A&p Ch.9 Muscle

Front 1

Functions of Skeletal Muscle

Back 1

1) Skeletal movement: pulls tendons to move bones

2)Maintain posture & Body Position

3) Support soft tissue: ex. muscles of abdominal wall

4)Guards entrances and exits: ex. openening of digestive tract

5) Maintain Body Temp

6)Store Nutrients: glucose, lipid,& even muscle proteins used during fasting

Front 2

myo/mys

Back 2

muscle

Front 3

sarco

Back 3

flesh

Front 4

Organization of skeletal muscle from largest to smallest

Back 4

1) Skeletal Muscle (organ)

2)Muscle Fasicle (bundle of cells)

3) muscle fiber (cell)

Front 5

Endomysium

Back 5

connective tissue which surrounds and individual muscle cell or fiber

Front 6

Perimysium

Back 6

fibrous layer that divides the skeletal muscle into fasicles

-posses collagen and elastic fibers, blood vessels and nerves

Front 7

Epimysium

Back 7

dense layer of collagen fibers that surrounds the entire muscle

Front 8

Myofibril

Back 8

systematic arrangement of proteins (myofilaments) which form the contractile unit of the muscle called a sarcomere

-striations

M

Front 9

Myosatellite cells

Back 9

stem cells that function to repair damaged muscle tissue

Front 10

Tendons

Back 10

- attaches muscle to a specific point on a bone

-made up of collagen fibers

-continuous with matrix of the bone they are attached to

Front 11

Aponeurosis

Back 11

-layers of flat broad tendons with fewer vessels and nerves

-may involve more than one bone

Front 12

Nerve and blood supply to muscle

Back 12

penetrate epimysium together and branch through perimysium and endomysium

Front 13

What make up myofibrils?

Back 13

myofilaments

Front 14

How does a muscle fiber develop

Back 14

1)myoblasts fuse together to make a fiber

2) a few myoblasts remain on the outside of the cell a Myosatellite cells

3) differentiate into skeletal muscle fibers

Front 15

T tubules

Back 15

conduct waves of electrical activity from the sarcolemma deep in the cell, for the cell to contract

-

Front 16

Structure of myofibrils

Back 16

bundles of thick and thin filaments

Front 17

z-line

Back 17

end of sarcomere unit, connects thin filaments

Front 18

H-zone

Back 18

area of just the thick filaments

Front 19

I band

Back 19

area of just the thin filaments

Front 20

A band

Back 20

area of thick filament

Front 21

Zone of overlap

Back 21

area where thick and thin filament overlap

Front 22

Sliding filament mechanism of contraction

Back 22

-effect on H zone: gets smaller

-effect on I band: gets smaller

-Effects on A band: stays the same

-effect on zine of overlap: gets bigger

-effects on sarcomeres

Front 23

Plasma membrane of muscle cell

Back 23

sarcolemma

Front 24

Sarcoplasmic Reticulum

Back 24

-stores and releases ca ions important for muscle contraction

-tubular network around each myofibril

Front 25

M line

Back 25

line of proteins that connect thick filaments

Front 26

Titin

Back 26

protein which anchors thick filaments z lines and provides elasticity

Front 27

Skeletal Muscle contraction

Back 27

1) muscle activated by neuron

2) Electrical activity passes over sarcolemma and down T-tubules triggering the release of Calcium from SR

3) Ca++ triggers interactions between thick and thin filaments, causing them to contract

4)cell shortens and generates active tension

Front 28

What does each myosin head contain

Back 28

binding sutes for actin and ATP

Front 29

What 4 proteins make up Thin filaments

Back 29

1) Actin

2)Nebulin

3)Tropomyosin

4)Troponin

Front 30

Contractile Proteins

Back 30

1) Myosin: LARGE; can use ATP

2) Actin:thinner; anchoring strand for myosin

3)tropomyosin: protects binding site on actin

4) Troponin: Ca binds to it stimulating tropomyosin to open binding site

Front 31

Cross Bridge cycle

Back 31

-The Process of the myosin heads binding to actin and the generation force to contract the muscle fibre

1) myosin binds to actin and myosin head is 'energized' from a molecule of ATP

2)Myosin head changes shape, pulling on the actin and releasing ADP. Sarcomere shortens

Front 32

What allows actin and myosin to interact?

Back 32

calcium in the cytosol

Front 33

How many nerves are connected to each skeletal muscle cell?

Back 33

ONE

Front 34

Stimulation by motor neuron

Back 34

1)arrival of action potential, the stimulus for ACh release

2)Exocytosis of into the synaptic cleft

3)Diffusion of ACh molecules and their binding receptorson the motor end of the plate

4)Generation of new AP by Na and breakdown of ACh by AChE

5)dumping of Ca onto sarcomeres from AP down T Tubule (EXCITATION COUPLING)

6)Contraction of sarcomere

Front 35

Component of a Muscle twitch

Back 35

-latent

-contraction

-relaxation

T

Front 36

ension

Back 36

Active shortening force exerted by a muscle when it contracts

-must be able to vary

Front 37

Treppe

Back 37

muscle stimulated again after relaxation

-increased tension

Front 38

Wave summation

Back 38

stimulated again before relaxation

never relaxes and tension rises

Front 39

Incomplete/ unfused tetanus

Back 39

stimulated repeatedly never relaxing completely

reaches sub max

Front 40

Complete/fused tension

Back 40

No relaxation between stimuli

Front 41

Isotonic contration

Back 41

length changes

Front 42

concentric contraction

Back 42

muscle shortens

Front 43

eccentric contractions

Back 43

muscle lengthens

Front 44

isometric

Back 44

tension doesn't overcome resistance

no change in length

Front 45

Mechanisms that return muscle to resting length

Back 45

1)elastic forces

2)opposing muscle contractions

3)Gravity

Front 46

How is ATP generated in muscle cells

Back 46

a) direct phosphorylation ADP by creatine phosphate

b)aerobic metabolism

c)glycosis

Front 47

Aerobic metabolism

Back 47

Glycogen--glucose--GLYCOSIS(2ATP)--2 pyruvates +2 ATP+O2--CITRIC ACID CYCLE AND ELECTRON TRANSPORT CHAIN (34 ATP)= CO2 +H20 +34 ATP

Front 48

Anarobic Metabolism

Back 48

Glucose--2 pyruvates + 2ATP= lactic acid (to liver)

Front 49

Limited use on anaerobic respiration

Back 49

-lowered pH

-depletion of metabolic reserves

-damage to sarcolemma

Front 50

Causes of muscle fatigue

Back 50

-depletion of glycogen, lipid and amino acid reserves

-accumulation of lactic acid

Front 51

Type IIb

Back 51

Fast glycotic

-large

-lots of glycogen

-fe mitochondria

-powerful contractions but fatigues quickly

Front 52

Type I

Back 52

Slow oxidiative

-small

-lots of mitochondria, surrounded by blood vessels=high O2

-slowercontractions

-fatigues slower

Front 53

Type IIa

Back 53

Fast oxidative

-intermediate

-lots of mitochondria

-intermediate contractions and fatigue

Front 54

Structure of smooth muscle

Back 54

No T tubules, sarcomeres, striations