Chapter 10: muscle tissue

Hypertrophy results from an increase in the number of ____ in a muscle cell.

myofibrils

myofibrils consist of bundles of short __________

myofilaments

After stimulation of ACh receptors, a muscle impulse spreads quickly along the ______ and into the muscle fiber along T-tubules.

sarcolemma

within a myofibril, Z discs separate the functional units known as _________

sarcomeres

the ________ filament theory explains how muscle fibers shorten during contraction

sliding

An individual has better proficiency in performing repeated contractions under aerobic conditions if he or she has a greater percentage of ______ fibers in specific muscles

slow

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

slow oxidative

Over longer distances, runners who have higher proportions of ______ muscle fibers in their leg muscles are able to outperform runners who have a greater number of ______ muscle fibers in their leg muscles.

slow; fast

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

t-tubule

deep invagination of sarcolemma are called _______

t-tubules

narrow, tubular extensions of the sarcolemma into the sarcoplasm

t-tubules

what is the arrow pointing to?

t-tubules

a thick cordlike structure that attaches muscle to a bone is called a __________

tendon

as a result of ACh stimulation, calcium ions are released from the ________ of the sarcoplasmic reticulum

terminal cisternae

Bind to thin filaments and cause contraction

thick filament

bind to thick filaments and cause contraction

thin filament

an action potential is carried along the sarcolemma, then down _______ tubules to the terminal cisternae of the sarcoplasmic reticulum

transverse

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

more

the vascular supply to slow muscle fibers is ________ than the network of capillaries around fast muscle fibers

more extensive

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

motor

a motor unit is composed of a single ________ and all of the muscle fibers it controls

motor neuron

what is 2 referring to?

I band

metabolic activities; contraction

muscle fiber

when an action potential travels down t-tubules to the terminal cisternae of the SR, what ion is released into the sarcoplasm?

calcium

functionally, troponin provides a binding site for _____ ions

calcium (Ca2+)

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

debt

muscle cells are said to have what characteristic because they can respond to stimulation from the nervous system?

excitability

The majority of skeletal muscle fibers in the body are ______ fibers

fast glycolytic

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

fast glycolytic

after the cross bridges are formed, ATP is required to detach the _________ and complete the sequence of cyclic events

myosin head

thick and thin filaments maintain their ______, whether the muscle is relaxed or contracted

same length

what is the arrow pointing to?

synaptic cleft

what is this pointing to?

synaptic vesicle

The deep invaginations of the sarcolemma that extend into the sarcoplasm of skeletal muscle fibers as a network of narrow membranous tubules are called ______.

transverse tubules

a tropomyosin molecule is a short, thin, twisted filament that covers small sections of the _______ strands

actin

binding site for myosin to shorten a sarcomere

actin

each myosin head in a thick filament can bind to the protein in a thin filament called

actin

two intertwined strands; each bead has a myosin-binding site

actin

what protein is found in a thin filament?

actin

each myosin strand has a free _______ and an attached tail

head

the act of shivering is an example of skeletal muscle performing what function?

heat production

If a muscle cell is stimulated to contract, allowed to partially relax, then stimulated again, its force of contraction the second time will be ______

higher

the diameter of a muscle fiber will predict _______

how much power it will produce

An increase in the number of mitochondria can be observed in ______. Multiple choice question.

hypertrophy

There are two types of isotonic contractions, which include eccentric and _______

concentric

In an isometric contraction, the muscle ______ body movement.

doesn't produce

muscle tissue demonstrates the property of ______ when its done contracting and returns to its resting legnth

elasticity

what is the arrow pointing to? (surrounding the muscle cell)

endomysium

the three connective tissues layers that surround the individual components of a muscle are called what?

endomysium, perimysium, epimysium

what is the arrow pointing to? (surrounding the muscle)

epimysium

a skeletal muscle cell is also called a muscle ______

fiber

When a nerve impulse reaches the end of an axon of a neuromuscular junction, calcium flows _______ the synaptic knob

into

What is the arrow pointing to?

mitochondrion of mucle fiber

what is the force generated when a skeletal muscle is stimulated to contract called?

muscle tension

contain myofilaments that are responsible for muscle contraction

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

Termination of the nerve impulse at an NMJ results in the passive sliding of ______ back to their original state.

myofilaments

What is the arrow pointing to?

nucleus of muscle fiber

As you struggle to twist open a jar, more motor units are called into action until you finally generate enough force to open it. This is an example of ______

recruitment

what are characteristics of oxidative fibers?

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

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

reticulum

what activities are muscles in an isometric contraction?

sitting up straight, holding a yoga pose, pushing on a locked door

an individual has been proficiency in performing repeated contractions under aerobic conditions if he or she has a greater percentage of _________ fibers in specific muscles

slow

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

_________ distribute muscle impulses throughout the inside of the muscle fiber

t-tubule

The force generated when a skeletal muscle is stimulated to contract is muscle ________

tension

slow-twitch and fast-twitch muscle fibers differ primarily in _______

their ATPase which splits ATP

As you sit there reading this your muscles, even your relaxed ones are not completely relaxed and soft. This is because they have some background tension called resting muscle ______

tone

as the troponin changes shape (due to binding calcium), it moves the ________ molecule to which it is attached, thus exposing the active sites on the G-actin molecules

tropomyosin

covers the active sites on actin when muscle cells are at rest

tropomyosin

two intertwined strands; cover myosin-binding sites

tropomyosin

the two regulatory proteins associated with thin myofilaments are _________

tropomyosin and troponin

Upon release from the terminal cisternae, some calcium ions bind to ______ causing it to change shape.

troponin

bound to tropomyosin; can bind calcium ions

troponin

if the sarcoplasm of a muscle sell is flooded with calcium ions, to which protein will they bind?

troponin

upon release from the terminal cisternae, some calcium ions bind to ________ causing it to change shape

troponin

True or false: Most muscles contain a combination of all three muscle types, slow oxidative, fast oxidative, and fast glycolytic

true

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

true

A single contraction and relaxation of a muscle fiber is referred to as a muscle _______

twitch

each myosin protein molecule in a thick filament consists of ________ strands

two

what are characteristics of glycolytic fibers?

white; low concentration of myoglobin

After breaking your arm, you have a cast on it for three months. When the cast is removed, your arm looks much smaller than it did before. The process called ______ caused this to happen.

atrophy

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

calcium

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

cellular

as a result of a muscle fiber contraction, thick filaments in neighboring sarcomeres move _______

closer together

stores calcium ions needed for muscle contraction

sarcoplasmic reticulum

what is the arrow pointing to? (Organelle of the muscle fiber that stores calcium)

sarcoplasmic reticulum

Concentric isotonic contractions actively ______ a muscle.

shorten

when a muscle fiber contracts, which parts of the sarcomere maintain a constant length throughout contraction?

A band

to start a muscle contraction, a nerve impulse causes _________ release at a neuromuscular junction

ACh

what is 7 referring to?

a band

ACh is an acronym for _______

acetylcholine

in a muscle cell, the short term energy is supplied by _________ respiration, whereas long term energy is supplied by ______

anaerobic; aerobic

A piano player uses her hands for brief quick movements. Which muscle fiber type would you therefore predict to be predominant in these muscles?

fast glycolytic

after you stop running, you notice that you keep breathing heavily for some time. this is because your body is in __________

oxygen debt

what is the arrow pointing to? (surrounding the fascicle)

perimysium

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

regulates entry and exit of materials

sarcolemma

the plasma membrane of a skeletal muscle fiber is called the _________

sarcolemma

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

sarcomere

A contracting skeletal muscle fiber typically shortens as all of its ______ shorten in length.

sarcomeres

site of metabolic processes for normal muscle fiber activities

sarcoplasm

the cytoplasm of a skeletal muscle cell has a specific name and is known as

sarcoplasm

at the end of muscle contraction, calcium ions are moved back into the _______ reticulum by ATP-driven ion pumps

sarcoplasmic