Chapter 9 Muscle Tissue

____________ muscles are responsible for the pumping action of the heart.

Cardiac

The area in the center of the A band that centains no thin filaments is the

H band.

The region of the sarcomere that always contains only thin filaments is the

I band

In a sarcomere, thick filaments are linked laterally by proteins of the

M line

Skeletal muscle fibers are formed from embryonic cells called

Myoblasts

Muscles that move a limb away from the midline are called ____.​

abductors

As the nerve impulse of an axon reaches the neuromuscular junction, it triggers the release of a neurotransmitter called ____.​

acetylcholine

The light bands are made of the thin filaments of the protein ____.​

actin

Adductor, flexor, and extensor muscles are named according to their ____.​

action

In performing any given movement, the muscles performing the actual movement are called the prime movers or _____.​

agonists

Tendons that are wide and flat form what is known as a(n) ____.​

aponeurosis

A decrease in muscle bulk due to a lack of exercise is called ____.​

atrophy

The action potential traveling down the T tubule causes the sarcoplasmic reticulum to release ____ ions into the fluids surrounding the myofibrils.​

calcium

Which type of striated muscle is controlled by the autonomic nervous system?​

cardiac

​In the small intestine, smooth muscle is arranged in two layers: an outer longitudinal layer and an inner ____ layer.

circular

Muscle tissue, one of the four basic tissue groups, consists chiefly of cells that are highly specialized for

contraction.

Physical evidence that supports the sliding filament theory of muscle contraction includes

decreased width of the H band during contraction.

The main muscle used in breathing is the ____.​

diaphragm

Individual muscle cells are surrounded by what connective tissue?

endomysium

The ____ is a delicate connective tissue that surrounds the sarcolemma.

endomysium

The delicate connective tissue that surrounds the skeletal muscle fibers and ties adjacent muscle fibers together is the

endomysium

The coarse irregular connective tissue that surrounds the whole muscle is called the ____.​

epimysium

The dense layer of connective tissue that surrounds an entire skeletal muscle is the

epimysium

Each individual bundle of muscle cells is called a ____.​

fascicle

Because skeletal muscles are much longer than their width, they are often called muscle ____.​

fibers

A form of rheumatism that does not affect the joints is called ____.​

fibromyalgia

The flexor digitorum muscles flex the ____.​

fingers

Muscles that bend a limb at a joint are called ____. ​

flexors

The brachialis, the biceps brachii, and the brachioradialis muscles flex the ____ at the elbow.​

forearm

The ____ muscle raises your eyebrows and wrinkles the skin of your forehead.​

frontalis

The biceps femoris, the semitendinosus, and the semimembranosus muscles are also known as the ____.​

hamstrings

The movable attachment, where the effects of muscle contraction are seen, is called the _____.​

insertion

When lifting a weight, muscles become shorter and thicker but the tone or tension remains the same and is referred to as a/an _______.​

isotonic contraction

If oxygen is not available to a muscle cell, pyruvic acid is changed to ____ and builds up in the muscle cell.​

lactic acid

Muscles that raise a part of the body are called ____.​

levators

What are the functions of skeletal muscle?

maintain body temperature, maintain posture, guard body entrances and exits, produce movement

Closes the jaw

masseter

All of the muscle cells or fibers innervated by one motor neuron is called a(n)

motor unit

Interactions between actin and myosin filaments of the sarcomere are responsible for

muscle contraction.

The dark bands of skeletal muscle are made of thick filaments of the protein _______.​

myosin

Cross-bridges are portions of

myosin molecules

Closes lips

orbicularis oris

Flexes and adducts the arm

pectoralis major

Nerves and blood vessels that service the muscle fibers are located in the connective tissues of the

perimysium.

What is the molecule that is found only in muscle tissue and provides a rapid source of high-energy ATP for muscle contraction?​

phosphocreatine

​Flexes the thigh

psoas

Extends the knee

quadriceps femoris

The muscle we develop when we do sit-ups is the ____.​

rectus abdominis

The electrically polarized cell membrane of a skeletal muscle cell is called the

sarcolemma

The plasma membrane of skeletal muscle is called the

sarcolemma.

The area between two adjacent Z lines is called a(n)

sarcomere

The repeating contractile unit of a skeletal muscle fiber is the

sarcomere

Since each myofibril is attached at either end of the muscle fiber, when sarcomeres shorten, the muscle fiber

shortens.

The structural explanation of how a muscle fiber contracts is called the

sliding filament theory

The type of muscle found in the uterus, blood vessels, and urinary bladder is known as ____ muscle.​

smooth

Muscle cells have positively charged ____ ions in greater concentration outside the muscle cell than inside the cell.​

sodium

Plantar flexes the foot

soleus

​Moves the head

sternocleidomastoid

The ____ rectus muscle raises the eye.​

superior

At the end of each muscle, the collagen fibers of the epimysium and each perimysium and endomysium, come together to form a

tendon.

The bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to bone is called a(n)

tendon.

Inflammation of a tendon is called ____.​

tendonitis

Rapid, uncontrolled contraction of individual cells in the heart is known as

tetanus

When a skeletal muscle fiber contracts

the z lines get closer together, the H bands and I bands get smaller, the width of the a band remains constant, and the zones of overlap get larger

At rest, active sites on the actin are blocked by

tropomyosin molecules.

At rest, the tropomyosin molecule is held in place by

troponin molecules

Each thin filament consists of

two actin protein strands coiled helically around each other

Which of the following best describes the term "Z line"?

where thin filaments are anchored

The extensor digitorum communis muscle extends the ____ joint in conjunction with the three extensor carpi muscles.​

wrist

​Flexes the knee

​Biceps femoris

​Extends the great toe

​Extensor hallucis

​Abducts the thumb

​abductor pollicis

Also known as Lou Gehrig's disease, ____ is a progressive, degenerative disease of the motor neurons.​

​amyotrophic lateral sclerosis