Chapter 15 Flashcards
What tracts continue in the brainstem without alteration?
corticospinal tract
What tracts leave the brainstem?
reticulospinal tract
What tracts synapse in the brainstem nuclei?
corticobrainstem
What two sections is the brainstem divided into longitudinally?
basilar and tegmentum
What is the tectum involved in?
reflexive control of intrinsic and extrinsic eye muscles and in movements of the head
Where is the basilar section located?
anteriorly
What does the basilar section contain?
predominantly motor system structures
What descending axons from the cerebral cortex does the basilar contain?
corticospinal, corticobulbar, corticopontine, corticoreticular tracts
What motor nuclei does the basilar contain?
substantia nigra, pontine nuclei, inferior olive
Where is the tegmentum located?
posteriorly
What does the tegmentum contain?
reticular formation
Sensory nuclei and ascending sensory tracts
Cranial nerve nuclei
The medial longitudinal fasciculus
What does the medial longitudinal fasciculus do?
coordinates eye and head movements
What does the reticular formation include?
the reticular nuclei, their connections, and ascending and descending reticular pathways
What does the reticular formation do?
Integrates sensory and cortical information. Regulates somatic motor activity, autonomic function, and consciousness. Modulates nociceptive (pain) information
Where are the neurons that produce dopamine?
midbrain
substantia nigra
ventral tegmental
What does activation of VTA affect?
the ventral striatum producing feelings of pleasure and reward
Where is the Pedunculopontine Nucleus (PPN) located?
caudal midbrain
What does the PPN influence?
movement
How does the PPN influence movement?
Globus pallidus and subthalamic nucleus
Limbic system
Reticular areas that give rise to reticulospinal tracts
Where are cells that produce serotonin?
found along the midline of the brainstem in raphe nuclei.
Where does the raphe nuclei supply serotonin to?
to the cerebral cortex, thalamus, tectum, cerebellum and spinal cord (rahpespinaltract)
What are the sources of most norepinephrine in the CNS?
Locus Ceruleus and Medial Reticular Zone
What do the ascending axons of the locus ceruleus do?
provides ability to direct attention
What do the descending axons of the locus ceruleus do?
form the ceruleospinal tract as part of non-specific UMNs
What does the medial reticular zone do?
regulates autonomic functions – cardiovascular, respiratory and visceral
Consciousness:
awareness of self and surroundings
Consciousness system:
governs alertness, sleep, and attention
What are the brainstem components of the consciousness system?
reticular formation and its ascending reticular activating (ARA) system
Pons:
processes motor information from the cerebral cortex and forwards the information to the cerebellum
Midbrain:
controls many functions such as visual and auditory systems as well as eye movements
Medulla
controlling head movements, coordinating swallowing and helping regulate cardiovascular, respiratory, and visceral activity
What part of the medulla contain cranial nerve structures?
lower medulla
What does the medullary neuronal network do?
contributes to control of head movements
coordinates swallowing
helps regulate cardiovascular, respiratory, and visceral activity
What tracts synapse in the pons?
corticopontine and some corticobrainstem
What processes sensory information from the face (CNV)?
pontine CN
What does the midbrain do?
the diencephalon and the pons
What regions is the midbrain divided into?
Basis pedunculi
Tegmentum
Tectum
What joins the third and fourth ventricles?
Cerebral aqueduct, a small canal through the midbrain
What does the pretectal area involved in?
the pupillary, consensual, and accommodation reflexes of the eye.
What does the inferior colliculi do?
relay auditory information from the cochlear nuclei to the superior colliculus and to the medial geniculate body of the thalamus
What does the superior colloculi do?
involved in reflexive eye and head movements
Summary of cerebellar functions:
Coordination of movement
Motor planning
Cognitive functions, including rapid shifts of attention
What is the brain stem responsible for?
basic involuntary functions as breathing, heart rate and blood pressure
