Muscle fibers use ATP to generate force
-3 types: Skeletal, cardiac, and smooth

Muscle tissue

usually attached to bones of skeleton, boluntary and striated (alternating light/dark bands on stained fibers)

Muscle tissue
Skeletal

Forms most of wall of hear, involuntary, branched, striated and contains intercalated discs (with gap junctions and desmosomes)

Muscle tissue
Cardiac

Located in walls of hollow organs (blood vessels, airways, digestive, urinary, reproductive), involuntary, and nonstriated

Muscle tissue
Smooth

basic functional units of a myofibril in muscle, separated by Z discs

sarcomeres

Actin and myosin

contractile Proteins

in thin filaments

actin

in thick filaments

myosin

troponin and tropomysosin in thin filaments

regulatory proteins

resting membrane potential

-70 mV

threshold Potential

-55 mV

The functional unit of a skeletal muscle fiber is the

sarcomere.

The space between the neuron and the muscle is the:

synaptic cleft.

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

action potential.

Which of the following allows recoil of the muscle fiber when contraction ends?

Elastic filaments

Elasticity refers to the ability of a muscle fiber to

recoil and resume its resting length after being stretched.

A sarcomere is part of a:

myofibril.

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

repolarization

What is the cause of rigor mortis?

Calcium influx into the cell after death

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

ATP

An entire skeletal muscle is surrounded by:

epimysium.

s 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:

motor unit.

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

neuromuscular junction.

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

myosin

Single, fusiform, uninucleate; no striation

Smooth muscle cells

Single, very long, cylindrical, multinucleate cells with striation

Skeletal muscle fibers

Branching chains of cells; uni- or binucleate striations; intercalated discs

Cardiac muscle cells

Ability to receive and respond to a stimulus

Excitability

Ability to shorten forcibly when adequately stimulated

Contractility

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

Elasticity

Ability to be stretched or extended

Extensibility

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

Concentric contraction

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

Fast oxidative fibers

Type of fibers that have few mitochondria

Fast glycolytic fibers

Type of muscle fibers that are most resistant to fatigue

Slow oxidative fibers

Plasma membrane of skeletal muscle fiber

Sarcolemma

Cytoplasm of a skeletal muscle fiber

Sarcoplasm

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

Sarcoplasmic reticulum

Rod-like contractile elements within a muscle fiber

Myofibril

Area of the sarcomere with overlapping thick and thin filaments

A band

Area of the sarcomere containing only thin filaments

I band

Functional unit of a skeletal muscle fiber

Sarcomere

Contains vesicles filled with acetylcholin

Synaptic knob

Space between the neuron and the muscle

Synaptic cleft

Contains receptors for acetylcholine

Motor end plate

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

Twitch

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

Wave summation

Activities best suited for slow oxidative fibers

Endurance-type activities

Activities best suited for fast oxidative fibers

400M or 800M sprint

Activities best suited for fast glycolytic fibers

Short-term intense movements

Branching chains of cells; uni- or binucleate striations; intercalated disc

cardiac muscle

Single, fusiform, uninucleate; no striations

smooth muscle

Single, very long, cylindrical, multinucleate cells with striations

skeletal muscle

Ability to receive and respond to a stimulus

Excitability

Ability to shorten forcibly when adequately stimulated

Contractility

Ability to be stretched or extended

Extensibility

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

Elasticity

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

Isotonic contraction

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

Isometric contraction

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

Concentric contraction

Contraction of muscle in which the muscle contracts as it lengthens

Eccentric contraction

Type of muscle fibers that are most resistant to fatigue

Slow oxidative fibers

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

Fast oxidative fibers

Type of fibers that have few mitochondria

Fast glycolytic fibers

The time between the stimulus or the electrical event and the mechanical event of contraction

Latent period

The time during which the muscle is shortening

Contraction period

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

Relaxation period

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

Refractory period

Pulling on something to change its position

movement

Development of tension to prevent movement, as in keeping the vertebral column uprigh

Maintaining posture

Attaching to bones and keeping them in close proximity to one another

Stabilizing joints

Release of energy during metabolism.

Generation of heat

major function of muscle

movement, maintain posture, stabilizing joints, generating heat