Anatomically and physiologically, the midbrain lies between the forebrain and the _____.
The most obvious feature of the midbrain is the narrow cerebral aqueduct connecting the _____ and _____ ventricles.
- Fourth
The periaqueductal gray is a region of gray matter surrounding the _____.
The mesencephalic tract of the ______ nerve continues into the midbrain in the lateral edge of the periaqueductal gray.
Tectum is Latin for roof. Thus the region dorsal to the cerebral aqueduct is called the _____ of the midbrain.
The roof of the fourth ventricle is the _____, but the roof of the cerebral aqueduct is the _____ of the _____.
The midbrain _____ is dorsal to the cerebral aqueduct and the periaqueductal gray and also dorsal to the lateral parts of the midbrain tegmentum.
The midbrain _____ lies partially lateral and mostly ventral to the periaqueductal gray.
The _____ of the pons is ventral to the fourth ventricle, but the _____ of the midbrain is ventral to the periaqueductal gray.
- Tegmentum
Just as the pontine nuclei and corticospinal fibers form the _____ of the pons, the substantia nigra and the corticospinal tracts form the cerebral peduncles of the midbrain.
The gray matter of the substantia nigra and the white matter of a corticospinal tract make up the _____ of the midbrain.
The heavily myelinated corticospinal tracts form the ventral (or anterior) 2/3 of the _____ of the midbrain.
The _____ in the midbrain was once called the basis pedunculi, but the official term is now crus cerebri.
The white matter of the _____ is separated from the tegmentum of the midbrain by the gray matter of the substantia nigra.
The substantia nigra is a band of gray matter between the _____ and the _____ of the _____.
The substantia nigra is ventral to the _____ of the _____ and dorsal to the _____.
The band of gray matter between the crus cerebri and the midbrain tegmentum is the _____.
The right side of the cerebellum projects to the _____ side of the midbrain and thalamus through the _____.
- Superior cerebellar peduncles
The superior cerebellar peduncles cross ventral to the periaqueductal gray in the _____ of the lower midbrain.
Just as the crossing of the internal arcuate fibers to form the medial lemniscus is called the _____ of the medial lemniscus, the crossing of the superior cerebellar peduncles is called the _____ of the superior cerebellar peduncles.
- Decussation
The center of the tegmentum of the lower midbrain is occupied by the _____ of the _____.
- Superior cerebellar peduncles
Most neurologists keep the name “superior cerebellar peduncles” for these tracts in the upper midbrain beyond their _____.
Half of the fibers in each superior cerebellar peduncle synapse in the red nucleus of the upper midbrain after crossing in the _____.
Each side of the cerebellum projects to the _____ red nucleus via the superior cerebellar peduncle.