Class 3

Question 1

Muscle cramps commonly involve what part of the body?

Answer 1

Calf, foot, thigh

Question 2

What is observed during and immediately after a muscle cramp?

Answer 2

A hard knot

Question 3

Muscle cramps are characterized by

Answer 3

Sudden onset of painful, involuntary squeezing or contraction of muscle

Question 4

Constant muscle cramps are indication of what?

Answer 4

High frequency stimulation

Question 5

Observation of hard knot after cramp occurs could indicate what?

Answer 5

Deficiency in muscle relaxation, could be cytosolic Ca or ATP concentration

Question 6

• High frequency of stimulation
• Cumulation of cytosolic Ca
• Constant muscle contraction

Answer 6

During muscle cramps

Question 7

• Lack of ATP
• Deficiency of SERCA
• Cytosolic Ca remains high

Answer 7

After muscle cramps

Question 8

Appearance of hard knot in affected muscle could be an indication of (-) depletion

Answer 8

ATP

Question 9

Can speed of relief of muscle cramps by:

Answer 9

• stretching affected muscle
• contraction of its antagonist muscle

Question 10

In muscle cramp, (-) is not getting to the muscle, resulting in no (-) in the muscle to allow it to relax

Answer 10

Oxygen, ATP

Question 11

After muscle cramps, some symptoms are

Answer 11

• soreness
• swelling

Question 12

Elevated serum creatine kinase (CK) indicates

Answer 12

Skeletal muscle damage, or muscle cramps

Question 13

Muscle cramps can cause what kind of damage to muscle?

Answer 13

Hypoxic/metabolic damage

Question 14

Two hypothesis for causation of muscle cramps

Answer 14

1. dehydration and electrolyte depletion
2. neuromuscular

Question 15

Triggering factors of muscle cramps - dehydration and electrolyte depletion

Answer 15

• sweat loss
• pH disturbances
• thermal strain

Question 16

Stretch receptors that can be found in the capsules of the extrafusal muscle fibers are

Answer 16

Muscle Spindles

Question 17

Triggering factors of muscle cramps - neuromuscular hypothesis

Answer 17

• muscle fatigue
• motor neuron disease (like ALS)
• changes in electrolyte concentration or mechanical effects

Question 18

Onset of muscle cramp requires what?

Answer 18

Alpha motor neuron to fire in high frequency

Question 19

Sequence of events for neuromuscular hypothesis

Answer 19

1. triggering factors
2. increase afferent sensory neuron excitability
3. increase alpha motor neuron firing frequency
4. increase frequency of muscle contraction
5. muscle cramp

Question 20

For muscle contraction is it very necessary for (neural or physiological) control?

Answer 20

Neural

Question 21

EMGs are used to look at muscles after muscle cramps and can show

Answer 21

Involuntary repetitive high frequency firings of the motor neuron that innervates the cramping motor unit

Question 22

High frequency firings of the motor neuron can mean what?

Answer 22

Leakage in Ca

Question 23

EMG data suggests muscle twitch are of peripheral nerve origin (T/F)

Answer 23

True

Question 24

Why are muscles in the lower extremities effected more?

Answer 24

Longer axon in lower limb, the longer it is the more damage that can happen

Question 25

Who is more frequently affected with muscle cramps?

Answer 25

- Pregnant women - Elderly people - People with thyroid disease - People with liver disease

Question 26

Why are elderly more effected by muscle cramps?

Answer 26

Effected by mild loss of motor neurons

Question 27

Why are pregnant people more effected by muscle cramps?

Answer 27

Physical distortion of neuromuscular junction as byproduct of fluid retention and joint laxity

Question 28

Why are those with thyroid disease/hypoadrenalism affected with more muscle cramps?

Answer 28

Adrenal gland controls electrolyte balance by sodium uptake, pH effected

Question 29

Why are those with liver disease and cirrhosis effected with muscle cramps?

Answer 29

Could be decrease in intravascular volume and edema

Question 30

Neurophysiology of muscle cramps are related to what?

Answer 30

Somatic motor neuron

Question 31

When are muscle spindles firing?

Answer 31

Constantly, they are tonically active

Question 32

Sensory neuron spans

Answer 32

The length of the muscle

Question 33

Impulses on somatic motor neuron has a (higher, lower) frequency than that of descending tract of the axons within spinal cord

Answer 33

Higher

Question 34

Maintaining tension at rest shows

Answer 34

Muscle tone

Question 35

Impulses from sensory neuron originate from where?

Answer 35

Muscle spindle

Question 36

Impulses from sensory neuron will integrate from (-) at the level of (-)

Answer 36

Brain, spinal cord

Question 37

Stretching of extrafusal muscle will also stretch

Answer 37

Muscle spindles

Question 38

Alpha motor neuron activation process

Answer 38

1. Alpha motor neuron fires 2. Muscle contracts 3. Less stretch on center of intrafusal fibers 4. Firing rate of spindle sensory neuron decreases

Question 39

Stretching helps muscle cramps which is mediated by:

Answer 39

Central Inhibition

Question 40

What induces involuntary repetitive high frequency firings of the motor neuron that innervates the cramping motor unit

Answer 40

Stretching

Question 41

Further increase in frequency of impulses to the stretched muscle through

Answer 41

The alpha motor neuron