Physiology Exam 3 -- Metabolism and Other Muscle Cells

glycolysis

begins glucose breakdown; creates ATP and high energy electrons

Kreb's cycle

finishes glucose breakdown; creates CO2, ATP, and high energy electrons

oxidative phosphorylation

consumes O2 and high energy electron to create water and many ATP

phosphagen system

the combination of ATP and creatinine phosphate which provides nearly all energy for short bursts of activity

myoglobin

used when there is limited O2 supply and is rapidly depleted

creatine kinase

breaks down into creatine and ATP; fuels brief, intense activity

glycogen-lactate system

glycolysis with byproducts of pyruvic and lactic acid; used for short-term energy after the phosphagen system; varies between muscles (anaerobic threshold)

aerobic respiration

Respiration that requires oxygen; oxidative phosphorylation

aerobic respiration

what method of ATP production is utilized first during exercise

phosphagen system

what method of ATP production is utilized second during exercise

glycogen-lactate system

what method of ATP production is utilized third during exercise

aerobic respiration

what method of ATP production is utilized fourth during exercise

electron transport chain

series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions

lipids

what is used as breakdown for ATP production when carbohydrate stores are exhausted

amino acids

what is used as breakdown for ATP when other fuel sources are not available

K+ and ADP

what accumulates during high-intensity fatigue

ADP

slows cross-bridge cycle

insufficient ATP, electrolyte loss, excess ammonia

what three things result in low-intensity fatigue

VO2max

Maximum oxygen uptake during intense exercise.

EPOC (excess postexercise oxygen consumption)

O2 debt, uptake remained elevated post exercise for several minutes; Effect is to restore CP/ATP in muscles and O2 in blood

slow-twitch

type I fibers, smaller motor unit, more excitable, postural muscles; good fatigue resistance

fast-twitch

type II fibers, larger motor unit that are less excitable, generates power; lower fatigure resistance

fine control

slow oxidative fibers are recruited first for ______ ___________

power

fast glycolytic fibers are recruited later for ________

pennate muscle

muscle fiber orientation that can generate more force

nervous stimulation

cardiac and smooth muscle do not require ________ ___________ to contract

cardiomyocytes

1-2 nuclei, shorter and thicker, uses purely aerobic respiration, and is joined by intercalated discs

fibrosis

how are cardiomyocytes repaired

pacemaker cells

cells that generate action potentials and conduct autonomic innervations

stem cells

in cardiomyocytes, there is minimal mitosis and no ____________ _________

contractility

when the myocardium is repaired with fibrosis, there is less _____________

gap junctions

smooth muscle may be joined by ____ _____________

autonomic

if smooth muscle is innervated, then innervation is ___________

mitochondria

what does smooth muscle have very few of that skeletal muscle is rich in

dense bodies

intermediate filaments used to create more structure in smooth muscle

unitary

sheets with gap junctions that have fewer synapses and contract as one

multiunit

groups without gap junctions that contract independently

ion channels

what is there a lot of that keeps action potentials moving in smooth muscle

length-tension

there is no _____________ ___________ relationship in smooth muscle because there are no Z discs to stop thick filaments

latch-bridge mechanism

enables myosin to remain attached to actin for a prolonged time without consuming more ATP in smooth muscle

stress-relaxation response

if contraction doesn't work in smooth muscle, then decrease tone

plasticity

viscera can expand and contract while maintaining constant pressure (e.g. bladder)

absent

graded changes in Vm lead to graded changes in muscle size

plateaus

produce periodic slow contractions

spikes

more rapid increase in smooth muscle tone