Pnb 2264 Practical 2 Expected Questions And Answers 2027

PNB 2264 PRACTICAL 2 EXPECTED QUESTIONS AND ANSWERS 2027

Question 1.
What does a force transducer do?




Correct Answer: Converts mechanical force into an electrical signal that can be
interpreted by software to measure muscle tension


Question 2.
Why do we need calibration?

Correct Answer: Raw output (millivolts) needs to be calibrated to give us the
more meaningful force unit of milli-Newtons (mN), gain precise measurements,
remove tension that is not a result of muscle contraction, zero force transducer


Question 3.
What is a threshold stimulus?

Correct Answer: Voltage at which we first see a twitch response


Question 4.
What is a maximal stimulus?

Correct Answer: The stimulus voltage at which the response amplitude no longer
increases


Question 5.
What is a supramaximal ulus?

Correct Answer: excitation stim- 1.5 times the maximal stimulus; recruitment of
all muscle fibers


Question 6.
What kind of response does a single muscle fiber have?

Correct Answer: All or none

,Question 7.
What kind of response many muscle fibers)

Correct Answer: do muscles (with Graded have?


Question 8.
What is a motor unit?

Correct Answer: One motor neuron and all the muscle fibers it innervates


Question 9.
What causes increased contraction of a muscle?

Correct Answer: Increase in voltage


Question 10.
What is changed to achieve tetanus?

Correct Answer: Frequency of stimulus


Question 11.
Prolonged contraction of a muscle that results from rapidly repeating stimuli; Occurs
because the stimulus frequency is so high that the relaxation stage goes away completely
leading to a sustained contraction

Correct Answer: Tetanus


Question 12.
What has to be changed imal contraction?

Correct Answer: to achieve max- Increased stimulus amplitude


Question 13.
What are the causes of fatigue in muscles?

Correct Answer: Build up of ADP, Pi, Mg2+, H+ (lactic acid); H+ competes with
Ca2+ in binding to troponin; Conduction failure (lack of power stroke)


Question 14.
What is the optimal

,Correct Answer: physiological length? C


Question 15.
What is the range of physiological lengths?




Correct Answer: B, D


Question 16.
Which are outside of physiological range?




Correct Answer: A, E


Question 17.
Relates the strength traction to the length which the contraction

Correct Answer: Length-Tension Relationship of an isometric con-of the muscle
at occurs


Question 18.
In a state of rigor mortis, the muscles are highly contracted and difficult to manipulate.
Why does this phenomenon occur?

Correct Answer: Lack of ATP

, Question 19.
Why does rigor mortis go away?

Correct Answer: Decomposition of tissue (release of enzymes over time)


Question 20.




Correct Answer: Know twitch, summation, tetanus recordings and explanations


Question 21.
Has pyramidal cells




Correct Answer: Cerebral Cortex


Question 22.
Has purkinje fibers




Correct Answer: Cerebellum


Question 23.
What happens to concentration decreases?

Correct Answer: Vrest if the internal Na+ It becomes more positive.