Bio 101-Chapter 9

Front 1

Functions of a muscle system

Back 1

heart beat
posture
constriction of blood vessels and organs
communication
tempersature regulation
movement

Front 2

Contractility

Back 2

the ability to shrink and return to original size

Front 3

excitability

Back 3

the ability to respond to stimuli (muscles stimuli are nerves)

Front 4

extensibility

Back 4

the ability to be streched

Front 5

elasticity

Back 5

the ability to stretch and return to original state

Front 6

sarcolemma

Back 6

muscle cell membrane

Front 7

sarcoplasm

Back 7

muscle cell cytoplasm

Front 8

sarcoplasmic reticulum

Back 8

specialized ER in skeletal muscle that stores Ca++

Front 9

myofiber

Back 9

muscle cell

Front 10

myofibril

Back 10

rod shaped structures within a cell

Front 11

myofilaments

Back 11

actin (thin) and myosin (thick) filaments inside of the myofirils

Front 12

fasciculi

Back 12

bundles of myofibers

Front 13

endomysium

Back 13

loose CT within fasciculi surrounding myofibers

Front 14

perimysium

Back 14

heavier CT which makes up then wall of fasciculi

Front 15

Epimysium

Back 15

dense collagenous CT surrounding bundles of fasciculi coving of muscle also called fascia.

Front 16

fascia

Back 16

sheets of dense CT that covers body underneath the skin. in muscle it is the same as the epimysium.

Front 17

sarcomere

Back 17

the functional unit of a muscle fiver.

Front 18

Tropomyosin

Back 18

protein strand that coils around the actin, which hides the myosin head binding sites.

Front 19

troponin

Back 19

smaller globular proteins attached to tropomyosin and actin when cell is at rest. Also binds to calcium.

Front 20

Striations in skeletal muscle

Back 20

caused by actin and myosin fillaments

Front 21

z disk

Back 21

a protien that attaches to the actin.

Front 22

troponin's binding sites

Back 22

actin, tropomyosin, and calcium.

Front 23

motor neuron

Back 23

neuron that is responsible for motion.

Front 24

neuromuscular junction

Back 24

where the neuron and muscles come together.

Front 25

propagation

Back 25

AP moveing down a membrane because the AP stimulates an Ap at the next location

Front 26

Synaptic vessicles

Back 26

contain neurotransmitters

Front 27

postsynaptic membrane

Back 27

the sarcolemma of the muscle cell.

Front 28

acetlycholine

Back 28

neurotransmitter that binds to the postsynaptic membrane

Front 29

Cross-bridge

Back 29

Formed when myosin heads attached to the actin.

Front 30

Power-stroke

Back 30

ATP binds to myosin head, then breaks down to ADP + P, the myosin head then pulls away from the actin. when they release the myosin head attatches to the next actin stite causing a racheting motion and contraction of muscle

Front 31

Motor unit summation

Back 31

the process of using all the recruited motor units

Front 32

motor unit recruitment

Back 32

when one motor unit is not enough to cause a strong enogh contraction more motor units are stimulated. which creates a graded contraction

Front 33

graded contraction

Back 33

recruiting more than one motor unit.

Front 34

tetany

Back 34

caused by increased frequency of AP traveling down sarcolemma. the contraction becomes fused.

Front 35

incomplete tetanus

Back 35

caused when muscles have some time to relax.

Front 36

complete tetanus

Back 36

due to no time to relax.

Front 37

supramaximal

Back 37

after all motor units are recruited, there can not be a stronger contraction, becuase there is nothing left to add.

Front 38

isometric contraction

Back 38

the length of the muscle does not change, but the amount of tension increases during a contraction

Front 39

isotonic contraction

Back 39

when the length of the muscle changes, but the amount of tension does not.

Front 40

muscle length vs. muscle tension

Back 40

the longer the muscle is stretched the more tension it has, unless stretched too far then the myosin can not reach the actin.

Front 41

psychological fatigue

Back 41

when you dont think that you are capable of doing any more work.

Front 42

muscular fatigue

Back 42

when your muscles run out of ATP. cross bidges are not forms so tension declines.

Front 43

Synaptic fatige

Back 43

at the neuromuscluar junction, the high AP frequency is releasing too much ACH.

Front 44

Sources of ATP

Back 44

creatine phosphate
aerobic respiration
anaerobic respiration

Front 45

glycogen

Back 45

storage form of glucose(important becuase it is used in aerobic respiration to form 38 ATP or anearobic respiration to form 2 ATP)

Front 46

Creatine Phosphate

Back 46

storage of ATP, stored in the muscles, when muscles are using up ATP and build up ADP, the CrPO4 releases the stored energy. ADP + CrPO4= creatine + ATP

Front 47

Aerobic respiration

Back 47

when oxygen is available. uses pyruvic acid (which is made from glucose) goes through TCA cycle to make CO2, water and 38 ATP. can use other fatty acids as energy.
Slower but longer lasting.

Front 48

Anaerobic respiration

Back 48

when oxygen is not available. glucose yields 2 ATP. this and the breakdown of CrPO4 is used for Fast contractions for about 3 minutes. produces lactic acid which is removed into the blood>liver>glucose

Front 49

Oxygen debt

Back 49

panting to get oxygen into the body, convert lactic acid into glucose in the liver. and restore the ATP, CrPO4 and others that were used up.

Front 50

Slow twitch

Back 50

more mitochondira
contract slowly
smaller
good blood supply
use aerobic respiration more than anaerobic
lots of myoglobin
ATP is broken down slowly
use lipids as well as glycogen for energy
Endurance

Front 51

Fast twitch

Back 51

skeletal muscles
fast contractions
ATP broken down faster
large myofibers
densely packed-powerful
fewer mitochondria
use anaerobic respiration
fatige fast
hypertophy
contract fast for short time

Front 52

steroids

Back 52

increase size of muscles significantly and fast. not safe.

Front 53

structure of smooth muscle contractile elements

Back 53

actin and myosin complexes are loosely arranged (there are fewer)
actin attaced to dense bodies
dense bodies are attached to intermediate fiibers
when actin slides over myosin, the muscle cell gets shorter and fatter.

Front 54

general info of smooth muscle

Back 54

contracts slower, relaxes slower, and effects are mroe widespread throughout a sheet of muscle. RMP is not as negative as in skeletal muscles.

Front 55

visceral

Back 55

sheets
most common
in digestive, reproductive, and urinary tracts
many gap junctions, to spread cotraction.
autorhythmic
function as a single unit.

Front 56

autorhythmic

Back 56

doesnt need a stimulus from the brain. spontaneous depolarizations due to leak of Na+ and Ca++

Front 57

multiunit

Back 57

less common, may occur in sheets/bundles/or single cells. fewer gap junctions. function as individual units

Front 58

pacemaker areas

Back 58

develop AP's faster, so they set the pace of the waves of depolarization.

Front 59

cardiac muscle

Back 59

striated, uninucleate, involuntary, leaky cells, pacemaker, intercalated disks (gap junction to allow the wave of depolarization to pass quickly between cells.