Question 1

The H zone contains

Accepted Answer

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

Question 2

________ is the backup energy molecule that can be rapidly converted to ATP in active skeletal muscle.

Accepted Answer

A)  Protein 
B)  Glucose 
C)  Fatty acid 
D)  Phosphocreatine 
A)  Protein 
B)  Glucose 
C)  Fatty acid 
D)  Phosphocreatine

Question 3

A flexor is a skeletal muscle whose shortening moves attached bones

Accepted Answer

A)  away from one another. 
B)  towards one another. 
C)  medially. 
D)  laterally. 
A)  away from one another. 
B)  towards one another. 
C)  medially. 
D)  laterally.

Question 4

This protein is activated by the Ca²⁺-calmodulin complex to phosphorylate the myosin light chain protein.

Accepted Answer

A)  tropomyosin 
B)  myosin heavy chain 
C)  myosin light chain kinase 
D)  myosin light chain phosphatase 
A)  tropomyosin 
B)  myosin heavy chain 
C)  myosin light chain kinase 
D)  myosin light chain phosphatase

Question 5

A contraction that generates enough force to move a load is known as ________, whereas one that generates force that equals the load is known as ________.

Accepted Answer

A)  isotropic, isometric 
B)  isometric, eccentric 
C)  isotonic, isometric 
D)  isometric, isotonic 
E)  isotonic, eccentric 
A)  isotropic, isometric 
B)  isometric, eccentric 
C)  isotonic, isometric 
D)  isometric, isotonic 
E)  isotonic, eccentric

Question 6

Which of the following statements is NOT correct regarding the motor units and their activation?

Accepted Answer

A)  A motor unit in muscles of gross movement can have thousands of muscle cells. 
B)  All muscle fibers in a single motor unit are of the same fiber type. 
C)  A weak contractile stimulus activates fast-twitch motor units. 
D)  The metabolic capacity of muscle fibers within a motor unit can be altered. 
E)  At its peak intensity, a contractile stimulus will activate muscle fibers that are easily fatigued. 
A)  A motor unit in muscles of gross movement can have thousands of muscle cells. 
B)  All muscle fibers in a single motor unit are of the same fiber type. 
C)  A weak contractile stimulus activates fast-twitch motor units. 
D)  The metabolic capacity of muscle fibers within a motor unit can be altered. 
E)  At its peak intensity, a contractile stimulus will activate muscle fibers that are easily fatigued.

Question 7

Match from the following list.
-The band with the most overlap between thick and thin filaments, which unevenly scatters light leading to its' dark appearance.

Accepted Answer

A) A band 
B) I band 
C) Z disk 
D) H zone 
E) M line 
A) A band 
B) I band 
C) Z disk 
D) H zone 
E) M line

Question 8

Smooth muscle cells of blood vessels are described as integrating centers.Outline the various inputs that affect smooth muscle cells and how those are integrated.

Accepted Answer

Myogenic responses, autonomic neurotrans

Question 9

Put these events in the correct chronological sequence:
1)End-plate potentials trigger action potentials.
2)Transverse tubules convey potentials into the interior of the cell.
3)Acetylcholine binds to receptors on the motor end plate.
4)Ca²⁺ is released from the sarcoplasmic reticulum.

Accepted Answer

A)  1, 2, 3, 4 
B)  3, 1, 2, 4 
C)  2, 1, 4, 3 
D)  3, 1, 4, 2 
E)  4, 3, 2, 1 
A)  1, 2, 3, 4 
B)  3, 1, 2, 4 
C)  2, 1, 4, 3 
D)  3, 1, 4, 2 
E)  4, 3, 2, 1

Question 10

Myasthenia gravis is a disease characterized by reduction in the number of acetylcholine receptors on skeletal muscles.Which physiological process would be affected? What would someone afflicted by this disease experience? How may this disease be treated?

Accepted Answer

Neuromuscular transmission would be affe

Question 11

________ is composed of multiple globular molecules polymerized to form long chains or filaments.

Accepted Answer

A)  Actin 
B)  Tropomyosin 
C)  Troponin 
D)  Myosin 
E)  Titin 
A)  Actin 
B)  Tropomyosin 
C)  Troponin 
D)  Myosin 
E)  Titin

Question 12

For antagonistic muscle groups to move a limb, flexor contraction occurs coincident with

Accepted Answer

A)  contraction of the extensor. 
B)  relaxation of the extensor. 
C)  no changes in the extensor. 
D)  contraction of the tendon. 
A)  contraction of the extensor. 
B)  relaxation of the extensor. 
C)  no changes in the extensor. 
D)  contraction of the tendon.

Question 13

Which of the following would cause the crossbridge to transition from a high force state to a low force state?

Accepted Answer

A)  increasing myosin ATPase activity 
B)  increasing intracellular calcium 
C)  decreasing intracellular calcium 
D)  energizing the myosin head 
E)  decreasing myosin ATPase activity 
A)  increasing myosin ATPase activity 
B)  increasing intracellular calcium 
C)  decreasing intracellular calcium 
D)  energizing the myosin head 
E)  decreasing myosin ATPase activity

Question 14

The tension generated in a skeletal muscle fiber is directly proportional to the number of

Accepted Answer

A)  thick and thin filaments present. 
B)  nebulin and titin molecules present. 
C)  high-energy crossbridges formed. 
D)  low-energy crossbridges formed. 
E)  active sarcomeres. 
A)  thick and thin filaments present. 
B)  nebulin and titin molecules present. 
C)  high-energy crossbridges formed. 
D)  low-energy crossbridges formed. 
E)  active sarcomeres.

Question 15

The reductions in muscle force generation at lengths different from optimal are a result of a(n)________.

Accepted Answer

decrease i

Question 16

Match the structures with the accurate description.
-inward extensions of 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 17

Smooth muscle fibers can sustain a contraction without fatigue by allowing dephosphorylated myosin to remain attached to actin in what is called the ________.

Accepted Answer

The answer of Smooth muscle fibers can sustain a contraction...

Question 18

The hydrolysis of ATP causes myosin to immediately

Accepted Answer

A)  swivel, moving the actin molecule. 
B)  release ADP. 
C)  release from the actin. 
D)  rotate into a position (cocked) to bind to actin. 
E)  bind more tightly to the actin (rigor). 
A)  swivel, moving the actin molecule. 
B)  release ADP. 
C)  release from the actin. 
D)  rotate into a position (cocked) to bind to actin. 
E)  bind more tightly to the actin (rigor).

Question 19

The molecular event that occurs immediately after the power stroke is the

Accepted Answer

A)  release of actin from the myosin head. 
B)  hydrolysis of ATP by the myosin head. 
C)  release of ADP from the myosin. 
D)  binding of tropomyosin to the myosin. 
E)  binding of actin to the myosin. 
A)  release of actin from the myosin head. 
B)  hydrolysis of ATP by the myosin head. 
C)  release of ADP from the myosin. 
D)  binding of tropomyosin to the myosin. 
E)  binding of actin to the myosin.

Question 20

The force generated by a single muscle fiber can be increased by

Accepted Answer

A)  increasing frequency of action potentials only. 
B)  increasing muscle length beyond optimal only. 
C)  increasing the asynchrony of recruitment only. 
D)  increasing frequency of action potentials and increasing muscle length beyond optimal only. 
A)  increasing frequency of action potentials only. 
B)  increasing muscle length beyond optimal only. 
C)  increasing the asynchrony of recruitment only. 
D)  increasing frequency of action potentials and increasing muscle length beyond optimal only.

Exam 12: Muscles

The H zone contains

________ is the backup energy molecule that can be rapidly converted to ATP in active skeletal muscle.

A flexor is a skeletal muscle whose shortening moves attached bones

This protein is activated by the Ca²⁺-calmodulin complex to phosphorylate the myosin light chain protein.

A contraction that generates enough force to move a load is known as ________, whereas one that generates force that equals the load is known as ________.

Which of the following statements is NOT correct regarding the motor units and their activation?

Match from the following list. -The band with the most overlap between thick and thin filaments, which unevenly scatters light leading to its' dark appearance.

Smooth muscle cells of blood vessels are described as integrating centers.Outline the various inputs that affect smooth muscle cells and how those are integrated.

Put these events in the correct chronological sequence: 1)End-plate potentials trigger action potentials. 2)Transverse tubules convey potentials into the interior of the cell. 3)Acetylcholine binds to receptors on the motor end plate. 4)Ca²⁺ is released from the sarcoplasmic reticulum.

Myasthenia gravis is a disease characterized by reduction in the number of acetylcholine receptors on skeletal muscles.Which physiological process would be affected? What would someone afflicted by this disease experience? How may this disease be treated?

________ is composed of multiple globular molecules polymerized to form long chains or filaments.

For antagonistic muscle groups to move a limb, flexor contraction occurs coincident with

Which of the following would cause the crossbridge to transition from a high force state to a low force state?

The tension generated in a skeletal muscle fiber is directly proportional to the number of

The reductions in muscle force generation at lengths different from optimal are a result of a(n)________.

Match the structures with the accurate description. -inward extensions of the muscle cell membrane

Smooth muscle fibers can sustain a contraction without fatigue by allowing dephosphorylated myosin to remain attached to actin in what is called the ________.

The hydrolysis of ATP causes myosin to immediately

The molecular event that occurs immediately after the power stroke is the

The force generated by a single muscle fiber can be increased by

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

A contraction that generates enough force to move a load is known as , whereas one that generates force that equals the load is known as .