Topic 4

difference in electrical charge between the inside and outside of a cell

membrane potential

what are voltage differences in the membranes of excitable cells at rest called

resting membrane potential

Na+, K+, Cl-, and proteins are _ distributed on either side of the plasma membrane

unequally

There is typically more sodium on the _ of the cell rather than the _

outside, inside

There is typically more potassium _ the cell rather than _

inside, outside

There is typically more chloride _ the cell rather than _ the cell

outside, inside

When the cell is at rest, which channel is more open over the other types of ion channels?

K+

The inside of the cell is mostly what charge?

negative

In the sodium potassium ATPase pump, sodium _ the cell

leaves

In the sodium potassium ATPase pump, potassium _ the cell

enters

What are the 3 basic steps of skeletal muscle contraction?

Excitation, contraction, relaxation

When the skeletal muscle cell is stimulated at the sarcolemma by a motor neuron

excitation

When the stimulus leads to the shortening of sarcomeres

contraction

When cellular mechanisms stop the contraction process

relaxation

A single motor neuron and all the muscle fibers in innervates is called a

motor unit

the process of generating force in a muscle due to cross bridge activity

contraction

force exerted by a muscle on a load

tension/effort

force that opposes the tension/effort generated by muscle contraction

load

muscle changes in length and moves a load

isotonic

what are the two types of isotonic contraction?

concentric and eccentric

the type of isotonic contraction that shortens muscles

concentric

the type of isotonic contraction that lengthens muscles

eccentric

the type of contraction where tension is generated but there is no shortening or lengthening

isometric

muscle contraction classifications that measure strength of a contraction as weak to strong are called

graded muscle contractions

rapid and strong stimuli to muscle cause what contractions

strong

low frequency and weak stimuli causes what contractions

weak

when a second stimulus is applied to a muscle before it finishes relaxing

summation

similar to wave summation but stimuli are delivered more frequently

incomplete, unfused tetanus

prolonged smooth contractions caused by rapid stimulation

complete, fused tetanus

what are the two ways to increase the strength/tension of a contraction?

increased frequency, increased stimuli strength

What is the preferred fuel for muscle contraction?

ATP

What fuel is needed to fuel the power stroke, detach cross bridges, and relax sarcomeres?

ATP

what accounts for 8-10 seconds of contraction?

creatine phosphate

what process makes ATP quick but has a lower yield?

anaerobic glycolysis

what process makes ATP slow but has a high yield?

aerobic respiration

length of time that a muscle can continue to contract using aerobic pathways

aerobic endurance

point at which muscle metabolism switches from aerobic to anaerobic

anaerobic threshold

state where a muscle is physiologically unable to contract bc ATP consumption is higher than production

muscle fatigue

term for the amount of oxygen needed to restore muscle to its resting metabolic state

oxygen debt

oxygen helps the muscle convert lactic acid back to what

pyruvic acid

pyruvic acid can be metabolized into what

ATP

in the liver lactic acid is converted to what and stored as what?

glucose, glycogen