Unit 3: Chapter 9 (Muscular System: Part A)

Which of the following are types of muscles and are involuntary? Multiple choice question. skeletal regular irregular cardiac

cardiac

At neuromuscular junctions, acetylcholine binds to ______. Multiple choice question. receptors in the muscle fiber membrane sodium ions in the extracellular fluid myosin cross-bridges troponin in the actin filament

receptors in the muscle fiber membrane

During muscle contraction, the sarcomeres shorten because ______. Multiple choice question. myosin filaments shorten and in the process pull the actin filaments towards the center of a sarcomere thick and thin filament slide past one another, decreasing their overlap thick and thin filament slide past one another, increasing their overlap

thick and thin filament slide past one another, increasing their overlap

What prefix means work? Multiple choice question. tetan- laten- erg- sarco-

erg-

Within a muscle fiber, troponin and tropomyosin are associated with ______. Multiple choice question. myosin actin the sarcoplasmic reticulum

actin

I band (light band)

actin (thin) filaments only

The process of a neuron, its axon, conducts electrical impulses called _____ _______ towards the end of the axon that innervates a target cell.

action potentials

Actin molecules are globular and have binding sites to which the heads of a(n)_______ molecule can attach.

myosin

The globular actin proteins making up thin filaments have binding sites for ______. Multiple choice question. T tubules myosin calcium titin

myosin

H zone

myosin (thick) filaments only

A sarcomere extends from one ______ to the next. Multiple choice question. T tubule Z line I band A band

Z line

Due to their shape, muscle cells are also called muscle ______

fibers

What root word means hidden? Multiple choice question. tetan- calat- laten- myo-

laten-

endomysium

muscle fiber

Which muscle type has multinucleated cells that are cylindrical in shape? Multiple choice question. cardiac muscle smooth muscle skeletal muscle

skeletal muscle

Intertwined strands of actin make up part of the ______ filaments. Multiple choice question. thin thick

thin

What structures are positioned between adjacent cisternae of the sarcoplasmic reticulum? Multiple choice question. a bands transverse tubules neuromuscular junctions mitochondria

transverse tubules

thin filaments

troponin tropomyosin actin

What is the name of the process on a neuron that carries electrical impulses toward the cell to be stimulated? Multiple choice question. dendrite filament T tubule axon

axon

What is the meaning of the root word fasc-? Multiple choice question. something inserted together equal bundle

bundle

Correctly list, from superficial to deep, the connective tissue layers associated with a skeletal muscle. Start with the most superficial layer at the top.

epimysium perimysium endomysium

What is the meaning of the word root iso- (as in isotonic)? Multiple choice question. equal over muscle together

equal

Which prefix means bundle? Multiple choice question. iso- inter- erg- fasc-

fasc-

perimysium

fascicle

Muscle cells are also known as muscle fibers. In a skeletal muscle, muscle fibers are found as bundles called _______ , each enclosed in a connective tissue sheath, called the _______

fascicle perimysium

What term is used for the plasma membrane of a muscle fiber? Multiple choice question. sarcoplasm striation sarcolemma T-tubule

sarcolemma

What forms the striations seen in skeletal muscle? Multiple choice question. the arrangement of fascicles the arrangement of muscle fibers within the muscle the arrangement of epimysium, perimysium, and endomysium the arrangement of thin and thick filaments

the arrangement of thin and thick filaments

How many protein strands are found in each myosin molecule? Multiple choice question. 4 1 2

2

Within a sarcomere, the ______ band includes the area of overlap between actin (thin) filaments and myosin (thick) filaments. Multiple choice question. I Z A

A

The chemical called ______- is the neurotransmitter for skeletal muscle contraction.

ACh

The region of a sarcomere composed primarily of actin is called the ____ band

I

True or false: The transverse tubules are located between structures called cisternae.

TRUE

What are myofibrils? Multiple choice question. individual muscle cells bundles of proteins in a muscle cell bundles of muscle cells connections to the tendon

bundles of proteins in a muscle cell

Indicate three characteristics of skeletal muscle fibers. Multiple select question. spherical cells elongated cells cylindrical shape single nucleus multinucleated tapered ends

elongated cells cylindrical shape multinucleated

What is the meaning of the root word laten- (as in latent period)? Multiple choice question. more between hidden late

hidden

The prefix _______ means over or more.

hyper

Long bundles of contractile proteins found in the sarcoplasm are called

myofibrils

long bundles of contractile proteins found in the sarcoplasm are called ______

myofibrils or myofibril

Each myofibril contains many _____ , each extending from one Z line to the next.

sarcomere

The _______ are repeating units within muscle fibers that act as the functional units of muscle contraction.

sarcomeres

The three types of muscle are ____ muscle, _____ muscle and ________ muscle

skeletal, smooth, cardiac

What is the name of the invaginations of the sarcolemma that extend through the muscle fiber? Multiple choice question. sarcoplasmic reticulum M lines Z lines transverse (T) tubules

transverse (T) tubules

epimysium

entire muscle

What are tendons? Multiple choice question. bands of dense connective tissue that attach bones to other bones sheets of dense connective tissue that anchor muscles to surrounding tissues bands of dense connective tissue that attach skeletal muscles to bones

bands of dense connective tissue that attach skeletal muscles to bones

What is the meaning of the root word inter- (as in intercalated disc)? Multiple choice question. hidden together between above

between

What root word means something inserted? Multiple choice question. calat- laten- erg- tetan-

calat-

The organization of the thin and thick filaments within a muscle cell results in the formation of what muscle feature? Multiple choice question. fascicles perimysium striations sarcoplasmic reticulum

striations

The organization of the thin and thick filaments within a muscle cell results in the formation of what muscle feature? Multiple choice question. sarcoplasmic reticulum fascicles striations perimysium

striations

he different connective tissue coverings in a skeletal muscle fuse to form cordlike structures called _____ which attach muscles to bones.

tendons

A skeletal muscle fiber has a circular shape with many small discs and a holder at the center. A cylindrical shape extends from the holder which has many half hexagonal patterns and a thin strip in between the half hexagonal patterns. A bar with multiple repeating units, representing the organization of the half hexagonal pattern and its thin strip is present below the cylindrical shape. Each unit in the bar contains five segments of colors. The outer lines at the start and the end of each unit represent the outline of the half hexagonal pattern and it is labeled as A. The second, third, and fourth segments are collectively labeled as C, the third segment is labeled as D, and the fifth segment of the first unit and the first segment of the second unit are collectively labeled as B.

A matches Choice Z line B matches Choice I band C matches Choice A band D matches Choice M line

A skeletal muscle fiber has a circular shape with many small discs and a holder at the center. A cylindrical shape extends from the holder. The holder is labeled as A. The cylindrical shape has many half hexagonal patterns and a thin strip in between the half hexagonal patterns. The thin strips are labeled as D. The half hexagonal patterns are labeled as C. The edge surface of the cylindrical shape is labeled as B. A bar with multiple repeating units, representing the organization of the half hexagonal pattern and its thin strip is present below the cylindrical shape. Each unit in the bar contains five segments of colors

A matches Choice sarcoplasmic reticulum B matches Choice myofibril C matches Choice thin filament D matches Choice thick filament

A cross-section of a skeletal muscular system shows a circular shape on the left side that has many discs, and closely packed cylindrical shapes extending from the discs. An oval shape on the top edge of the circular shape is labeled as C. The cylindrical shape has a thin tube on its surface labeled as A. A small vertical tube on a ring surrounding the cylindrical shape is labeled as B. A small spherical particle in between the circular discs at the right bottom is labeled as D.

A matches Choice sarcoplasmic reticulum B matches Choice transverse tubule C matches Choice nucleus D matches Choice mitochondrion

A cross-section of a skeletal muscular system shows a circular shape on the left side that has many discs, and closely packed cylindrical shapes extending from the discs. An oval shape on the top edge of the circular shape is labeled as D. The outline of the circular edge on the left is labeled as A. A small vertical tube on a ring surrounding the cylindrical shape is labeled as B. A layer below the cylindrical shape is labeled as C.

A C

How many myofibrils and sarcomeres are found in a muscle fiber? Multiple choice question. Each muscle fiber contains a single myofibril made of 10-15 sarcomeres. Each muscle fiber contains a single myofibril made of a single, long sarcomere. Each muscle fiber contains many myofibrils, each made of many sarcomeres joined end to end.

Each muscle fiber contains many myofibrils, each made of many sarcomeres joined end to end.

Actin (thin) filaments are attached to a Z line, which is located in the middle of what region of the striations? Multiple choice question. H zone A band I band

I band

Actin (thin) filaments are attached to a Z line, which is located in the middle of what region of the striations? Multiple choice question. H zone I band A band

I band

The ______ of a sarcomere is composed primarily of actin. Multiple choice question. Z line I band H zone A band

I band

Which statements correctly describe changes in a skeletal muscle cell during muscle contraction? Multiple select question. Sarcomeres overlap during contraction. Myofilaments overlap during contraction. Sarcomeres shorten during contraction. Myofilaments shorten during contraction. Muscles shorten during contraction.

Myofilaments overlap during contraction. Sarcomeres shorten during contraction. Muscles shorten during contraction.

List in order the events leading to excitation of a muscle fiber.

Nerve impulse arrives distal end of axon. Release of acetylcholine. Diffusion of ACh across synaptic cleft. Binding of ACh to receptors on muscle fiber sarcolemma. Increase in membrane permeability to sodium ions.

True or false: Within a myofibril, each I band is bisected by a Z line to which the thin filaments are attached.

TRUE

Describe the dark bands in the striations of skeletal muscle fibers. Multiple choice question. They are called I bands and include the area of actin and Z disc interaction. They are called A bands and include the area of overlap of actin and myosin. They are called A bands and include the area of actin and Z disc interaction. They are called I bands and include the overlap of actin and myosin.

They are called A bands and include the area of overlap of actin and myosin.

What is muscle fiber? Multiple choice question. a whole muscle a bundle of muscle cells a muscle group a muscle cell

a muscle cell

When is acetylcholine released into the synaptic cleft of a neuromuscular junction? Multiple choice question. When a nerve impulse reaches the end of the axon. When ATP binds to the myosin cross-bridges. After the muscle contraction is completed

When a nerve impulse reaches the end of the axon.

What is a muscle fascicle? Multiple choice question. a bundle of skeletal muscle fibers a connective tissue layer surrounding individual muscle fibers a connective tissue structure that anchors skeletal muscles to bone a calcium storing organelle within muscle fibers

a bundle of skeletal muscle fibers

What is a muscle fascicle? Multiple choice question. a connective tissue layer surrounding individual muscle fibers a bundle of skeletal muscle fibers a connective tissue structure that anchors skeletal muscles to bone a calcium storing organelle within muscle fibers

a bundle of skeletal muscle fibers

When a nerve impulse reaches the end of the motor neuron axon, what is released into the synaptic cleft? Multiple choice question. ATP acetylcholine tropomyosin calcium

acetylcholine

When a nerve impulse reaches the end of the motor neuron axon, what is released into the synaptic cleft? Multiple choice question. ATP tropomyosin calcium acetylcholine

acetylcholine

During excitation of a muscle fiber, which one of the following events comes immediately after the release of acetylcholine from the motor neuron? Multiple choice question. action potential arrives at the synaptic knob of the motor neuron acetylcholine binds to its receptors acetylcholine diffuses across the synaptic cleft sodium enters the muscle cell

acetylcholine diffuses across the synaptic cleft

In a muscle contraction, the force that shortens the sarcomeres comes from the myosin cross-bridges pulling on the ____ filaments

actin

Describe the Z line that is seen within striations of skeletal muscle. Multiple choice question. direct attachment for the thin filaments; bisects the I band direct attachment for the thin filaments; bisects the A band direct attachment for the thick filaments; bisects the A band direct attachment for the thick filaments; bisects the H zone

direct attachment for the thin filaments; bisects the I band

thick filaments

myosin

What are the two major protein types found in myofibrils? Multiple select question. myostatin myosin actin isotropin

myosin actin

Each thick filament is composed of many molecules of ______, each of which is consists of two twisted protein strands with globular parts called ______

myosin heads

A band (dark band)

myosin and actin filaments

What generates the force that shortens the sarcomeres to bring about muscle contraction? Multiple choice question. troponin pulling on the tropomyosin myosin cross-bridges pulling on the actin filaments cross-bridges dissociating from actin filaments ATP binding to myosin heads

myosin cross-bridges pulling on the actin filaments

What is the function of acetylcholine? Multiple choice question. the fuel source for the production of ATP protein that forms part of the thick filaments neurotransmitter that stimulates the muscle to contract enzyme that initiates the breakdown of glucose to produce ATP

neurotransmitter that stimulates the muscle to contract

What is the meaning of the word root hyper-? Multiple choice question. over equal stretched hidden

over

The T tubules of a muscle fiber are extensions of the ______ and contain extracellular fluid.

sarcolemma

What term is used for the plasma membrane of a muscle fiber? Multiple choice question. sarcoplasm sarcolemma striation T-tubule

sarcolemma

Within myofibrils, the area between two successive Z lines is called a(n) ______. Multiple choice question. A band sarcomere thick filament thin filament

sarcomere

Myofibrils are formed by many ______ positioned end-to-end. Multiple choice question. muscle fibers T tubules sarcomeres myofilaments

sarcomeres

The cytoplasm of a muscle fiber is called the _____

sarcoplasm

The membranous organelle within muscle fibers, called the _______ reticulum, corresponds to the smooth endoplasmic reticulum of other cells.

sarcoplasmic

What is the name of the network of membranous channels that surrounds each myofibril within a muscle fiber? Multiple choice question. endomysium Golgi apparatus transverse tubules sarcoplasmic reticulum

sarcoplasmic reticulum

When a nerve stimulates a skeletal muscle fiber, the response of the sarcolemma is to increase its permeability to ______. Multiple choice question. calcium acetylcholine sodium

sodium

The response of the sarcolemma to stimulation by a nerve impulse is to open ______. Multiple choice question. sodium channels, allowing sodium to enter the cell acetylcholine channels, allowing ACh to enter the cell calcium channels, allowing calcium to enter the cell

sodium channels, allowing sodium to enter the cell

What is the meaning of the prefix calat- (as in intercalated disc)? Multiple choice question. over or more between something catabolic something inserted

something inserted

In excitation-contraction coupling, the protein called _____ moves to expose binding sites on the actin filaments that can form cross-bridges.

tropomyosin

What are thin filaments composed of? Multiple choice question. bundles of myosin bundles of myosin and troponin two intertwined strands of actin

two intertwined strands of actin

What are thin filaments composed of? Multiple choice question. bundles of myosin two intertwined strands of actin bundles of myosin and troponin

two intertwined strands of actin

What is the meaning of the root word erg- (as in the term synergist)? Multiple choice question. stiff together work muscle

work