Anatomy Second Semester 1st Test

myology

study of muscle

What are the functions of muscle tissue?

1. body movement
2. stabilizing body positions
3. regulate organ volume
4. generate heat

What are the three types of muscle tissue?

skeletal, smooth, cardiac

Describe skeletal muscle tissue. Striated or nonstriated? Voluntary or involuntary? Where is it located?

\-striations

\-voluntary

\-attached to and moves bones

Describe smooth muscle tissue. Striated or nonstriated? Voluntary or involuntary? Where is it located?

\-nonstriated

\-involuntary

\-around organs that need to squeeze

Describe cardiac muscle tissue. Striated or nonstriated? Voluntary or involuntary? Where is it located?

\-striated

\-involuntary

\-heart

Draw a relaxed and contracted sarcomere and label the myosin, actin, and cross bridge, and z-line.

(make sure your drawing and labels matches this picture)

What is a sarcomere?

functional unit of muscle

What is a muscle fiber?

muscle cell

Describe how muscle contraction occurs.

1. stimulus arrives at neuromuscular junction
2. acetylcholine released
3. calcium released
4. ATP released
5. cross bridges on myosin release from actin
6. myosin pulled down actin by cross bridges
7. z-lines pulled closer together
8. sarcomere contracted → myofibril contracted → muscle fiber (cell) contracted → muscle fiber bundle contracted → whole muscle contracted

How does skeletal muscle produce body motion?

\-muscles exert force on tendons which pull on bones

\-bones act as levers (rigid rod) and joint act as fulcrums (fixed point or pivot point)

\-motion is achieved when the effort (muscle contraction) is greater than the resistance (weight of part being moved) M=E>R

Draw the muscle parts and label the origin, belly, and insertion.

(make sure your drawing and labels matches this picture)

What is the origin of a muscle?

attachment of muscle tendon to stationary bone

What is the belly of a muscle?

fleshy part between origin and insertion

What is the insertion of a muscle?

attachment of a muscle tendon to the moving bone

What does high strength mean?

low range of motion (ROM)

What does low strength mean?

high range of motion (ROM)

What is the prime mover?

muscle causing desired movement

What is the antagonist?

opposite action to prime mover

What is the synergist?

muscles that help steady movement

What does rectus mean?

fibers run parallel to midline

What does transverse mean?

fibers run perpendicular to midline

What does oblique mean?

fibers run at an angle to midline

What does location have to do with muscle names?

sometimes muscles named for a structure near where they are found in the body

What does maximus mean?

largest of muscle group

What does minimus mean?

smallest of muscle group

What does longus mean?

longest of muscle group

What does brevis mean?

shortest of muscle group

How many origins does a bicep have?

two

How many origins does a tricep have?

three

How many origins does a “quadricep” have? (group of muscles)

four

What shape is a deltoid?

triangle

What shape is a trapezius?

trapezoid

What shape is a rhomboideus?

rhomboid

What does a flexor do?

decrease the angle of the joint

What does an extensor do?

increase the angle of the joint

What does an abductor do?

move away from midline

What does an adductor do?

move toward midline

What does a levator do?

lifts body part

What does a depressor do?

lowers body part

What does a supinator do?

turns palm upward

What does a pronator do?

turns palm downward

What does a tensor do?

makes body part rigid/tight to stabilize position

What does a sphincter do?

muscle that encloses an opening

What is fascia?

white connective tissue binding muscle together

Describe thumb movements.

most dexterous in terms of muscle movement

Name the different types of thumb movements.

\-flexion

\-extension

\-abduction

\-adduction

\-circumduction

\-opposition

What is opposition?

\-thumb can touch each finger tip

\-most important movement