Chapter 10 muscles

Question 1

what are the 4 muscle functions

Answer 1

produce body movement, stabilize body, storage and moving substances in the body, heat

Question 2

what are the 4 properties of muscles

Answer 2

electrical excitability
contractility
extensibility
elasticity

Question 3

electrical excitability

Answer 3

muscle is able to respond to stimuli through action potentials

Question 4

contractibility

Answer 4

tension is created when proteins in myofibrils make attachment points

Question 5

extensibility

Answer 5

muscle can stretch without damage

Question 6

elasticity

Answer 6

muscle can return to its original shape

Question 7

what is skeletal muscle surrounded by

Answer 7

a protective layer of connective tissue- usually composed of areolar and adipose tissues

Question 8

fascia

Answer 8

dense irregular connective tissue - holds muscles with similar functions together

Question 9

epimysium

Answer 9

an extension of the fascia that encircles an entire muscle

Question 10

perimysium

Answer 10

creates bundles of muscle fibers calls fascicles - there are 10-100 muscle fibers per fascicle

Question 11

endomysium

Answer 11

a thin layer of areolar tissue that surrounds each individual muscle fiber

Question 12

what is the order of muscle terms from large to small

Answer 12

skeletal muscle - has an origin and insertion made of tendons at different locations on a bone or more often bones
fascicle - bundle of muscle fibers
muscle fiber - the same as a muscle cell, it extends the length of the entire muscle

Question 13

myofibril

Answer 13

a contractile unit of muscle fiber, contains the proteins needed for contraction arranged in smaller units called sarcomeres

Question 14

what are skeletal muscles stimulated by

Answer 14

somatic motor neurons

Question 15

how do somatic motor neurons work

Answer 15

multi branched axons that touch individual muscle fibers

Question 16

why are skeletal muscles vascular

Answer 16

muscle is very dependent on a reliable supply of oxygen, nutrients and minerals, since muscle fibers require a very high amount of ATP

Question 17

antagonistically

Answer 17

one reverses the action of the other

Question 18

synergistically

Answer 18

the contraction of one stabilizes the contraction of another

Question 19

reciprocal innervation

Answer 19

only one muscle of an antagonistic pair can be stimulated at a time

Question 20

“slow” muscle

Answer 20

red in color due to myoglobin and blood capillaries, its contractions are slower but more sustained

Question 21

“fast or “white” muscle

Answer 21

contain fewer mitochondria and less myoglobin but can contract rapidly and powerfully for short periods

Question 22

muscle tone

Answer 22

continued steady, low level of contraction that stabilizes joints and maintains general muscle health

Question 23

muscle tension

Answer 23

the force of a contracting muscle exerts on an object
to contract, a muscle’s tension must exceed the load opposing it

Question 24

isotonically

Answer 24

contracting muscle shortens and moves a load

Question 25

isometrically

Answer 25

contracting muscle develops tension but does not shorten

Question 26

strains

Answer 26

movement that stretches or tears muscle fibers

Question 27

spasm

Answer 27

sudden, involuntary contraction that rapidly releases

Question 28

muscular dystrophies

Answer 28

genetic diseases leading to breakdown of muscle fibers over time

Question 29

myotonic muscular dystrophy

Answer 29

muscles of the hands and feet contract strongly but fail to relax normally

Question 30

muscles that are damaged or which go unused for prolonged periods of time will

Answer 30

atrophy (waste away)

Question 31

aerobic exercise

Answer 31

improves the capacity of muscles to do work

Question 32

strength training

Answer 32

improves function of fast muscle but does not increase endurance