Chapter 29: Midbrain Flashcards
(104 cards)
1
Q
Anatomically and physiologically, the midbrain lies between the forebrain and the _____.
A
- Pons
2
Q
The most obvious feature of the midbrain is the narrow cerebral aqueduct connecting the _____ and _____ ventricles.
A
- Third
- Fourth
3
Q
The periaqueductal gray is a region of gray matter surrounding the _____.
A
- Cerebral aqueduct
4
Q
The mesencephalic tract of the ______ nerve continues into the midbrain in the lateral edge of the periaqueductal gray.
A
- Trigeminal
5
Q
Tectum is Latin for roof. Thus the region dorsal to the cerebral aqueduct is called the _____ of the midbrain.
A
- Tectum
6
Q
The roof of the fourth ventricle is the _____, but the roof of the cerebral aqueduct is the _____ of the _____.
A
- Cerebellum
- Tectum
- Midbrain
7
Q
The midbrain _____ is dorsal to the cerebral aqueduct and the periaqueductal gray and also dorsal to the lateral parts of the midbrain tegmentum.
A
- Tectum
8
Q
The midbrain _____ lies partially lateral and mostly ventral to the periaqueductal gray.
A
- Tegmentum
9
Q
The _____ of the pons is ventral to the fourth ventricle, but the _____ of the midbrain is ventral to the periaqueductal gray.
A
- Tegmentum
- Tegmentum
10
Q
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.
A
- Base
11
Q
The gray matter of the substantia nigra and the white matter of a corticospinal tract make up the _____ of the midbrain.
A
- Cerebral peduncles
12
Q
The heavily myelinated corticospinal tracts form the ventral (or anterior) 2/3 of the _____ of the midbrain.
A
- Cerebral peduncles
13
Q
The _____ in the midbrain was once called the basis pedunculi, but the official term is now crus cerebri.
A
- Corticospinal tract
14
Q
The white matter of the _____ is separated from the tegmentum of the midbrain by the gray matter of the substantia nigra.
A
- Crus cerebri
15
Q
The substantia nigra is a band of gray matter between the _____ and the _____ of the _____.
A
- Crus cerebri
- Tegmentum
- Midbrain
16
Q
The substantia nigra is ventral to the _____ of the _____ and dorsal to the _____.
A
- Tegmentum
- Midbrain
- Crus cerebri
17
Q
The band of gray matter between the crus cerebri and the midbrain tegmentum is the _____.
A
- Substantia nigra
18
Q
The right side of the cerebellum projects to the _____ side of the midbrain and thalamus through the _____.
A
- Left
- Superior cerebellar peduncles
19
Q
The superior cerebellar peduncles cross ventral to the periaqueductal gray in the _____ of the lower midbrain.
A
- Tegmentum
20
Q
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.
A
- Decussation
- Decussation
21
Q
The center of the tegmentum of the lower midbrain is occupied by the _____ of the _____.
A
- Decussation
- Superior cerebellar peduncles
22
Q
Most neurologists keep the name “superior cerebellar peduncles” for these tracts in the upper midbrain beyond their _____.
A
- Decussation
23
Q
Half of the fibers in each superior cerebellar peduncle synapse in the red nucleus of the upper midbrain after crossing in the _____.
A
- Lower midbrain
24
Q
Each side of the cerebellum projects to the _____ red nucleus via the superior cerebellar peduncle.
A
- Contralateral (opposite)
25
Half of the projections of each side of the cerebellum are to the contralateral _____.
- Red nucleus
26
The midbrain tectum is divided into 4 small hills which are called colliculi because the Latin word for small hills is _____.
- Colliculi
27
The 2 inferior colliculi form the _____ of the lower midbrain, and the 2 superior colliculi form the _____ of the upper midbrain.
- Tectum
| - Tectum
28
Each of the inferior colliculi of the _____ contains a large mass of gray matter called the nucleus of the inferior colliculus.
- Lower midbrain
29
The nucleus of the inferior colliculus receives auditory information from the ipsilateral _____ via the lateral lemniscus.
- Superior olivary nucleus
30
Some projections of the superior olivary nucleus synapse in the ipsilateral nucleus of the lateral lemniscus which relays the information to the nucleus of both inferior colliculi via the _____.
- Lateral lemniscus
31
Upward projections of the superior olivary nucleus are _____, but projections of the nucleus of the lateral lemniscus are _____l.
- Ipsilateral
| - Bilateral
32
The nucleus of the superior colliculus receives direct input from the ipsilateral _____ and both _____.
- Superior olivary nucleus
| - Nuclei of the lateral lemnisci
33
A relay in the _____ allows information from the contralateral _____ to reach the nucleus of the superior colliculus.
- Nucleus of the lateral lemniscus
| - Superior olivary nucleus
34
Each ______ of the _____ colliculus also receives auditory information directly from the contralateral anterior and posterior cochlear nuclei via the lateral lemniscus.
- Nucleus
| - Inferior
35
The nucleus of the inferior colliculus receives direct input from the _____ superior olivary nucleus, the _____ anterior cochlear nucleus, the _____ posterior cochlear nucleus, and _____ of the lateral lemniscus.
- Ipsilateral
- Contralateral
- Contralateral
- Both nuclei
36
All upward auditory projections reach the nucleus of the inferior colliculus via the _____.
- Lateral lemniscus
37
The nucleus of the inferior colliculus receives auditory information directly from the _____ cochlear nuclei and indirectly from both cochlear nuclei.
- Contralateral
38
Connections between right and left nuclei at the same level are called _____.
- Commissures
39
The nuclei of the inferior colliculi are connected to each other by the _____ of the inferior colliculi.
- Commissures
40
The nucleus of the inferior colliculus receives auditory information from _____ and relays it to the medial geniculate nucleus of the thalamus.
- Both ears
41
The inferior colliculus projects to the _____ of the _____ via the brachium of the inferior colliculus.
- Medial geniculate nucleus
| - Thalamus
42
The medial geniculate nucleus of the thalamus receives information from the _____ of the _____ via the _____ of the _____.
- Nucleus
- Inferior colliculus
- Brachium
- Inferior colliculus
43
The trochlear nerve is the only _____ nerve of the lower midbrain.
- Cranial
44
The lower motor neurons in the trochlear nucleus of the lower midbrain project to the superior oblique muscle via the _____ nerve.
- Trochlear
45
The trochlear nuclei lie just ventral to the periaqueductal gray of the _____.
- Lower midbrain
46
The trochlear nuclei lie near the midline of the _____ of the lower midbrain.
- Tegmentum
47
In myelin-stained sections the trochlear nuclei look like pale gray circles cut into the medial longitudinal fasciculus which is jet black because it is _____.
- Heavily myelinated
48
The heavily-myelinated tract ventral to the trochlear nuclei is the _____.
- Medial longitudinal fasciculus
49
The trochlear nerves run dorsal around the periaqueductal gray and exit the _____ surface of the lower midbrain and exit on the caudal (inferior) side of the inferior colliculi.
- Dorsal
50
The trochlear nerves are the only cranial nerves to exit the _____ surface of the brainstem.
- Dorsal
51
Each trochlear nerve makes a semicircle around the ipsilateral side of the _____ to reach the _____ surface of the tectum of the _____.
- Periaqueductal gray
- Dorsal
- Lower midbrain
52
The trochlear nerves cross just above the commissure of the inferior colliculi so that the right _____ is the source of the _____ trochlear nerve, and the left trochlear nucleus is the source of the _____ trochlear nerve.
- Trochlear nucleus
- Left
- Right
53
The only cranial nerves that cross are the _____ which cross between the _____.
- Trochlear nerves
| - Inferior colliculi
54
The trochlear nerve innervates the _____ muscle which turns the eyeball so that the pupil points down and out.
- Superior oblique
55
The right trochlear nerve is made up of axons of lower motor neurons in the _____.
- Left trochlear
| - Nucleus
56
The trochlear nuclei are just ventral to the periaqueductal gray of the _____, and the oculomotor nuclei are just ventral to the periaqueductal gray of the upper midbrain.
- Lower midbrain
57
The oculomotor nuclei flank the midline of the _____.
- Upper midbrain
58
Each oculomotor nucleus is the source of an _____.
- Oculomotor nerve
59
Since the abducens nerve innervates the_____, and the trochlear nerve innervates the _____, the oculomotor nerve must innervate remaining extrinsic muscles of the eye.
- Lateral rectus
| - Superior oblique
60
The superior rectus, medial rectus, inferior rectus, and inferior oblique are innervated by the _____.
- Oculomotor nerve
61
The lower motor neurons for the superior rectus, medial rectus, inferior rectus, and inferior oblique are in the _____ in the _____.
- Oculomotor nucleus
| - Upper midbrain
62
The oculomotor nucleus is just lateral to the _____ of the _____ of the upper midbrain.
- Midline
| - Tegmentum
63
The medial longitudinal fasciculi are a pair of heavily myelinated _____ matter tracts stretching from the lower forebrain to the sacral cord.
- White
64
The medial longitudinal fasciculi are on the ventral side of the _____ in the lower midbrain and on the lateral sides of the oculomotor nuclei in the upper midbrain.
- Trochlear nuclei
65
Since there is no space between the oculomotor nuclei, the medial longitudinal fasciculi are just _____ to the oculomotor nuclei in the _____.
- Lateral
| - Upper midbrain
66
The oculomotor nerves extend ventrad from their origins in the _____ and exit the ventral surface of the upper midbrain between the cerebral peduncles
- Oculomotor nuclei
67
The oculomotor nerve exits the upper midbrain through the interpeduncular fossa between the _____.
- Cerebral peduncles
68
Each medial longitudinal fasciculus lies next to the _____ in the upper midbrain and next to the _____ in the lower midbrain and exchanges fibers with them.
- Oculomotor nerve
| - Trochlear nucleus
69
The medial longitudinal fasciculi run between the abducens nuclei in the _____ and exchange fibers with them.
- Lower pons
70
The medial longitudinal fasciculi exchange fibers with the vestibular nuclei, the _____, the _____, and the _____.
- Oculomotor nuclei
- Trochlear nuclei
- Abducens nuclei
71
The medial longitudinal fasciculi coordinate _____ movements with each other and with movements of the head.
- Eye
72
The inferior olivary nucleus of the _____ receives input from the ipsilateral red nucleus of the upper midbrain via the _____.
- Medulla
| - Central tegmental tract
73
The central tegmental tract is a projection of the _____ which is a round structure in the tegmentum of the _____.
- Red nucleus
| - Upper midbrain
74
The central tegmental tract leaves the dorsal side of the _____ in the upper midbrain and runs into the lower midbrain lateral to the medial longitudinal fasciculus.
- Red nucleus
75
The central tegmental tract is _____ to the medial longitudinal fasciculus, _____ to the periaqueductal gray and _____ to the decussation of the superior cerebellar peduncles in the lower midbrain.
- Lateral
- Ventral
- Dorsal
76
The red nucleus is a round structure in the _____ of the _____.
- Tegmentum
| - Upper midbrain
77
The central tegmental tract starts from the _____ side of the _____.
- Dorsal
| - Red nucleus
78
Half of the fibers in each superior cerebellar peduncle synapse in the _____.
- Red nucleus
79
Fibers from the right side of the cerebellum synapse in the left _____ or continue on and synapse in the left side of the thalamus.
- Red nucleus
80
Half of the fibers from the right side of the cerebellum pass to the left of the _____ red nucleus and synapse in the left side of the _____.
- Left
| - Thalamus
81
The right side of the thalamus receives half of the projections of the _____ side of the cerebellum.
- Left
82
Axons in the superior cerebellar peduncle that do not synapse in the _____ synapse in the thalamus.
- Red nucleus
83
The axons in the superior cerebellar peduncle that do not synapse in the _____ pass on its lateral side en route to the _____.
- Red nucleus
| - Thalamus
84
As in the pons, a large part of the tegmentum of the midbrain is occupied by the _____ formation.
- Reticular
85
The center of the tegmentum is of the lower midbrain is occupied by the _____ of the _____.
- Decussation
| - Superior cerebellar peduncles
86
The reticular formation is necessarily _____ to the decussation of the superior cerebellar peduncles and the central tegmental tract in the lower midbrain.
- Lateral
87
The remnant of the anterolateral system is still further lateral, between the _____ and the surface of the lower midbrain.
- Reticular formation
88
Because all of the remaining fibers of the anterolateral system in the midbrain synapse in the _____, these fibers are often called the spinothalamic tracts.
- Thalamus
89
The spinothalamic tracts are between the _____ and the surface of the lower midbrain.
- Reticular formation
90
The alternating input to the upper motor neurons in the pontine and medullary reticular formations that produce unconscious _____ comes from the midbrain reticular formation.
- Walking
91
Unconscious walking is coordinated by neurons in the _____ of the _____.
- Reticular formation
| - Midbrain
92
In both the lower midbrain and the upper midbrain the reticular formation is medial to the _____ and lateral to the _____ tract.
- Spinothalamic tract
| - Central tegmental
93
The nucleus of the inferior colliculus in the tectum of the _____ is a processing center for _____.
- Lower midbrain
| - Hearing
94
The nucleus of the inferior colliculus receives _____ information via the _____ and projects to the _____ via the _____ of the _____.
- Auditory
- Lateral lemniscus
- Thalamus
- Brachium
- Inferior colliculus
95
The _____ are embedded in the medial longitudinal fasciculus in the lower midbrain.
- Trochlear nuclei
96
Automatic tracking of a moving object is programmed by the _____ in the _____.
- Superior colliculi
| - Upper midbrain
97
The inferior and superior colliculi make up the quadrigeminal plate or _____ of the midbrain.
- Tectum
| - Oculomotor
98
The _____ nucleus abuts the ventral side of the periaqueductal gray of the upper midbrain.
- Oculomotor
99
The _____ are the largest things in the tegmentum of the upper midbrain.
- Red nuclei
100
The largest projection to the red nuclei is the _____ which crossed in the tegmentum of the _____.
- Superior cerebellar peduncles
| - Lower midbrain
101
The largest projection of the red nuclei in humans is the _____ which ends in the _____ of the _____.
- Central tegmental tract
- Inferior olivary nucleus
- Medulla
102
The base of the midbrain is mostly occupied by the _____.
- Corticospinal tracts
103
The medial lemniscus passes through the lateral part of the _____ of the midbrain without synapsing.
- Tegmentum
104
The spinothalamic tract is _____ to the lateral edge of the medial lemniscus in the midbrain.
- Dorsal
