DIENCEPHALON, CEREBRAL CORTEX, AND LIMBIC SYSTEM Flashcards
List the different parts of the diencephalon.
Thalamus
Hypothalamus
Epithalamus (includes pineal gland)
Subthalamus
What is the thalamus? Where is the thalamus?
The thalamus is a paired structure in the diencephalon of the brain, located just above the brainstem, deep in the brain.
It relays sensory and motor signals to the cerebral cortex and plays a role in consciousness and sleep.
With regard to sensory function, what senses pass through the thalamus and what sense(s) do not?
All senses except smell (olfaction) pass through the thalamus before reaching the cerebral cortex.
What are the MAIN functions of the hypothalamus?
The hypothalamus regulates:
Autonomic functions: Heart rate, digestion, etc.
Body temperature
Hunger and thirst
Circadian rhythms
Controls the pituitary gland (hormonal regulation)
What different types of information are sent to the hypothalamus (think brain and body, think about delivery system)?
Brain: Emotional states, stress responses, sleep, and circadian rhythms.
Body: Feedback about temperature, hydration, hunger, and hormonal levels.
List a function for the following hypothalamic nuclei:
Anterior nucleus: Regulates body temperature and parasympathetic functions.
Paraventricular nucleus: Produces oxytocin and vasopressin; regulates stress response.
Posterior nucleus: Regulates sympathetic functions and temperature regulation.
Suprachiasmatic nucleus: Controls circadian rhythms (biological clock).
Supraoptic nucleus: Produces vasopressin and oxytocin.
How many layers make up the cerebral cortex?
What is the main cell type within each layer?
What are the main connections of each layer?
The cerebral cortex has 6 layers.
Main cell type: Predominantly pyramidal neurons in most layers.
Main connections: Different layers are connected by vertical (from layer to layer) and horizontal (across layers) fibers.
Is the cortex the same all over?
No, the cortex varies across different regions in terms of thickness, organization, and function (e.g., primary sensory areas, motor areas, association areas).
What is the functional unit of the cerebral cortex?
The neuron (specifically pyramidal neurons) is the functional unit.
What are the 3 main types of connections made by the subcortical white matter? Give examples of each.
Commissural fibers: Connects the right and left hemispheres. Example: Corpus callosum.
Projection fibers: Connects the cerebrum to the brainstem and spinal cord. Example: Corticospinal tract.
Association fibers: Connect different parts of the same hemisphere. Example: Long association fibers (e.g., arcuate fasciculus).
What is the main function of the amygdala?
The amygdala processes emotions, particularly fear and anxiety.
Of the 2 groups of nuclei within the amygdala, which is associated with:
Olfactory bulb: Nuclei related to olfaction (smell).
Cortex: Nuclei related to emotion regulation and emotional responses to stimuli.
What is the main function of the hippocampal formation?
The hippocampal formation is crucial for memory formation, particularly for converting short-term to long-term memory.
What are the 3 components of the hippocampal formation?
Hippocampus
Dentate gyrus
Subiculum
Name the layers of the hippocampus and dentate gyrus.
Hippocampus has 3 layers:
Molecular layer
Pyramidal layer
Polymorphic layer
Dentate gyrus also has 3 layers:
Molecular layer
Granular layer
Polymorphic layer
