cranial nuclei: sensory

Question 1

• 3 sensory somatic nuclei
• 3 sensory nuclei from the trigeminal because of 3 branches
• each of these branches goes to all 3 somatic sensory nuclei
• these 3 nuclei take all of incoming info from the face plus the small area behind the ear over mastoid

Answer 1

somatic sensory input

Question 2

where does the majority of the input come from for the sensory somatic input?

Answer 2

trigeminal nerve

Question 3

the 3 sensory nuclei come from the trigeminal because of the 3 branches which are

Answer 3

maxillary, mandible, ophthalmic

Question 4

each of the branches goes to all 3 somatic sensory nuclei

Answer 4

each nuclei is receiving info from all 3 branches of the trigeminal

Question 5

• responsible for touch receptors which is analogous to the dorsal column in the spinal cord
• the axons here are similar to those found at the level of the spinal cord
• from here at the brainstem, the information goes to the contralateral dorsal thalamus

Answer 5

principle trigeminal nuclei

Question 6

• goes to the ventroposterior medial nucleus nucleus (VPMN)
• topographical info in maintained all the way up
• from here projections carry the info to the ipsilateral sensory cortex (areas 3,1,2) where topographical maps are maintained

Answer 6

beyond the brain stem for trigeminal nuclei

Question 7

the VPMN is the

Answer 7

portion of the thalamus that receives info from the trigeminal

Question 8

what region does the VPMN reflect?

Answer 8

neck and ophthalmic region

Question 9

• responsible for pain and temp info which is similar to the spinothalamic tracts within the spinal cord
• this tract extends down into the spinal cord
• from here the inf goes to contralateral dorsal thalamus

Answer 9

spinal nuclei V

Question 10

• goes onto VPMN
• topographical info is maintained all the way up
• from here projections carry the info to the ipsilateral sensory cortex (areas 3, 1, 2)

Answer 10

beyond the brain spinal nuclei V

Question 11

• carries proprioception info
• does not have an ascending tract going to the thalamus but feeds directly into the cerebellum
• similar to clarkes column / external cuneate
• ipsilateral and went straight to cerebellum, then crossed to thalamus

Answer 11

mesencephalic V

Question 12

• only one
• located more medially in the brain stem
• monitors gag reflex, vomitting, sneezing
• taste receptors are associated with the visceral sensory system

Answer 12

visceral sensory nucleus

Question 13

• gets input from nerves IX and X
• sensory portion of the parasympathetic NS
• monitors nutrient levels and blood (BP, glucose, HR, O2, and pH)
• area postrema

Answer 13

nuclei solitarius

Question 14

• located at the back/dorsal area of the brainstem
• the area postrema is one of the few areas where the blood/brain barrier breaks downs
• toxins can actually get to the tractus solitarius, which is the inner-most area of the nucleus solitarius

Answer 14

area postrema

Question 15

the idea that specific substances are restricted from moving from the blood into the brain tissue and the fluid that surrounds the brain tissue

• keeps may toxins out, as well as many therapeutic drugs

Answer 15

blood/brain barrier

Question 16

• a fiber bundle that runs inside a cylinder
• this area is almost like a sensory receptor in that it is associated with vomiting, gag reflex, etc because it receives info concerning the toxin levels in the blood

Answer 16

tractus soliarius

Question 17

• receives all the taste info via nerves

VII, IX, X

Answer 17

lateral dorsal portion of the nuclei solitarius

Question 18

• the vagus only carries taste info in kids
• in infants, the vagus innervates the pharynx which also contains taste buds
• these taste buds are lost by the time adulthood is reached

Answer 18

vagus in the lateral dorsal portion of the nuclei solitarius

Question 19

• the uncrossed fibers go to the contralateral thalamus
• no on is really sure, but it is possible that salt, sugar, bitter and sweet each have their own topographical mapping sytem

Answer 19

from the nuclei solitarius to the thalamus