Muscular System: Chapter 6

Question 1

muscles

Answer 1

comprised of fascicles

Question 2

fascicles

Answer 2

groups of muscle fibers bound together

Question 3

muscle fibers

Answer 3

compromised of myofibrils

Question 4

myofibrils

Answer 4

composed of sarcomeres

Question 5

sarcomeres

Answer 5

composed of actin and myosin (contractile proteins)

Question 6

tendon

Answer 6

connects muscle to bone

Question 7

musculotendinous junction

Answer 7

where muscle meets tendon

Question 8

tenoperiosteal junction

Answer 8

where tendon meets bone

Question 9

origin

Answer 9

where the muscle starts (more on the stationary bone)

Question 10

insertion

Answer 10

where it ends

Question 11

oblique

Answer 11

• shorter, more numerous
• Greater potential for strength
• Produces smaller ROM

Question 12

parallel

Answer 12

• longer
• greater potential for shortening
• produces greater ROM

Question 13

strap muscles

Answer 13

long, thin fibers running length of muscle

Question 14

fusiform muscles

Answer 14

• spindle shape
• widest in the middle
• tapers on both ends
• fibers still run the entire length of the muscle
• biceps, brachialis, brachioradialis

Question 15

triangular muscles

Answer 15

trapezius or pectoralis major

Question 16

Sub category for oblique muscle oriented fibers

Answer 16

• unipennate
• bipennate
• multipennate

Question 17

pennate muscles

Answer 17

• feather arrangement
• oblique fibers attached to tendon

Question 18

unipennate

Question 19

bipennate

Answer 19

• on central tendon
• oblique oriented fibers on either side
• (rectus femoris)

Question 20

multipennate

Answer 20

• multiple tendons
• oblique fibers sit in between each tendon
• (deltoid)

Question 21

muscle tissue properties

Answer 21

• irritability
• contractility
• extensibility
• elasticity

Question 22

irritability

Answer 22

ability to response to a stimulus

Question 23

contractility

Answer 23

ability to generate force with sufficient stimulus

Question 24

extensibility

Answer 24

ability to lengthen

Question 25

elasticity

Answer 25

ability to return to resting length (recoil)

Question 26

sliding filament theory

Answer 26

- describes the interaction between actin and myosin - muscle receives stimulus to contract

Question 27

muscle receives stimulus to contract and what happens?

Answer 27

- myosin heads reach out, bind to actin filaments, and pulls them together - this causes the sarcomere to shorten

Question 28

all sarcomeres of a muscle fiber shorten _____________

Answer 28

simultaneously

Question 29

sarcomeres shorten the __________ _________

Answer 29

entire muscle

Question 30

optimal length

Answer 30

- slight stretch - max interface between actin and myosin - some passive tension present - increases the force generating capacity

Question 31

a muscle is able to shorten to _______ its resting length

Answer 31

half

Question 32

a muscle is able to lengthen _____ times its resting length

Answer 32

1.5

Question 33

agonist

Answer 33

prime mover - performs the movement

Question 34

antagonist

Answer 34

performs the opposite movement of the agonist

Question 35

co contraction

Answer 35

agonist & antagonist contract at the same time

Question 36

synergist

Answer 36

a muscle that works in conjunction with another to perform the same action

Question 37

passive insufficiency

Answer 37

- a multi-joint muscle cannot lengthen any further without damage - occurs to the antagonist - ex: hamstrings stretched with hip flexion and knee extension

Question 38

active insufficiency

Answer 38

- a multi-joint muscle cannot shorten any further due to length - occurs to the agonist - ex: hamstrings shortened with hip extension and knee flexsion

Question 39

tenodesis

Answer 39

- utilizes the principle of passive insufficiency - allows for opening/closing of the hand in Pt's with spinal cord injuries

Question 40

muscle contractions

Answer 40

- concentric - eccentric - isometric - isokinetic contractions

Question 41

concentric contraction

Answer 41

muscle shortens as it contracts against gravity

Question 42

eccentric contraction

Answer 42

muscle lengthens and decelerates against gravity

Question 43

isometric contraction

Answer 43

muscle length stays the same during contraction

Question 44

isokinetic contractions

Answer 44

- speed of motion stays the same throughout the contraction - resistance changes in order to maintain speed - ex: biodex

Question 45

open chain

Answer 45

distal segment is not fixed

Question 46

closed chain

Answer 46

distal segment is fixed