Orientation to CNS Flashcards
Functional group of neurons within the CNS
nuclei (sing. nucleus)
Three major types of CNS pathways
1) association pathways
2) commissural pathways
3) projection pathways
Association Pathway
Axons connect different cortical areas within one hemisphere
Commissural Pathway
Axons connect areas on both sides of the brain (generally homotopic areas)
Projection Pathway
Axons connect specific areas to other areas or nuclei; can be ascending or descending
Major subdivisions of adult human brain
Telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon
Subdivision(s) of the brain making up the forebrain
Telencephalon and Diencephalon
Subdivision(s) of the brain making up the midbrain
Mesencephalon
Subdivision(s) of the brain making up the hindbrain
Metencephalon and Myelencephalon
Brain subdivisions making up what is called the brain stem
Midbrain, Pons, Medulla
What subdivision of the brain are the cerebral hemispheres (incl. cerebral cortex) included in?
Telencephalon (part of the forebrain)
The numerous foldings or crevices in the cerebral cortex
Sulci or fissures (if they’re deep)
Bumps and ridges in the cerebral cortex
gyri
Two deepest sulci in the cerebral cortex
Lateral and central sulci
Lobes of the brain
Frontal, temporal, parietal, occipital
Four “subcortexes” of the cerebral cortex
1) primary sensory/motor cortex
2) unimodal association cortex
3) hetermodal association cortex
4) limbic cortex
Unimodal Association Cortex
Higher order processes take place here for a single sensory or motor modality; these areas generally lie near or adjacent to the primary area for that sense
Hetermodal Association Cortex
Involved in integrating functions from multiple sensory and/or motor modalities. Involved in executive function and decision making
Limbic Cortex
Regulates emotion and memory in conjunction with deeper brain structures
Subcortical gray matter nuclei forming a complex network of inhibitor and excitatory connections
Basal ganglia
Four main regulatory channels the basal ganglia are involved in
1) Motor channel (General motor control)
2) Oculomotor Channel (eye movement)
3) Prefrontal Channel (cognitive function)
4) Limbic Channel (emotional function)
Major sensory relay station in center of brain. Most pathways that project to the cortex have synaptic relays here. Also conveys inputs from cerebellum and basal ganglia.
Thalamus
These two structures form the link between the neural and endocrine systems
Hypothalamus and Pituitary
The hypothalamus forms the walls and floor of which ventricle
Third ventricle
The limbic system constitutes a diverse interaction of cortical and subcortical structures that regulate:
1) olfaction
2) memory
3) emotions and drives
4) homostatic function
Three main parts of the midbrain
1) colliculi
2) tegmentum
3) cerebral peduncles
Functions in the colliculi, part of the midbrain
Auditory signal processing (inferior) and visual signal processing (superior)
Functions in the tegmentum, part of the midbrain
Movement (red nucleus) and pain processing (periaqueductal grey)
Part of the midbrain which serves as a major signaling connection
cerebral peduncles
Found between the tegmentum and peduncles (part of midbrain). Play role in dopamine tract and fine motor control
substantia nigra
Part of the brain which contains the cranial nerves and their nuclei
brain stem
Long tracts of the brain stem
motor and somatosensory pathways. White matter tracts carrying information to and from spinal cord.
Circuitry made up of white matter tracts connect the brain stem to what adjacent brain structure
cerebellum (Cerebellar Circuitry)
Component of the brain stem with the following characteristics: Systems (cholinergic/serotinergic/dopaminergic) with widespread projections; nuclei for sleep; pain modulatory systems; motor control areas (respiration); autonomics
Reticular formation of the brain stem
Lies within the posterior fossa. Forms the roof of the fourth ventricle. Integrates sensory and other inputs from brain and spinal cord.
Cerebellum
Functional regions of the cerebellum (4)
1) lateral hemispheres (motor planning for extremities)
2) intermediate hemispheres (distal limb coordination)
3) Vermis lobe (proximal limb/trunk coordination)
4) flucculonodular lobe (balance and vestibulo-ocular reflexes)
