Muscle System

Question 1

Muscular Dystrophy

Answer 1

Inherited disorders, muscle enlarge due to increased fat and connective tissue, but fibers generate and atrophy over time

Question 2

Duchenne MD

Answer 2

Most common; proteins to maintain sarcolemma not present so sarcolemma breaks down

Question 3

Myasthenia Gravis

Answer 3

Problem with acetylcholine receptors because there aren’t enough or they don’t work

Question 4

Treatment for MD

Answer 4

No treatment to stop/reverse; therapy, orthopedic appliances for support, medication, and corrective orthopedic surgery to slow it down

Question 5

Sarcolemma

Answer 5

Specialized plasma membrane involved in muscle contraction

Question 6

Sacromere

Answer 6

Contractile unit of muscle fiber

Question 7

Myosin

Answer 7

Think muscle fiber in sacromere

Question 8

Actin

Answer 8

Thin muscle fiber in sacromere

Question 9

Flexibility

Answer 9

Bending something; decreasing angle of joint to bring two bones together

Question 10

Extension

Answer 10

Increasing angle of joint

Question 11

Abduction

Answer 11

Moving it away from midline

Question 12

Addiction

Answer 12

Bringing it toward midline

Question 13

Skeletal Muscle

Answer 13

Attached to bone by tendon; multinucleated; striated; voluntary; surrounded and bundled by connective tissue; tires quickly; generates great force

Question 14

Smooth Muscles

Answer 14

No striations; spindle-shaped cells; single nucleus; mainly in walls of hollow organs; slow, sustained, tireless; involuntary

Question 15

Cardiac muscles

Answer 15

Stirations; single nucleus; cells joined at intercalated discs; involuntary; only in heart; steady pace

Question 16

7 Steps of Neuromuscular Contraction

Answer 16

1) signal from brain travels length of axon/nerve
2) calcium channels open and calcium diffuses into terminal end of axon
3) acetylcholine is released
4) acetylcholine binds to receptors on muscle (sarcolemma)
5) cation ion channels open
6) Na ions in, K ions out of muscle fibers
7) once action potential is reached, muscle contracts

Question 17

Action potential

Answer 17

When the ratio of Na entering and K editing is great enough to cause muscle contraction

Question 18

Frontalis

Answer 18

Raises eyebrows; wrinkles forehead

Question 19

Obiclaris Occuli

Answer 19

Closes eyes; squinting

Question 20

Obiculais Oris

Answer 20

Purses and puckers lips

Question 21

Trapezius

Answer 21

Laterally rotates, elevates, and retracts scapula; extends and laterally rotates neck

Question 22

Sternocleidomastoid

Answer 22

Flexes and laterally rotates cervical spine; protracts head; extends neck

Question 23

Deltoid

Answer 23

Abducts arm; ant fibers- flex and medically rotate; post fibers-extend and laterally rotate

Question 24

Pectoralis Major

Answer 24

Clavicular head- flexes and adducts arm; sternal head- afduxts and

Question 25

Frontalis

Answer 25

Raises eyebrows; wrinkles forehead

Question 26

Obiclaris Occuli

Answer 26

Closes eyes; squinting

Question 27

Obiculais Oris

Answer 27

Purses and puckers lips

Question 28

Trapezius

Answer 28

Laterally rotates, elevates, and retracts scapula; extends and laterally rotates neck

Question 29

Sternocleidomastoid

Answer 29

Flexes and laterally rotates cervical spine; protracts head; extends neck

Question 30

Deltoid

Answer 30

Abducts arm; ant fibers- flex and medically rotate; post fibers-extend and laterally rotate

Question 31

Pectoralis Major

Answer 31

Clavicular head- flexes and adducts arm; sternal head- afduxts and