Lecture 8 - Diencephalon, Basal Ganglia And Brain Ventricles Flashcards
What are the four components of diencephalon?
Epithalamus, Thalamus, Subthalamus and Hypothalamus
What are the two structural roles of diencephalon?
- Connect the cerebral cortex to the rest of the body
- Connect the brain to the endocrine system (hormone system)
What are the functions of thalamus?
- A relay station: Relaying all sensory information (except olfactory) to different areas in the cortex for further processing
- involved in motor control
How many hemispheres are there in thalamus?
2 hemispheres
What is the function of medial geniculate body?
Auditory pathway for auditory information
Where is medial geniculate body from and to?
from the inner ear, to the primary auditory cortex
Where is lateral geniculate body from and to?
From the eyes, to primary visual cortex
What is the function of lateral geniculate cortex?
Visual pathway for visual information
What are the two ventral posterior?
Ventral Posterior Lateral and Ventral Posterior Medial
Where is Ventral Posterior from and to?
From medial leminiscus, spinothalamic tract, trigeminothalamic tract, to postcentral gyrus (somatosensory cortex)
What are the functions of Ventral Posterior?
Conveys touch, temperature, pain, proprioception
What sends information to the Ventral Posterior?
The entire body sends information to the Posterior Lateral
What information do Ventral Posterior Lateral and Ventral Posterior Medial receive?
Ventral Posterior Lateral: receives information from your body
Ventral Posterior Medial: receives information fro your head and neck
Where are Ventral Lateral and Ventral Anterior from and to?
From basal ganglia and cerebellum, to motor vortices
What is the function of Ventral Lateral and Ventral Anterior?
Motor control
Where are Anterior Nucleus and Lateral Dorsal from and to?
From mammillary body to cingulate cortex
What are the functions fo Anterior Nucleus and Lateral Dorsal?
Cognitive control, emotion, memory
What is associated with long-term memory that is connected to mammillary body?
Hippocampus
What is visual imaginary?
The internal vision generated by yourself: you imagine a tiger with your eyes closed, your hippocampus will send information generated from long-term memory to the mammillary body and then send information to the Anterior Nucleus and Lateral Dorsal.
Where is Dorsomedial Nucleus from and to?
From hypothalamus, amygdala, to prefrontal cortex
What is the function of Dorsomedial Nucleus?
Cognitive control and emotion
Where is Pulvinar from and to?
From superior colliculus reciprocal connection to cortex, to mainly primary visual cortex, parietal and temporal lobes
What is the function of Pulvinar?
Visual attention and navigation
Where is Median nuclei from and to?
From and to are non-specific and widespread
What is the function of Median Nuclei?
Arousal, awareness by overriding mental state
What happens if you don’t have Median Nuclei?
Don’t have conscious
Where is hypothalamus located?
Below the thalamus
What control centre is hypothalamus?
Control centre for endocrine system
How does hypothalamus controls things?
Controls things in a slow time scale
how does the nuclei in hypothalamus control endocrine system?
Through the pituitary gland
What are the functions of Hypothalamus?
- Regulates the growth and development
- Drives sexual behaviour
- Regulates reproduction behaviour (birth, breastfeeding)
- Regulates autonomic functions (sympathetic/ parasympathetic)
- Maintains the homeostasis of the body (circadian rhythm, stress regulation, body temperature, water balance, appetite, blood pressure)
What are in the hypothalamus to release hormones to control different body parts?
Lots of nuclei stimulating pituitary gland
Where is epithalamus located?
Behind the thalamus
What is the major function of epithalamus?
Release of melatonin (regulate sleep-wake cycle)
What is responsible to release melatonin in the epithalamus?
Pineal Gland
Where is subthalamus located?
Below the thalamus
WHat is the major function of subthalamus?
Motor control (part of the basal ganglia movement)
WHat are the three parts of the basal ganglia?
Caudate nucleus, putamen, Globus pallidus
What forms lentiform nucleus?
Putamen and Globus Pallidus (medial to putamen)
What is basal ganglia responsible for?
Motor Movement
How is our muscle system in the entire body when it is not activated?
Constantly inhibited
How is our initiation of moment related to muscles?
It releases muscles when initiating our movement as we initiate disinhibition to release the muscles for movement
What are the two pathways in the basal ganglia?
Direct pathway and Indirect pathway
What does the direct pathway do in the basal ganglia?
It facilitates you to initate some movements
What is the process of direct pathway in the basal ganglia?
If the neural fibre is being activated, the striatum will be activated the neuron from striatum to medial globus pallidus is inhibitory is being activated, the neuron to the thalamus will be suppressed and silenced, the thalamus will be activated to send information to motor cortex, and the motor cortex will initiate motor activity.
What is inhibitory pathway?
You need to initiate a command to stop the motor activity through inhibitory pathway
What is the process of indirect pathway?
A command will be sent form motor vortices to lateral globus pallidus, then it will reduce activity of neuron to subthalamus nucleus (inhibitory), then it will send excitatory pathway to the medial globus pallidus, the pathway form medial globus pallidus to thalamus will have more inhibitory activity on thalamus, the thalamus is inhibited and cannot send information to motor cortices. The motor cortices will stop the motor activity.
What releases dopamine?
Substantial nigra, that enhances direct pathway and suppresses indirect pathway
