1st semester: Muscle Physiology

Question 1

TRUE about the A band

Answer 1

the lateral edges are formed by ends of thick filament

Question 2

the physiological property unique to muscle cells is due to the presence of

Answer 2

organized myofilaments

Question 3

when acetylcholine acts on the end-plate, it will initially affect activity of the

Answer 3

voltage gates CALCIUM channels

Question 4

what happens when ATP binds to the myosin head?

Answer 4

there is cross bridge formation

Question 5

TRUE about the spatial and temporal summation

Answer 5

results to an increase in force of contraction

Question 6

an applicant in athletics practiced for 4 hours when he complained of inability to continue further and cannot continue the mechanical event. What case is this most likely?

Answer 6

Fatigue due to high levels of lactic acid in the sarcoplasm

Question 7

Maximum tension is generated by an activated muscle if the sarcomere length is _____

Answer 7

Ideal (resting) length

Question 8

Reconstitution of energy stores after contraction (exercise) results to body heat production known as _____

Answer 8

Recovery heat

Question 9

When a skeletal muscle attains maximum work and it was given

Answer 9

decrease work performed

Question 10

This characteristic is associated with cardiac and skeletal muscles but NOT in smooth muscle

Answer 10

Their contraction is thin filament regulated

Question 11

Primary function of sarcalumenin in muscles

Answer 11

transport Ca++ from the uptake site to the release site

Question 12

When the skeletal muscles contract and was able to carry a lighter load to a greater distance, it is performing

Answer 12

Isotonic concentric contraction

Question 13

The absolute refractory period of the muscle twitch is during the

Answer 13

LATENT period

Question 14

SERCA 2 are used by this type of muscle fiber

Answer 14

type 1

Question 15

TRUE regrading the sarcotubular system of skeletal muscles

Answer 15

contains the receptors acting as Ca++ channels

Question 16

A series of sarcomeres form the ____.

Answer 16

myofibril

Question 17

Which activity is happening during the latent period of the muscle twitch?

Answer 17

Inhibition of ligand gated ion channels in the end plate

Question 18

TRUE of regarding activity of skeletal muscle

Answer 18

Heat production in a muscle is observed even if it is resting

Question 19

The ff. physiological events immediately precedes the generation of AP during excitation-contraction coupling in skeletal muscle?

Answer 19

generation of END PLATE POTENTIAL

Question 20

Immediately after the release of phosphate from the myosin head, the muscle fiber in ____

Answer 20

power stroke state

Question 21

Which activity is happening during the relaxation period of the muscle twitch?

Answer 21

UTILIZATION of ATP

Question 22

Location of the transverse tubules in skeletal muscle responsible for formation of “triad” is

Answer 22

A-I junction

Question 23

a 21 year old medical student is an avid body builder who lifts weights approximately 2-3 hours per day. Which of the following BEST describes the latent phase of his muscle twitch during work out?

Answer 23

Requires the mechanical activation of calcium channels attached on the cisterns

Question 24

Urinary smooth muscle communicate _____

Answer 24

electrically

Question 25

The normal position of the troponin-tropomyosin complex on the actin filament covering the myosin binding site is MOSTLY due to the effect of _______

Answer 25

Troponin I

Question 26

Exposing skeletal muscles to supramaximal stimulus intensity could lead to a response _______

Answer 26

equal to its response to a maximal intensity