Brainstem Flashcards
Another name for midbrain?
mesencephalon
What makes up the hindbrain?
Pons
Medulla oblongata
The brainstem is divided into regions by?
Anteriorly and posteriorly
What are the anterior/ventral parts of the brainstem?
Cerebral peduncles of the midbrain
Basal pons
Pyramids and olives of the medulla
Where is the tegmentum?
Posterior portion of the medulla and pons
Middle portion of the midbrain
What does the basal pons do?
it acts as an important connection between the cerebrum and cerebellum.
What do the pyramids of the medulla do?
White matter structures that contain motor fibers of the corticospinal tracts.
What do the olives of the medulla do?
They contain the olivary nuclei.
What do the cerebral peduncles do?
are the two stalks that attach the cerebrum to the brainstem
What is the tectum?
Only found in the midbrain
- Is posterior and dorsal part of the midbrain sitting behind the cerebral aqueduct.
- Contains major nuclei
What are the two major nuclei that the tectum contain?
Superior colliculus
Inferior colliculus
What are three things the brainstem contains?
Ascending sensory tracts
descending motor tracts
Cranial nerve nuclei
What does the nuclei of the brainstem modulate?
Heart rate and blood pressure
Breathing
Arousal
Pain control
Which ascending sensory tracts run bilaterally in the medulla and caudal pons.?
Spinothalamic tract
Posterior spinocerebellar tract
Cuneocerebellar tract
-Only in the medulla
What is the medial lemniscus?
Second order neuron somas in nuclei in caudal medulla
-Axons cross in anteromedial caudal medulla (posterior to the pyramids) and ascend in the contralateral medial lemniscus
Descending motor tracts - the Neurons of which two spinal cord tracts travel together in the corticospinal tract in the ventral brainstem.
Anterior corticospinal tract
Lateral corticospinal tract
In the midbrain the corticospinal tract goes through the?
Cerebral peduncle
-Most ventral part of the midbrain
Travels with corticobrainstem and corticopontine fibers
In the pons the corticospinal tract travels medially in the?
basal pons
The corticobrainstem tract used to be called?
the corticobulbar tract
What is the corticobrainstem tract?
UMN
Innervates LMNs in cranial nerves rather than spinal nerves except neurons to extraocular muscles
Where does the corticobrainstem tractd originate?
in the primary motor cortex on the paracentral gyrus of the frontal lobe
Via the cerebral peduncles travels with the corticospinal tracts
The corticobrainstem tracts do have a single point of decussation like the LCST but instead?
descussate at the level of the cranial nerve nuclei they are innervating.
The corticobrainstem tracts decussate at the following location?
Mid pons - CN V Trigeminal
Caudal pons - CN VII Facial
Rostral medulla - CN IX Glossopharyngeal, CN XII Hypoglossal
Upper cervical spinal cord - CN XI Accessory
The corticobrainstem tracts UMN innervate?
LMNs bilaterally except muscles of facial expression lower face
-Very dominate contralateral control of LMN in CN XII Hypoglossal
T/F
Damage to one corticobrainstem tract produces no functional paralysis/paresis for most muscles after the acute phase?
T
