Test 2

Front 1

Somatic sensation

Back 1

enables our body to feel, to ache, to chill and to know what its parts are doing

Front 2

The somatic sensory system is different from other sensory systems in two ways

Back 2

1. receptors are distributed all over the body
2. Responds to different kinds of stimuli: 4 senses: touch, pain, body position, & temperature

Front 3

Proprioception

Back 3

the sense of body position

Front 4

The two types of skin

Back 4

hairy and glabrous

Front 5

Inner and outer layer of skin

Back 5

dermis and epidermis

Front 6

Skin is important because

Back 6

1. a protective function
2. prevents evaporation of body fluids into dry environment
3. provides direct contact with the world

Front 7

Mechanoreceptors are sensitive to what

Back 7

physical distortions such as stretching or bending

Front 8

Mechanorectors do what

Back 8

monitor contact with skin

Front 9

At the heart of each mechanoreceptor is

Back 9

unmeyelinated axon branches with mechanosensitive ion channels

Front 10

The gating of mechanosensitive ion channels depends on

Back 10

stretching or changes in tension

Front 11

Name some mechanoreceptors

Back 11

1. Pacinian corpuscle
2. Ruffini's ending
3. Merkel's disk
4. Meissners corpuscle

Front 12

Rapidly adapting

Back 12

Tend to respond quickly at first but then stop firing even though the stimlulus continues
ex: Meissner and Pacinian corpuscles

Front 13

Primary afferent axons

Back 13

Axons bringing information from the somatic sensory receptors to the spinal cord or brain stem

Front 14

The primary afferent nerves enter the spinal cord where, and their cell bodies lie where

Back 14

1. dorsal root
2. dorsal root ganglion

Front 15

What group has the most unmeyelinated axons

Back 15

Group C or IV

Front 16

How many spinal segments are there and what are the names of the four groups

Back 16

30, cervical, thoracic, lumbar and sacral

Front 17

Dermatome

Back 17

The area of skin innervated by the right and left dorsal roots of a single spinal segment

Front 18

The organization of the dermatone is best revealed when

Back 18

one bends over to stand on both hands and feet

Front 19

Spinal grey matter is divided into

Back 19

1. dorsal horn
2. intermediate zone
3. ventral horn

Front 20

Second-order sensory neurons

Back 20

The neurons that recieve sensory input from primary afferent neurons

Front 21

Dorsal coloumn-medial leminiscal pathway

Back 21

Pathway serving touch

Front 22

Ipsilateral

Back 22

touch information from the left side of the body is represented in the activity of cells in the left dorsal coloumn nuclei

Front 23

Dorsal coloumn nuclei

Back 23

The axons of the dorsal coloumn terminate here

Front 24

The dorsal coloumns carry information about

Back 24

tactile sensation (limb position) toward the brain

Front 25

Medial lemniscus

Back 25

The axons of the dorsal column nuclei ascend within this white matter tract

Front 26

The route of the axon synapse in the dorsal cloumn-medial lemniscal pathway

Back 26

Large dorsal root axons through dorsal coloumn through dorsal coloumn nuclei in medial lemniscus rises throug the medulla. Its axons synapse upon neurons of VP of the thalamas. Thalamic neurons of the VP nucleus then project to specific regions of the primary somatosensory cortex (S1)

Front 27

Trigeminal nerves (cranial nerve V)

Back 27

Somatic sensation of the face is supplied here

Front 28

Brodmann's area 3b is the primary somatic sensory cortex because

Back 28

1. it recieves dense inputs from the VP nucleus of the thalamus
2. its neurons are very responsive to somatosensory stimuli (but not to other sensory stimuli)
3. lesions here impair somatic sensation
4. electrically stimulated, it evokes sensory experiences

Front 29

Somatotopy

Back 29

The mapping of the body's surface sensations onto a structure in the brain

Front 30

Nociceptors

Back 30

The free, branching, unmeyelinated nerve endings that signal that body tissue is being damaged

Front 31

Nociception

Back 31

The sensory process the provides the signals that trigger pain

Front 32

Substance P

Back 32

A peptide synthesized by the nociceptors themselves

Front 33

Information about touch ascends which way, while information about pain ascends

Back 33

ipsilaterally, contralaterally

Front 34

The rate of a chemical reaction depends on

Back 34

Temperature

Front 35

Thermoreceptors

Back 35

Neurons due to specific membrane mechanisms are exquisitely sensitive to temperature. Contribute to perception of temperature

Front 36

The sensitivity of a sensory neuron to a change in temperature depends on

Back 36

The type of ion channels the neuron expresses