Subcortical Structures Flashcards
Describe the layout of the subcortical structures
Subcortical structures are located beneath the cerebral cortex and play a critical role in a wide range of functions, including motor control, sensory processing, and emotional regulation. These structures are positioned deep within the brain, beneath the cortical surface, and are essential for processing information between the cortex and other parts of the brain.
The major subcortical structures include:
Basal nuclei (ganglia): Involved in motor control and procedural learning.
Thalamus: Serves as a relay station for sensory and motor signals.
Hypothalamus: Regulates autonomic functions such as temperature control, hunger, and thirst.
Limbic system: Involved in emotion, memory, and behavior regulation.
Epithalamus: Includes the pineal gland, which plays a role in sleep-wake cycles
List the components of the basal nuclei
Basal nuclei - collection of nuclei deep to the white matter of cerebral cortex
group of nuclei involved in the regulation of voluntary motor movements, procedural learning, and cognitive functions
Caudate nucleus: Involved in learning, memory, and motor control.
Putamen: Works with the caudate nucleus to control movement and influence behavior.
Globus pallidus: Regulates voluntary movement and helps inhibit unnecessary movement.
Subthalamic nucleus: Plays a role in motor control by helping to regulate movements initiated by other basal nuclei.
Substantia nigra: Produces dopamine, which is essential for motor control and affected in conditions like Parkinson’s disease.
These structures interact in a complex network to regulate movement and prevent motor abnormalities.
Describe the anatomical structures and functions of the limbic system
The limbic system is a group of interconnected structures located in the brain that is involved in emotions, memory, and behavior. The key anatomical components of the limbic system include:
Amygdala: Key for processing emotions, particularly fear and aggression.
Hippocampus: Crucial for forming new memories and spatial navigation.
Hypothalamus: Works with other parts of the limbic system to regulate emotional responses and autonomic functions such as hunger, thirst, and temperature regulation.
Cingulate gyrus: Plays a role in processing emotions and regulating behavior.
Fornix: A fiber bundle that connects the hippocampus to other parts of the brain, especially the hypothalamus.
Mammillary bodies: Involved in recollective memory.
The limbic system is essential for emotional responses, memory consolidation, and managing stress and anxiety.
Describe the thalamus and its motor and sensory relay nuclei
Anatomy and Function:
- 2 on each side of 3rd ventricle
- connected by interthalamic
connection
- receives and processes all information coming to cerebrum
- mediates emotional response, arousal and emotion
Sensory Relay Nuclei:
Lateral Geniculate Nucleus - relays visual information
Medial Geniculate Nucleus - relays auditory information.
Ventral Posterior Nucleus -processes somatosensory signals
Motor Relay Nuclei:
Ventral Anterior and Ventrolateral Nuclei - relay motor signals from the basal nuclei and cerebellum to the motor cortex
Association Nuclei:
- pulvinar : has extensive reciprocal connections
with parietal, temporal, frontal and occipital
association areas
Describe the Hypothalamus
Anatomy
- forms floor of diencephalon
- attached to pituitary gland at ventral side by infundibulum
- penetrated by 3rd ventricle
Function:
- regulates homeostasis
- controls the autonomic nervous system and endocrine system
- governs circadian rhythms via the suprachiasmatic nucleus
- connects to the pituitary gland to regulate hormonal secretion
Afferent connections:
- general somatic, visceral
- limbic system
- olfactory information
- Thalamohypothalamic and retinohypothalamic
Efferent connections:
- descending to visceral motor nuclei via brainstem & spinal cord
- ascending to thalamus
Nuclei:
- Supraoptic and Paraventricular Nuclei: Regulate water balance and produce oxytocin and vasopressin.
- Arcuate Nucleus: Modulates appetite and metabolism.
Describe the epithalamus
Forms the roof of the diencephalon
Function - links limbic system with other brain regions
Consists of;
Pineal gland - plays a role in circadian rhythm by producing melatonin
Habenular nucleus - centre for integration for olfactory, visceral and somatic efferent pathways
