Muscles

Question 1

Flexion

Answer 1

Decreases the angle of the joint (forward)

Question 2

Extension

Answer 2

Increases the angle between two bones

Question 3

Rotation

Answer 3

Movement of a bone around its longitudinal axis

Question 4

Abduction

Answer 4

Movement of a limb away from the midline

Question 5

Adduction

Answer 5

movement of a limb toward the midline

Question 6

Dorsiflexion

Answer 6

Lifting the foot toward the shin (flexing toes/foot)

Question 7

Plantar flexion

Answer 7

depressing/extending the foot (pointing)

Question 8

Inversion

Answer 8

Turning sole of foot medially (turn in)

Question 9

Eversion

Answer 9

Turning sole of foot laterally (turn out)

Question 10

Supination

Answer 10

forearm rotates laterally so palm faces anterior

Question 11

Pronation

Answer 11

forearm rotates medially so palm faces posterior (palm facing back)

Question 12

Smooth Muscle

Answer 12

-non-striated
-involuntary
-visceral (internal organs)
-contractions are slow and sustained

Question 13

Skeletal Muscle

Answer 13

“Muscular system” refers to
-attach to bones by tendons
-multinucleated
-skeletal (bones)
-voluntary
-striated

Question 14

Cardiac Muscle

Answer 14

-striated
-involuntary
-cardiac (heart)
-cells connected by intercalated disks

Question 15

Muscle fiber

Answer 15

a single muscle cell

Question 16

Fascicle

Answer 16

a bundle of muscle fibers

Question 17

Tendon

Answer 17

-attach muscles to bones
-mostly collagen fibers
-often cross a joint because of their toughness and small size

Question 18

Endomysuim

Answer 18

-connective tissue
-encloses a single muscle fiber

Question 19

Epimysium

Answer 19

-connective tissue
-covers the entire skeletal muscle

Question 20

Perimysium

Answer 20

-connective tissue
-wraps around a fascicle (bundle) of muscle fibers

Question 21

Skeletal muscle functions (4)

Answer 21

-produce movement (all muscle types)
-maintain posture
-stabilize joints
-generate heat

Question 22

Sarcolemma

Answer 22

specialized plasma membrane

Question 23

Myofibrils

Answer 23

long organelles inside a muscle cell
- light (i) bands and dark (a) bands produce striations

Question 24

I Band

Answer 24

Light band
- contains only thin actin filaments
- Z disc provides anchor for thin filaments

Question 25

A Band

Answer 25

Dark band - contains think myosin filaments

Question 26

Sarcoplasmic reticulum (SR)

Answer 26

Specialized Smooth ER - surrounds myofibrils - stores and releases calcium

Question 27

Sarcomere

Answer 27

Contractile unit of a muscle fiber

Question 28

Five Golden Rules of Muscle Contraction (#1)

Answer 28

1. With a few exceptions, all skeletal muscles cross at least one joint

Question 29

Five Golden Rules of Muscle Contraction (#2)

Answer 29

2. Typically, the bulk of a skeletal muscle lies proximal to the joint crossed

Question 30

Five Golden Rules of Muscle Contraction (#3)

Answer 30

3. All skeletal muscles have at least two attachments: the origin and the insertion

Question 31

Five Golden Rules of Muscle Contraction (#4)

Answer 31

4. Skeletal muscles can only pull; they never push

Question 32

Five Golden Rules of Muscle Contraction (#5)

Answer 32

5. During contraction, a skeletal muscle insertion moves toward the origin

Question 33

Origin

Answer 33

Attachment to an immovable or less movable bone *movement always occurs from the insertion point toward the origin

Question 34

Insertion

Answer 34

Attachment to a movable bone *movement always occurs from the insertion point toward the origin

Question 35

Prime Mover

Answer 35

Muscle with the major responsibility for a certain movement

Question 36

Antagonist

Answer 36

Muscle that opposes or reverses prime mover

Question 37

Synergist

Answer 37

Muscle that aids a prime mover

Question 38

Fixator

Answer 38

Specialized synergists that hold a bone still

Question 39

Motor Neutron

Answer 39

Skeletal muscles must be stimulated by a motor neuron to contract

Question 40

Motor unit

Answer 40

One (motor) neuron and all the skeletal muscle cells stimulated by that neuron

Question 41

Neuromuscular junction

Answer 41

Site at which an axon terminal and sarcolemma of the muscle fiber meet - synaptic cleft

Question 42

Synaptic cleft

Answer 42

The fluid-filled space at a synapse between neutrons

Question 43

Neurotransmitter

Answer 43

Chemical released from synaptic vesicles - stimulates the muscle fibers

Question 44

Acetylcholine (ACh)

Answer 44

The neurotransmitter that stimulates the muscle fibers