Muscles 1

Question 1

Within a specific group of muscles, the muscle that is mostly responsible for the action produced is the

Answer 1

prime mover.

Question 2

The most important factor in decreasing the intracellular concentration of calcium ion after contraction is:

active transport of calcium into the sarcoplasmic reticulum.
active transport of calcium into the synaptic cleft.
ative transport of calcium across the sarcolemma.

Answer 2

active transport of calcium into the sarcoplasmic reticulum.

Question 3

Holding your head upright is an example of \_\_\_\_\_\_\_\_\_\_ contraction.
isotonic 
isometric 
eccentric 
treppe 
concentric

Answer 3

isometric

Question 4

Identify the insertion for the Sternocleidomastoid muscle.

Answer 4

Temporal bone

Question 5

The number of muscle fibers controlled by a single motor neuron:

is greater in muscles where precise control is needed.
is less in postural muscles.
is less in muscles where precise control is needed.
is greater in muscles moving the fingers.

Answer 5

is less in muscles where precise control is needed.

Question 6

Whenever a muscle fiber is stimulated by a threshold stimulus, it

Answer 6

contracts completely.

Question 7

Which type of muscle has striations, a single nucleus, intercalated discs, sarcomeres, transverse tubules and gap junctions between the fibers?

Answer 7

Cardiac muscle

Question 8

You would find dense bodies on which of the following?

Answer 8

Mulit-unit smooth muscle fiber

Question 9

Identify the origin for the orbicularis oris

Answer 9

Mandible Maxillae

Question 10

The muscle that adducts and elevates the scapula, and also extends the head is the

Answer 10

trapezius.

Question 11

The doctor believes that Joe may have skeletal muscle damage. He does a urine test and confirms this diagnosis. What did he find in the urine?

Answer 11

Creatine phosphate

Question 12

Skeletal muscle fibers are formed from embryonic cells called

Answer 12

myoblasts

Question 13

Skeletal muscle fibers are multinucleated because

Answer 13

all fibers formed from fusion of many smaller cells during embryonic development.

Question 14

Energy for muscle contraction comes directly from high-energy bonds of

Answer 14

ATP.

Question 15

During prolonged muscle contraction, after the initial store of ATP are used up, what energy source will the muscle cell use next?

Answer 15

Creatine phosphate

Question 16

The protein that helps reinforce the sarcolemma and transmit tension generated by the sarcomeres to the tendons is

Answer 16

dystrophin

Question 17

Skeletal muscles are attached to muscles, skin or bands of connective tissue (not bone) by

Answer 17

aponeuroses.

Question 18

Thin filaments at either end of the sarcomere are attached to the

Answer 18

Z line.

Question 19

After death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. This results in a condition known as

Answer 19

rigor mortis.

Question 20

What is the origin (bone) for the teres minor muscle?

Answer 20

scapula

Question 21

The smallest stimulus capable of causing a contraction is a/an

Answer 21

threshold stimulus.

Question 22

Active sites on the actin become available for binding when
calcium binds to tropomyosin.
myosin binds to troponin. 
troponin binds to tropomyosin. 
actin binds to troponin.
calcium binds to troponin.

Answer 22

calcium binds to troponin.

Question 23

The sliding filament mechanism of muscle contraction involves
myosin filaments sliding along collagen fibers.
collagen fibers sliding along actin filaments
elastin fibers sliding along myosin filaments.
actin filaments sliding along myosin filaments.

Answer 23

actin filaments sliding along myosin filaments.

Question 24

When energy reserves in a muscle are exhausted and lactic acid levels increase, \_\_\_\_\_\_ occurs:
fatigue
atrophy 
treppe 
tetanus

Answer 24

fatigue

Question 25

A disorder caused by a bacterial neurotoxin that prevents release of acetylcholine from synaptic end bulbs, possibly causing paralysis of breathing muscles, is known as

Answer 25

botulism.

Question 26

The muscle that plantar flexes the foot and flexes the leg is the

Answer 26

gastrocnemius

Question 27

The movable attachment of a muscle is the

Answer 27

insertion.