52 terms

Anatomy Chapter 10 Study Guide

all of the above
Which of the following is not a function of skeletal muscle?
Skeletal muscles are responsible for the pumping action of the heart.
Which of the following statements is incorrect?
The dense layer of collagen fibers that surround an entire skeletal muscle is the
Nerves and blood vessels that service the muscle fibers are located in the connective tissues of the
The delicate connective tissue that surrounds the skeletal muscle fibers and ties adjacent muscle fibers together is the
The bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to bone is called a(n)
have many nuclei
Muscle fibers differ from "typical cells" in that muscle fibers
the ability to produce large amounts of the enzymes and structural proteins needed for contraction
The advantage of having many nuclei in a skeletal muscle fiber is
Skeletal muscle fibers are formed from embryonic cells called
The cell membrane of skeletal muscle is called the
The cytoplasm of a skeletal muscle fiber is called the
transverse tubule
The series of membranous channels that surround each myofibril is the
The functional unit of a skeletal muscle fiber is the
muscle contraction
Interactions between actin and myosin filaments of the sarcomere are responsible for
M line
In a sarcomere, thick filaments are linked laterally by
Z line
Thin filaments at either end of the sarcomere are attached to the
Z line
The area of the sarcomere containing the thick filaments is the
I band
The area of the sarcomere containing only thin filaments is the
H band
The area in the center of the A band that contains only thick filaments is the
a pair of protein strands wound together
Each thin filament consists of
calcium ions
The sarcoplasmic reticulum stores
a transverse tubule and terminal cisternae
The skeletal muscle complex known as the triad consists of
myosin molecules
Cross-bridges are portions of
tropomyosin molecules
At rest, active sites on the actin are blocked by
troponin molecules
At rest, the tropomyosin molecules is held in place by
neuromuscular junction
Each skeletal muscle fiber is controlled by a neuron at a single
synaptic cleft
The space between the neuron and the muscle is the
motor end plate
Receptors for acetylcholine are located on the
transverse tubules
Action potentials are conducted into a skeletal muscle fiber by
calcium binds to troponin
Active sites on the actin become available for binding when
calcium ions
In response to action potentials arriving from the transverse tubules, the sarcoplasmic reticulum releases
myosin cross-bridges
Which of the following acts as an ATPase during the contraction cycle of muscle?
active sites on the myosin are exposed
When calcium ion binds to troponin,
diffusion of calcium into the sarcoplasmic reticulum
The most important factor in decreasing the intracellular concentration of calcium ion after contraction is
When the sarcomeres are slightly less than fully shortened, contraction cannot occur.
Which of the following statements is incorrect?
latent period
Calcium ions are released from the sarcoplasmic reticulum during the _____ of contraction.
The type of contraction represented by a single stimulus / contraction / relaxation sequence is a(n)
complete tetanus
When a muscle is stimulated repeatedly for several seconds with a constant stimulus, the amount of tension gradually increases to a maximum. This phenomemnon is called
incomplete tetanus
A muscle producing peak tension with rapid cycles of contraction and relaxation is said to be in
wave summation
If a second stimulus arrives before the relaxation phase has ended, a second, more powerful contraction occurs. This is called
complete tetanus
A muscle that is stimulated so frequently that the relaxation phase is completely eliminated is said to exhibit
The increase in muscle tension that is produced by increasing the number of active motor units is called
The type of contraction in which the muscle fibers produce increased tension but do not shorten is called
aerobic respiration
A resting muscle generates most of its ATP by
acts as an energy reserve in muscle tissue
Creatine phosphate
A and B only
During anaerobic glycolysis
only about 1/3 of the enrgy required by the muscle
At peak levels of muscle exertion the mitochondria can supply
When energy reserves in a muscle are exhausted and lactic acid levels increase, _______ occurs.
muscle fibers remain contracted
During the recovery period following exercise, all of the following are true, except
glucose is produced from lactic acid
During the Cori cycle in the liver
additional oxygen is required to metabolize the lactic acid produced during exercise
During the recovery period the body's need for oxygen is increased because
produce powerful contractions
Fast fibers