Question 1

When a skeletal muscle generates enough force during contraction to shorten,

Accepted Answer

A)  only the sarcomere will shorten. 
B)  only the A band will shorten. 
C)  only the I band will shorten. 
D)  the sarcomere and the I band will shorten. 
E)  the sarcomere, the A band, and the I band will shorten. 
A)  only the sarcomere will shorten. 
B)  only the A band will shorten. 
C)  only the I band will shorten. 
D)  the sarcomere and the I band will shorten. 
E)  the sarcomere, the A band, and the I band will shorten. D

Question 2

The origin is the end of the skeletal muscle that attaches to the

Accepted Answer

A)  more stationary bone. 
B)  more mobile bone. 
C)  tendon. 
D)  ligament. 
A)  more stationary bone. 
B)  more mobile bone. 
C)  tendon. 
D)  ligament. A

Question 3

Most of the time, the parallel thick and thin filaments of the myofibrils are connected by ________ that span the space between myosin and actin molecules.

Accepted Answer

A)  tropomyosin molecules 
B)  crossbridges 
C)  nebulin molecules 
D)  sarcomeres 
E)  calcium ions 
A)  tropomyosin molecules 
B)  crossbridges 
C)  nebulin molecules 
D)  sarcomeres 
E)  calcium ions B

Question 4

Match the structures with the accurate description.
-the muscle cell membrane

Accepted Answer

A) muscle fiber 
B) fascicle 
C) sarcolemma 
D) myofibril 
E) t-tubules 
A) muscle fiber 
B) fascicle 
C) sarcolemma 
D) myofibril 
E) t-tubules

Question 5

Within a single fiber, the tension developed during a twitch depends upon the

Accepted Answer

A)  amplitude of the action potential. 
B)  length of the sarcomeres prior to contraction. 
C)  length of the thick filament. 
D)  duration of the stimulus. 
A)  amplitude of the action potential. 
B)  length of the sarcomeres prior to contraction. 
C)  length of the thick filament. 
D)  duration of the stimulus.

Question 6

The T-tubular membrane contains ________ receptors that are ________ and therefore respond to action potentials.This receptor is mechanically linked to ________ receptors in the adjacent sarcoplasmic reticulum.

Accepted Answer

dihydropyridine (DHP) or L-typ

Question 7

Each myosin head has a binding site for

Accepted Answer

A)  calcium only. 
B)  actin only. 
C)  ATP only. 
D)  calcium and ATP. 
E)  actin and ATP. 
A)  calcium only. 
B)  actin only. 
C)  ATP only. 
D)  calcium and ATP. 
E)  actin and ATP.

Question 8

The brief period of time between the beginning of the action potential in the muscle and the beginning of contraction is referred to as the

Accepted Answer

A)  refractory period. 
B)  latent period. 
C)  relaxation phase. 
D)  depolarization period. 
E)  repolarization period. 
A)  refractory period. 
B)  latent period. 
C)  relaxation phase. 
D)  depolarization period. 
E)  repolarization period.

Question 9

In order for high force crossbridges to form in contracting skeletal muscle, calcium must

Accepted Answer

A)  bind to calmodulin to phosphorylate the myosin. 
B)  phosphorylate the tropomyosin which moves it. 
C)  phosphorylate the troponin to move the tropomyosin. 
D)  bind to tropomyosin which moves the troponin. 
E)  bind to troponin which moves the tropomyosin. 
A)  bind to calmodulin to phosphorylate the myosin. 
B)  phosphorylate the tropomyosin which moves it. 
C)  phosphorylate the troponin to move the tropomyosin. 
D)  bind to tropomyosin which moves the troponin. 
E)  bind to troponin which moves the tropomyosin.

Question 10

In the lever system that characterizes the interaction between bones and muscle, the bones act as the ________ whereas the joints form the ________.

Accepted Answer

A)  lever, fulcrums 
B)  fulcrum, levers 
C)  lever, pulleys 
D)  fulcrum, pulleys 
A)  lever, fulcrums 
B)  fulcrum, levers 
C)  lever, pulleys 
D)  fulcrum, pulleys

Question 11

The relaxation of skeletal muscle relies on the activity of the ________, which decreases cytoplasmic calcium concentration.

Accepted Answer

A)  ryanodine receptor 
B)  dihydropyridine (DHP) receptor (L-type calcium channel) 
C)  acetylcholine receptor 
D)  Ca²⁺ ATPase 
A)  ryanodine receptor 
B)  dihydropyridine (DHP) receptor (L-type calcium channel) 
C)  acetylcholine receptor 
D)  Ca²⁺ ATPase

Question 12

The action potential traveling along the t-tubule is detected by the

Accepted Answer

A)  ryanodine receptor. 
B)  dihydropyridine (DHP) receptor (L-type calcium channel). 
C)  acetylcholine receptor. 
D)  Ca²⁺ ATPase. 
A)  ryanodine receptor. 
B)  dihydropyridine (DHP) receptor (L-type calcium channel). 
C)  acetylcholine receptor. 
D)  Ca²⁺ ATPase.

Question 13

________ and ________ are striated muscles.Why are these muscles classified as striated muscles?

Accepted Answer

Skeletal, cardiac mu

Question 14

The I band contains

Accepted Answer

A)  thick filaments only. 
B)  thin filaments only. 
C)  myosin only. 
D)  thick and thin filaments. 
A)  thick filaments only. 
B)  thin filaments only. 
C)  myosin only. 
D)  thick and thin filaments.

Question 15

Before the entire muscle can change length, the force generated by the muscle must stretch the

Accepted Answer

A)  eccentric contractile elements. 
B)  parallel elastic elements. 
C)  series elastic elements. 
D)  contractile elements. 
A)  eccentric contractile elements. 
B)  parallel elastic elements. 
C)  series elastic elements. 
D)  contractile elements.

Question 16

The interaction between Ca²⁺ and calmodulin in smooth muscle cells has been described as a second messenger system.Develop an argument to support this position, using another second messenger system you have studied for comparison.

Accepted Answer

Ca²⁺ forms a complex with calmodulin.Thi

Question 17

The factor(s)that determine the duration of a twitch in various types of fibers is the speed of the

Accepted Answer

A)  removal of Ca²⁺ ions from the sarcoplasm only. 
B)  hydrolysis of ATP only. 
C)  movement of Na⁺ across their membranes only. 
D)  removal of Ca²⁺ ions from the sarcoplasm and hydrolysis of ATP. 
E)  removal of Ca²⁺ ions from the sarcoplasm and hydrolysis of ATP and movement of Na⁺ across their membranes. 
A)  removal of Ca²⁺ ions from the sarcoplasm only. 
B)  hydrolysis of ATP only. 
C)  movement of Na⁺ across their membranes only. 
D)  removal of Ca²⁺ ions from the sarcoplasm and hydrolysis of ATP. 
E)  removal of Ca²⁺ ions from the sarcoplasm and hydrolysis of ATP and movement of Na⁺ across their membranes.

Question 18

The contraction cycle is triggered by the rise in ________ released from the sarcoplasmic reticulum (SR).

Accepted Answer

A)  Na⁺ 
B)  K⁺ 
C)  Ca²⁺ 
A)  Na⁺ 
B)  K⁺ 
C)  Ca²⁺

Question 19

Which fibers fatigue sooner?

Accepted Answer

A)  fast-twitch fibers 
B)  slow-twitch fibers 
A)  fast-twitch fibers 
B)  slow-twitch fibers

Question 20

Match the structures with the accurate description.
-a single muscle cell

Accepted Answer

A) muscle fiber 
B) fascicle 
C) sarcolemma 
D) myofibril 
E) t-tubules 
A) muscle fiber 
B) fascicle 
C) sarcolemma 
D) myofibril 
E) t-tubules

Exam 12: Muscles

When a skeletal muscle generates enough force during contraction to shorten,

The origin is the end of the skeletal muscle that attaches to the

Most of the time, the parallel thick and thin filaments of the myofibrils are connected by ________ that span the space between myosin and actin molecules.

Match the structures with the accurate description. -the muscle cell membrane

Within a single fiber, the tension developed during a twitch depends upon the

The T-tubular membrane contains ________ receptors that are ________ and therefore respond to action potentials.This receptor is mechanically linked to ________ receptors in the adjacent sarcoplasmic reticulum.

Each myosin head has a binding site for

The brief period of time between the beginning of the action potential in the muscle and the beginning of contraction is referred to as the

In order for high force crossbridges to form in contracting skeletal muscle, calcium must

In the lever system that characterizes the interaction between bones and muscle, the bones act as the ________ whereas the joints form the ________.

The relaxation of skeletal muscle relies on the activity of the ________, which decreases cytoplasmic calcium concentration.

The action potential traveling along the t-tubule is detected by the

________ and ________ are striated muscles.Why are these muscles classified as striated muscles?

The I band contains

Before the entire muscle can change length, the force generated by the muscle must stretch the

The interaction between Ca²⁺ and calmodulin in smooth muscle cells has been described as a second messenger system.Develop an argument to support this position, using another second messenger system you have studied for comparison.

The factor(s)that determine the duration of a twitch in various types of fibers is the speed of the

The contraction cycle is triggered by the rise in ________ released from the sarcoplasmic reticulum (SR).

Which fibers fatigue sooner?

Match the structures with the accurate description. -a single muscle cell

Introduction to Physiology

Molecular Interactions

Compartmentation: Cells and Tissues

Energy and Cellular Metabolism

Membrane Dynamics

Communication, Integration, and Homeostasis

Introduction to the Endocrine System

Neurons: Cellular and Network Properties

The Central Nervous System

Sensory Physiology

Efferent Division: Autonomic and Somatic Motor Control

Integrative Physiology I: Control of Body Movement

Cardiovascular Physiology

Blood Flow and the Control of Blood Pressure

Blood

Mechanics of Breathing

Gas Exchange and Transport

The Kidneys

Integrative Physiology II: Fluid and Electrolyte Balance

The Digestive System

Metabolism and Energy Balance

Endocrine Control of Growth and Metabolism

The Immune System

Integrative Physiology III: Exercise

Reproduction and Development

Filters

The T-tubular membrane contains receptors that are and therefore respond to action potentials.This receptor is mechanically linked to receptors in the adjacent sarcoplasmic reticulum.

In the lever system that characterizes the interaction between bones and muscle, the bones act as the whereas the joints form the .

and are striated muscles.Why are these muscles classified as striated muscles?