Biomechanics: Functional Neuro-Muscular Units

Front 1

Skeletal Muscle is
-surrounded by: _____
-contains: _____

Back 1

Skeletal Muscle is
-surrounded by EPIMYSIUM
-contains: MUSCLE FASCICLES

Front 2

Muscle Fascicle is
-surrounded by: _____
-contains: _____

Back 2

Muscle Fascicle is
-surrounded by: PERIMYSIUM
-contains: MUSCLE FIBERS

Front 3

Muscle Fibers is
-surrounded by: _____
-contains: _____

Back 3

Muscle Fibers is
-surrounded by: ENDOMYSIUM
-contains: MYOFIBRILS

Front 4

Myofibril is
-surrounded by: _____
-contains: _____

Back 4

Myofibril is
-surrounded by: SARCOPLASMIC RETICULUM
-contains: SARCOMERES

Front 5

Sarcomere
-contains: _____

Back 5

Sarcomere
-contains: THICK AND THIN FILAMENTS

Front 6

What are the 5 basic components of a neuromuscular junction?

Back 6

1. motor neuron
2. motor end plate
3. synaptic cleft
4. synaptic vesicles
5. neurotransmitters

Front 7

During muscle relaxation...

-________ breaks down acetylcholine
- motor neuron impulses _____
- calcium moves back into _____ _____
- mysoin and actin binding prevented

Back 7

During muscle relaxation...

-ACETYLCHOLINESTERASE breaks down acetylcholine
- motor neuron impulses STOP
- calcium moves back into SARCOPLASMIC RETICULUM
- mysoin and actin binding prevented

Front 8

Describe what happens during a muscle contraction.

Back 8

Motor nerve impulses cause release of acetylcholine (ACh) from synaptic vesicles which bind to receptors on the motor end plate and generate muscle contraction.

Front 9

What is a motor unit?

Back 9

A single motor neuron and all the muscle fibers it controls.

The functional connection between the nervous system adn the muscular system.

Front 10

TRUE or FALSE

When a motor unit fires, all the muscle fibers contract together.

Back 10

TRUE

its an "all or none" situation

Front 11

TRUE or FALSE

One neuron innervates on muscle fiber.

Back 11

FALSE

One neuron may innervate SEVERAL muscle fibers

Front 12

MATCH gastrocnemius or extraocular with one of the following:

a. Fine control, small motor unit
b. Strength control, large motor unit

Back 12

Extraocular muscles = fine control & small motor unit

Gastrocnemius = strength contol & large motor unit

Front 13

Which of the following is assoicated with moderate frequency stimuli (between 10-20 stimuli/sec)
a. Twitch
b. Treppe
c. Wave summation
d. Incomplete tetanus
e. Tetanus

Back 13

b. Treppe

Front 14

Which of the following is assoicated with low frequency stimuli (up to 10 stimuli/sec)
a. Twitch
b. Treppe
c. Wave summation
d. Incomplete tetanus
e. Tetanus

Back 14

a. Twitch

Front 15

Two of the following are associated with higher frequency stimuli (between 20-40 stimuli/sec)
a. Twitch
b. Treppe
c. Wave summation
d. Incomplete tetanus
e. Tetanus

Back 15

c. Wave summation
d. Incomplete tetanus

Front 16

Name the 3 functional classes of neurons and their functions. Which are Efferent, Association or Afferent?

Back 16

Sensory- Afferent; transmit impulses from receptors to the brain or spinal cord
Motor- Efferent; transmit impulses from brain or spinal cord to effector sites (muscles, glands, organs)
Interneuron- Association; transmit impulses from one neuron to another

Front 17

What are the 4 subtypes of "A" fibers? Are all of them myelinated? Which is the fastest?

Back 17

Aα- Fastest; largest diameter; motor efferents; muscle spindle afferent
Aβ- Touch & pressure efferents (mechanoreceptors)
Aγ- Motor efferents to muscle spindle
Aδ- Skin temp & pain (noxious stimuli)

Front 18

Name the 3 types of nerve fibers. Which are unmyelinated? Which fibers are the smallest in diameter and what do they conduct?

Back 18

A, B, C fibers. B & C fibers are unmyelinated.

C fibers are the smallest. They conduct burning and aching pain sensations. Sympathetic postganglionic.

Front 19

What is the basic fundamental unit of the nervous system and what is its function?

Back 19

Spinal cord reflex arc. It's the automatic response to stimulus without conscious thought.

Front 20

What are the 5 basic components of the reflex arc?

Back 20

1. Sensory receptor- transmits APs stimulated by sensation
2. Sensory neuron- transmits impulses to spinal cord
3. Interneuron- connects/switches impulses to other neurons
4. Motor neuron- transmits motor impulses
5. Effector organ- responds with reflex contraction of muscle/gland

Front 21

Which of the following is assoicated with maximum frequency stimuli (between 40-50 stimuli/sec)
a. Twitch
b. Treppe
c. Wave summation
d. Incomplete tetanus
e. Tetanus

Back 21

e. Tetanus

Front 22

Name the 5 steps of the functional spinal cord reflex.

Back 22

1- Controlled condition
2- Receptor
3- Control center
4- Effectors
5- Return to homeostasis

Front 23

____ is the sense of position and movement of one's own limbs and body without using vision.

Back 23

Proprioception

Front 24

What 3 types of mechanoreceptors detect proprioception?

Back 24

Muscle spindle receptors
Golgi tendon organs
Joint kinesthetic receptors

Front 25

What are the 2 components of the intrafusal fibers of muscle spindle receptors? Which is sensitive to sudden rate of change in muscle length? Which is sensitive to steady change in muscle length?

Back 25

Nuclear bag fibers- sensitive to sudden changes

Nuclear chain fibers- sensitive to steady changes

Front 26

What 2 types of sensory nerve endings wrap about the non-contractile region of a muscle spindle receptor? Of the 2 types, which conducts impulses faster?

Back 26

Primary endings type Ia fiber- annulospiral sensory; conducts impulses faster

Secondary endings type II fiber- flower spray sensory; conducts impulses slower

Front 27

The contractile ends of muscle spindle receptors receive input from ___ ___ neurons to contract.

Back 27

Gamma motor

Front 28

____ activates sensory neurons of the muscle spindle receptor causing them to signal the ____ & ____.

Back 28

Stretching
Spinal cord & brain

Front 29

What are the 2 ways that the CNS responds to muscle stretch?

Back 29

Monosynaptic spinal reflex- rapid adjustment to prevent a fall

Response controlled by cerebellum- regulates muscle tone to resist stretching

Front 30

What type of neurons let the brain preset the sensitivity of muscle spindle receptors to stretch?

Back 30

Gamma motor neurons. When they fire, the INTRAFUSAL muscle contracts so that very little stretch is needed to stimulate the sensory endings.

Front 31

What type of neurons are activated by the CNS to contract EXTRAFUSAL muscle to prevent further stretching?

Back 31

Alpha motor neurons