Review of proprio

Question 1

Proprioception
- 4 elements of information provided by muscles and joints

Answer 1

The body’s ability to sense movement, action, and location (closing the eyes and touching nose with index finger)
- direction, speed, amount, force of movement

Question 2

Muscle afferents provide general and specific information about

the information is carried through (2)

Answer 2

muscle length and tension

dorsal root and anterolateral column

Question 3

What is a muscle spindle

what do they respond to

it has both _____ and ____ innervation

Answer 3

a sensory receptor that lies parallel with an extrafusal fiber

stretching of a muscle

afferent and efferent

Question 4

Afferent

Answer 4

sensory neurons that carry information to CNS (brain or spinal cord)

Question 5

Efferent

Answer 5

carry motor information away from CNS (brain or spinal cord)

Question 6

Specialized muscle fibers spindles are composed of

Answer 6

intrafusal

Question 7

The 3 types of intrafusal muscle fibers

Each spindle contains how many intrafusal fibers

Answer 7

nuclear bag 1
nuclear bag 2
nuclear chain

2-12 (at least 2)

Question 8

The central part of each intrafusal fiber is innervated
by a ______

aka

the central portion is composed of what type of tissue

Answer 8

sensory 1a primary ending, that wraps around each and every fiber

annulo- spiral fibers

noncontractile tissue

Question 9

At the junction of the central part and the contractile
area, nuclear bag2 and chain fibers are also
innervated by

Answer 9

type 2 spindle endings

Question 10

The endings of the intrafusal fibers are innervated by

Answer 10

gamma motor neurons

Question 11

The 2 types of sensory endings

Answer 11

Primary (1a)
Secondary (2)

Question 12

Where do secondary (type 2) SENsory endings innervate on the intrafusal fibers

Answer 12

on one or both sides of the primary endings (mainly inn nuclear chain fibers)

Question 13

The motor supply innervates the _____ ends of the intrafusal fibers,
it is what type of neuron?

Answer 13

contractile

gamma motor

Question 14

_ motor neruon innervates extrafusal fibers

Answer 14

Alpha

Question 15

For motor output both ____ and ____ spindle endings make _____ excitatory connections to synergistic muscle

Answer 15

primary, secondary
polysynaptic

Question 15

What is autogenic excitation?

%?

Answer 15

Primary spindle endings make monosynaptic connections to motor neuron cells innervating the same muscle to provide excitation to the muscle

greater than 70%

Question 16

Efferent innervation of a spindle is called the

Answer 16

gamma system

Question 17

Which gamma fibers innervate bag 1,2, and chain fibers?

Answer 17

gamma dynamic fibers innervate bag 1
gamma static fibers innervate bag 2 and chain

Question 18

GTO

where does it lie and where is it located

what is it innervated by

Answer 18

golgi tendon organ

in series with muscle fibers, musculotendinous junction

1b sensory fiber

Question 19

The overall purpose of the gamma system

Answer 19

maintain spindle sensitivity during muscle shortening

Question 20

Functions of the GTO

Answer 20

• signal information about muscle tension
• inhibit muscle through 1b inhibitory interneuron
• excite antagonists through polysynaptic pathways

Question 21

Small muscle receptors are innverated by

Answer 21

type 3 and 4 fibers

Question 21

The GTO is only activated when ….

Answer 21

muscle contracts bc of how elastic it is

Question 22

In order to avoid damage the GTO will …

Answer 22

shut down a muscle

Question 23

Reciprocal inhibition

Answer 23

muscle spindle will activate the agonist while also inhibiting the antagonist

Question 23

Why can’t the GTO measure change in length?

Answer 23

Bc it does not get shorter or longer

Question 23

Stretch relaxation allows …

explain

Answer 23

the body to stretch beyond normal limits under stressed conditions

• during isometric contraction, muscle tension increases (relaxation allows further stretching)
• MTU under constant stress over fixed time decreases the force of viscous material of the tendon and muscle, losing its ability to resist stretch over time
• MTU slowly increases in length

Question 24

Explain autogenic inhibition

Answer 24

GTO senses too much tension that may cause the muscle damage, so it will inhibit the MTU it is in and make it weaker so that the muscle relaxes