Subcortical Nuclei and Structures Flashcards
Limbic System - Function and Areas (5)
Process internal mental/emotional processes. Satiety and hunger, memory, emotional response, sexual reproduction, maternal instincts, sexual arousal.
- Hippocampus (HPC)
- Amygdala (AM)
- Thalamus (THA)
- Hypothalamus (HPT)
- Hypophysis (HYP)
Hippocampus (HPC) - Location, Divisions and Function
Located in the floor of the posterior horn (lateral ventricle). It is divided into 4 fields CA 1-4 (cornu ammonis). Mostly involved in memory processes (declarative, long term memory).
Amygdala (AM) - Function (7) and Location
Located anterosuperior to the inferior horn of the lateral ventricle.
Emotional processes related to memory, memory consolidation and decision making, regulation of selective attention.
AM is the center of innate and acquired fear!
- Death
- Suffocation
- Incapacitation
- Physical injury
- Isolation
- Disgust
- Unknown/abnormal
Cingulate Cortex (CC) - Location and Function
Located above corpus callosum, spreading posteroanterior along temporal, parietal and frontal lobes connecting to subcortical structures. Divided in anterior (aCC) and posterior (pCC).
Plays a role in different processes, most involving reasoning, higher cognitive functions and its connection to memory and emotions.
Anterior Cingulate Cortex (aCC) - Function and connection with AM
Decides on the probability of doing/something happening.
Connects to the Amygdala and they modulate each other, controlling fear.
Thalamus - Location and Function
The thalamus is a paired gray matter structure of the diencephalon located near the center of the brain, above the midbrain.
Assemble of nuclei that receive sensory or motor information from the rest of the body and present selected information via nerve fibers to the cerebral cortex. Has a role in perception of the environment.
Hypothalamus - Location and Function
Composed of 9 nuclei. Connects the nervous system and endocrine system, production of hormones to regulate the autonomous functions of the body.
Sits below the hypothalamic sulcus within the medial wall of the third ventricle, which separates the hypothalamus from the thalamus above.
Hypophysis - Location, Lobes and Function
Small, ovoid structure, situated in the sella turcica of the sphenoid bone. Controls the activity of other endocrine glands in the body and consequently has many vital functions and roles in metabolism, growth, sexual maturation, reproduction, blood pressure and many other processes.
Two main lobes:
Adenohypophysis (anterior lobe)
Neurohypophysis (posterior lobe)
Basal Nuclei - Location, Function and Different Nuclei
Located around the thalamus which surrounds the 3rd ventricle.
Directly or indirectly involved in the regulation of almost all systems, in specific of motor processes.
- Caudate
- Putamen
- Globus Pallidus (external and internal) GPi GPe
- Nucleus accumbens (NAcc)
Subthalamic nucleus and substantia nigra are not anatomically connected but are functionally connected.
Striatum - Divisions (4) and Function
Has a direct connection to the cerebral cortex, for both inputs and outputs. Considered a doorway connecting the basal nuclei to the cerebral cortex.
Ventral striatum: Nucleus accumbens and olfactory tubercle.
Dorsal striatum: Caudate and putamen
Corpus striatum: Caudate, putamen and Globus pallidus
Putamen - Function
Regulation of movements and goal-directed/addictive behavior.
Connects directly to the cerebral cortex and other basal nuclei, especially GPi, GPe, participating in a self-regulatory loop of the other structures.
Substantia Nigra - Function and Division
SNc: Substantia Nigra compact
SNr: Substantia Nigra reticulate
Most relevant producer of dopamine for the CNS.
Main output nucleus of regulatory pathways.
Nucleus Basales Meynert
Connects ACh to different parts of the frontal and temportal cortices, and the amygdala. Due to its decreased volume in dementia and severe cognitive deficit, suggests an excitatory/regulatory role in rational and emotional processes.
Claustrum - Location and Function
Builds connection between cortical areas for high cognitive functions. Has a high developed neuroplasticity due to high concentrations of BDNF and GNF. Can be used as an on/off switch for deep brain stimulation in disorders of consciousness.
Located inside the temporal lobe.
Locus Coeruleus - Function and Location
Lower than the basal nuclei, close to the brainstem (some are inside).
Produces norepinephrine, affecting behavior, memory and hormone regulation.
NE activates the AM, AM acts on the Hypothalamus, HPT increases the activity of Hypophysis that activates the suprarenal gland.
LC (NE) → AM → HPT → HYP → SRG