Trigeminal System N22

Question 1

Origin of Sensory division of Trigeminal N.

Answer 1

Trigeminal ganglion –>
Spinal Trigeminal nucleus/tract
Chief (main/principle) sensory nucleus
Mesencephalic nucleus/tract

Question 2

Origin of Motor division of Trigeminal N.

Answer 2

Motor nucleus of trigeminal n

Question 3

Trigeminal n Sensory division function

Answer 3

GENERAL SOMATIC SINSIBILITY (vibration, touch, conscious and unconscious proprioception, pain and temperature)

Question 4

Trigeminal n Motor division function

Answer 4

innervation of muscles of mastication (temporal is, masseter, medial/lateraly pterygoids, tensor tympani, tensor veli palatine, anterior digastric belly, mylohyoid)

Question 5

Function of general somatic afferent (GSA) components of Trigeminal n.

Answer 5

General sensations of the face, nasal and oral cavities, dura mater and proprioception

Question 6

GSA Nuclei (3)

Answer 6

Spinal Trigeminal Nucleus, Chief (main/principle) sensory nucleus, Mesencephalic nucleus
Which all form a continuous column of cells

Question 7

Spinal Trigeminal Nucleus

Answer 7

Lateral tegmentum of medulla and caudal pons; considered to be a rostral continuation of the SUBSTANTIA GELATINOSA

Question 8

Spinal Trigeminal Tract continuation of ______

Answer 8

Considered to be a rostral continuation of Lissauer’s Tract

Question 9

Spinal Trigeminal Tract is analogous to _______

Answer 9

ANTEROLATERAL SYSTEM: pain, temperature, crude touch

Question 10

Chief (Main/Principle) Sensory Nucleus

Answer 10

Located in the dorsolateral pontine tegmentum (midpons)

Question 11

Chief Nucleus Function

Answer 11

Fine touch, 2-pt discrimination, vibration, conscious proprioception of head

Question 12

Chief Nucleus is analogous to ________

Answer 12

DC-ML

Question 13

Mesencephalic Nucleus location

Answer 13

Rostral pons and caudal midbrain

Question 14

Mesencephalic Nucleus Function

Answer 14

UNCONSCIOUS PROPRIOCEPTION - acts as primary sensory ganglia (DRG)

Question 15

Mesencephalic Nucleus is analogous to _____

Answer 15

Spinocerebellar System

Question 16

Peripheral Sensory division is split into 3 divisions:

Answer 16

V1: opthalmic V2: maxillary V3: mandibular (NO overlap)

Question 17

Trigeminal ganglion of the sensory root contains

Answer 17

Cell bodies of peripheral processes; in trigeminal cave (Meckel’s) in middle cranial fossa; acts like DRG

Question 18

Trigeminal ganglion of motor root contains

Answer 18

Cell bodies for fibers in V3: mandibular division

Question 19

Primary afferent axons will enter either

Answer 19

Chief sensory nucleus at same level (midpons) or descend to spinal trigeminal nucleus

Question 20

Chief Nucleus receives which primary afferent axons

Answer 20

Large afferent inputs for fine touch, vibratory and conscious proprioception

Question 21

Spinal Trigeminal Nucleus receives which primary afferent axons

Answer 21

Small afferent inputs for pain, temperature, and crude touch

Question 22

Afferents path to synapse on Spinal trigeminal nucleus

Answer 22

descend lateral to spinal trigeminal nucleus as SPINAL TRACT OF TRIGEMINAL N (Sp V Tr)

Question 23

Mesencephalic nucleus receives

Answer 23

afferents that travel from the periphery via mesencephalic tract for unconscious proprioception information from muscle spindles in the muscles of mastication

Question 24

Motor Component fibers paths

Answer 24

Motor Trigeminal nucleus (pons)–> middle cerebellar peduncle –> V3

Question 25

Motor trigeminal nucleus receives

Answer 25

bilateral cortical input

Question 26

Ventral Trigeminothalamic Tract (VTTT) have fibers from which two nuclei

Answer 26

Spinal trigeminal and Chief sensory

Question 27

VTTT fibers from Spinal Trigeminal Nucleus

Answer 27

Exit nucleus --> decussate --> ascend as VTTT (near ALS) --> VPM of thalamus --> lateral primary somatosensory cortex (3,1,2)

Question 28

VTTT fibers from Spinal Trigeminal Nucleus carry

Answer 28

sensory information for slow, dull pain, and reflexes

Question 29

Reflexes from VTTT spinal Trigeminal Nucleus synapse on

Answer 29

Reticular Formation

Question 30

VTTT fibers from Chief Sensory Nucleus

Answer 30

Exit nucleus --> decussate --> ascend as VTTT (near ML) --> VPM of thalamus --> lateral primary somatosensory cortex (3,1,2)

Question 31

VTTT fibers from Chief Sensory Nucleus carry

Answer 31

sensory information for 2-point discrimination, fien touch, vibration, conscious proprioception

Question 32

Dorsal Trigeminothalamic Tract (DTTT)

Answer 32

small, IPSILATERAL, from chief nucleus to ipsilateral VPM

Question 33

Processes leaving the Spinal trigeminal nucleus

Answer 33

1. VTTT --> VPM of thalamus 2. Reticular formation --> Intralaminar thalamic nuclei 3. PAG and SC --> reflexive movement of head and control of pain