Chapter 9 A&P

The sliding filaments model of contraction involves

Actin and myosin sliding past each other and partially overlapping

Hypothetically, if a muscle were stretched to the point where thick and thin filaments no longer overlapped___

No muscle tension could be generated

An anaerobe metabolic pathway that results in the production of two net ATPs per glucose plus two pyrvic acts molecules is

glycolysis

Creating phosphate functions in the muscle cell by

storing energy that will be transferred to ASP to resynthesizes to ATP

Which of the following statement is true

striated muscle cells are long and cylindrical with many nuclei

The mechanism of contractions in smooth muscle is different from skeletal muscle in the______

The site of calcium regulations differs

Which of the following describes the cells of single--unit visceral muscle

They exhibit spontaneous actions potential

The gains protein titian maintains the organizations of the____ assisting in muscle

A band

Excitations-contractions coupling requires which of the following substance

Ca 2+ and ATP

Immediately following the arrival of the stimulus at a skeletal muscle cell there is short period called the ______ period during which the events of excitations--contractions coupling occur

Latent

Which of the following statement is most accurate

Muscle tension remains relatively constant during isotonic contractions

The muscle cells membrane is called the

Sarcolemma

What structure in skeletal muscle cells functions in calcium storage

Sarcoplasmic reticulum (SR)

Myoglobin

Stores oxygen in muscle cells

What is the most distinguishing characteristics of muscle tissue

The ability to transform chemical energy into mechanical energy

What produced the striations of a skeletal muscle cell

The arrange,ent of myofilaments

What does oxygen deficit represent

The difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used.

What is the role of tropomyosin in skeletal muscles

Tropomyosin serves as contractions inhibitor by blocking by blocking the myosin binding sites on the actin molecules.

Three discrete types of muscle fibers are identified on the basis of their size, speed and endurance. Which of the of the following athletic endeavors best represent the use of red fibers?

a long, relaxing swim

Most skeletal muscles contain

a mixture of fiber types

What is the functions unit of a skeletal muscle called

a sarcomere

The term aponeurosis refers to

a sheetlike indirect attachment to a skeletal element

Muscle tone is

a state of sustained partial contractions

After nervous stimulations stopes, what prevents ACh the synaptic cleft from connoting to stimulate contractions

acetylcholinesterase destroying the ACh

during muscle contractions, myosin cross bridges attach to which active sites

actin filaments

Which of the following is not a role of ionic calcium in muscle contractions

activates epinephrine release from adrenal gland

What is the role of calcium ions in muscle contractions

bind to regulatory sites on troponin to remove contractions inhabitation

Which of the following statement is false or incorrect

cardiac muscle fibers depend mostly on anaerobic cellsuerl respirations to generate ATP

Which of the following is true about smoothie muscle contractions

certain smooth muscle cells can actually divided to increase their numbers

In an isotonic contractions the muscle

changes in the length and moves the "load"

Which of the following is not a way muscle contractions can be graded

changing the type of muscle fibers involved in the contractions

Which of the following surrounds the individual muscle cell

endomysium

What is the functional role of the T tubules

enhance cellular communications during muscle contraction

The main effect of the warm-up period of athletes as the muscle contractions increase in strength, it to

enhance the availability of calcium and the efficiency of enzymes system

Which of the following is not a usual result of resistance exercise

increase in the number of muscles cells

Which of the choices below does not describe how recovery oxygen uptake (oxygen deficit)

increase the level of lactic acid in the muscle

The strongest muscle contractions are normally achieved by

increasing the stimulations up to the maximal stimulus

Fatigued muscle cells that recover rapidly are the products of

intense exercise of short duration

During vigorous exercise, there may be insufficient oxygen available to completely break down pyretic acid energy. As a result, the pyruvie acid is converted to

lactic acid

Which of the following is a factor that affects the velocity and duration of muscle contractions

load on the fiber

What part of the sarcolemma contains acetylcholine receptors

motor end plate

which of the following is the correct sequences of events for muscle contractions

motor neuron actions potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP--driven power stroke, sliding of myofilaments.

Which of the following would be recruited later in the muscle stimulations when contractile strength increase

motor unties with larger, less excitable neurons

What controls the force of muscle contraction

multimotor unit summations

Smooth muscles that act like skeletal mescals but are controlled by autonomic nerves and hormones are________

multiunit muscles

Of the following muscle types, which had only one nucleus, o sarcomeres and rare gap junctions

multiunit smooth muscle

The contractile units of skeletal muscles are

myofibrils

The oxygen--binding protein found in muscle cells is____

myoglobin

Rigor mortis occurs because

no ATP is available to release attached actin and myosin molecules

When a muscle is unable to respond to stimuli temporarily it is in which of the following periods

refractory period

The major functions of the sarcoplasm reticulum in muscle contractions is to

regulate intracellular calcium concentration

muscle tissue had all of the following properties except

secretion

Which muscle cess have the greatest ability to regenerate

smooth

Smooth muscle is characterized by all of the following expect

there are more thick filament than thin filaments

Which of the following are compose of myosin

thick filaments

The warm-up period required of athletes in order to bring their muscle to perk performance is called_____

treppe