Neurosciences part 2 Flashcards
(10 cards)
The role of the basal ganglia?
The motor cortex sends info to the basal ganglia and cerebellum and they feedback to the cortex via the thalamus.
The output of the cerebellum is excitatory
The output of the basal ganglia is inhibitory
The balance of these two processes’ allows for smooth, coordinated movement
The components that make up the Basal Ganglia
Striatum: Caudate and Putamen Nucleus Accumbens Globus Pallidus Substantia Nigra Subthalamic Nucleus
What are the 4 main inputs of the hypothalamus
Nucleus of the Solitary Tract
Reticular formation
Circumventricular organ
Limbic and Olfactory Systems
Purpose of the Nucleus of the Solitary Tract
nucleus collects visceral sensory information from vagus and relays it to the hypothalamus an other targets. Info includes blood pressure and gut tension.
Purpose of the Reticular formation
This is a catchall nucleus in the brainstem receiving inputs from the spinal cord. Among is info about skin temperature and is relayed to the hypothalamus
Purpose of the Circumventricular organs
Nuclei located around ventricles & and are unique because they lack a blood-brain barrier. This allows them to monitor substances in the blood that would be shielded from neuronal tissue. One nuclei is OVLT which is sensitive to osmolarity changes, and Area Postrema which is sensitive to toxins in the blood and can induce vomiting. Both these project to the hypothalamus
Purpose of the Limbic and Olfactory Systems
structures such as the amygdala , hippocampus, and the olfactory cortex project to the hypothalamus. And can regulate behaviours such as eating and drinking.
The main outputs of the hypothalamus
Neural signals to the Autonomic system & Endocrine Signals to/through the pituitary
What are the details of the Neural signals from the hypothalamus regarding the autonomic system
The lateral hypothalamus projects to the lateral medulla → here there are cells that drive autonomic systems.
These include: Parasympathetic vagal nuclei and a group of cells that project to the sympathetic system in the spinal cord.
With access to these systems , hypothalamus can control HR, vasoconstriction, digestion and sweating etc.
What are some of the hypothalamic nuclei
Medial Preoptic Nucleus. Contains the GnRH nucleus releasing gonadotropin releasing hormone
Supra Optic Nucleus → oxytocin and vasopressin (ADH)
Paraventricular Nucleus→ Corticotropin releasing hormone, oxytocin and vasopressin release
Anterior hypothalamic nucleus → thermoregulation
Suprachiasmatic nucleus → vasopressin release, circadian rhythms
Ventromedial Nucleus → satiety and sexual behaviour
Arcuate Nucleus → feeding and dopamine release
Lateral Nucleus → hunger and thirst
Dorsomedial hypothalamic nucleus: blood pressure & HR
Mammillary Nuclei → hippocampus
