Muscular System Test (Combined)

A movement which brings a limb - arm or leg - away from the body is ____________________.

Abduction

This means that the muscle can function under your control of it.

Voluntary

The russian twist exercise or side planks helps to strengthen which muscle?

External Obliques

What is an area of discolored skin that appears after an injury causing blood vessels to rupture beneath the skin and leak?

Bruise

The tough tissue that attaches a muscle to bone is a ________________________.

Tendon

The action of closing or shortening muscle fibers at a joint is _______________________.

Contraction

The natural tension in the fibers of a muscle is _______________________.

Muscle Tone

The muscle type that attaches to bone and provides body movement is the ______________________ muscle.

Skeletal

What is the muscle type that lines the walls of your blood vessels?

Smooth

This is the result of when a muscle pulled because it is stretched or partially torn due to overexertion.

Muscle Strain

The action of opening or lengthening muscle fibers at a joint is _____________________.

Extension

The best treatment for a cramp is to massage the muscle, stretch, and increase levels of what mineral?

Potassium

What are the 4 main functions of the Muscular System?

Maintenance of Posture, Movement, Production of Body Heat, Joint Stability

What type of exercise gets your heart rate up?

Aerobic Exercise

A movement which brings a limb - arm or leg - closer towards the body is ______________________.

Adduction

The ____________________ muscle is the only type of muscle that is voluntary.

Skeletal

When your muscles become weaker and decrease in size and strength due to the lack of use over a period of time they begin to ________________________.

Atrophy

The muscle type that allows your heart to contract and beat is the _________________ muscle.

Cardiac

The type of muscle that is found in the esophagus is the ____________________ muscle.

Smooth

Tendon

Connects muscle to bone

Fascia

Layers of connective tissue that bind and separate muscles.

Epimysium

Connective tissue layer surrounding an entire muscle

Perimysium

Connective tissue surrounding a fascicle

Endomysium

Connective tissue surrounding a muscle fiber

Fascicle

A bundle of muscle fibers

Muscle Fiber

A single unit (cell) that make up skeletal muscle; often multinucleated

Sarcolemma

The plasma membrane of a muscle cell.

Sarcoplasmic Reticulum

The smooth ER of a muscle cell, enlarged and specialized to act as a Ca2+ reservoir. It around each myofibril in the muscle cell.

Myofibril

Bundles of fibers; composed of thin filaments of actin and a regulatory protein and thick filaments of myosin.

Myosin

A thick protein filament found in skeletal muscle

Actin

A thin protein filament found in skeletal muscle

All or none response

muscle fiber contracts completely or not at all

Sarcomere

The basic functional unit of skeletal muscle; smallest contractile unit of muscle

Motor unit

a motor neuron and all the muscle fibers it stimulates

Neuromuscular Junction

Point of contact between a motor neuron and a skeletal muscle cell

Action potential

a neural impulse; a brief electrical charge that travels down an axon

Acetylcholine

neurotransmitter released into the synapse at a neuromuscular junction; stimulates muscle contraction

Calcium

Released from the sarcoplasmic reticulum; uncovers myosin binding sites on actin in a sarcomere enabling cross bridge cycling

Cross bridge cycle

Repeated sequential interactions between myosin and actin filaments that cause a muscle fiber to contract

ATP

Energy source for crossbridge cycling; must be present for myosin to bind to actin AND for the release of myosin from actin

Creatine Phosphate

An energy storage molecule used by muscle tissue. Phosphate can be removed from it and attached to an ADP to generate ATP quickly.

Smooth Muscle

Muscular tissues that surround tubular organs such as the stomach, intestines and blood vessels

Skeletal Muscle

A muscle that is attached to the bones of the skeleton and provides the force that moves the bones; also called striated muscle; voluntary;

Cardiac Muscle

Muscular tissue that together forms the heart; Contain intercalated discs; striated and involuntary

Voluntary Muscle

A muscle that is under conscious control

Involuntary Muscle

A muscle that is not under conscious control

Slow twitch fibers

Always oxidative; Slow to fatigue and have a high level of aerobic endurance, used for long-term, low to moderate intensity activities ranging from maintaining proper posture to long-distance running or swimming

Fast twitch fibers

Primarily glycolic; poor aerobic endurance, short-duration, high-intense activities and fatigue quickly; weight lifting or sprinting

Prime mover

The muscle that acts as the initial and main source of motive power. (aka agonist)

Synergist

Muscle that assists a prime mover

Antagonist muscle

A muscle that works in opposition to the specific movement generated by the agonist and is responsible for returning a limb to its initial position. (must relax and lengthen during contraction of the agonist)

Isometric

Exercises in which there is tension on a muscle but no movement is made causing the length of the muscle to remain the same. Ex. trying to move an immoveable object, holding weight out.

Isotonic exercises

Contracting muscle shortens against a constant load as in lifting weight. The tension remains the same, but the muscle length changes, this includes both eccentric and concentric movement

Tonic

degree of muscle contraction allowing for good posture; absent during sleep

Rigor Mortis

Temporary rigidity of muscles occurring after death due to lack of ATP to break bond betwee actin and myosin

Adduction

Movement toward the midline of the body

Abduction

Movement away from the midline of the body

Flexion

A bending movement around a joint in a limb (as the knee or elbow) that decreases the angle between the bones of the limb at the joint

Extension

An unbending movement around a joint in a limb (as the knee or elbow) that increases the angle between the bones of the limb at the joint

Extensor

If a flexor is a prime mover, what is the antagonist?

Adductor

If an abductor is a prime mover, what is the antagonist?

Atrophy

A decrease in the size of muscle fibers typically as a result of chronic disuse.

Hypertrophy

An increase in the size of muscle fibers, typically accomplished through resistance training.

Neuron

The name of the nerve cells that carries signals from the brain to initiate muscle movement is called a

Insertion

The movable end of a muscle connects at the...

Origin

The immovable end of a muscle connects to a bone at the...

Hernia

A protrusion of the abdominal viscera through a portion of the abdominal wall is called a(n):

Frontalis and Occipitalis

muscles that raise eyebrow; move scalp

Masseter and Temporalis

muscles of mastication (chewing)

Muscle Function

movement of the body, maintenance of posture, body temp, and support of soft tissue

Epimysium

collagenous connective tissue layer that covers entire muscle

Perimysium

folds of epimysium that separates the muscle into bundles of muscle cells called fascicles

endomysium

extensions of perimysium that surround each individual muscle fibers

Sarcolemma

cell membrane of a muscle fiber

T Tubules

connect sarcolemma to the muscle fiber; pass contraction stimuli

Myofibrils

rods of protein inside the muscle fiber

Sarcoplasmic recticulum

site of calcium storage that surrounds myofibrils

Actin & Myosin

protein filaments that produce tension and shorten muscle

Sarcomere

repeating patterns of actin + myosin filaments

Tropomyosin

protein that regulates muscle contracting by blocking myosin binding sites

Troponin

protein that holds tropomyosin in position and binds calcium

Excitable

produce electrical impulses in response to stimuli

Extensible

Stretch

Elastic

recoil to its original size

Muscle Contraction Steps

1. muscle relaxed state until a stimuli (action potential) causes calcium to be released from sarcoplasmic reticulum

2. Calcium binds to troponin and moves tropomyosin, freeing binding sites allowing myosin to attach to actin

3. myosin slides actin shortening the sarcomere of the myofibril resulting in muscle contraction.

Flexion

bending a joint so the angle between two bones is decreased and bones come closer

Extension

straightening a joint so that the angle between the bones is increased

Hyperextension

excessive extension beyond normal posture

Abduction

moving away from midline

Adduction

moving toward the body’s midline

Eversion

outward rotation of foot

Inversion

inward rotation of foot

Circumduction

moving a part so that its end follows circular pattern

Rotation

moving a part around an axis

Antagonist Movement

opposing actions of 2 or more muscles

ex: glutes abduct, adductor longus adduct.

Synergistic movement

2 or more muscles that perform the same action

ex: adductor longus and gracilis are both adductor muscles

What kind of muscle helps in the muscular system?

skeletal

H-band

myosin only

Z-line

actin connecting

A-line

myosin length