questions from 10

Sarcomeres

What structure similarities are shared by all muscle tissue?

All muscle tissue contain the myofilaments acting and myosin, which generate contractile forces;

The functional properties of muscle tissue are?

Contractility, excitability, extensibility and elasticity

Name the connective tissue that surounds a fascicle?

Perimysium is the fibous connective tissue that surrounds a fascicle.

What are the functional definition of the origin and insertion of a muscle?

The insertion is the attachment site on the bone that does not move when muscle contracts. The insertion, it's the attachment site on the bone that does move when the muscle contracts.

What are the functions of the terminal cistern and the T tubules?

The terminal cistern stores Ca?t. The T tubules carry the stimulus to contract from the surface sarcolemma to the deeper regions of the muscle fiber, initiating the release of Ca?* from the terminal cistern.

Why overlap of the thin and thick filaments essential for muscle contraction?

The myosin heads must attach to the overlapping thin filament to generate a contractile force; if there is no overlap, the myosin heads have nothing to attach to.

Which region of the myofibril changed during contraction: the A band, the i band or the z disc?

The length of the i band shortens during muscle contraction.

Differentiate a neuromuscular junction from a motor unit

The neuromuscular junction is the connection between a single terminal bouton and a muscle fiber. A motor unit is a single motor neuron and all of the muscle fibers it innervates.

Why are skeletal muscle fibers multinucleated?

Skeletal muscle fibers form the fusion of multiple embryonic cell; thus, they are multinucleated.

whch of the following are importan similarities among skeletal, cardiac, and smooth muscle?

all three depend on myofilaments for contraction. their plasma membrane is called sarcolemma.

another name for muscle fiber is?

muscle fibers

Which of the following describes the functional characteristic of muscle called contractility?

When muscle cells shorthen, they generate a strong pulling force.

The sliding Filament mechanism explains which type of muscle contraction?

concentric contraction

which of the following describes the funtional characteristic of muscle called extensibility?

Muscle tissue can be stretched by the contraction of an opposing muscle.

Describe the events that occur during a muscle contraction of Z discs?

These structures move closer together, causing the sarcomer to shorten.

T tubules

Are deep invaginations of the sarcolemma, and conduct impulses into deepest region of muscle fibers.

How does the sliding filaments mechanism result in concentric of skeletal muscle?

Myosin heads of thick filaments attach to thin filaments at both enss of a sarcomere and pull the thin filaments toward the center of the sarcomer.

What is a motor unit?

one motor neuron and all the muscle fibers it innervates.