somatosensory system

Question 1

sensitivity to stimuli interacting with ones body (touch temp pain)

Answer 1

exteroception

Question 2

ability to sense position, location and orientation

Answer 2

proprioception

Question 3

stimuli originating from inside body

Answer 3

interoception

Question 4

information from ___ is carried by dorsal root ganglia and spinal cord

Answer 4

trunk

Question 5

information from ___ is carried by cranial nerves

Answer 5

face and head

Question 6

dorsal root ganglia contain __ ___ __ that innervate skin, muscles, joints and organs

Answer 6

neuronal cell bodies

Question 7

___ ___ of nerve fibers (DRG) involved in touch are encapsulated by special end organs

Answer 7

peripheral process

Question 8

DRG neurons are

Answer 8

pseudounipolar

Question 9

information carried by DRG enters in ___ spinal cord in each of the regions

Answer 9

dorsal

Question 10

receptor type and fiber which carries proprioception

Answer 10

muscle spindle, and Ia, II (large and well myelinated); fast

Question 11

receptor type and fiber which carries touch

Answer 11

merkel, meissner and ruffini cells (end organs), A beta (well myelinated not as big)

Question 12

receptor type and fiber which carries pain and temperature

Answer 12

free nerve endings, A delta

Question 13

receptor type and fiber which carries pain, temp, itch

Answer 13

free nerve endings, C fibers (smallest and unmyelinated)

Question 14

cell that responds to mechanical stimulus

Answer 14

mechanoreceptors

Question 15

the nerve endings of mechanoreceptors respond to stimulus by

Answer 15

stretching (as plasma membrane stretches it opens Na channels –> depolarization)

Question 16

depolarizing potenial that accomponies stimulation of a sensory nerve (varies according to strength of stimulus)

Answer 16

receptor potential

Question 17

part of a sensory field that can elicit neuronal responses when stimulated (each neuron has one but size and freq. can be different)

Answer 17

receptive field

Question 18

decline of electrical response in a receptor cell over time, even thouhg stimulus id still present

Answer 18

adaptation

Question 19

in the glaborous skin receptors (very sensitive skin) have

Answer 19

free nerve endings (no end organs)

Question 20

small receptive fields near surface of skin that tracks motion; rapidly adapting

Answer 20

meissner corpuscle

Question 21

small receptive fields near surface of skin that tracks shape and texture; slowly adapting

Answer 21

merkel cell

Question 22

large receptive fields deeper in skin that tracks skin stretch; slowly adapting

Answer 22

ruffini corpuscle

Question 23

large receptive fields deeper in skin that tracks skin vibration; rapidly adapting

Answer 23

pacinian corpuscle

Question 24

the layers of the pacinian corpuscle get depressed and after a certain point stop ____

Answer 24

responding

Question 25

superficial receptors

Answer 25

merkels and meissners

Question 26

deep receptors; distributed more evenly throughout hand

Answer 26

ruffini and pacinian

Question 27

type of hair follicle: longest, nerve fibers form touch domes and circumferential nerve endings

Answer 27

guard

Question 28

type of hair follicle: longitudinal lanceolate endings

Answer 28

awl

Question 29

type of hair follicle: circumferential and longitudinal endings

Answer 29

zigzag

Question 30

innervation arising from one DRG and its spinal nerve

Answer 30

dermatome

Question 31

2 types of muscle fibers

Answer 31

extrafusal and intrafusal

Question 32

muscle fibers that contract and do the work

Answer 32

extrafusal

Question 33

muscle fibers that detect stretch and dont contract

Answer 33

intrafusal

Question 34

each ____ muscle fiber is innervated

Answer 34

intrafusal

Question 35

____ ___ ___ signal changes in muscle lenght by muscle tension and correlation with muscle spindle

Answer 35

golgi tendon organ

Question 36

the golgi tendon organ activates when __ ___ contract

Answer 36

extrafusal fibers

Question 37

the __ neurons innervate golgi tendon and synspase on interneurons

Answer 37

Ib

Question 38

_____ fibers enter into dorsal spinal cord

Answer 38

mechanosensitive

Question 39

one branch of dorsal column synapses onto motor neuron and interneurons; other branch travels in the dorsal columns to ____

Answer 39

medulla

Question 39

the dorsal column pathway decussates and then synapses at the ____

Answer 39

medulla

Question 40

the dorsal column pathway finally hits the thalamus VPL then to

Answer 40

primary somatosensory cortex

Question 41

major cranial nerves involved in ____ and pain is the ___ nerve

Answer 41

mechanoreception; trigeminal

Question 42

the cranial nerves make synapses at ____ of the trigeminal complexes

Answer 42

nucleus

Question 43

after it synapses it goes to the ___ of the thalamus and primary somatosensory

Answer 43

VPM

Question 44

representation of body and face

Answer 44

somatopic

Question 45

sensory cortices and thalamus are organized into ____ in the mammalian brain

Answer 45

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