CH 9

A motor neuron controls several Blank______.

several muscle fibers

True or false: A whole muscle is usually innervated by more than one neuron.

true

Each myosin molecule is composed of Blank______ heavy chains and Blank______ myosin heads.

2,2

A myofibril is about Blank______ than a human hair.

6 times smaller

The layer of connective tissue that separates muscle fibers is called Blank______.

epimysium

List the functional properties of all muscle tissue types..

excitability, contractility, extensibility, and elasticity.

Myofibrils Blank______.

extend from one end of the muscle fiber to the other are bundles of protein filaments

Myosin heads bind to Blank__

globular actin

The fibrous protein that winds along the groove of the F actin double helix and blocks the myosin-binding sites on the actin filaments is called

tropomysoin

The function of a tendon is to Blank__

connect muscles to bone connect muscles to the skin

The major functions of muscle cells include Blank__

constriction of organs and vessels body movement respiration

The H zone Blank______

contains only myosin myofilaments

The A band of the sarcomere Blank__

contains the H zone and M line extends the length of the myosin myofilaments contains both actin and myosin proteins

The sarcomere is called the basic functional unit of a muscle fiber because it is the smallest part of the fiber that is capable of Blank___

contracting

A neuron that innervates skeletal muscle fibers is called a(n) neuron.

motor

Hypertrophy of muscles results from an increase in the Blank______.

size of muscle fibers

Production of body heat is a function of Blank______ muscle cells.

skeletal

What type of muscle tissue is depicted in the given figure? 3 straight flat lines

skeletal

Which muscle tissue type has cells with multiple nuclei?

skeletal

Which muscle tissue type is the most abundant? Multiple choice question.

skeletal

The sarcolemma is Blank______.

a cell membrane

A sarcomere is formed from the arrangement of and myosin myofilaments.

actin

Which is the thinnest myofilament?

actin

During contraction of the sarcomere, the Z disk helps hold the Blank______ in place.

actin myofilaments

What type of muscle cell is responsible for voluntary contraction or movement?

skeletal muscle cells

Striated, multinucleate myofibers would be classified as Blank______ muscle tissue; striated, uninucleate, branching myofibers are Blank______ muscle and non-striated, filiform myofibers are Blank______ muscle. Multiple choice question.

skeletal, cardiac, smooth

Constriction of organs and blood vessels is a function of Blank______ muscle cells.

smooth

The muscle tissue type found in the walls of hollow organs, such at the stomach and uterus, is Blank______ muscle tissue

smooth

The type of muscle that is primarily responsible for the movement of food down the esophagus and through the intestine is muscle.

smooth

Muscles are connected to bones or the skin by

tendons

A skeletal muscle fiber is Blank______ a skeletal muscle cell.

the same as

Cardiac muscle is found within Blank______.

the wall of the heart

What are the transverse (T) tubules?

they are tube-like invaginations of the sarcolemma that extend inward throughout the muscle cell.

Choose the large protein that is attached to Z disks and extends along the myosin myofilaments to the M line and functions as a spring.

titin

Tube-like invaginations of the sarcolemma that conduct action potentials toward the center of the muscle fiber are called Blank______.

transverse tubules

Skeletal muscle tissue is Blank______.

voluntary

Muscle fibers are found Blank______ a muscle fascicle.

within

The muscle tissue type shown here is _____ muscle. gaps

cardiac

The chambers of the heart are composed of Blank______ muscle tissue; food is propelled through the intestines by Blank______ muscles and Blank______ muscles allow voluntary movements like walking and talking. Multiple choice question.

cardiac, smooth, skeletal

The area of the sarcomere where the actin and myosin myofilaments overlap is called the Blank___

A band

Which of the following labels (A-D) represents the epimysium?

B

Identify the structure indicated by the letter B in the figure of a muscle.

Epimysium

The figure represents a cross section through the sarcomere. This cross section was most likely taken from which of the following areas?

A band

How are muscle fibers and muscle fascicles structurally related to each other?

A muscle fasciculus is composed of groups of muscle fibers bundled together.

Which of the following accurately describes the structure of a muscle?

A single skeletal muscle fiber can extend from one end of a muscle to the other. A skeletal muscle fiber is a single, long, cylindrical cell containing several peripherally located nuclei

Identify characteristics of hypertrophy.

Can occur in response to exercise Is an increase in the size of a muscle fiber

Which muscle tissue types are striated?

Cardiac muscle and skeletal muscle

The ability of muscle to shorten forcefully is called Blank______.

Contractility

The active site for myosin binding is indicated by which of the labeled structures (A-D)?

D

Cardiac muscle cells are Blank______, which allows them to contract spontaneously and rhythmically.

autorhythmicity

During muscle contraction, each Blank______ monomer has an open active site to bind with the protein myosin.

G-Actin

Each Blank______ includes a Z disk and extends from each side of the Z disk to the ends of the myosin myofilaments

I band

Each Blank______ includes a Z disk and extends from each side of the Z disk to the ends of the myosin myofilaments.

I band

Smooth muscle cells

Involuntary contraction of the GI tract spindle-shaped cells with a single centrally located nucleus Surrounds hollow organs, filiform in shape, non-striated

Cardiac muscle cells

Involuntary contraction of the heart muscle Cylindrical, branched cells with a single centrally located nucleus Striated, uninucleate, striated and possessing intercalated disks

Which are true of troponin?

It has a binding site for calcium ions. It is bound to both actin and tropomyosin. It is a globular protein composed of three subunits.

The line in the center of the H zone that holds myosin myofilaments in place is the line.

M

Which of the following are characteristics of a skeletal muscle fiber?

Multinucleate Cylindrical

Which best describes how skeletal muscle fibers are produced?

Several myoblasts fuse to form a single myofiber.

Contractility is the ability of a muscle to Blank______ forcefully.

Shorten

Which muscle tissue types are striated?

Skeletal and cardiac

Which are types of muscle tissue?

Smooth, skeletal, and cardiac

Which structure associated with a muscle fiber is indicated by the letter B?

T tubule

Epimysium

The dense collagenous connective tissue that surrounds the entire muscle

Muscular fascia

The dense irregular collagenous connective tissue located superficially that separates and compartmentalizes individual muscles or groups of muscles

Perimysium

The heavy connective tissue layer surrounding each fasciculus

List the arrangement of connective tissue layers from most superficial to deepest in a muscle.

The muscular fascia overlays the epimysium which overlays the perimysium which overlays the endomysium.

Within a myofibril, calcium-binding sites are found on Blank____

Troponin

True or false: A whole muscle is usually innervated by more than one neuron.

True

Skeletal muscle cells

Voluntary movement of the bones Long, cylindrical, non-branching cells with many peripherally located nuclei Most abundant muscle type, multinucleate, and striated

A whole muscle is typically innervated by Blank______.

more than one neuron

Tendons are formed from Blank______.

collagen fibers

The H zone is Blank______ than the A band.

smaller

Hypertrophy of muscles results from an increase in the Blank__

size

The A band of the sarcomere Blank___

extends the length of the myosin myofilaments contains the H zone and M line contains both actin and myosin proteins

Muscle tissue has four major functional properties including ___, ____, ___ , and elasticity.

extensibility contractility excitability

The structure labeled A in the figure of a skeletal muscle is a(n) Blank______

fascicle

Another name for a skeletal muscle cell is a muscle ______

fiber

A muscle fascicle is Blank______ than a muscle fiber.

larger

Titin is the Blank______ protein in humans.

largest

An I band is a Blank______ staining region of a sarcomere. Multiple choice question.

lighter

What structure of skeletal muscle is the letter A indicating in the given figure?

muscle fiber or 1 cell

Muscle fibers develop from less mature, multinucleated cells called Blank______

myoblasts

Each G-actin monomer has an active site for the binding of what molecule?

myosin

The golf club shaped contractile molecule which includes an ATPase enzyme is called Blank__

myosin

During contraction of the sarcomere, the M line helps hold the Blank______ in place.

myosin filaments

What part of the myosin filaments bind to actin?

myosin heads

Motor neurons extend to skeletal muscle fibers through Blank_

nerves

The nerve fiber innervates the muscle fiber at the Blank__

neuromuscular junction

The plasma membrane of a muscle fiber is called the

sarcolemma

The actin and myosin myofilaments form highly ordered units called Blank______, which are joined end to end to form the Blank______.

sarcomeres, myofibrils

The structure that is a modified form of smooth endoplasmic reticulum located in muscle cells is called reticulum.

sarcoplasmic

In a muscle cell, the highly specialized, smooth endoplasmic reticulum is called the Blank__

sarcoplasmic reticulum