Chapter 10 Anatomy and Physiology

The smallest contractile (functional) unit of skeletal muscle is the

sarcomere

Bundles of muscle fibers held together by perimysium are called

fascicles

What do you call the dense connective tissue layer that encloses the entire muscle?

epipmysium

Which neurotransmitter is released at motor end plates by the motor neuron?

ACh

Holding a plank is an example of a _____ contraction.

isometric

What is the function of the sarcoplasmic reticulum in skeletal muscle?

store calcium

Extensions of the ______ are called T tubules.

sarcolemma

A ______ is dense regular connective tissue that attached a muscle to a bone.

tendon

Muscle fibers that use glycolysis to produce ATP are called ______.

fast glycolytic

The myosin-binding sites are blocked by ______ in a resting muscle cell.

tropomyosin

What is the only energy source used directly for muscle contraction?

ATP

In order for the myosin heads to detach from actin, what must bind?

ATP

Which filaments run throughout the entire A band?

thick

Thick filaments are mostly made of the protein, _______.

myosin

What is the space called between the axon terminal and the sarcolemma?

synaptic cleft

Does a sarcomere shorten during muscle contraction to generate force?

yes

Which zone of the sarcomere shortens and can fully disappear when a muscle contracts?

h zone

What causes rigor mortis in muscles after death?

not enough ATP

Which ion links excitation to contraction?

ca2+

Put in order smallest to biggest: fascicles, myolfilaments, myofibrils, muscle fibers, muscle

myofilaments, myofibrils, muscle fibers, fascicles, muscle

Which type of muscle contraction occurs when the muscle shortens during contraction?

concentric

Which type of muscle is striated and voluntary?

skeletal

A 10K race would be considered _____ exercise while a 100 meter dash is _______ exercise.

aerobic; anaerobic

For skeletal muscles to contract, calcium ions must bind to _____ in the sarcoplasm.

troponin

When we lift weights, do we make new muscle fibers or do our existing muscle fibers get bigger?

existing muscle fibers hypertrophy

Fast glycolytic fibers are _____ in color.

white

Slow oxidative fibers are _____ in color.

red

Which type of muscle contraction occurs when the muscle neither shortens nor lengthens during contraction?

isometric

Thin filaments are mostly made of a contractile protein called _______________.

actin

What builds up during intense exercise without sufficient oxygen?

lactic acid

What do you call muscle fibers that use oxygen and cellular respiration to produce ATP?

slow oxidative

Holding a tray of food in the same position is an example of a ____ contraction.

isometric

A single contraction in response to a single threshold stimulus is called a muscle ______.

twitch

What is an aponeurosis?

flat, sheet-like tendon

A single muscle cell is called a

muscle fiber

Myofibrils are composed primarily of

actin and myosin

The striated appearance of skeletal muscle results from the

arrangments of filaments

__________ is the space between each myosin filament where there is actin only.

I band

The plasma membrane of a muscle cell is called the

sarcolemma

Groups of skeletal muscle fibers are bound together by a connective tissue envelope called the

perimysium

Each fascicle contain many

muscle fibers

What is in the middle of the H zone?

M line

Sections of the sarcomere that includes actin only.

I band

A bundle of muscle fibers are called.....

fascicles

Sections of the sarcomere that includes the myosin and some of the actin.

A band

Which muscle tissue is voluntary?

skeletal

Which muscle tissue does not have a banded appearance?

smooth

Which muscle tissue has dense connective tissue packaging?

skeletal

Which muscle tissue coordinates activity allowing it to act as a pump?

cardiac

Which muscle tissue has one single centrally located nucleus?

smooth

Which muscle tissue is often referred to as the muscular system?

skeletal

Which muscle tissue aids in the movement of the facial skin?

skeletal

Which muscle tissue has intercalated disks?

cardiac

What areas in the sarcomere change when contraction occurs?

I band, H zone, Z lines/discs