Musculoskeletal

Question 1

ability of a muscle to shorten, accompanied by mechanical force generation: role in movement

Answer 1

contractility

Question 2

capacity of muscle to respond to a stimulus

Answer 2

excitability

Question 3

muscle can be stretched to its normal resting length and beyond to a limited degree

Answer 3

extensibility

Question 4

ability of muscle to recoil to original resting length after being stretched

Answer 4

elasticity

Question 5

What are a few properties of skeletal cells

Answer 5

-attached to bones
-nuclei are multiple per cell and peripherally located
-striated
-under voluntary and involuntary control

Question 6

Fibrous connective tissues that connects muscle fibers to bones and serve as elastic anchors

Answer 6

Tendons

Question 7

Muscle end attached to more stationary of two bones

Answer 7

origin or head

Question 8

muscle end attached to bone with greatest movement

Answer 8

insertion

Question 9

largest portion of the muscle between origin and insertion

Answer 9

belly

Question 10

separate muscles that work together to cause a movement around a joint

Answer 10

synergists

Question 11

muscle causing a particular action when it contracts

Answer 11

agonist

Question 12

muscle working in opposition to agonist; typically relaxes during contraction of agonist

Answer 12

antagonist

Question 13

What is parallel fiber arrangement?

Answer 13

parallel to the longitudinal axis of the muscle

Question 14

What is pennate fiber arrangement?

Answer 14

fibers are at an angle to the longitudinal axis of the muscle
-typically generate a greater force per mass of tissue compared to parallel fiber arrangement, but have shorter range on motion

Question 15

What surrounds muscle fibers?

Answer 15

connective tissue

Question 16

What organizes muscle fibers into multiple bundles parallel to each other and provides a parallel component of elasticity?

Answer 16

connective tissue

Question 17

plasma membrane of muscle fibers

Answer 17

sarcolemma

Question 18

product of fusion of multiple cells sharing internuclear content

Answer 18

multinucleated syncytium

Question 19

the fundamental contractile structure (defined by z lines)

Answer 19

sarcomere

Question 20

bundles of myofilaments packed within the muscle fiber and constitute the contractile machinery

Answer 20

myofibrils

Question 21

prevents interaction between actin and myosin in absence of Ca2+

Answer 21

tropomyosin

Question 22

promotes a change in tropomyosin allowing binding of actin and myosin with binding of Ca2+

Answer 22

troponin

Question 23

at what point does ADP and Pi dissociate from the myosin head

Answer 23

power stroke

Question 24

what allows for the release of myosin from actin

Answer 24

ATP binding to myosin head

Question 25

rapid net redistribution of ions across the plasma membrane, driven by previously established concentration gradients (transmission of electrical signals)

Answer 25

action potential

Question 26

specialized ca2+ reservoir within cells

Answer 26

sarcoplasmic reticulum

Question 27

resides in the sarcolemma/t tubule, a voltage sensitive channel which opens in response to membrane depolarization, allows a slow influx of calcium

Answer 27

DHPR

Question 28

resides in SR membrane, opened directly by activated DHPR, allows release of Ca2+ stores in SR into the sarcoplasm

Answer 28

RyR

Question 29

ion pump protein principally responsible for moving Ca2+ from sarcoplasm into the SR and restoring the Ca2+ gradient to terminate contractile response

Answer 29

SERCA (SR Ca2+ ATPase)

Question 30

a motor neuron plus all the muscle fibers to which it connects

Answer 30

motor unit

Question 31

varying degrees of force produced by variations in number of motor units activated

Answer 31

graded contractions

Question 32

fibers per neuron can vary based on functional requirements of muscle in question

Answer 32

innervation ratios

Question 33

generates a contractile force of contraction that decays as fiber relaxes, stimulated by a single isolated electrical stimulus

Answer 33

twitch

Question 34

more frequent stimuli each production units of contractile force, next stimulus arrives before relaxation from previous stimulus is complete

Answer 34

summation of twitches

Question 35

frequency high enough to produce steady contraction (no relaxation) and maximal force development

Answer 35

tetanic contraction

Question 36

the effect of the series elastic component of the actively stretched muscle

Answer 36

elastic recoil

Question 37

in muscle stretched to an extreme via an autonomic nervous signal to contract and thus shorten, protecting the muscle

Answer 37

stretch relex

Question 38

high myosin ATPase activity, thus more rapid cross bridge cycling and high shortening velocity, fatigue rapidly

Answer 38

fast fibers

Question 39

low myosin ATPase activity and lower shortening velocity, fatigue more slowly

Answer 39

slow fibers

Question 40

numerous mitochondria, high capacity of oxidative phosphorylation, ATP production dependent on blood borne oxygen and fuel, contain myoglobin which increase rate of oxygen capture in fiber

Answer 40

oxidative fibers

Question 41

high concentration my glycolytic enzymes and glycogen, larger and have more thick and thin filaments and can develop more tension, fatigue rapidly

Answer 41

glycolytic fibers

Question 42

low intensity exercise effects

Answer 42

oxidative fibers

Question 43

high intensity exercise effects

Answer 43

glycolytic fibers

Question 44

ability to adapt in size and composition to needs and activity

Answer 44

plasticity