Chapter 11- Muscular System

The muscular system is comprised of....

voluntary controlled muscles of the body

What is the origin?

attachment of a muscle tendon to the stationary bone

What is the attachment of a muscle tendon to the stationary bone called?

origin

What is the attachment of the muscle tendon to the movable bone called?

insertion

What is insertion?

attachment of the muscle tendon to the movable bone

What is the fleshy portion of the muscle between the tendons called?

belly or body

The origin is usually the ______ attatchment.

proximal

The insertion is usually the _____ attatchment.

distal

Muscles are attached to _________.

the articulating bones that form

What is RMA?

reverse muscle action

The _____ is pulled toward the ______.

Insertion to origin

Bones act as _______

levers

Joints function as the _______ of the lever like bones.

fulcrums

What are the two different types of forces?

effort and load/resistance

What is effort?

the force exerted to achieve a movement

What is load/resistance?

the weight that opposes movement

Levers are classified into three types:

first-class

second-class

third-class

Leverage is the _____ or ______ gained by a lever.

mechanical advantage or mechanical disadvantage

Whats an example of a first-class lever?

muscles in back of neck

Whats an example of a second-class lever?

calf muscle

Which lever is the most uncommon in the human body?

second-class levers

What should you think of when you think of first-class levers?

scissors

Whats an example of a third-class lever?

the arm (elbow and biceps brachii)

Which lever is the most common?

third class lever

What should you think of when you think of second-class levers?

wheel-barrow

What should you think of when you think of third-class levers?

tweezers

What is the first-class lever?

the fulcrum between the effort and load (EFL)

What is the second-class lever?

the fulcrum ay one end, the effort at the opposite end, and the load between them (ELF)

What does E, L and F stand for?

Effort

Load

Fulcrum

What is the third-class lever?

the fulcrum at one end, the load at the opposite end, and the effort between the (FEL)

Skeletal muscle fibers within a muscle are arranged in bundles?

fascicles

What are all the arrangements of fascicles called?

parallel

fusiform

circular

triangular

pennate

What do the arrangements of fascicles affect?

the power of a muscle and its range of motion

What is an agonist?

a muscle that causes a desired action

Another word for agonist is?

prime mover

Most movements require ______ muscles

several

What is the muscle, whose effect is opposite to that of the prime mover, called?

antagonist

An _______ must relax in order to permit the _______ to cause the desired action.

antagonist, agonist

A _________ is a muscle that serves to prevent unwanted movements at intermediate joints to helps the prime mover function more efficiently

synergist

What does a fixator muscle do?

stabilizes the origin of a prime mover

T/F: A muscle can only be one of these: antagonist, synergist, fixator, or agonist

False, a muscle can be more than one of these

What is a muscle compartment?

a group of muscles that have a common function

How many skeletal muscles are there?

over 600

rectus

straight

transversus

crosswise

oblique

indirect; slanting

maximus

largest of group

minimus

smallest of group

medius

middle

brevis

short

major

more important, bigger or more serious than others of the same type

minor

small, unimportant than others of same type

delta

deltoid

trapezius

trapezoid shape

serrates

saw-toothed

rhomboid

shaped like rhombus

extensor

extends

abductor

away from the midline

adductor

muscle that moves a part toward the midline

levator

raises or elevates a body part

depressor

lowers or depresses a body part

supinator

supinates

tensor

makes a body part rigid

biceps

two heads

triceps

three heads

quadriceps

four heads

What is innervation?

nerve supply

______ is the movable or more movable bone.

insertion

_____ always moves toward the ______.

insertion, origin

Most facial muscles are very ______.

thin

Facial Expressions are innervated by:

Roman numeral 7/VII

How many bellies does the occipitofrontalis have?

2, frontal, occipital

Where is the orbicularis oculi?

around the eye

Whats the origin of orbicularis oculi?

muscle fibers around mouth

What's nicknamed the "kissing muscle"?

orbicularis oculi

Whats the insertion of orbicularis oculi?

into skin at corners/angles of mouth

Whats the action of orbicularis oculi?

close and protrude lips; as in kissing

Whats nicknamed the "smiling muscle"?

Zygomaticus Major/Minor

Whats the origin of the zygomaticus major?

zygomatic bone

Whats the insertion of the zygomaticus major?

skin at angles of mouth