Lecture 12: Trigeminal System Flashcards
Where is the apparent origin of the trigeminal nerve? where is the real sensory origin? real motor origin?
Apparent: Pons, as a small motor root and large sensory root
Real Sensory: Trigeminal Ganglion
Real Motor: Motor nucleus of trigeminal nerve
The central fibers of the trigeminal ganglion (sensory) project to which three structures?
- Spinal trigeminal nucleus + tract (medulla)
- Chief (main/principal) sensory nucleus (pons)
- Mesencephalic nucleus + tract
____ nerve is responsible for transmission of general somatic sensibility (vibration, touch, conscious, and unconscious proprioceptive, pain, and temperature sensations of the greater part of the head and motor innervation of muscles of mastication
Trigeminal Nerve
True or False: The Trigeminal nerve is involves in general sensations of face, oral/nasal cavities, dura mater, and proprioception for associated muscles
True
True or False: The sensory portion of the Trigeminal Nerve functions like the dorsal columns, LAS, and spinocerebellar tracts for rest of the body
True
___ nuclei form an almost continuous column of cells from cervical spinal cord to midbrain
A. Two
B. Three
C. Six
D. Four
B. Three
Where is the spinal trigeminal nucleus and spinal trigeminal tract located?
A. thalamus
B. medial tegmentum of medulla and rostral pons
C. lateral tegmentum of medulla and caudal pons
C. lateral tegmentum of medulla and caudal pons
The spinal trigeminal nucleus is considered to be the rostral continuation of the ____ of the dorsal horn while the tract is considered to be the rostral continuation of ____ tract
A. Lissauer’s tract; substantia gelatinosa
B. FG; FC
C. Nucleus of Lissauer; substantia gelatinosa
D. substantia gelatinosa; Lissauer’s tract
D. substantia gelatinosa; Lissauer’s tract
The spinal trigeminal nucleus and spinal trigeminal tract is concerned with pain, temperature, and crude touch information from the head, making it functionally analogous to the ____
A. DC-ML
B. ALS
C. Spinocerebellar system
B. ALS
Where are the chief (main/principal) sensory nucleus of the Trigeminal Nerve located?
A. Lateral Tegmentum of medulla and caudal pons
B. Dorsolateral Pontine Tegmentum (midpontine level)
B. Dorsolateral Pontine Tegmentum (midpontine level)
True or False: The Chief (Main/Principal) Sensory Nucleus of the Trigeminal Nerve is concerned with: fine touch, two point discrimination, vibratory, and conscious proprioception information from the head, making it functionally analagous to the ALS
False - chief sensory nucleus of CN 5 is functionally analogous to the DC-ML
Where is the mesencephalic nucleus of CN 5 located?
A. Lateral Tegmentum of medulla and caudal pons
B. Dorsolateral Pontine Tegmentum (midpontine level)
C. Rostral pons and caudal medulla (adjacent to PAG)
C. Rostral pons and caudal medulla (adjacent to PAG)
True or False: The mesencephalic nucleus represents primary sensory ganglia (like DRG) that have become incorporated into the CNS during the development of the brainstem
True
Which of the following are concerned with UNCONSCIOUS PROPRIOCEPTION information from the head and is functionally ANALAGOUS to the SPINOCEREBELLAR SYSTEM?
A. Special Visceral Efferent
B. Chief (main/principal) Sensory Nucleus
C. Spinal Trigeminal Nucleus
D. Spinal Trigeminal Tract
E. Mesencephalic Nucleus
E. Mesencephalic Nucleus
_____: Important role in motor innervation of muscles of mastication
A. Special Visceral Efferent
B. Chief (main/principal) Sensory Nucleus
C. Spinal Trigeminal Nucleus
D. Spinal Trigeminal Tract
E. Mesencephalic Nucleus
A. Special Visceral Efferent
Where is the motor nucleus of the trigeminal nerve found?
A. VPL
B. DRG
C. Dorsolateral pontine tegmentum (mid-pontine)
C. Dorsolateral pontine tegmentum (mid-pontine)
True or False: The sensory root (portio major) of the trigeminal nerve corresponds to V1, V2, and V3
true
True or False: The Trigeminal Nerve has overlapping dermatomes
False - no overlapping dermatomes
The trigeminal ganglion are similar to the ___ of the ___ nervous system
A. DRG; peripheral nervous system
B. VRG; central nervous system
A. DRG; peripheral nervous system
True or False: The trigeminal ganglion contains neuronal cell bodies of the motor neurons of the trigeminal nerve
False - contains neuronal cell bodies of sensory neurons of trigeminal nerve
The motor root (portio major) of the trigeminal nerve contains fibers that are only found in the __ division
A. V1 (opthalmic)
B. V2 (maxillary)
C. V3 (mandibular)
C. V3 (mandibular)
The sensory component of the central distribution of the trigeminal nerve enters the brainstem at the ___, passed through the middle ____ _____
mid-pontine; middle cerebellar peduncle
The primary afferent axons will enter either the ____ or descend along lateral margin of brainstem to enter _____ nucleus
chief sensory nucleus; spinal trigeminal
True or False: Chief Sensory Nucleus (Chief Sensory V) while Spinal Trigeminal Nucleus (Spinal VV)
False - Spinal Trigeminal Nucleus (Spinal V)
____ receives large afferent inputs concerned with fine touch, vibratory and conscious proprioception info from the head (via all three divisions)
Chief Sensory Nucleus
True or False: Primary afferents of the Chief Sensory Nucleus synapse on neurons in the nucleus
True
Which of the following receive small caliber afferents concerned with pain, temp, crude touch info from head (via all three peripheral divisions)?
A. Chief Sensory Nucleus
B. Spinal Trigeminal Nucleus
B. Spinal Trigeminal Nucleus
Incoming afferents descend through brainstem lateral to spinal trigeminal nucleus as the spinal tract of the trigeminal nerve (____)
A. Spinal VI
B. Spinal III
C. Spinal V
C. Spinal V
True or False: Other primary afferents enter through sensory root and ascend to midbrain - these afferents constitute mesencephalic tract of CN V and are the peroipheral processes of neurons in the mesencephalic nucleus of the trigeminal nerve, known as ____
Mesencephalic V
Fibers may course through the DRG but they do not stop within DRG itself because?
Cell bodies located in mesencephalic nucleus
Which nucleus represent misplaced ganglion cells that have become incorporated into the brainstem?
Mesencephalic nucleus
Which nucleus is the only case of sensory neurons housed within the CNS and NOT in the peripheral sensory ganglia?
Mesencephalic nucleus
The motor component of the trigeminal nerve has fibers that original from neurons in the motor trigeminal nucleus in the ___
A. thalamus
B. cerebellum
C. VPL
D. pons
D. pons
How do fibers of the motor component of CN 5 exit the brainstem?
A. Pass through the middle cerebellar peduncle
B. Pass through superior cerebellar peduncle
A. Pass through the middle cerebellar peduncle
The motor component (portio minor) of the trigeminal nerve will only travel in which division of the trigeminal nerve to innervate muscles of mastication and other muscles of head/neck?
A. V1
B. V2
C. V3
C. V3
True or False: The motor trigeminal nucleus receives unilateral cortical inputs
False - bilateral
Where do the fibers of the ventral trigeminothalamic tract originate?
Neurons in spinal trigeminal, chief sensory nuclei, and spinal trigeminal nucleus
In the ventral trigeminothalamic tract (VTTT), fibers exit nucleus, decussate, and ascend up the brainstem. Fibers of the VTT that carry pain, and temp will ascend to the ___
thalamus (VPM)
True or False: Axons carrying similar info tend to travel together in the brainstem
True
True or False: The Ventral Trigeminothelamic Tract conveys ONLY slow pain and temperature information from one side of the face to the contralateral VPM nucleus of the thalamus
False - the ventral trigeminothelamic tract carries BOTH slow/fast pain and temperature from one side of the face to the contralateral VPM nucleus of the thalamus
Where do VPM neurons of the ventral trigeminothalamic tract project to?
Primary sensory cortex in postcentral gyrus (Brodmann’s Area 3, 1, and 2)
How is the VTTT (ventral trigeminothalamic tract) similar to the spinoreticulothalamic and spinotectal tracts of the ALS?
VTTT gives off collateral branches to the retricular formation and tectum for reflexes
In the Trigeminal system, fibers originate from which three places?
- Spinal Trigeminal Nucleus and tract
- Chief Sensory Nucleus
- Mesencephalic Nucleus
Fibers originating from Chief Sensory Nucleus exit nucleus decussate and ascend brainstem as part of the ___
VTTT
Fibers of the VTTT that carry information from chief sensory nucleus will ascend to the ___ in close proximity to the medial lemniscus
thalamus (VPM)
In fiber originating from spinal trigeminal nucleus and those originating from chief sensory nucleus, axons carrying similar info travel together in the brainstem
True
True or False: The VTTT tract conveys 2 point discrimination, fine touch, vibration, + conscious proprioception info from one side of the face to c/l _____
VPM nucleus of the thalamus
Where do VPM neurons project to?
Lateral aspects of primary sensory cortex in postcentral gyrus (Brodmann Area 3,1,2)
Which of the branches of the Trigeminal Nerve carries both sensory and motor information?
V3
True or False: The fibers carried only in V3 division of trigeminal are sensory and play a role in function of muscles of mastication
False - they are motor (SVE) ; they have a role in function of muscles of mastication
For unconscious proprioception from the face, ____ order neurons is located in the _____
A. 1st; DRG
B. 1st; VPN
C. 1st; Mesencephalic nucleus
C. 1st; Mesencephalic nucleus
____ is the rostral continuation of the substantia gelantinosa
A. Mesencephalic Nucleus
B. Chief Sensory Nucleus
C. Spinal Trigeminal Nucleus
C. Spinal Trigeminal Nucleus
Which of the following deals with tactile and conscious proprioception?
A. Mesencephalic Nucleus
B. Chief Sensory Nucleus
C. Spinal Trigeminal Nucleus
B. Chief Sensory Nucleus
Which of the following deals with unconscious proprioception?
A. Mesencephalic Nucleus
B. Chief Sensory Nucleus
C. Spinal Trigeminal Nucleus
A. Mesencephalic Nucleus
Which are more dorsal? medial?
A. spinal trigeminal tract; nucleus
B. nucleus; spinal trigeminal tract
A. spinal trigeminal tract; nucleus
_____ is the continuation of the Lissauer’s Tract
A. Spinal Trigeminal Nucleus
B. Spinal Trigeminal Tract
B. Spinal Trigeminal Tract
____ receives conscious and tactile proprioception from face
A. Main sensory nucleus
B. Mesencephalic nucleus and tract
A. Main sensory nucleus
Which of the following receives unconscious proprioception?
A. Mesencephalic Nucleus
B. Chief Sensory Nucleus
C. Spinal Trigeminal Nucleus
A. Mesencephalic Nucleus
True or False: We have corticobulbar projections through the posterior limb of the internal capsule, crus cerebri, and basilar pons
True
True or False: Unilateral lesion at motor cortex effects mastication
False - does not