psychobiology exam 4: kinesthesis and vestibular system

in joints

where are receptors that give conscious sensations of limb and jaw position located?

Pacinian corpuscles

what are the type of receptors in the joints?

the angle between adjacent bones changes

what happens any time one moves an arm, leg, or their jaw?

in joints

where does the angle change between adjacent bones occur?

activates different receptors for kinesthesis

what does each angle change between adjacent bones do in the nervous system?

within inner ear

where is the vestibular apparatus located?

3 semicircular canals, utricle, saccule

what does the vestibular apparatus consist of?

vestibular apparatus

the semicircular canals, utricle, and saccule make up which structure?

utricle

saclike structure connected to semicircular canals

saclike structure that semicircular canals connect to

what is the utricle?

saccule

large saclike structure connected to the utricle

large saclike structure that the utricle is connected to

what is the saccule?

in 3 different planes at right angles to each other

how are the semicircular canals situated?

endolymph

what is the fluid that composes the semicircular canals?

filled with endolymph and enlarged at base where it connects to the utricle

what is the structure of the semicircular canals?

ampulla

enlarged portion of semicircular canals with receptor hair cells

enlarged portion of semicircular canals that contains the hair cells

what is the ampulla?

specialized epithelial cell-neuron combinations

what type of receptors are hair cells?

cupula

jellylike mass covering the hair cells

jellylike mass covering the hair cells in the ampula

what is the cupula?

in the semicircular canals (enlarged portion)

where are the cupula and ampula located?

rotation of the head

what are semicircular canals sensitive to?

fluid in semicircular canals continuous with fluid in the utricle and saccule

what is true about the fluid in the vestibular system?

receptor hair cells

what is contained in the utricle and saccule?

in the ampula of semicircular canals and in utricle and saccule

where in the vestibular system are receptor hair cells found?

gelatinous substance with otoliths

what are the hair cells in the utricle and saccule covered by?

otoliths

calcium carbonate particles covering hair cells in the utricle and saccule

calcium carbonate particles found in gelatinous substance covering hair cells in the utricle and saccule

what are otoliths?

receptor hair cells and gelatinous covering with otoliths

what is the macula?

macula

receptor cells and gelatinous covering with otoliths

utricle and saccule

where is the macula located?

up and down head movement, tilt of head, linear acceleration

what are receptor cells in the utricle and saccule sensitive to?

vestibular component of cranial nerve viii

what are the fibers that leave the vestibular apparatus traveling in?

vestibular nuclei in medulla

immediate destination of vestibular system fibers

oculomotor centers, cerebellum, spinal cord, reticular formation, vomiting center

what are the possible destinations for fibers once they leave the vestibular nuclei?

brainstem

where are the oculomotor centers located?

mediate reflexes such as movement of eyes to the left when the head rotates to the right

function of oculomotor centers

oculomotor centers

found in brainstem, mediate reflexes such as movement of eyes to the left when the head rotates to the right

III, IV, VI

which cranial nerves are associated with the oculomotor centers?

medulla

where is the vomiting center located?

vestibulospinal tract

what tract in the spinal cord is associated with vestibular fibers?

head movement causes disorientation, distress, nausea, frequent vomiting

what occurs with unilateral damage to vestibular apparatus?

unilateral damage

what type of damage is it when head movement causes disorientation, distress, nausea, frequent vomiting?

they disappear in a short time showing the CNS has adapted to the new situation of vestibular input only on one side

what is true about the symptoms caused by unilateral damage to the vestibular system? what does this indicate?

person shows loss in ability to stand upright with the eyes closed

what are the symptoms of bilateral damage to the vestibular system?

bilateral damage

what type of damage is it when person shows loss in ability to stand upright with the eyes closed?

no

do symptoms like nausea and distress occur when the vestibular system has bilateral damage?

motion sickness

there is evidence linking the vestibular system with what?

conflicting signals from visual system and vestibular system

why is the vestibular system associated with motion sickness?

Henry Head

proposed epicritic and protopathic sensitivity

epicritic and protopathic sensitivity

what did Henry Head propose?

kinesthesis, pressure, specific light touch

what is epicritic sensitivity?

epicritic sensitivity

kinesthesis, pressure, and specific light touch

protopathic sensitivity

pain, temperature, and diffuse light touch

pain, temperature, diffuse light touch

what is protopathic sensitivity?

start at pacinian corpuscles, go through dorsal root of spinal cord through gracilis and cuneate tracts to gracilis and cuneate nuclei, go through medial lemniscus tract to PVN in thalamus and then to areas 3-1-2

what is the pathway of fibers for kinesthesis?

start at pacinian corpuscles, ruffini endings, meissner's corpuscles; travel through dorsal root of spinal cord and cross to the other side, travel through ventral spinothalamic tract to PVN and then to areas 3-1-2

what is the pathway of fibers for pressure and specific light touch?

gracilis and cuneate tracts, medial lemniscus tract

tract associated with kinesthesis pathway

ventral spinothalamic tract

tract associated with pressure and specific light touch pathway

start at free nerve endings, tactile disks, and basket endings and synapse in dorsal horn with lateral spinothalamic tract, project upwards to PVN and to areas 3-1-2

what is the pathway for receptors that subserve pain, temperature, and diffuse light touch?

free nerve endings, tactile disks, basket endings

where does the pathway for pain, temp, and diffuse light touch originate?

pacinian corpuscles

where does the pathway for kinesthesis originate?

pacinian corpuscles, meissner's corpuscles, ruffini endings

where does the pathway for specific light touch and pressure originate?

pain, temp, diffuse light touch; starts in dorsal horn and ends in the PVN

what pathway is the lateral spinothalamic tract used for and where does it start and terminate?

pressure and specific light touch; starts at dorsal horn and ends in PVN

what pathway is the ventral spinothalamic tract used for and where does it terminate?

kinesthesis; starts at dorsal horn and goes to gracilis and cuneate nuclei in medulla

what pathway is the gracilis and cuneate tracts associated with and where do they start and end?

kinesthesis; starts in gracilis and cuneate nuclei and ends at PVN

what pathway is the medial lemniscus tract associated with and where does it start and end?

they all end in the PVN and project to areas 3-1-2

how are the three pathways from the trunk and limbs similar?

directly over cranial nerves, especially nerve V

how do somesthetic and kinesthetic impulses from the face and head enter the brain?

trigeminal (V)

nerve associated with impulses from face and head

divides into 3 main roots that go to corresponding nuclei in the brain

upon approaching the brain, what does the trigeminal nerve do?

face and head pathway; starts at 3 nuclei in brain and ends at arcuate nucleus of PVN

what pathway is the bulbothalamic tract associated with and where does it start and end?

bulbothalamic tract

tract associated with face and head pathway

spinal, sensory, mesencephalic

what are the 3 nuclei in the brain that the trigeminal nerve goes to?

spinal nucleus

nucleus subserving temp, pain, diffuse light touch from face and head

temp, pain, diffuse light touch from face and head

what does the spinal nucleus subserve?

medulla

spinal nucleus location

pons

sensory nucleus location

pressure, specific light touch from face and head

what does the sensory nucleus subserve?

sensory nucleus

subserves pressure, specific light touch from face and head

mesencephalic nucleus

subserves kinesthesis from face and head

kinesthesis from face and head

what does the mesencephalic nucleus subserve?

midbrain

mesencephalic nucleus location

starts at trigeminal nerve and branches into 3 roots that go to spinal, sensory, and mesencephalic nuclei, travel up bulbothalamic tract and to arcuate nucleus then to area 3-1-2

pathway of face and head somesthesis/kinesthesis

ascend to higher areas with the bulbothalamic tract

following synapses with nuclei, what happens to trigeminal impulses?

arcuate nucleus of PVN

where does the bulbothalamic tract terminate?

areas 3-1-2

from the arcuate nucleus, where do impulses from the face and head go?

no segregation according to function

what is true about all pathways once they reach the thalamus?

no

is there segregation according to function in the thalamus?

topographical

organization of the PVN

kinesthetic and somesthetic senses of legs, arms, and face

what do the three parts of the PVN represent?

face is in the arcuate nucleus of the PVN, arms and legs are in the general PVN

how do the pathways for arms and legs vs face and head differ in their points of termination?

face (arcuate nucleus)

which part of the body receives the most space in the PVN?

areas 3-1-2 (parietal lobe)

where does the PVN project to?

topographic

what is the organization of area 3-1-2?

it does not correspond with size but rather corresponds with importance

what is true about the space in the cortex given to different areas of the body?

importance of area

what does space in the cortex given to different body areas correspond with?

no

does space in the cortex given to different areas correspond with size of body area?

face

which area is given the most space in the cortex?