Chapter 11

Front 1

Relative to a healthy membrane phospholipid bilayer, where should you find sodium, potassium, and calcium?

Back 1

sodium- outside
potassium- inside
calcium- stored/ transported in special structures: Sarcoplasmic reticulum/ T-tubules

Front 2

T or F: There is a super tiny amount of calcium in the sarcoplasm.

Back 2

True.

Front 3

1mM vs. 0.00000001mM
Which way would calcium move faster?

Back 3

0.00000001mM b/c it has a greater concentration gradiant

Front 4

_______ manipulates membrane potential, so it can choose when to depolarize.

Back 4

exciteable membrane

Front 5

How do epithelial cells differ from neurons and myofibers?

Back 5

Epithelial cells can manipulate the membrane potential.

Front 6

_____ is the electric charge difference across the plasma membrane

Back 6

membrane potential

Front 7

We make a myofiber (muscle cell)______ by depolarizing it and causing calcium release into it.

Back 7

contract

Front 8

In an unstimulated cell there are more anions on the inside of the plasma membrane than on the outside thus the plasma membrane is electrically ______.

Back 8

polarized

Front 9

______ is a difference in electrical charge from one point to another.

Back 9

voltage

Front 10

______ is a shift in the electrical potential across a plasma membrane toward 0mV

Back 10

depolarization

Front 11

When a cell dies, it can't pump voltage, Na+, K+, Ca++, so it becomes ________.

Back 11

depolarized

Front 12

_____ open in response to voltage.

Back 12

voltag-gated channels

Front 13

_____ open in response to a chemical

Back 13

Ligand-gated channels

Front 14

Neurotransmitters like acetycholine are chemical ______.

Back 14

ligands

Front 15

______ lets muscle contract.

Back 15

acetylcholine

Front 16

The channel of acetylcholine only opens if _____ is present.

Back 16

ligand

Front 17

______ are holes between cardiac cells allowing ions to pass from cell to cell down their concentration gradient.

Back 17

gap junctions

Front 18

Damage to the _______ explains soreness after a race.

Back 18

plasma membrane

Front 19

4 additional ways besides cell death to depolarize membranes

Back 19

1) voltage-gated channels
2) ligand-gated channels
3) gap junctions
4) stretch or damage plasma membrane

Front 20

Nerve cell axon ending meets myofiber at a structure called the ______.

Back 20

Motor end plate or synapse or neuromuscular junction (all mean relatively same thing)

Front 21

_____ is the space between axon and myofiber

Back 21

synaptic cleft

Front 22

_____ contains/releases synaptic vesicles

Back 22

axon

Front 23

Vesicles contain the neurotransmitter _______

Back 23

acetylcholine (ACH)

Front 24

acetylcholine opens ___ channels that cause depolarization.

Back 24

Na+

Front 25

3 factors that limit duration of depolarization

Back 25

1) voltage gated channels (Na+ & Ca++) only stay open for a few milliseonds.
2) Acetylcholinesterase degrades aceylcholine.
3) Sodium and calcium are rapidly pumped out.

Front 26

Depolarization of the target cell occurs when what 3 things happen to ACH.

Back 26

1)exocytosis
2)diffuses across synapse
3)binds/opens receptor (a ligand gated-Na+ channel)

Front 27

_____ is the rapid fluctuation in membrane voltage at the motor end plate.

Back 27

end-plate potential

Front 28

One exocytosis may not release enough ACH to open enough ligand-gated channels to create enough depolarization to cause enough depolarization to open the ____________.

Back 28

voltage gated channels

Front 29

_____ means the same length, but generates more tension.

Back 29

isometric

Front 30

_____ means the same tension, but more length

Back 30

isotonic

Front 31

muscle is the sum of many _____

Back 31

sarcomeres

Front 32

____,____,&_____ have an ideal length that gives them the best contractile performance for a given stimulation. This is called the length-tension relationship.

Back 32

1) muscles
2) myofibers
3) sarcomeres

Front 33

Which is further away from zero and more negative, hyperpolarization or depolarization?

Back 33

hyperpolarization

Front 34

Which is closer to zero and less negative, hyperpolarization or depolarization?

Back 34

depolarization

Front 35

_____ prevent acetylcholinesterase from degraging ACH and are used for chemical warefare, cause a fatal seizure.

Back 35

cholinesterase

Front 36

______ allows a muscle to relax.

Back 36

acetylcholinesterase

Front 37

4 major phases of muscle contraction and relaxation

Back 37

1) excitation
2) excitation-contraction coupling
3) contraction
4) relaxation

Front 38

_____ is the process in which action potentials in the nerve fiber lead to action potentials in teh muscle fiber.

Back 38

excitation

Front 39

Which stage of muscle contraction contains an end plate potential?

Back 39

excitation

Front 40

What stage links action potentials in the muscle fiber to the release and binding of calcium ions?

Back 40

excitation-contraction coupling

Front 41

_____ is a quick up-&-down voltage shift from -to+to-

Back 41

action potential

Front 42

_____ is the stage in which the muscle fiber develops tension and may shorten.

Back 42

contraction

Front 43

_____ stage contains the sliding filament theory that causes a thin filament to slide over a thick filament and generate tension in the muscle.

Back 43

contraction

Front 44

_____ stage leads from the cessation of a nerve signal to the release of thin filaments by myosin.

Back 44

relaxation

Front 45

What happens if the muscle is overly contracted?

Back 45

Thick filaments butt against the Z discs and the fiber can't contract very much more when stimulated.

Front 46

What happens if the muscle is overly stretched?

Back 46

Little overlap between thick and thin filaments that few cross-bridges can form between myosin and actin.

Front 47

_______ is a stable voltage across the plasma membrane of an unstimulated cell

Back 47

resting membrane potential (rmp)