Question 1

Rigor mortis occurs when Ca2+ links actin and the myosin globular head together in a rigor complex.

Accepted Answer

A) True 
 B)False

Question 2

Sequence the following events involved in muscle cell contraction: 
1.	Sodium channels open and sodium flows in.
2.	Impulse reaches axon's synaptic knob.
3.	ACh binds to receptors on the muscle cell membrane.
4.	Synaptic vesicles fuse with neuron's membrane and release ACh via exocytosis.
5.	If enough sodium moves in to the muscle cell, an impulse (action potential) develops.

Accepted Answer

A)  1, 2, 3, 4, 5 
B)  2, 1, 3, 4, 5 
C)  2, 4, 3, 1, 5 
D)  3, 4, 5, 1, 2 
E)  3, 5, 2, 1, 4 
A)  1, 2, 3, 4, 5 
B)  2, 1, 3, 4, 5 
C)  2, 4, 3, 1, 5 
D)  3, 4, 5, 1, 2 
E)  3, 5, 2, 1, 4

Question 3

Complete each of the following statments.
____________________ occurs when acetylcholine is no longer available in adequate amounts to stimulate muscle fibers.

Accepted Answer

Neuromuscu

Question 4

Z lines

Accepted Answer

A)  are formed by the T tubules 
B)  extend down the middle of the I band 
C)  are formed by the cross bridges 
D)  are the thin filaments 
E)  extend down the middle of the sarcomere 
A)  are formed by the T tubules 
B)  extend down the middle of the I band 
C)  are formed by the cross bridges 
D)  are the thin filaments 
E)  extend down the middle of the sarcomere

Question 5

Which of the following changes in banding pattern occur during muscle relaxation?

Accepted Answer

A)  Thin filaments stretch away from the Z lines. 
B)  I bands get wider. 
C)  H zones get narrower. 
D)  Thick filaments stretch and become longer. 
E)  I bands get wider and H zones get narrower. 
A)  Thin filaments stretch away from the Z lines. 
B)  I bands get wider. 
C)  H zones get narrower. 
D)  Thick filaments stretch and become longer. 
E)  I bands get wider and H zones get narrower.

Question 6

Calcium turns on cross bridges by physically repositioning the troponin-tropomyosin complex to uncover the actin cross-bridge binding sites in

Accepted Answer

A)  skeletal muscle 
B)  cardiac muscle 
C)  smooth muscle 
D)  all of these 
E)  skeletal and cardiac muscles 
A)  skeletal muscle 
B)  cardiac muscle 
C)  smooth muscle 
D)  all of these 
E)  skeletal and cardiac muscles

Question 7

Select the correct statement regarding smooth muscle.

Accepted Answer

A)  It composes the walls of the heart. 
B)  It is absent in the walls of hollow organs. 
C)  Its cells are multinucleated. 
D)  Its cells are spindle-shaped. 
E)  Its cells lack actin and myosin. 
A)  It composes the walls of the heart. 
B)  It is absent in the walls of hollow organs. 
C)  Its cells are multinucleated. 
D)  Its cells are spindle-shaped. 
E)  Its cells lack actin and myosin.

Question 8

In an isotonic contraction, about 50 percent of the energy consumed is realized as external work and the remaining 50 percent is converted to heat.

Accepted Answer

A) True 
 B)False

Question 9

The functional unit of skeletal muscle is the

Accepted Answer

A)  smallest contractile component of a muscle fiber 
B)  area between two Z lines 
C)  sarcomere 
D)  area between two Z lines and sarcomere 
E)  all of these 
A)  smallest contractile component of a muscle fiber 
B)  area between two Z lines 
C)  sarcomere 
D)  area between two Z lines and sarcomere 
E)  all of these

Question 10

Complete each of the following statments.
____________________ refers to the series of events linking muscle excitation to muscle contraction.

Accepted Answer

Excitation

Question 11

The corticospinal system

Accepted Answer

A)  consists of fibers that originate within the primary motor cortex and terminate on motor neurons 
B)  involves the motor regions of the cortex, the cerebellum, the basal nuclei, and the thalamus 
C)  is primarily concerned with regulation of overall body posture 
D)  consists of fibers that originate within the primary motor cortex and terminate on motor neurons, and is primarily concerned with regulation of overall body posture 
E)  involves the motor regions of the cortex, the cerebellum, the basal nuclei, and the thalamus and is primarily concerned with regulation of overall body posture 
A)  consists of fibers that originate within the primary motor cortex and terminate on motor neurons 
B)  involves the motor regions of the cortex, the cerebellum, the basal nuclei, and the thalamus 
C)  is primarily concerned with regulation of overall body posture 
D)  consists of fibers that originate within the primary motor cortex and terminate on motor neurons, and is primarily concerned with regulation of overall body posture 
E)  involves the motor regions of the cortex, the cerebellum, the basal nuclei, and the thalamus and is primarily concerned with regulation of overall body posture

Question 12

Complete each of the following statments.
Slow-oxidative fibers are type ____________________ fibers; fast glycolytic fibers are type ____________________ fibers; and fast, oxidative fibers are type ____________________ fibers.

Accepted Answer

The answer of Complete each of the following statments.
Slow-oxidative fibers...

Question 13

The thick filaments within a myofibril have ATPase activity.

Accepted Answer

A) True 
 B)False

Question 14

A single muscle cell is known as a myofibril.

Accepted Answer

A) True 
 B)False

Question 15

Bones serve as fulcrums for muscle action.

Accepted Answer

A) True 
 B)False

Question 16

Tropomyosin covers the cross bridge binding sites on the thick filaments when a sarcomere is not contracting.

Accepted Answer

A) True 
 B)False

Question 17

The T tubules

Accepted Answer

A)  store Ca2+ 
B)  provide a means of rapidly transmitting the action potential from the surface into the central portions of the muscle fiber 
C)  store ATP 
D)  run longitudinally between the myofibrils 
E)  have expanded lateral sacs 
A)  store Ca2+ 
B)  provide a means of rapidly transmitting the action potential from the surface into the central portions of the muscle fiber 
C)  store ATP 
D)  run longitudinally between the myofibrils 
E)  have expanded lateral sacs

Question 18

Muscle cells require ATP in order to relax, following a contraction.

Accepted Answer

A) True 
 B)False

Question 19

Which one of the following statements about cardiac muscle is incorrect?

Accepted Answer

A)  It contains gap junctions. 
B)  It is found only in the heart 
C)  It is self-excitable. 
D)  It is striated with intercalated disks. 
E)  It lacks tropomyosin. 
A)  It contains gap junctions. 
B)  It is found only in the heart 
C)  It is self-excitable. 
D)  It is striated with intercalated disks. 
E)  It lacks tropomyosin.

Question 20

Complete each of the following statments.
A(n) ____________________ is a motor neuron and all the muscle fibers it recruits.

Accepted Answer

The answer of Complete each of the following statments.
A(n) ____________________...

Exam 8: A--Muscle Physiology

Rigor mortis occurs when Ca2+ links actin and the myosin globular head together in a rigor complex.

Complete each of the following statments. ____________________ occurs when acetylcholine is no longer available in adequate amounts to stimulate muscle fibers.

Z lines

Which of the following changes in banding pattern occur during muscle relaxation?

Calcium turns on cross bridges by physically repositioning the troponin-tropomyosin complex to uncover the actin cross-bridge binding sites in

Select the correct statement regarding smooth muscle.

In an isotonic contraction, about 50 percent of the energy consumed is realized as external work and the remaining 50 percent is converted to heat.

The functional unit of skeletal muscle is the

Complete each of the following statments. ____________________ refers to the series of events linking muscle excitation to muscle contraction.

The corticospinal system

Complete each of the following statments. Slow-oxidative fibers are type ____________________ fibers; fast glycolytic fibers are type ____________________ fibers; and fast, oxidative fibers are type ____________________ fibers.

The thick filaments within a myofibril have ATPase activity.

A single muscle cell is known as a myofibril.

Bones serve as fulcrums for muscle action.

Tropomyosin covers the cross bridge binding sites on the thick filaments when a sarcomere is not contracting.

The T tubules

Muscle cells require ATP in order to relax, following a contraction.

Which one of the following statements about cardiac muscle is incorrect?

Complete each of the following statments. A(n) ____________________ is a motor neuron and all the muscle fibers it recruits.

Introduction to Physiology and Homeostasis

Cell Physiology

The Plasma Membrane and Membrane Potential

Principles of Neural and Hormonal Communication

A--The Central Nervous System

B--The Central Nervous System

A--The Peripheral Nervous System: Afferent Division; Special Senses

B--The Peripheral Nervous System: Afferent Division; Special Senses

The Peripheral Nervous System: Efferent Division

B--Muscle Physiology

A--Cardiac Physiology

B--Cardiac Physiology

The Blood Vessels and Blood Pressure

The Blood

Body Defenses

A--The Respiratory System

B--The Respiratory System

A--The Urinary System

B--The Urinary System

A--Fluid and Acid-Base Balance

B--Fluid and Acid-Base Balance

A--The Digestive System

B--The Digestive System

Energy Balance and Temperature Regulation

A--Principles of Endocrinology: the Central Endocrine Glands

B--Principles of Endocrinology: the Central Endocrine Glands

A--The Peripheral Endocrine Glands

B--The Peripheral Endocrine Glands

A--The Reproductive System

B--The Reproductive System

Filters

Rigor mortis occurs when Ca²⁺ links actin and the myosin globular head together in a rigor complex.

Complete each of the following statments. Slow-oxidative fibers are type fibers; fast glycolytic fibers are type fibers; and fast, oxidative fibers are type fibers.