MUSCULAR SYSTEM

Functions of the Muscular System

The ability of muscle to shorten forcefully, or
contract

A type of muscle that is attached to bones, striated, and voluntarily controlled.

A type of muscle that is located in the heart, striated, and involuntarily controlled

A type of muscle that is located in blood vessels,
hollow organs, non-striated, and involuntarily controlled

The capacity of muscle to respond to a stimulus

The ability to be stretched beyond it normal
resting length and still be able to contract

The ability of the muscle to recoil to its original
resting length after it has been stretched

Skeletal muscle, or striated muscle, with its associated
connective tissue, constitutes approximately how many percent of body weight?

Skeletal muscle is so named because many of the
muscles are attached to the _____ system.

True or False? Some skeletal muscles attach to the skin or connective tissue sheets
True False

Skeletal muscle is also called _____ muscle because
transverse bands, or striations, can be seen in the
muscle under the microscope.

Individual skeletal muscles, such as the biceps brachii,
are complete _____ , as a result of being comprised of
several tissues: muscle, nerve, and connective tissue.

Each skeletal muscle is surrounded by a connective tissue sheath called ____.

A skeletal muscle is subdivided into groups of muscle cells, termed ____.

Each fascicle is surrounded by a connective tissue covering, termed _____.

Each skeletal muscle cell (fiber) is surrounded by a connective tissue covering, termed _____.

A _____ is a large cell, with several hundred nuclei located at its periphery.

Muscle fibers range in length ____ to ____.

Alternating light and dark bands give muscle fibers a _____.

True or False? The number of muscle fibers do not remain constant after birth so enlargement of muscles results from an increase in the size of muscle fibers and also an increase in fiber number.
True False

The sarcolemma (cell membrane) has many tubelike inward folds, called ____.

The T tubules are associated with enlarged portions of the smooth endoplasmic reticulum called the _____.

Basically the enlarged portions of the sarcoplasmic reticulum (SR),

Two terminal cisternae and their associated T tubule form a ____.

The sarcoplasmic reticulum has a relatively high concentration of
Ca2+, which plays a major role in ______.

The cytoplasm of a muscle fiber is called the _____, which
contains many bundles of protein filaments.

These are bundles of protein filaments

Myofibrils consist of two types of myofilaments; These are?

Actin and myosin are arranged into repeating units called?

These are are networks of protein fibers that serve as an anchor for actin myofilaments, and separate one sarcomere from the
next.

The myofilaments slide past each other, causing the sarcomeres to ____ .

True or False? Each sarcomere consists of two dark-staining bands separated by a light-staining band.
True False

Light bands, consist only of actin, and are called ____ . They extend from the Z disc, toward the center of the sarcomere, to the ends of the myosin myofilaments.

Dark staining bands are called _____ . They extend the length of the myosin myofilaments.

Actin and myosin myofilaments overlap for some distance on both ends of the A band; this overlap causes the _____.

Actin myofilaments are made up of three components: _____, _____ and ____.

____ molecules have binding sites for Ca2+

_____ filaments block the myosin myofilament binding sites on the actin myofilaments.

______ or thick myofilaments, resemble bundles of tiny golf clubs.

Myosin heads have ATP binding sites, ATPase and attachment spots for ____.

It is a nerve cell that stimulates muscle cells.

It is a synapse where a neuron connects with a muscle fiber

It refers to the cell-to-cell junction between a nerve cell
and either another nerve cell or an effector cell, such as in a muscle or a gland.

It is a group of muscle fibers that a single motor neuron stimulates.

It is the end of a neuron cell axon fiber

It is the space between the presynaptic terminal and
postsynaptic membrane.

It is the muscle fiber membrane (sarcolemma).

It is a vesicle in the presynaptic terminal that stores and
releases neurotransmitter chemicals.

These are chemicals that stimulate or inhibit postsynaptic
cells

It is the neurotransmitter that stimulates skeletal muscles

When a muscle contracts, the actin and myosin myofilaments in thesarcomere slide past one another and shorten the ____ .

True or False? When sarcomeres shorten, myofibrils, muscle fibers, muscle fascicles, and muscles all shorten to produce muscle relaxation.
True False

True or False? During muscle relaxation, sarcomeres lengthen.
True False

Muscle fibers are ____ excitable.

Electrically excitable cells are _____.

In Excitability of Muscle Fibers,  the inside of the cell membrane is ____  charged compared with the outside.

A ______ , or electrical charge difference, exists across each
cell membrane.

The charge difference is due to differences in concentrations of ions on either side of the membrane of an unstimulated cell is called?

The phospholipid bilayer is impermeable to ___ .

Two types of membrane proteins, called ____ , permit ions to pass through the membrane.

____  allow the slow leak of ions down their concentration gradient.

____  may open or close in response to various types of stimuli.

The electrical charge difference across the cell membrane of an
unstimulated cell is called the _____ .

_____ have a resting membrane potential but can also perform action potentials.

These are due to the membrane having gated channels

The ____ of ions through these channels changes the charge
across the cell membrane and produces an action potential.

Action potential lasts for ____ to ______.

The entry of Na+ causes the inside of the cell membrane to become more ____ than when the cell is at resting membrane potential.

It is the increase in positive charge inside the cell membrane

If the depolarization changes the membrane potential to a value
called _____, an action potential is triggered.

______ is a rapid change in charge across the cell
membrane

Opening of gated K+ channels starts ____ of the cell
membrane.

In muscle contraction, an action potential travels down the motor neuron to the _____ .

The mechanical component of muscle contraction is called
______.

True or false? The energy from one ATP molecule is required for one cross bridge cycle.
True False

It is the movement of the myosin heads

Energy for muscle contractions is supplied by ____.

____  will occur when a person dies and no ATP is available
to release cross-bridges.

Muscle relaxation occurs when ___ is no longer released at the neuromuscular junction.

In muscle relaxation, the cross-bridge cycle stops and the muscle ____.

It is a single contraction of a muscle fiber in response
to a stimulus.

A muscle twitch has three phases. What are these?

____ is the time between the application of a stimulus
and the beginning of contraction.

____ is the time during which the muscle contracts.

It is the time during which the muscle relaxes.

There are two types of muscle contractions:

The ____ has an increase in muscle tension, but no change in length.

It increases the tension in a muscle and decreases the length.

It is the amount of force in an individual muscle fiber.

It is the amount of force in a whole muscle.

It consists of a single motor neuron and all the muscle
fibers it innervates.

True or false? 
Small, delicate muscles have very few fibers per motor unit.
Large, powerful, less precise muscles have fewer, larger motor units.
True False

Individual muscle fibers can generate different amounts of ____.

The amount of force generated depends upon the number of
_____ formed.

One factor that influences the number of cross-bridges formed is the frequency of _____.

______ occurs when the frequency of stimulation only allows for
partial relaxation of the muscle fiber.

It is a sustained contraction that occurs when the frequency of
stimulation is so rapid that no relaxation occurs.

It is the stimulation of several motor units.

It is the constant tension produced by body muscles over long periods of time.

_______ are isotonic contractions in which muscle
tension increases as the muscle shortens.

______ are isotonic contractions in which tension is
maintained in a muscle, but the opposing resistance causes the
muscle to lengthen.

It is a type of skeletal muscle fiber that has the following characteristics;

• contract slowly
• fatigue slowly
• have a considerable amount of myoglobin
• use aerobic respiration
• are dark in color
• used by long distance runners

It is a type of skeletal muscle fiber that has the following characteristics;

• contract quickly
• fatigue quickly
• use anaerobic respiration
• energy from glycogen
• light color
• used by sprinters

True or False?
The large postural muscles of the back and lower limbs
contain more fast-twitch muscle fibers.
The muscles of the upper limbs contain more slow-twitch fibers.
True False

Muscle fibers have three ATP dependent proteins;

Muscle fibers store enough ATP to contract for about how many seconds?

This enzyme is involved conversion of two ADP to one ATP and one adenosine monophosphate (AMP)

The transfer of a phosphate from a molecule called _____ by the enzyme creatine kinase from ADP to form ATP.

A type of production of ATP during intensive short-term exercise.

A type of production of ATP during most exercise and normal
conditions

True or False? 
When a muscle fiber is working too strenuously for ATP stores and creatine phosphate to be able to provide enough ATP, aerobic respiration predominates.
True False

It is a temporary state of reduced work capacity.

True or False? Without fatigue, muscle fibers would be worked to the point of structural damage to them and their supportive tissues.
True False

Mechanisms of fatigue include:

It is the lag time between when a person begins to exercise and when they begin to breathe more heavily because of the exercise.

_______ is the lag time before breathing returns to its preexercise rate once exercise stops.

______ cells are non-striated small, spindle-shaped muscle
cells, usually with one nucleus per cell. It comprise organs controlled involuntarily, except the heart. Neurotransmitter substances, hormones, and other factors can stimulate it.

This type of muscle is long, striated, and branching, with usually
only one nucleus per cell. It is striated as a result of the sarcomere arrangement. Its contraction is autorhythmic.

Cardiac muscle cells are connected to one another by specialized
structures that include desmosomes and gap junctions called
_______ .

It connects skeletal muscle to bone.

These are broad, sheetlike tendons

It is a band of connective tissue that holds down the tendons at each wrist and ankle.

Skeletal muscle attachments have an origin and an insertion, with the _____ being the attachment at the least mobile location.

It is the end of the muscle attached to the bone undergoing the greatest movement.

The part of the muscle between the origin and the insertion

A group of muscles working together are called ____ .

A muscle or group of muscles that oppose muscle actions are termed _____.

Muscles are named according to:

The Abdominal Wall Muscles

Pelvic Diaphragm Muscles

Muscles of Lower Leg

Muscles of the Upper Leg

Muscles of Hips and Thighs

Upper Limb Muscles

Upper Limb Muscles

Upper Scapular and Limb Muscles