as the ___________.
Fornix
The _____________ receives a considerable amount of input from the amygdala via the stria terminalis and diagonal band.
Septal region (septum)
The major limbic structures within the hypothalamus are the _______________.
Mammillary bodies
The mammillary bodies receive a great deal of their input from the (ipsilateral/contralateral) fornix.
Ipsilateral fornix
The mammillary bodies have a major efferent tract termed the ___________________ tract.
Mammillothalamic tract
The mammillothalamic tract terminates in the __________ thalamic nucleus.
Anterior
(T/F) The olfactory system projects to the amygdala without making use of the thalamus.
True.
The major pathway to and from the amygdala is the ______________. It connects the amygdala with the septal region and hypothalamus.
Stria terminalis
The _____________ nuclei are involved with integrating information concerned with reproduction.
Habenular nuclei
The septum projects to the habenular nuclei via the ______________.
Stria medullaris
One of the main functions of the hippocampus is the conversion of ____________ to _____________.
Short-term memory to long-term memory