lecture 5

Question 1

exteroception

Answer 1

vision, hearing, smell, touch

Question 2

interoception

Answer 2

internal objects, organs

Question 3

proprioception

Answer 3

position of body parts

Question 4

proprioceptor neuron

Answer 4

the body of a sensory neuron is located in a ganglion hear the spinal cord. One branch of its T-shaped axon goes to the peripheral sensory ending, and another branch goes through the dorsal roots into the spinal cord.

Question 5

Body of proprioceptor neuron

Answer 5

long T-shaped axon, and sensory ending.

body is in spinal ganglia

Question 6

sensory endings of proprioceptor neuron

Answer 6

sensory endings generate APs in response to a specific stimulus (deformation, light, etc.)

Question 7

conduction in proprioceptor neuron

Answer 7

primarily antidromic (toward the cord or body). Does not do orthodomic conduction.

Question 8

dendrite and synapses in proprioceptor neuron

Answer 8

No dendrites, no synapses on the body

Question 9

muscle spindle orientation

Answer 9

muscle spindle is oriented parallel to extrafusal muscle fibers.

Question 10

Two types of sensory endings can be found in muscle spindles: _______ and _______.

Answer 10

primary (Ia)

secondary (II)

Question 11

Primary endings are typically seen in virtually ___ intrafusal fibers.

Answer 11

All

Question 12

Secondary endings not seen in ______.

Answer 12

dynamic bag fibers

Question 13

Muscle spindles contain three components. They are:

Answer 13

1. intrafusal fibers
2. afferent sensory fiber endings
3. efferent motor fiber endings

Question 14

Gamma motor neurons in muscle spindles

Answer 14

smaller than alpha motor neurons, innervate the contractile polar region of the intrafusal fibers. When a gamma motor neurons activates an intrafusal fiber, it will contract, thus increasing its sensitivity to stretch.

Question 15

dynamic bag fibers

Answer 15

innervated by a single primary (Ia) sensory ending. Also innervated by a dynamic gamma motor neuron.

Question 16

static bag fibers

Answer 16

innervated by a single primary (Ia) sensory ending and a secondary (II) ending. also innervated by a static gamma motor neuron.

Question 17

chain fibers

Answer 17

innervated by a single primary (Ia) sensory ending and a secondary (II) ending. also innervated by a static gamma motor neuron.

Question 18

typical response of primary spindle ending to an externally imposed muscle stretch at different velocities

Answer 18

the response increases with muscle length and with the velocity of the stretch.

Question 19

A typical response of a secondary spindle ending to an externally imposed muscle stretch and shortening

Answer 19

The response increases with muscle length and does not depend on velocity

Question 20

there are two types of small motoneurons innervating intrafusal fibers of muscle spindles. They are:

Answer 20

dynamic motoneurons

static motoneurons

Question 21

dynamic motoneurons innervate

Answer 21

dynamic bag fibers and change the sensitivity of primary endings

Question 22

static motoneurons innervate

Answer 22

static bag and chain fibers. They change the sensitvity of primary and secondary endings

Question 23

Golgi tendon organs are located:

Answer 23

in the junction between muscle fibers and the tendon, and are considered to be in series with a group of muscle fibers

Question 24

Golgi tendon organs are not innervated by ____.

Answer 24

gamma motor neurons

Question 25

Golgi tendon organs are not sensitive to changes in ___________.

Answer 25

muscle length, only tension

Question 26

Golgi tendon organs are sensitive to changes in ____________, such as when a muscle contracts

Answer 26

tension

Question 27

golgi tendon organ is a slender, encapsulated structure innervated by a single _______.

Answer 27

Afferent (Ib) sensory neuron

Question 28

golgi tendon organ response to muscle force

Answer 28

a response of the golgi tendon organ to muscle force. note that it is similar to the response of secondary endings to muscle length

Question 29

how do articular receptors fire?

Answer 29

most articular receptors fire in rather narrow ranges of joint angle, mostly close to the anatomical limits.

an increase in muscle force leads to an increase in joint capsule tension, and articular receptors increase their response (bold lines)

Question 30

golgi tendon organ

Answer 30

a passive sensory ending sensitive only to tendon force

Question 31

articular receptors are sensitive to

Answer 31

joint angle close to the anatomical limits of joint rotation

to joint capsule tension

Question 32

Merkel disks measures

Answer 32

vertical pressure

Question 33

merkel disk features:

Answer 33

several are innervated by one axon

Question 34

meissner copuscles measures

Answer 34

quickly changing pressure

Question 35

meissner features:

Answer 35

each is innervated by 2 or more axons

Question 36

ruffini endings measures

Answer 36

deformation of large skin areas

Question 37

ruffini endings features:

Answer 37

slowly adapting

Question 38

pacinian corpuscles measure

Answer 38

rapidly changing mechanical deformation (such as vibration)

Question 39

pacinian corpuscles features:

Answer 39

huge (1-5 mm)

Question 40

Afferent nerves from peripheral receptors go into the spinal cord through the _______.

Answer 40

dorsal roots

Question 41

Proprioceptors induce changes in muscle activity that bypass ________.

Answer 41

consciousness

Question 42

Proprioceptors tell us ____________ are and how heavy or light, or rough or soft the objects we handle are

Answer 42

where are arms and legs

Question 43

Proprioceptors help create an _____________ system the brain uses to plan and execute movements

Answer 43

internal reference