Chapter 9- Muscular system

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

Slow reflexes Weak contractions Atrophy

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

Transverse (T) tubules

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

Transverse tubules

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

Transverse tubules

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

Triad

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

Tropomyosin

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

Troponin

List the three components of thin filaments.

Troponin, Actin, Tropomyosin

What three proteins from the thin filaments of muscle myofibrils?

Troponin, Actin, Tropomyosin

True or false: Muscles tend to atrophy with age.

True

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

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

What are thin filaments composed of?

Two intertwined strands of actin

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

4

Identify the components of a muscle triad.

A T tubule and its associated cisternae

The root word -troph means "well _____".

Fed

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

Fiber

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

Fibers

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

First

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

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

Agonist

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

Actin

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

Actin

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

Antagonist

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

Aponeuroses

Where is perimysium found?

Around individual muscle fascicles

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

Sarcoplasmic reticulum

What are tendons?

Bands of dense connectie tissue that attach skeletal muscles to bones

What are tendons?

Bands of dense connective tissue that attach skeletal muscles to bones

What are myofibrils?

Bundles of proteins in a muscle cell

What root word means something inserted?

Calat-

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

Compartment

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

Skeletal muscle

Differentiate between the deep fascia and the subcutaneous fascia.

Deep fascia surrounds individual muscles; subcutaneous fascia underlies the skin

What is fascia?

Dense connective tissue surrounding and separating muscles

Indicate three characteristics of skeletal muscle fibers.

Elongated cells, Multinucleated, Cylindrical shape

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

Endomysium

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

Epimysium

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

Epimysium Perimysium Endomysium

Match the connective tissue layers with the structures they surround.

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

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

Equal

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

Fascicles

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

Fulcrum-resistance-force

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

H zone

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

Hidden

The prefix _____ means over or more.

Hyper-

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

I band

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

I band

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

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

Insertion

What root word means between?

Inter-

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

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 biceps brachii is an organ of the _____ system.

Muscular

What root word means "muscle"

Myo-

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

Myofibrils

The thick filaments are composed of _____ proteins.

Myosin

What are the two major protein types found in myofibrils?

Myosin, actin

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

Origin

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

Origin

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

Perimysium

Within a sarcomere, what is the H zone?

Region within the A band that lacks thin filaments

List the four components of a lever.

Rigid bar or rod Pivot point Object to move Force

What word root means flesh?

Sarco-

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

Sarcolemma

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

Sarcomere

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

Sarcomeres

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

Striations

What root word means "together"?

Syn-

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

Synergists

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

Tendons

What root word means stiff?

Tetan-

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.

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.

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

Thin

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

Third

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

Titin

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

To cause an action

What is the meaning of the root word syn-?

Together

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

Work

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

tendons