ap lecture 4 ch 9

surrounds entire muscle

surrounds each muscle fiber

surrounds each muscle bundle (fascicle)

binds muscles into functional groups

plasma membrane of skeletal muscle fiber

cytoplasm of skeletal muscle fiber

Series of membranous channels (modified ER) that surround each myofibril

Rod-like contractile elements within a muscle fiber

Functional unit of a skeletal muscle fiber

Area of the sarcomere with overlapping thick and thin filaments

Area of the sarcomere containing only thin filaments

Area in the center of the A band containing only thick filaments

cross bridges

Contains vesicles filled with acetylcholine

Space between the neuron and the muscle

Contains receptors for acetylcholine

Type of contraction represented by a single stimulus/contraction/relaxation sequence

A muscle producing peak tensions with visible relaxation during rapid cycles of contraction and relaxation

A muscle that is stimulated so frequently that the relaxation phase is completely eliminated

When a muscle is stimulated repeatedly for several seconds with a constant stimulus, the amount of tensions gradually increases to a maximum.

skeletal, striated, voluntary

heart, striated, involuntary

visceral, nonstriated, voluntary

Ability to receive and respond to a stimulus

Ability to shorten forcibly when adequately stimulated

Ability to be stretched or extended

Ability of a muscle to resume its resting length after being stretched

Contraction of muscle during which the muscle changes in length and the tension remains constant through most of the contractile period

Contraction of muscle during which the tension continues to increase but the muscle neither shortens nor lengthens

Contraction of the muscle in which the muscle shortens and does work

Contraction of muscle in which the muscle contracts as it lengthens

Neurotransmitter at the neuromuscular junction

stored in muscles and tapped to regenerate ATP while metabolic pathways are adjusting to the higher demands for ATP

red pigment that stores oxygen

Product of anaerobic glycolysis

Type of muscle fibers that contract quickly and rely on aerobic respiration for ATP

Type of muscle fibers that are most resistant to fatigue

Type of fibers that have few mitochondria

Sustained spasm, or tetanic contraction

Inflammation of a muscle, its connective tissue coverings and tendons, and capsules of nearby joints

Muscle pain resulting from any muscle disorder

Excessive stretching and possible tearing of a muscle caused by muscle overuse or abuse

period of time between stimulation and the onset of muscle contraction

The time during which the muscle is shortening

The time during which the muscle is returning to its original length

The very brief time after one stimulus during which the muscle is unresponsive to a second stimulus

Propagation of an electrical current along the sarcolemma

The initial polarized state

Restoration of membrane potential to resting potential

The time when fiber cannot be stimulated until repolarization is complete

Electrical event occurring only at neuromuscular junction

Neurotransmitter released into the neuromuscular junction

Enzyme released into neuromuscular junction to break down acetylcholine

Released by terminal cisternae into the sarcoplasm to bind with troponin

Cytoplasmic, calcium-binding protein

Changes shape during the contraction cycle

Slides toward the M line during a contraction

Covers the binding site

Binds Ca2+ and starts the contraction cycle

An entire skeletal muscle is surrounded by

As an axon enters a muscle, it branches into a number of axonal terminals, each of which forms a neuromuscular junction with a single muscle fiber. A motor neuron and all the muscle fibers it supplies is called a:

What is the ion released from the terminal cisternae that combines with troponin and removes the blocking action of tropomyosin, resulting in the formation of cross bridges?

Each skeletal muscle fiber is controlled by a neuron at a single:

best describes the composition of the structure known as a triad in a skeletal muscle fiber

In the sliding filament model of muscle contraction, the myofilaments slide over each other, resulting in the overlapping of actin and _________.

The dense layer of collagen fibers that surround an entire skeletal muscle is the

The functional unit of a skeletal muscle fiber is the:

The space between the neuron and the muscle is the

The term that means a continued mild or partial contraction of an entire muscle is muscle:

The type of muscle contraction in which the muscle fibers produce increased tension, but the muscle neither shortens nor lengthens, is called:

increases in quantity during repetitive muscle contraction

The sequence of electrical changes that occurs along the sarcolemma when a muscle fiber is stimulated is known as the:

allows recoil of the muscle fiber when contraction ends

Which one of the following binds calcium ions in a smooth muscle, causing contraction?

A sarcomere is part of a

Cross bridges that link between the thick and thin filaments are formed by the:

Which of the following is thought to be an autoimmune disease of acetylcholine receptors?

The refractory period in which the muscle will not contract if stimulated occurs during __________ of the muscle cell.

What is the cause of rigor mortis?

Where does 95% of the energy needed for contraction come from during moderate exercise?

The alternating contraction and relaxation of opposing layers of smooth muscle is referred to as:

characteristic that is unique to smooth muscle?

Which of the following muscle types is both voluntary and striated?

Muscle cells initiate nerve impulses.
True False

Which of the following is a special adaptation present in muscle cells, but absent in most other cells?

The final "go" signal for skeletal muscle contraction is

The ___________ serve as a communication network that coordinates the contraction of each myofibril that makes up the muscle fiber

Thin myofilaments are composed chiefly of:

Acetylcholinesterase breaks down

Myofibrils are composed of repeating contractile elements called:

When an action potential arrives at the neuromuscular junction, the most immediate result is:

If a muscle is applied to a load that exceeds the muscle's maximum tension

The variation of stimulation needed in skeletal muscle contraction in order to have controlled movement is called a:

The most efficient means of producing ATP is:

What would occur if a muscle became totally depleted of ATP?

Duchenne muscular dystrophy is more common in females than in males.
True False