Topography of the Brain Flashcards
What are the pyramidal tracts/medullary pyramids?
Motor fibres for the corticospinal and corticobulbar tracts (pyramidal tracts) which pair as white matter structures (medullary pyramids)
What are the peduncles?
Elongated stalks of tissue that connect structures of the brain
What are the red nuclei?
The red nucleus is one of the brainstem nuclei and part of the extrapyramidal system. They are situated within the tegmentum of the midbrain. Involved in coordination of muscle tone, body position and gait
What are the substantia nigra?
Pat of the midbrain, the substantia nigra is an important player in brain function, in particular, in eye movement, motor planning, reward-seeking, learning, and addiction. It is closely linked to the striatum
What are the colliculi?
Make up the corpora quadregemina - reflex centres involving hearing and balance. Two superior two inferior. Superior - preliminary visual processing, control of eye movements Inferior - auditory processing
What is the inferior olivary nucleus?
The largest nucleus situated in the olivary body, part of the medulla oblongata. It is involved in motor control. It is a major source of input to the cerebellum. The hypoglossal nucleus sends its fibers ventrally between the pyramid and inferior olivary nucleus to exit as the hypoglossal nerve
What is the reticular formation?
A set of interconnected nuclei located throughout the brainstem
What are the two key functions of the cerebellum?
Maintain posture
Fine tune motor activity
How can signals reach the cerebellum?
Information from pyramidal tracts - motor intention of the brain
Information from the ipsilateral proprioceptors
Information from vestibular nuclei(in the vestibule) re balance and posture
What are the three main components of the brainstem?
Midbrain, pons, medulla
What does the brainstem contain?
CN III-XII, tracts from spinal cord, vital centres e.g. cardiorespiratory centre
Generally speaking, what do the brainstem centres govern?
The rigidly programmed automatic behaviours essential for survival
With how many of the cranial nerves is the brainstem involved?
10
From where does the medulla develop?
Hindbrain vesicle
What is the cavity of the medulla also known as?
The IV ventricle
At what point do the medullary pyramids cross over?
The decussation (at the lower limit of the pyramids)
Which cranial nerves emerge from the surface of the medulla?
IX, X, XI & XII
What structure connects the medulla to the cerebellum?
The inferior cerebellar peduncle
From where does the pons develop?
Mentencephalon part of the hindbrain vesicle
What structure is the pons anterior to?
The IV ventricle
What peduncle is present on the surface of the pons?
Middle cerebellar peduncle
Which cranial nerves originate from the surface of the pons?
V, VI, VII & VIII
From where does the midbrain originate?
The mesencephalon
What is the name of the central cavity of the midbrain?
Cerebral aqueduct
