PBL 2 Flashcards
where is the midbrain?
between the cerebrum and the pons
what is the tectum?
where the 4 colliculi are found
what are the 3 regions of the midbrain?
tectum (behind cerebral aqueduct), tegmentum (in front of cerebral aqueduct) and basis pedunculi (2 anterolateral portions)
what is the structure called that surrounds the cerebral aqueduct?
the periaqueductal grey
a nucleus that plays a critical role in autonomic function, motivated behavior and behavioural responses to threatening stimuli. and is the primary control centre for pain.
where is the tectum?
directly inferior to pineal gland
how are the colliculi separated?
by the cruciform sulcus
what are the functions of superior colliculi?
for reflexes that govern movements of the head, eyes, and trunk in response to visual stimuli.
what are the functions of inferior colliculi?
relaying impulses from the receptors for hearing in the inner ear to the brain and reflex centres for the startle reflex (sudden movements of the head, eyes, and trunk that occur when you are surprised by a loud noise).
describe the general structure of the cerebral peduncles?
they extend from the cerebral hemispheres to converge as they meet the pons
how are cerebral peduncles separated?
by the interpeduncle fossa
what are the functions of the cerebral peduncles?
consist of axons of the corticospinal, corticobulbar, and corticopontine tracts, which conduct nerve impulses from motor areas in the cerebral cortex to the spinal cord, medulla, and pons, respectively
what does the tegmentum consist of?
medial lemniscus anterolateral tracts fibres from superior cerebellar peduncles red nucleus raphe nuclei neurones ventral tegmental area
what does the basis pedunculi consist of?
cura cerebri
substantia nigra
where is the pons found?
above the medulla but below the midbrain
what does the pons consist of?
mainly nerve fibres that connect the 2 hemispheres of the cerebellum
what is behind the basal pons?
the pontine tegmentum
what is the ventral region of the pons?
The ventral pons contains the pontine nuclei, which are responsible for coordinating movement. Fibres from the pontine nuclei cross the midline and form the middle cerebellar peduncles on their way to the cerebellum
what is the dorsal region of the pons?
The tegmentum forms part of the reticular formation – a set of nuclei found throughout the brainstem that are responsible for arousal and attentiveness.
what do the middle cerebellar peduncles do?
connects the transverse fibers of the pons with the cerebellum,
where do we find the fourth ventricle?
in the pons