A + P ch 9

True or false: Human muscles contain both fast-twitch and slow-twitch muscle fibers in equal amounts.

False

True or false: Smooth muscle responds in an all-or-nothing fashion to action potentials.

False

Name the muscle fiber type that has fewer mitochondria, less myoglobin and fewer blood capillaries?

Fast glycolytic fibers

Identify the structures in which cardiac muscle is located.

Heart

What are the transverse (T) tubules?

They are tube-like invaginations of the sarcolemma that extend inward throughout the muscle cell.

A sarcolemma is ______.

a cell membrane

Muscle fiber fatigue results from ______.

calcium ion imbalances as ATP levels drop

Describe what occurs when recruitment increases. Both fast-twitch and slow-twitch muscle fibers can increase in _____ as a result of exercise and training.

capacity size strength efficiency

In comparison to skeletal muscle, smooth muscle contains ______ myosin and actin myofilaments.

fewer

Another name for a skeletal muscle cell is a muscle ______.

fiber

Another name for a single skeletal muscle cell is a skeletal muscle

fiber or myocyte

Whole muscles respond to stimuli in a _____ fashion.

graded

Fast twitch or Type II muscle fibers ______. Select all that apply.

have a fast form of myosin ATPase, which allows them to break down ATP more rapidly than other muscle fiber types respond rapidly to nervous stimulation

Slow twitch or Type I muscle fibers ______. Select all that apply.

have the highest resistance to muscle fatigue have well developed blood supplies have high aerobic capacity but low anaerobic capacity

Increasing recruitment in a muscle, causes the strength of the contraction to _____ by ______.

increase, increasing the number of muscle fibers contracting

Smooth muscle regulation is _____ while the regulation of skeletal muscle is ______.

involuntary, voluntary

The protein found in muscle cells that stores and then releases oxygen when needed is called

myoglobin

The voltage of a repolarizing neuron or muscle fiber is becoming more ______ with respect to the extracellular fluid around it.

negative

When a cell is in the repolarizing phase of an action potential, its intracellular environment is becoming more ______ when compared with the extracellular environment.

negative

The muscle plasma membrane in the area of the neuromuscular junction is the ______. Select all that apply.

postsynaptic membrane motor end plate

The rapid skeletal muscle contractions that produce shaking in response to reduced body temperature is called ______.

shivering

When the body temperature drops below a certain level, the nervous system induces rapid skeletal muscle contractions called

shivering

Voluntary movements such as raising your hand are produced by the contraction of _______ muscle cells.

skeletal

Myoblast(s) are ______.

the precursors of muscle fibers

True or false: Aerobic respiration does not require oxygen in order to produce ATP.

False

The mechanism of ATP production that requires oxygen is ______respiration

Aerobic

What process is used during resting conditions to produce creatine phosphate?

Aerobic respiration

Cells produce a small amount of ATP and lactic acid in the absence of oxygen through the process of_____ respiration

Anaerobic

In smooth muscle tissue there are more_____myofilaments than_____myofilaments

Blank 1: actin or thin Blank 2: myosin or thick

Which of the following is associated with the relaxation phase?

Calcium levels in the cytoplasm fall. Myosin releases thin filaments. Muscle tension declines.

List the types of muscle tissue.

Cardiac Smooth Skeletal

Which of the following is not a source of energy for the production of ATP in muscle?

Creatine

Which of the following are characteristics of a skeletal muscle fiber?

Cylindrical Multinucleate

Describe the composition of human muscles in regards to fast and slow-twitch muscle fibers.

Most muscles have have both fast and slow-twitch muscle fibers but the numbers of each fiber type will vary dependent upon the muscle.

Calcium ion imbalances that occur as ATP levels drop lead to_____ fatigue

Muscular

Sodium is more abundant in which fluid compartment?

Outside the plasma membrane

Myoglobin would be most abundant in what type of muscle fiber?

Oxidative (slow) fibers

List the actions that occur during the process known as cross-bridge cycling.

Recovery stroke Power stroke Cross-bridge formation Cross-bridge release

With which phase are the following associated: myosin releases thin filaments, muscle tension declines, and cytoplasmic calcium levels fall?

Relaxation

Which of the following occurs within muscle and the body immediately after a period of exercise has concluded? Select all that apply.

Respiration rate remains elevated for several minutes to several hours. Aerobic respiration continues to produce ATP. Creatine phosphate is produced.

Which are types of muscle tissue?

Smooth, skeletal, and cardiac

What type of muscle cell is responsible for voluntary contraction or movement?

Skeletal muscle cells

Smooth muscle responds to action potentials by ______.

Smooth muscle responds to action potentials by ______.

Which of the following demonstrates the graded response of whole muscle?

The force generated to lift a feather is much less than the force required to lift a 25-pound weight.

Describe what occurs when recruitment increases.

The number of fibers contracting increases. The amount of force produced during contraction increases

Skeletal muscle is described as striated. What does that mean?

The tissue exhibits alternating dark and light bands.

True or false: Smooth muscle tends to contract in response to being stretched.

True

True or false: Smooth muscles are under involuntary control.

True

True or false: There is a time lag between the onset of exercise and the change in respiration.

True

Anaerobic respiration allows the cell to make a small amount of ______ in the absence of oxygen, but also produces ______.

adenosine triphosphate (ATP), lactic acid

Resting muscles or muscles involved in long-term exercise primarily use ______ for ATP production.

aerobic respiration

The energy required to produce ATP comes from ______. Select all that apply.

anaerobic respiration creatine phosphate aerobic respiration

Myofibrils _____

are bundles of protein filaments extend from one end of the muscle fiber to the other

The muscle tissue found in the heart is called _____muscle

cardiac

A single muscle fiber twitch ______.

contains a contraction and relaxation phase is very short in duration

During rest conditions, the energy from aerobic respiration is used to produce ______.

creatine phosphate

During a single contraction, each myosin molecule undergoes the cycle of cross-bridge formation, movement, release, and return to its original position many times. This process is called _______.

cross-bridge cycling

The sarcoplasm of a muscle fiber is its ______.

cytoplasm

At the onset of exercise when the small ATP reserve in muscle fibers is quickly depleted, _____ occurs next.

direct phosphorylation of ADP

Highly repetitive ______ muscle contractions produce pain more readily that ______ contractions do.

eccentric, concentric

The capacity of a muscle to respond to an electrical stimulus is ______.

excitability

The ability of a muscle cell to respond to stimuli is called

excitability or irritability

The fundamental properties of smooth muscle include ______. Select all that apply.

exhibits a relatively constant tension exhibits autorhythmic contractions

True or false: The reduction of muscle mass with age is known as myoplasia.

false

True or false: The size and capacity of muscle fibers cannot be increased by exercise and training.

false

The concentration of sodium ions is _______ in the cytosol of the cell at rest than it is in the surrounding extracellular fluid.

lower, smaller, less, lesser, or low

Muscle fibers develop from less mature, multinucleated cells called _____.

myoblasts

Each _____ is a threadlike structure, approximately 1-3 micrometers in diameter, that extends from one end of the muscle fiber to the other.

myofibril

A chemical released at the distal end of an axon that either stimulates or inhibits an adjacent cell is called a(n) ______.

neurotransmitter

Substances that are released from a presynaptic membrane and inhibit or stimulate the activity of an adjacent cell are called ______.

neurotransmitters

The plasma membrane of a muscle fiber is called the

sarcolemma

The age-related loss of muscle tissue is known as ______.

sarcopenia

The cytoplasm of a muscle cell is called the

sarcoplasm

The ____ reticulum is a modified form of smooth endoplasmic reticulum located in muscle cells.

sarcoplasmic

In a muscle cell, the highly specialized, smooth endoplasmic reticulum is called the _________.

sarcoplasmic reticulum

When examined in a longitudinal section, skeletal muscle has alternating light and dark bands producing a(n) ______ appearance.

striated

Tube-like invaginations of the sarcolemma that conduct action potentials toward the center of the muscle fiber are called _____.

transverse tubules

Muscle soreness following exercise can be a result of inflammation.

true

True or false: A muscle fiber twitch does not last long enough or generate enough tension to perform any work.

true

True or false: Fast glycolytic, white fibers have fewer mitochondria, less myoglobin and fewer blood capillaries.

true

Visceral muscle is found in the_____ tract, reproductive tract, digestive tract and respiratory tract.

urinary

An example of visceral smooth can be found in which of the following systems?

urinary tract

Which of the following accurately describes the structure of a muscle?

~A single skeletal muscle fiber can extend from one end of a muscle to the other ~A skeletal muscle fiber is a single, long, cylindrical cell containing several peripherally located nuclei