Neuro Mod 7 Flashcards
Anterior view midbrain landmarks?
Midbrain (cerebral peduncles), pons, medulla (pyramids and pyramidal decussation), cranial nerves 1-12
Which cranial nerves (in anterior view) do not emerge from the brainstem?
1 & 2
Which cranial nerves (in anterior view) emerge from the midbrain (brainstem)?
3 & 4
Which cranial nerves (in anterior view) emerge from the pons (brainstem)?
5, 6, 7, 8
Which cranial nerves (in anterior view) emerge from the medulla (brainstem)?
9, 10, 11, 12
Medulla pyramids descend in the _______ _______ ______
corticospinal motor tract
Medulla pyramidal decussation represent the descending portion of the corticospinal motor tract that ________ _______
Crosses midline
A majority of medulla pyramidal decussation cross midline and descend in the spinal cord as _____ _____ ______
Lateral corticospinal tract
Some medulla pyramidal decussation do not cross midline and descend in the spinal cord as ______ _______ ______
Anterior corticospinal tract
Posterior view brainstem landmarks?
Superior colliculus, Inferior colliculus, CN4, 4th ventricle
Which CN is the only one to emerge from the posterior brainstem?
CN4
Sagittal view landmarks of the brainstem?
Midbrain, pons, medulla, superior colliculus, inferior colliculus, 4th ventricle, cerebral aqueduct
What are the three horizontal regions of the brainstem?
Brainstem, pons, medulla
External midbrain structures?
CN3, CN4, cerebral peduncles (descending motor tracts), superior colliculus (sub-cortical visual reflexes), inferior colliculus (sub-cortical auditory reflexes)
Internal midbrain structures?
Cerebral aqueduct, periaqueductal gray area (PAG), nuclei for CN3&CN4, red nucleus, substantia nigra, descending motor tracts in cerebral peduncles
Structures of the pons?
CN5 - CN8, motor tracts that descend from anterior pons, 4th ventricle
Structures of the medulla?
CN9 - CN12, pyramids (descending motor tracts), pyramidal decussation (descending motor tracts that cross midline)
What are the three vertical columns of the brainstem?
Tectum (posterior column), Tegmentum (middle column), Basis (anterior column)
Location of tectum?
Posterior column of brainstem, everything posterior to cerebral aqueduct
Structures of the tectum?
Superior colliculus, inferior colliculus
Function of superior colliculus (tectum)?
Some visual info from eye connects directly, creates circuitry for visual reflexes (pupillary light relfex, orienting eyes toward/away from stimuli)
Function of inferior colliculus (tectum)?
Some auditory info from ear connects directly, creates circuitry for auditory reflexes (loud sound -> shrug shoulders/duck head in protective position)
Location of tegmentum?
Middle column of brainstem, everything between cerebral aqueduct/4th ventricle, and basis
Structures of the tegmentum?
Reticular formation, ascending somatosensory tracts, nuclei of CN3 - CN12, descending motor tracts of spinal cord that originate from brainstem nuclei
Function of ascending somatosensory tracts in tegmentum?
Proprioception, light touch, pain and temp from body & head
Midbrain portion of the tegmentum holds nuclei of which cranial nerves?
CN3 & CN4
Pons portion of the tegmentum holds nuclei of which cranial nerves?
CN5 - CN8
Medulla portion of the tegmentum holds nuclei of which cranial nerves?
CN9- CN12
Which descending motor tracts of the spinal cord that originate from the brainstem do the tegmentum hold?
Rubrospinal tract, Tectospinal tract, Reticulospinal tract, Vestibulospinal tract
Where does the Rubrospinal tract originate?
Red nucleus in brainstem
Where does the Tectospinal tract originate?
Tectum in midbrain
Where does the Reticulospinal tract originate?
Reticular nuclei in lower 2/3 of brainstem
Where does the Vestibulospinal tract originate?
Vestibular nuclei in lower brainstem
Location of basis?
Most anterior part of brainstem
What are the three descending spinal tracts of the basis that begin in the motor cortices?
Corticospinal tract, Corticobulbar tract, Corticopontine tract
Corticospinal tract pathway of the basis?
Motor tracts that begin in primary motor cortex/end in spinal cord to supply muscles in the body
Corticobulbar tract pathway of the basis?
Motor tracts that begin in primary motor cortex/end in spinal cord to supply muscles in the face/head
Corticopontine tract pathway of the basis?
Motor tracts that begin in premotor cortices/end in cerebellum via the pontine nuclei
Location of the reticular formation?
Cluster of nuclei located in tegmentum throughout the length of the brainstem
*2 sections
Where is the rostral reticular formation?
Upper pons and midbrain
Where is the caudal reticular formation?
Lower pons and medulla
Overall function of the reticular formation?
Regulates and modulates most areas of the CNS
What syndrome is not completely understood yet is suggested to be d/t reticular formation dysfunction?
SIDS (Sudden infant death syndrome)