A&P CH.10: muscle tissue

muscle tissue is responsive for the ________ of materials within and throughout the body

movement

skeletal muscle fibers are -anucleate -multinucleate -binucleate -uninucleate

multinucleate

which are characteristics of glycolytic fibers?

- white -low concentration of myoglobin

which of the following proteins are found within a sarcomere?

-connection -actin

blood vessels dilivernurients and oxygen to the muscle fibers so that they can produce the molecule _____ which is needed for contraction.

ATP

energy to drive the myosin movement in the sliding filament process is provided in the form of _______

ATP

Storage and movement of materials

Voluntary sphincter muscles of the gastrointestinal and urinary tracts can be kept closed or opened

contraction of a muscle fiber requires that the myosin heads in the thick filament bind to active sites on ______ molecule within the thin filaments

actin

each myosin head in a thick filament can bind to what protein in a thin filament?

actin

with endurance training, it is possible;e for fast _____ fibers to take take on characters of fast _____ fibers.

glycolytic, oxidative

in a concentric isotonic contraction, the tension produces is _____ than the resistance .

greater

Slow muscle fibers are about ____ the diameter of fast muscle fibers.

half

types of isotonic contractions

concentric and eccentric

a person tolerance for exercise _____ with age.

decreases

the motor neuron axon travels through the epimysium and perimysium, and enters the ______, where it delivers a nerve impulse to an individual _______.

endomysium, muscle fiber

muscle connective tissue layer

epimysium

order in which ACh diffuses across the synaptic cleft of a NMJ

-ACh binds to receptors on the motor end plate -the resulting action potential moves down the sarcolemma -the action potential moves down the t- tubules -the action potential reaches the terminal cistern of the SR -calcium ions are releases into sarcoplasm

what can cause muscle fatigue?

-Na+ or K + imbalances -insufficient Ca^2+ -build up of intracellular P¡

thin filaments in smooth muscle cells contain which proteins?

-actin -tropomyosin

where is smooth muscle found?

-around blood vessels -in the wall of the small intestines -in the wall of the uterus

multiunit smog muscle is found in where?

-arrector pili muscles in the skin -iris of eye

Events at the Neuromuscular Junction

-arrival of nerve signal at synaptic knob -calcium entry into synaptic knob -exocytosis of ACh into synaptic cleft -binding of ACh to motor end plate

characteristics of oxidative fibers

-high concentration of myoglobin -use aerobic respiration -red -good for endurance

Smooth muscle shows different length-tension relationship than skeletal muscle because...

-it lacks Z discs but has dense bodies -the arrangement of the thick and thin filaments allow for contraction even when stretched

a neuromuscular junction contains an...

-motor end plate -synaptic cleft -synaptic knob

cross bridge cycling

-myosin heads bind to actin -myosin heads pivot towards the M line -ATP releases the myosin heads -ATPase re-cocks the myosin heads

examples of isometric contraction

-sitting up very straight -holding a yoga pose -pushing on a locked door

steps of cross-bridge cycling

1. cross-bridge formation 2. power stroke 3. release of myosin head 4. reset myosin head

hypertrophy results from an increase in the number of _____ in a muscle cell.

myofibrils

the sarcoplasm of a skeletal muscle fiber contains hundreds to thousands of long, cylindrical structures called _______ that extend the length of the cell.

myofibrils

as a result of exercise, each muscle fiber develops more myofibrils, and each myofibril contains a larger number of ________.

myofilaments

muscle cells store oxygen bound to what molecule?

myoglobin

thick myofilaments are composed of bundles of what protein molecule?

myosin

Slow fibers or type 1 fibers are also called ____ fibers because they contain the pigment myoglobin

red

conduction speed of smooth muscle

slow

relaxation period

tension decreases

slow twitch and fast twitch fibers differ primarily in:

their ATPase which splits ATP

the sodium-potassium exchange pumps moves _____ sodium ions out of the cell for every ______ potassium ions it brings in

3;2

the sarcoplasmic reticulum stores ________ ions needed to initiate muscle contraction

Ca

in a thin filament, individual G-actin molecules are strung together to form _______.

F-actin

in a sarcomere, the ____ zone (or band) is the light, central region pf the A band,

H

when viewed under a light microscope, the light bands, called ____ bands, contain only _____ filaments

I, thin

in smooth muscle cells, the sarcoplasmic reticulum is sparse, and the __ tubules are absent

T

______ distribute the muscle impulse throughout the inside of the muscle fiber.

T-tubules

the _____ discs that anchor the sarcomere on either ending skeletal muscle are absent from smooth muscle cells.

Z

elasticity

a contracted muscle cells recoils to its resting length when the applied tensions is removed.

Extensibility

a muscle cell is capable of extending in length in response to the contraction of opposing muscle cells.

To start a muscle contraction, a nerve impulse causes ______ release at a neuromuscular junction.

acetylcholine

What does ACh stand for?

acetylcholine

to stop motor end plate stimulation, usually acetylcholine is quickly broken down and removed from the receptor by _______.

acetylcholinesterase

cardiac muscle cells use _____ respiration almost exclusively.

aerobic

a muscle cell obtains ATP in the short term via what process

anaerobic respiration

the ATP needed to fuel a 100mm sprint would be supplied primarily from.....

anaerobic respiration

the connective tissue layers in muscle provide: protection, distribution sites for blood vessels and nerves, and a means of ______ to the skeleton

attachment

the rate of rhythmic contraction of cardiac muscle is controlled by the ______ nervous system.

autonomic

troponin

bound to tropomyosin; can bind calcium ions

fascicle

bundle of muscle fibers

the cyclic events of "attach, pivot, detach, return" continue as long as ______ ions remain bound to the troponin

calcium

calmodulin

calcium binding protein

during contraction of smooth muscle, ________ binds to calcium and activates myosin light chain kinase

calmodulin

the wall of the heart is composed of _____ muscle

cardiac

a muscle fiber is what level of organization in the body?

cellular

the long tails of the myosin molecules in the thick filaments point toward the _______ of the filaments.

center

the ACh receptors on the motor end plate are ______ ion channels

chemically-gated

the enzyme acetylcholinesterase resides in the synaptic ______.

cleft

As a result of muscle fiber contraction, thick filaments in neighboring sarcomeres move ______.

closer together

in ______ tetany, a muscle cell is stimulated so frequently that it is not allowed to relax at all between stimuli.

complete

a _______ contraction of the arm muscle allows you to lift a book from the table, while a _______ contraction of he arm muscle allows you to lower the book back down to the table.

concentric, eccentric

when smooth muscle is stretched, it responds by...

contracting then relaxing

the skeletal muscles arranged in layers along the walls of the abdominal cavity and the floor of the pelvic cavity perform what function?

contraction support protection

posture

contraction pf a specific skeletal muscles tables joint

the amount of additional oxygen that must be inhaled in order to restore pre-exercise levels is called oxygen ________.

debt

a sheet of dens irregular connective tissue that is external to the epimysium and separates individual muscles is the ________.

deep fascia

Anchoring point between intermediate filaments and the sarcoplasm

dense body

in a muscle, the perimysium is composed of what type of connective tissue?

dense irregular

Anchoring point between intermediate filaments and the sarcolemma

dense plaque

MLCP

dephosphorylates myosin

a sarcomere is defines as the distance from one Z _____ to the next

disc

after a contraction, muscle returns to its original relaxed position due to its natural _______.

elasticity

muscle tissue demonstrates the property of _____ when it is done contracting and returns to its resting length

elasticity

muscle fiber

elongated multinucleate, cylindrical cell

muscle cell conceive tissue layer

endomysium

true or false: after diffusing across the synaptic cleft, ACh binds to receptors on the synaptic knob

false

true or false: in smooth muscle contraction the thick and tin filaments slide past one another causing the Z lines to move closer together.

false: there are no Z lines in smooth muscle cells

in a transverse section pf a muscle, you can see that each skeletal muscle is actually composed of many _____, which are bundles of muscle fibers.

fascicles

conduction speed of skeletal muscle

fast

a piano player uses her hands for bread quick movements. which muscle fiber type would you therefore predict to be predominant in these muscles.

fast glycolytic

which of the three skeletal muscle fiber types has the largest diameter and provides both power and speed?

fast glycolytic

if used repeatedly for endurance events, ______ fibers can develop the appearance and functional capabilities of ______ fibers.

fast/intermediate

intermediate fibers have a high resistance to _______.

fatigue

overall, as aging progresses, muscle strength and endurance are impaired, and the individual has a tendency to _____ quickly.

fatigue

smooth muscle is composed of short cells that have a _____ shape.

fusiform

each myosin strand has a free _____ and an attached tail

head

temperature regulation

heat is produced as a waste product of energy usage

the diameter of a muscle fiber will predict:

how much power it will produce

an increase in muscle fiber number is called______

hyperplasia

what structure anchors adjacent cardiac muscle cells together?

intercalate disc

cardiac muscle cells form Y shaped branches and join to adjacent muscle cells at junctions called ______ discs.

intercalated

an adult is holding a baby is a steady upright position, when he leans the baby down so it is facing the sky, is an example of an _______ contraction

isometric

during an ______ contraction, the length of the ,muscle does not change.

isometric

the ______ mechanism allows Smoot muscle to maintain muscle contraction without the use of additional ATP

latchbridge

in order to predict how much tension a muscle can produce when contracting, it is important to consider the ______ relationship of thick and thin filaments

length-tension

I band

light band containing thin filaments only

H Zone

lighter region in the middle of an A band

Myofibril

long, cylindrical contractile element within muscle cell

Z- disc

made of dark proteins that create a zig zag line

muscle fiber

metabolic activities, contraction

conduction speed of cardiac muscle

moderate

athletes have more defined muscles than non-athletes even while at rest because they have ______ motor units contracting all the time.

more

The neurons that stimulate muscle contraction are called _____ neurons.

motor

although muscle fibers obey the all-or-none principle, the force of muscle contraction can be varied depending on how many ______ units are used

motor

in a motor unit, a single ________ neuron typically controls numerous muscle fibers in a muscle.

motor

upon release from the synaptic knob, acetylcholine attaches to receptors on the _____.

motor end plate

muscle

multiple bundles housing many muscle fibers

body movement

muscle contract and pull on the tendon that attach the muscles to the bone

a skeletal muscle cell is also called a _____ ____.

muscle fiber

Myofibrils are made of ______.

myofilaments

the point where a motor neuron meets a skeletal muscle fiber is called the ______ junction

neuromuscular

where a motor neuron axon terminal and a muscle cell meet is called a _______ junction.

neuromuscular

the motor end plate is a specialized region of the ________.

sarcolemma

the plasma membrane of a skeletal muscle fiber is called the ________.

sarcolemma

within a myofibril, each _____ shortens as the muscle fiber contracts

sarcomere

within a myofibril, each ______ shortens as the muscle fiber contracts.

sarcomere

within a myofibril, z dies separate the functional contractile units known as ______.

sarcomere

in an isotonic contraction, the muscle fibers __________, resulting in the movement.

shorten or lengthen

cardiac muscle cells are _____ and thicker than skeletal muscle cells, and have only ______ nuclei.

shorter, 1-2

sarcoplasm

site of metabolic processes for normal muscle fiber activities

According to the sliding filament theory, when a muscle contracts, thick and thin filaments _____ past each other, and the ______ shortens.

slide, muscle

the _____ filament theory explains how muscle fibers shorten during contraction.

sliding

smooth muscle contraction is ______, resistant to ______, and usually sustained for an extended period of time.

slow, fatigue

the attachment of ACh to the receptor on the motor end plate causes the receptor to open, allowing _____ ions to enter the muscle fiber.

sodium

the sodium-potassium exchange pump maintains a higher concentration of which ion outside the sarcolemma?

sodium

contractibility

stimulation of muscle cells generates tension within cells

sarcoplasmic reticulum

stores calcium ions needed for muscle contraction

the superficial fascia is also known as the _____.

subcutaneous layer

a "step-wise" increase in the force of contraction of a single muscle fiber or single motor unit due to repeated stimulation is called _______.

summation

the narrow space separating the synaptic knob and the motor end plate is called the _______.

synaptic cleft

a nerve impulse travels through an axon to its _____.

synaptic knob

a cord like structure that attaches muscle to bone is a _____

tendon

the force generated when a skeletal muscle is stimulated to contract is muscle ______.

tension

contraction period

tension increases

T-tubules are located adjacent to _______, which are reservoirs storing the calcium ions required for muscle contraction.

terminal cisternae

the epimysium of a muscle surrounds __________.

the entire skeletal muscle

When calcium ion binds to troponin...

the myosin binding sites o action are exposed

latent period

there is no tension

In a sarcomere, the M-line serves as an attachment site for the ______ filaments and keeps them aligned during contraction and relaxation.

thick

in a sarcomere, the M-line serves as n attachment site for _____ filaments and keeps them aligned during contraction and relaxation.

thick

the H band (or H zone) is more lightly shaded because only _____ filaments are present

thick

a cross section of a myofibril through the A band contains which myofilaments?

thick and thin

a cross section of myofibril through the H zone contains which myofilaments?

thick only

the striated appearance in skeletal muscle cells is due to size and density differences between ______ and ______ filaments

thick/thin

single unit muscle cells contract _____.

together

T tubule

transports the action potential from the sarcolemma throughout the entire muscle fiber

in a skeletal muscle cell, two terminal cistern and the centrally places T-tubule from a structure called a _____.

triad

As the troponin molecules change shape, it moves the _____ molecule to which it is attached, thus exposing the active sites on the G-actin molecules

tropomyosin

the two regulatory proteins associated with thin myofilaments are:

tropomyosin and troponin

calcium ions bind to what protein in a thin myofilament?

troponin

true or false: in the absence of calcium, troponin attaches to tropomyosin to hold it in place on the surface of the F actin strand

true

true or false: most molecules contain a combination of all three muscle types, slow oxidative, fast oxidative, and fast glycolytic

true

true or false: playing the piano with your fingers uses very small motor units.

true

true or false: skeletal muscle is usually attached to the skeleton, but it is also found at the openings between the digestive tract and the external environment and the unitary tracts and the opening to the external environment

true

true or false: smooth muscle cells lack transverse tubules.

true

a single contraction and relaxation of a muscle fiber is referred to as a muscle _________.

twitch

tropomyosin

two intertwined strands; cover myosin binding sites

actin

two intertwined strands; each bead has a myosin binding site

thick filaments are about _____ the diameter of thin filaments.

two times

within a synaptic knob, synaptic _______ contain the neurotransmitter ACh

vesicles

have have hooked a frog calf muscle up to a myogram that records muscle tension. you notice that when you stimulate the muscle contract, then allow it to relax, and stimulate it again, that the next time it contracts the amount go tension generated is equal to the two previous waves added together. this phenomenon is called ___________.

wave summation

individual cardiac muscle cells can be stimulated to generate a muscle impulse ______ stimulation.

without nervous

M- line

appears as a dark protein doc in center of H zone

the endomysium is composed what type of connective tissue?

areolar

the superficial fascia, composed of _____ and adipose connective tissue, separates muscle from skin.

areolar

after breaking your arm, you have a cast on it for three months. when the cast is removes, your arm looks much smaller than it did before. what process caused this to happen?

atrophy

cardiac muscle cells are...

autorhythmic

if a skeletal muscle is injured, surrounding _____ cells may be stimulated to differentiate and assist in its repair and regeneration

satellite

Myofilament

short contractile proteins of two types: thick and thin

in a muscle, the perimysium surrounds ______ muscle cells.

fascicles of

cytoskeleton network

intermediate filaments

aerobic respiration requires the presence of what molecule?

oxygen

an extensive network of blood vessels and Nerve fibers extends through both the epimysium and the _____ of a muscle.

perimysium

fascicle connective tissue layer

perimysium

ATP is generated when the enzyme creatine kinase transfer Pi from creatine _______ to ADP

phosphate

MLCK

phosphorylates myosin

As you hold a barbell and begin to flex your arm in a curl, your biceps brachii slowly lifts the weight by using more and more motor units. This phenomenon, which increases the strength of the contraction, is referred to as__________

recruitment

if a skeletal muscle experiences markedly ______ ______, it loses both mass and tone.

reduced stimulation

sarcolemma

regulates entry and exit of materials

Excitability

restiveness to stimuli

an internal membrane complex in skeletal muscle cells that is similar to smooth endoplasmic reticulum of other cells is called the sarcoplasmic ________.

reticulum