Anatomy CH 10

Which of these correctly matches the property of muscle tissue with its definition? Contractility — the ability to recoil after stretching Elasticity — the ability to conduct an impulse Extensibility — the ability to be stretched Excitability — the ability to shorten with contraction

Extensibility — the ability to be stretched

The area that contains no thin filaments is known as the

H zone

A motor unit includes

a motor neuron and all of the muscle fibers it innervates.

An aponeurosis is

a sheet of dense connective tissue.

Myoglobin

binds and stores oxygen for ATP production.

Acetylcholine

binds to the sarcolemma and initiates an impulse in the muscle fiber.

The only muscle cells that branch are ________ muscle cells.

cardiac

A cell of this type of muscle is striated and can be uninucleated or binucleated.

cardiac muscle

Both single-unit smooth muscle and this type of muscle have gap junctions.

cardiac muscle

This type of muscle contains intercalated discs.

cardiac muscle

This type of muscle is found in the heart.

cardiac muscle

Visceral muscle refers to

cardiac muscle and smooth muscle.

When the distance between two adjacent Z disks grows shorter, the muscle fiber is experiencing

concentric contraction

Much of the natural elasticity of skeletal muscle tissue is provided by

connective tissue sheaths

A common characteristic of the three types of muscle tissue

contraction is triggered by the release of calcium.

In limbs, the insertions of muscles almost always lie ________ to their origins.

distal

The layer of connective tissue that surrounds the whole skeletal muscle is the

epimysium

The ability of the sarcolemma of muscle cells to conduct an impulse is an example of

excitability.

Of the various types of skeletal muscle fibers, the fibers that experience fatigue sooner are

fast glycolytic fibers

Of the various types of skeletal muscle fibers, the type containing the most glycogen granules is

fast glycolytic fibers

Of the various types of skeletal muscle fibers, the type that produces the most power is

fast glycolytic fibers

With intense resistance training,

fast glycolytic fibers can convert to fast oxidative fibers.

Eccentric contraction

generates force as the muscle lengthens.

After a muscle fiber has contracted, the calcium

is actively transported into the sarcoplasmic reticulum.

One of the largest and strongest muscles in the body is the gluteus maximus in the buttocks, which is important in these diverse muscular activities: walking, running, and jumping. It must consist of

mixture of fiber types

As skeletal muscles enlarge in a weight lifter, all of the following occur except -muscle cells grow larger. -myofilaments become more abundant in the muscle cells. -muscle cells divide mitotically. -myofibrils become more abundant in the muscle cells.

muscle cells divide mitotically.

The sleeve-like tubular network within skeletal muscle cells is the

sarcoplasmic reticulum.

Terminal boutons

sit within depressions in the sarcolemma.

Contractions of these muscles are under voluntary control.

skeletal muscle

This type of muscle attaches to bone, but may also attach to skin, cartilage, fascia or a raphe.

skeletal muscle

This type of muscle composes the largest share of muscle weight in the human body.

skeletal muscle

This type of muscle includes the fast oxidative fibers.

skeletal muscle

Of the various types of skeletal muscle fibers, the ones with the thinnest myofibrils, and, therefore, the ones that generate the least amount of power, are

slow oxidatitive fibers

Of the various types of skeletal muscle fibers, the ones supplied by the most capillaries are

slow oxidative fibers

Of the various types of skeletal muscle fibers, the fibers most resistant to fatigue are

slow oxidative fibers.

Of the various types of skeletal muscle fibers, the type with the most mitochondria is

slow oxidative fibers.

Which type of muscle fiber has caveolae but no T tubules?

smooth

Which type of muscle fiber has no myofibrils?

smooth

Both cardiac muscle and this type of muscle are called involuntary.

smooth muscle

This type of muscle is found in large blood vessels leading to and from the heart.

smooth muscle

This type of muscle makes up the walls of hollow organs, such as the stomach and uterus.

smooth muscle

Which of these is not in direct contact with thick myofilaments? -actin -ATPase -synaptic vesicles -myosin

synaptic vesicles

In striated muscle cells, which of these structures stores calcium ions that trigger contraction? -T tubules -the internal surface of the plasma membrane -the terminal cisterns -the myofibrils

the terminal cisterns

In striated muscle, the I band is where

thin filaments occur.

prevents a muscle from being overstretched.

titin

Which of the following correctly defines a triad of the sarcomere? -actin, myosin, and titin -a T tubule and two adjacent terminal cisterns -actin, troponin, and tropomyosin -an axon terminal, synaptic cleft, and sarcolemma

a T tubule and two adjacent terminal cisterns

A muscle fascicle is

a bundle of cells

sarcoplasmic reticulum lies...

between myofibrils but in fibers.

Sarcopenia is a condition that occurs in muscle tissue with aging. As a person ages, their muscle tissue

decreases overall, leading to a decrease in strength.

A skeletal muscle fiber

is a cylindrical cell formed by the fusion of many embryonic cells.

The embryonic origin of muscle tissue is from

mesoderm

The sarcoplasmic reticulum (SR) stores

Calcium

In muscular dystrophy, the protein dystrophin, which strengthens the sarcolemma by connecting the cytoskeleton with the extracellular matrix, is missing. What would be a consequence of these fibers lacking this important sarcolemma strengthening protein?

The sarcolemma would be weak and tear, allowing extracellular substances, including calcium ions, into the cell and disrupting muscle function.

The type of attachment in which the muscle fibers seem to attach directly to a bone is

a fleshy attachment

In skeletal muscle fibers, which band or zone contains both thick and thin myofilaments?

A

Which region of the sarcomere does not change in length during contraction?

A band

All of the following are true regarding motor units except: -If needed, additional motor units can be recruited to accomplish a movement. -Muscles in the fingers have a small number of muscle fibers per motor unit. -A single motor unit only innervates muscle fibers in a small area of a muscle. -A muscle can produce more force if more motor units are recruited

A single motor unit only innervates muscle fibers in a small area of a muscle.

All of the following are true regarding innervation of skeletal muscle except

A single muscle fiber is innervated by many different neurons.

Each nerve impulse to a muscle fiber is able to create just one twitch of that fiber because: -The muscle fiber is easily fatigued, so it can only twitch once before needing an interval of rest. -Acetylcholinesterase breaks down acetylcholine immediately after the contraction is signaled. -The sarcolemma is only able to release calcium once per millisecond. -acetylcholine is a weak neurotransmitter only capable of generating one twitch at a time.

Acetylcholinesterase breaks down acetylcholine immediately after the contraction is signaled.

As a muscle is stretched, the Z discs move further apart, and the I band increases in size. What is the role if titin in this situation?

It prevents the sarcomere from being pulled apart as this stretching occurs.

All of following are true regarding blood and nerve supply to muscles except -Generally, a muscle is supplied by one nerve and one artery. -Vessels and nerves enter a muscle near the middle of its length. -Nerves and vessels branch and travel within the connective tissue in the muscle. -Muscles have low need for nutrients and oxygen, so they have few blood vessels.

Muscles have low need for nutrients and oxygen, so they have few blood vessels.