Bio Ch 6

Front 1

3 types of muscles, their locations, and whether or not they are voluntary/involuntary

Back 1

skeletal-skeleton-striated-no cell junctions-voluntary; cardiac-heart-striated-cell junctions (intercalated discs)-involuntary; smooth-stomach, digestive organs, bladder, blood vessels, uterus-involuntary

Front 2

three functions of muscles

Back 2

produce movement by interacting with skeleton, resist movement by generating a force, generate heat to maintain body temperature

Front 3

what happens when muscle cell contracts and relaxes

Back 3

contracts- shortens, relaxes - returns to original length

Front 4

muscle groups that work together to create the same movement

Back 4

synergistic muscles

Front 5

muscle groups that oppose each other to produce opposite movements

Back 5

antagonistic muscles

Front 6

In muscle contraction, the point of attachment of muscle to bone that does not move is the ____. It is usually ___ to the body trunk. The point of attach. to the movable bone in a contraction is its ___. It is usually ___ from the body trunk.

Back 6

origin, proximinal, insertion, farther

Front 7

When a muscle contracts, its __ is pulled toward its __.

Back 7

insertion, origin

Front 8

explain how biceps and triceps works

Back 8

biceps contracts, insertion of biceps pulls on radius, which raises or flexes forearm; triceps contracts, the insertion of the triceps pulls on the ulna, which lowers or extends forearm

Front 9

the act of bending

Back 9

contracting

Front 10

a group of individual muscle cells or ____, which all have the same ___ and ___ and function

Back 10

fibers, origin, insertion

Front 11

groups of muscle cells/fibers arranged together in a bundle; surrounded by a fibrous conn tissue sheath called __

Back 11

fasicle; fascia

Front 12

myofibril striation due to ___ and ___

Back 12

actin and myosin

Front 13

the smallest contractile unit of a muscle myofibril

Back 13

sarcomere

Front 14

muscle contraction is caused by shortening of sarcomeres, which shorten by a _________, in which actin filaments slide past myosin filaments

Back 14

sliding filament mechanism

Front 15

skeletal muscle cells are stimulated by ____, which releases ____, which initiates the _______, which causes the shortening of sarcomeres and contraction of the muscle.

Back 15

neurons, calcium, sarcomeres

Front 16

the area where a motor neuron comes in close contact with a muscle cell

Back 16

neuromuscular junction

Front 17

Read this (muscle contraction).

Back 17

Electrical impulses from the brain and spinal cord travel through a motor neuron to a skeletal muscle. When an electrical impulse reaches the neuromuscular junction, a neurotransmitter called acetylcholine is released from the neuron. Bind of this neurotransmitter to the muscle cell membrane causes the membrane to generate an electrical impulse. Extensons of the membrane called T tubules carry this impulse deep into the interior of the muscle cell and the sarcoplasmic reticulum. The impulse stimulates the sarcoplasmic reticulum to release stored calcium ions, which then bind with special proteins on myosin and allow cross-bridges to form between the myosin heads and actin filaments. The myosin heads bend and physically pull the actin filaments, which causes the sarcomere to shorten.

Front 18

Read this (muscle relaxation).

Back 18

When nerve stimulation stops, electrical impulses in the muscle stop. The sarcoplasmic reticulum stops releasing calcium and any calcium that had already been released is transported back into the sarcoplasmic ret. by active transport. As the calcium concentration decreases, the cross bridges btwn actin and myosin dissemble, the sarcomere stretched back to original length and the muscle cell relaxes.

Front 19

energy for muscle activity

Back 19

ATP

Front 20

3 functions of ATP in muscle contract/relax

Back 20

binds myosin heads to actin to form cross bridges and to detach myosin heads from actin in sliding filament mechanism; transports calcium back into the sarcoplasmic ret at the end of contraction;detaches myosin heads from actin so that relaxation can occur

Front 21

What causes rigor mortis?

Back 21

shortly after death, calcium leaks out of sarcoplasmic ret, causes muscle contraction, uses up ATP, myosin heads cannot detach from actin, muscles remain contracted until they degenerate

Front 22

weight lifters muscles rely on stored ATP first, and then ___ and ___ stores

Back 22

creatine phosphate, glycogen

Front 23

slow twitch muscle fibers are for activities that require

Back 23

endurance

Front 24

fast twitch muscle fibers are for activities that require

Back 24

rapid contraction

Front 25

exercise increases aerobic capacity, muscle mass, and muscle strength, but not

Back 25

the number of muscle cells

Front 26

muscle weakness caused by immune system destruction of acetylcholine receptors on muscle cell membranes

Back 26

myasthenia gravis

Front 27

calcium leakage and destruction of muscle cells caused by lack of dystrophin muscle protein

Back 27

muscular dystrophy

Front 28

overstimulation of nerves and sustained muscle contractions produced by bacterial toxins from a puncture wound

Back 28

tetanus

Front 29

painful muscle contractions caused by dehydration and ion imbalances, esp. potassium

Back 29

muscle cramps