Chapter 7 Review

Slower

Are red muscles slower or faster than white muscles?

Neuromuscular junction

The communication link between the nervous system and a skeletal muscle fiber

A band

The dark band that is the area containing thick filaments

Break down

The enzyme acetylcholinesterase causes acetylcholine to

Muscular hypertrophy

The growth and increase of the size of muscle cells

Aerobic endurance

The length of time a muscle can continue to contract while supported by mitochondrial activities

Tibialis anterior

The muscle that dorsiflexes the foot

Actin and myosin arrangement

The striated appearance of skeletal muscle results from what?

Origin

The term for where a muscle begins

Insertion

The term for where a muscle ends

Hypertrophy

The term used to describe muscular growth in response to usage is

Obicularis oculi

This muscle is used in winking

Buccinator

Used to suck in your cheeks

Oxygen

When this type of muscle fiber is resting, it contains oxygen reserves

Elbow flexion

A muscle that inserts on the radial tuberosity is most likely involved in

Masseter

A muscle that originates from the zygomatic arch and functions in elevating the mandible?

Perimysium

A sheath of connective tissue surrounding a bundle of striated muscle fibers

Twitch

A single stimulus-contraction-relaxation sequence in a muscle fiber

Sodium ions

As a skeletal muscle contraction is initiated, acetylcholine binding alters the motor end plate membrane's permeability to what?

Aponeurosis

At the end of the muscle, collagen fibers come together to form a bundle of fibers known as a tendon, or a broad sheet know as what?

Motor end plate

Specialized sarcolemma that contains acetylcholine receptors

Smooth muscle

Spindle-shaped muscle cells

Obicularis oris

The "kissing" muscle

Axon terminal

The ________ contains vesicles filled with acetylcholine.

H zone

The area around the M line where there is only dark fibers present

Sarcomere

The area between Z lines

I band

The area of the sarcomere that is the light region between two successive A-bands

Z line

The boundary between sacromeres

Anaerobic endurance

The length of time muscle contractions can be supported by glycolysis and existing energy reserve of ATP and CP

Teres major

The muscle that adducts and medially rotates the shoulder

Rhomboid

The muscle that adducts and rotates the scapula laterally

Buccinator

The muscle that compresses the cheeks, as when pursing the lips and blowing forcefully

Sarcolemma

The plasma membrane of a muscle fiber

Atrophy

The process by which muscle fibers weaken and become smaller

Muscle tone

The resting tension in a skeletal muscle

Myofibrils

The skeletal muscle structures that actively shorten and are responsible for muscle fiber contraction

Sarcoplasmic reticula

The terminal cisternae are structural features of what?

Cardiac muscle

These muscle cells are striated.

acetylcholine

This is a stimulus for contraction in skeletal muscle

Muscle fatigue

This is caused by the exhaustion of energy reserves of the decline in pH due to production and dissociation of lactic acid

Motor unit

This is made up of a motor neuron and the skeletal muscle fibers innervated by that motor neuron's axonal terminals

erector spinae

This muscle functions to maintain an erect spinal column and head?

Masseter

This muscle is the prime mover of jaw closure

Frontalis

This muscle is used to form the horizontal frown crease on the forehead

Large in diameter, containing densely packed myofibrils, large glycogen reserves, and few mitochondria.

Describe a fast twitch fiber

Half the diameter of fast fibers, specialized for contracting for extended periods. Specialized with oxygen supply (many capillaries), oxygen storage (myoglobin), and oxygen use (many mitochondria)

Describe a slow twitch fiber

Troponin

During active-site exposure, calcium ions bind to what?

Complete tetanus

During which phase is the stimulus frequency so high that the relaxation phase is eliminated?

Acetylcholine

This neurotransmitter is a chemical released by a neuron to communicate with cells. The release of this results in changes in the sarcolemma that trigger the contraction of the muscle fiber

T tubules

This structure plays a major role in coordinating the contraction of all regions of the muscle fiber at the same time

Fast twitch

This type of muscle fiber has high glycogen reserves

Cardiac muscle

This type of muscle has intercalated discs

Smooth muscle

This type of muscle uses primarily aerobic metabolism

1. Produce movement of the skeleton 2. Maintain posture and body position 3. Support soft tissues 4. Guard entrances and exits 5. Maintain body temperature

What are the five functions of skeletal muscle?

Semitendinosus. Semimembranosus Biceps femoris

What are the muscles of the hamstrings?

Subscapularis, infraspinatus, supraspinatus, teres major (SITS)

What are the muscles of the rotator cuff?

Actin (thin), myosin (thick)

What are the two types of myofilaments and what are their widths?

Tension

What does muscle force rely on?

Abduct the arm

What does the deltoid do?

Active sites on actin are exposed

What happens when a calcium ion binds to troponin?

Myofilaments organized into repeating functional units

What is a sarcomere?

To transmit electrical impulses to the cell's interior

What is the function of the transverse tubule?

the vastus intermedius, the vastus medialis, the vastus lateralis, and the rectus femoris

What muscles make up the quadriceps femoris?

Incomplete tetanus

What occurs when tension production rises to a peak and very brief periods of relaxation occur

The A band

When a sarcomere contracts, which band does not change shape?

Synaptic cleft

Where is acetylcholinesterase found?

Triceps brachii

Which muscle extends the elbow during the action of push-ups?

Brachioradialis

Which of the following acts to flex the elbow?

flexor digitorum

Which of the following muscles acts to flex the finger joints and wrist?

Muscle tone

Which of the following occurs as a result of motor units in a particular muscle being always active, even though their contractions do not produce enough movement to cause contraction?

M line

Which of the following sarcomere components is made up of proteins that connect the central portions of each thick filament to its neighbors?

Fascicle

A bundle of muscle fibers

Epimysium

A layer of collagen fibers that surrounds an entire muscle

fiber

A muscle ________ contains a sarcolemma, sarcoplasm, myofilaments, and myofibrils.

Prime mover (agonist)

A muscle responsible for producing a particular movement

Perimysium

Muscle fascicles are separated by what?

Trapezius

Muscles that allow you to shrug your shoulders or extend your head

Antagonist

Muscles whose actions oppose movement produced by another muscle

Myofilaments

Myofibrils are bundles of what?

Actin and myosin

Myofibrils are made primarily of

motor neuron axon terminals.

Neurotransmitters that cause skeletal muscle contraction are normally stored in

Smooth muscle

Nonstriated, involuntary muscle

Pectoralis major

Prime mover for shoulder flexion and aduction

Sarcoplasmic Reticulum

Regarding a skeletal muscle fiber, wherever a T-tubule encircles a myofibril, the tubule is tightly bound to

ATP

Rigor mortis occurs at death due to a lack of

elevates, adducts, depresses, or rotates the scapula

describe the action of the trapezius

Synergist

A muscle that helps a prime mover work efficiently

Latent

Calcium ions are released from the sarcoplasmic reticulum during the ________ phase of contraction

10,000

Each myofibril consists of approximately ________ sarcomeres

Calcium ions

In response to action potentials arriving from the transverse tubules, the sarcoplasmic reticulum releases

Isotonic

In this type of muscle contraction, tension rises and the skeletal muscle's length changes

Isometric

In this type of muscle contraction, the muscle as a whole does not change length, and the tension produced never exceeds the load

Myofibrils

Inside each muscle fiber, branches of T tubules encircle cylindrical structures called what?

Mitochondria

Most of the muscle's energy is produced where during activities requiring aerobic endurance,

Fast twitch

Most of the skeleton muscles are made up of this type of muscle fiber

Have many nuclei

Skeletal muscle fibers differ from "typical cells" in that these muscle fibers