BIO 201 Chapter 9

What root word means "muscle"

Myo-

The point of attachment for a muscle that remains relatively stationary is its \_____.

Origin

A muscle that opposes the action at a joint is classified as a(n) \_____

Antagonist

When describing the roles of muscles in an action, what is the role of the agonist?

To cause an action

Any muscle that assists the agonist during a movement is called a(n) \_____.

Synergists

A muscle that functions to cause an action is referred to as the \_____.

Agonist

What three proteins from the thin filaments of muscle myofibrils?

Troponin, Actin, Tropomyosin

Myofibrils are formed by many \_____ positioned end-to-end.

Sarcomeres

Within myofibrils, the area between two successive Z lines is called a(n) \_____.

Sarcomere

What is the name of the network of membranous channels that surrounds each myofibril within a muscle fiber?

Sarcoplasmic reticulum

Numerous openings in the sarcolemma of a muscle fiber lead down into structures called the \_____.

Transverse tubules

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

True- Cisternae are enlarged (dilated) areas of the sarcoplasmic reticulum.

Name the invaginations of the sarcolemma that extend through the muscle fiber.

Transverse (T) tubules

What structures are positioned between adjacent cisternae of the sarcoplasmic reticulum?

Transverse tubules

The prefix \_____ means over or more.

Hyper-

What root word means between?

Inter-

What is the meaning of the word root iso- (as in isotonic)?

Equal

What are the two major protein types found in myofibrils?

Myosin, actin

The biceps brachii is an organ of the \_____ system.

Muscular

Dense connective tissue cords that anchor muscles to bone are called \_____.

tendons

A bundle of skeletal muscle fibers enclosed by a perimysium forms a(n) \_____ within a muscle.

Fascicles

Name the connective tissue layer that surrounds individual muscle fibers within a muscle.

Endomysium

What are myofibrils?

Bundles of proteins in a muscle cell

Due to their shape, muscle cells are also called muscle \_____.

Fibers

What are tendons?

Bands of dense connectie tissue that attach skeletal muscles to bones

Long bundles of contractile proteins found in the sarcoplasm are called \_____.

Myofibrils

Due to their shape, muscle cells are also called muscle \_____.

Fiber

Dense connective tissue cords that anchor muscles to bone are called \_____.

Tendons

Indicate three characteristics of skeletal muscle fibers.

Elongated cells, Multinucleated, Cylindrical shape

What term is used for the plasma membrane of a muscle fiber?

Sarcolemma

The thick filaments are composed of \_____ proteins.

Myosin

List the three components of thin filaments.

Troponin, Actin, Tropomyosin

The organization of the thin and thick filaments within a muscle cell results in the formation of what muscle feature?

Striations

What are thin filaments composed of?

Two intertwined strands of actin

Binding sites for the myosin heads (cross-bridges) are found on the which of the proteins found within the thin filaments?

Actin

Name the long rod-like protein that sets in the longitudinal grooves along the thin filaments.

Tropomyosin

Troponin and tropomyosin are associated with that other protein within the muscle fibers?

Actin

What is fascia?

Dense connective tissue surrounding and separating muscles

A broad sheet of fibrous connective tissue that attaches a muscle to aonnective tissues of adjacent muscles is called a(n) \_____.

Aponeuroses

The layer of connective tissue that most closely surrounds an entire skeletal muscle is called the \_____.

Epimysium

Match the connective tissue layers with the structures they surround.

Epimysium- Entire muscle, Endomysium- Muscle fiber, Perimysium- Fascicle

Name the connective tissue layer that separates a skeletal muscle into fascicles.

Perimysium

What are myofibrils?

Bundles of proteins in a muscle cell

What are tendons?

Bands of dense connective tissue that attach skeletal muscles to bones

Which muscle type has multinucleated cells that are cylindrical in shape?

Skeletal muscle

Intertwined strands of actin make up part of the \_____ filaments.

Thin

Correctly list, from superficial to deep, the connective tissue layers associated with a skeletal muscle.

Epimysium

Perimysium

Endomysium

Where is perimysium found?

Around individual muscle fascicles

Name the connective tissue layer that separates a skeletal muscle into fascicles.

Perimysium

When a muscle contracts, its attachment point, called its \_____, is pulled towards its origin.

Insertion

As indicated by its name, the quadriceps femoris has \_____ origins.

4

The triceps brachii is the main muscle that causes extension of the elbow. What is the name of the role of the triceps brachii in this example?

Acts as prime mover

List the four components of a lever.

Rigid bar or rod

Pivot point

Object to move

Force

A \_____-class leer has its components arranged as resistance-fulcrum-force.

First

List the arrangement of components found in a second-class lever.

Fulcrum-resistance-force

A \_____-class lever has its components arranged as resistance-foce-fulcrum.

Third

The upper limb, as it bends at the elbow, can be viewed as a lever. For each upper limb structure, indicate what part of a lever it corresponds to.

Muscles of anterior arm- Force that supplies energy

Forearm bones- Rigid bar/rod

Hand holding a weight- object moved against resistance

Elbow joint- Fulcrum (pivot point)

The end of a muscle that is fixed (relatively immovable) is called its \_____.

Origin

A simple mechanical device consisting of a rigid bar, a fulcrum, weight, and a force that is applied to some point on the bar is called a(n).\______

Lever

Which three characteristics are signs of aging in the muscular system?

Slow reflexes

Weak contractions

Atrophy

True or false: Muscles tend to atrophy with age.

True

What root word means "together"?

Syn-

The \_____ region of a sarcomere is composed primarily of actin.

I band

A T-tubule and its two adjoining cisternae constitute a(n) \_____.

Triad

The protein \_____ holds tropomyosin in place along the thin filament.

Troponin

Identify the components of a muscle triad.

A T tubule and its associated cisternae

Match each striation and with its composition.

I band (light band)- Actin (thin) filaments only

A band (dark band)- Myosin and actin filaments

H zone- Myosin (thick) filaments only

Differentiate between the deep fascia and the subcutaneous fascia.

Deep fascia surrounds individual muscles; subcutaneous fascia underlies the skin

Actin (thin) filaments are attached to a Z line, which is located in the middle of what region of the striations?

I band

Within a sarcomere, what is the H zone?

Region within the A band that lacks thin filaments

Which of the following best describes the M line found within sarcomeres?

The M line is in the middle of the H zone, providing an attachment point for the thick filaments.

The protein called \_____ anchors myosin filaments to the Z lines.

Titin

Describe the dark bands in the striations of skeletal muscle fibers.

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

Within a sarcomere, the region within the A band that lacks thin filaments is called the \_____.

H zone

The root word -troph means "well \_____".

Fed

What is the meaning of the root word laten- (as in latent period)?

Hidden

What word root means flesh?

Sarco-

What is the meaning of the root word syn-?

Together

What root word means stiff?

Tetan-

A space enclosed in fascia containing a group of muscles and their associated blood vessels and nerves is called a(n) \_____.

Compartment

What is the meaning of the root word erg- (as in the term synergist)?

Work

What root word means something inserted?

Calat-

* epimysium → entire muscle


* endomysium→ muscle fiber


* perimysium→ fascicle

The cytoplasm of a muscle fiber is called the

SARCOPLASM

Individual muscle fibers are surrounded by a connective tissue layer called the

endomysium

Indicate **three** characteristics of skeletal muscle fibers.

cylindrical shape

multinucleated

elongated cells

A bundle of skeletal muscle fibers enclosed by a perimysium forms a(n) __ within a muscle.

fascicle

What are *tendons*?

bands of dense connective tissue that attach skeletal muscles to bones