Chaper 9: The Somatic Sensory System

Question 0

What are the critical links to supply the CNS with information about what happens in the periphery in the BODY and the HEAD?

Answer 0

In head: Cranial Nerve Ganglia

In body: Dorsal Root Ganglia

Question 1

Mechanoreceptors are found at the end of WHAT KIND of fiber?

Answer 1

Afferent

Question 2

Name the types of mechanoreceptors from BEST to WORST spacial acuity.

Answer 2

Merkel > Meissner > Ruffini > Pacinian

Question 3

Which to mechanoreceptors are SLOW adapting?

Answer 3

Merkel and Ruffini

Question 4

Which two mechanoreceptors are RAPID adapting?

Answer 4

Meissner and Pacinian

Question 5

Which mechanoreceptor is best at processing form and texture (edges, points, corners, curvature)? (Not be be confused with identifying when an object is moving across the skin)

Answer 5

Merkel Afferents

Question 6

Where are Merkel afferents found?

Answer 6

in epidermal redges

Question 7

Where are Meissner afferents located?

Answer 7

in tips of dermal papillae

Question 8

Which mechanoreceptor is sensitive to internally generated stimuli?

Answer 8

Ruffini

Question 9

Which mechanoreceptor is best suited to detect when an object is moving across the skin?

Answer 9

Meissner Afferents

Question 10

What are free nerve endings good at processing?

Answer 10

The sensation of pain

Question 11

Are free nerve endings LESS or MORE sensitive than mechanoreceptors?

Answer 11

Less

Question 12

A smaller receptive field is associated with a __________ amount of arborization.

Answer 12

smaller

Question 13

RAPID adapting mechanoreceptors are good at sensing stimuli that _____ (change/do not change).

Answer 13

Change

Question 14

________ adapting afferents are best suited for processing spacial attributes (size, shape).

Answer 14

Slowly

Question 15

Describe the structure of a nociceptor.

Answer 15

free nerve ending

Question 16

A nociceptor is best as processing ________.

Answer 16

Pain

Question 17

Somatic sensory afferents constitute ______ pathways. Meaning that…

Answer 17

Parallel; meaning that they work together at the same time and only later will integrate their signals

Question 18

What is a dermatome?

Answer 18

Area innervated by each spinal nerve

Question 19

T/F: Dermatomes do not overlap.

Answer 19

False. They slightly overlap.

Question 20

Overlap in dermatomes is more extensive for what types of sensation?

Answer 20

Touch, pressure, vibration. There is less overlap for pain.

Question 21

Name the nerve ending types from MOST to LEAST superficial.

Answer 21

Free Nerve Endings
Merkel
Meissner
Ruffini
Pacinian

Question 22

Ipsilateral vs. Contralateral

Answer 22

Ipsilateral: same side
Contralateral: different side

Question 23

Of the autonomic division, the _______ branch is more active during stress.

Answer 23

Sympathetic

Question 24

Dorsal roots carry...

Answer 24

sensory afferents

Question 25

Ventral roots carry...

Answer 25

motor efferents.

Question 26

If the VENTRAL ROOT is cut, what function is affected?

Answer 26

Ability to control muscles

Question 27

The Diencephalon contains what?

Answer 27

Thalamus and Hypothalamus

Question 28

The Brainstem contains....

Answer 28

Midbrain, pons, medulla

Question 29

The forebrain contains...

Answer 29

Diencephalon and Cerebral Hemisphere

Question 30

"Nerves" in ______: "Tracts" in ______

Answer 30

Nerves in PNS; Tracts in CNS

Question 31

The subcortical ganglia contains...

Answer 31

basal ganglia | amigdala

Question 32

The cerebral cortex is ______ (gray/white) matter.

Answer 32

gray

Question 33

What number Broadman's area is the primary motor cortex?

Answer 33

4

Question 34

The basal ganglia mediates....

Answer 34

unconscious decisions regarding movement

Question 35

The _____ is the highest level of sensory integration in most organisms.

Answer 35

midbrain

Question 36

Function of the TECTUM

Answer 36

attention to visual and auditory stimuli

Question 37

Thalamus is relay station for all sensory inputs except THIS.

Answer 37

smell

Question 38

What structure contains the superior and inferior colliculus?

Answer 38

Tectum

Question 39

The superior colliculus collects inputs from the ______; Inferior collects from ____.

Answer 39

eye; ear

Question 40

Which brain part mediates reflex control of posture?

Answer 40

Pontine Nuclei

Question 41

Visceral receptors are found in...

Answer 41

blood vessels, heart, lungs, GI tract, bladder

Question 42

What two mechanoreceptors are very superficial in the skin?

Answer 42

Meissner and Merkel

Question 43

What mechanoreceptors are deepest in skin?

Answer 43

Pacinian and Ruffini

Question 45

What mechanoreceptors respond best to SUSTAINED stimulus

Answer 45

Merkel and Ruffini

Question 46

Define: Commisure

Answer 46

Tract that crosses midline of brain

Question 47

Sagittal Section: Axial Section: Coronal Section:

Answer 47

Sagittal Section: Across brain horizontally Axial Section: vertically, front to back Coronal Section: Vertically, side to side

Question 48

Efferent fibers go from _____ to _____

Answer 48

CNS to muscles

Question 49

Afferent fibers go from _____ to ______.

Answer 49

Muscle to CNS

Question 85

If you increase the intensity of a stimulus you _____ the rate of AP discharge.

Answer 85

increase