Test 1 Vocabulary

acute exercise

a single bout of exercise

big data

a term used for extremely large data sets that can be analyzed using sophisticated algorithms and computational methods to reveal patterns, trends, and associations

bioinformatics

the science of analyzing complex biological data such as genetic codes

chronic adaptation

a physiological change that occurs when the body is exposed to repeated exercise bouts over weeks or months; these changes generally improve body’s efficiency at rest and during exercise

control group

in an experimental design, the non treated group to which the experimental group is compared

crossover design

experimental design in which the control group becomes the experimental group after the first experimental period, and vice versa

cross-sectional research design

a research design in which a cross section of a population is tested at one specific time and then data from groups within that population are compared

cycle ergometer

an exercise device that uses cycling to measure physical work

dependent variable

the physiological factor that is allowed to vary as another factor (the independent variable) is manipulated; usually plotted on the y-axis

diurnal variation

fluctuations in physiological responses that occur during a 24 h period

dose-response relation

a relation between two variables in which one changes predictably as the other increases or decreases

environmental physiology

study the effects of the environment (heat, cold, altitude, hyperbaric, and so on) on the function of the body

epigenetics

the study of changes in organisms caused by modifying gene expression rather than changing the genetic code itself

ergometer

an exercise device that allows the amount and rate of a person’s physical work to be controlled (standardized) and measured

exercise physiology

the study of how body structure and function are altered by exposure to acute and chronic bouts of exercise

genomics

the branch of molecular biology concerned with the structure, function, evolution, and mapping of genomes

genotype

the genetic makeup of an individual

homeostasis

maintenance of a constant internal environment

independent variable

in an experiment, the variable that is manipulated by the experimenter to determine the response of the dependent variable; usually plotted on the x-axis

integrative physiology

the study of organisms as functioning systems of molecules, cells, tissues, and organs with an emphasis on whole-body function

longitudinal research design

a research design in which subjects are tested initially and then one or more times later to directly measure changes over time resulting from a given intervention

peer review

the process of evaluating scientific research by other knowledgeable scientists working in the same field

phenotype

observable characteristics of an individual resulting from the interaction of the person’s genotype with the environment

physiology

the study of the function of organisms

placebo group

the group in an intervention study given a placebo rather than a test substance

primary research article

a paper in a scientific journal that presents the results of an original research project

reliability

how repeatable a measurement is when taken several times under the same conditions

review paper

a paper that synthesizes the knowledge in a particular area, citing multiple primary research articles

sport physiology

the application of the concepts of exercise physiology to training athletes and enhancing sport performance

training effect

physiological adaptation to repeated bouts of exercise

translational physiology

the processes by which basic research findings are extended to the clinical research setting, then tot he realm of clinical practice, and finally to health policy

treadmill

an ergometer in which a motor and pulley system drive a large belt that a person can either walk or run on

validity

the extent to which a measurement truly represents the phenomenon you are attempting to measure

actin

a thin protein filament that acts with myosin filaments to produce muscle action

action potential

a rapid and substantial depolarization of the membrane of a neuron or muscle cell that is conducted through the cell

adenosine triphosphatase (ATPase)

an enzyme that splits the last phosphate group off ATP, releasing a large amount of energy and reducing the ATP to ADP and Pi

adenosine triphosphate (ATP)

a high-energy phosphate compound from which the body derives its energy

alpha-motor neuron

a neuron innervating extramural skeletal muscle fibers

concentric contraction

muscle shortening

dynamic contraction

any muscle action that produces joint movement

eccentric contraction

any muscle action in which muscle lengthens

endomysium

a sheath of connective tissue that covers each muscle fiber

epimysium

the outer connective tissue that surrounds an entire muscle, holding it together

excitation-contraction coupling

the sequence of events by which a nerve impulse reaches the muscle membrane and leads to cross-bridge activity and thus muscle contraction

fascicle

a small bundle of muscle fibers wrapped in a connective tissue sheath within a muscle

force-velocity relation

the force generated by a muscle is a function of its velocity; increasing the velocity of contraction while shortening reduces force, while faster contraction as the muscle is lengthening increases force

length-tension relation

the tension developed by a muscle is a function of its length; the highest force can be generated when there is optimal overlap between actin and myosin filaments

motor unit

the motor nerve and the group of muscle fibers it innervates

muscle fiber

an individual muscle cell

musculoskeletal system

body system composed of the skeleton and skeletal muscles that allows, supports, and helps control human movement

myofibril

the contractile element of skeletal muscle

myosin

one of the proteins that form filaments that produce muscle action

myosin cross-bridge

the protruding part of a myosin filament; it includes the myosin head, which binds to an active site on an actin filament to produce a power stroke that causes the filaments to slide across each other

nebulin

a giant protein that coextends with actin and appears to play a regulatory role in mediating actin and myosin interactions

perimysium

the connective tissue sheath surrounding each muscle fasciculus

plasmalemma

plasma membrane, the selectively permeable lipid bilayer coated by proteins the composes the outer layer of a cell

power stroke

the tilting of the myosin head, caused by a strong intermolecular attraction between the myosin cross-bridge and the myosin head, which causes the actin and myosin filaments to slide across each other

principle of orderly recruitment

the theory that motor units generally are activated on the basis of a fixed order of recruitment, in which the motor units within a given muscle appear to be ranked according tot he size of the motor neuron

rate coding or frequency coding

refers to the frequency of impulses sent to a muscle; increased force can be generated through increase in either the number of muscle fibers recruited or the rate at which the impulses are sent

sarcolemma

a muscle fiber’s cell membrane

sarcomere

the basic functional unit of a myofibril

sarcoplasm

the gelatin-like cytoplasm in a muscle fiber

sarcoplasmic reticulum (SR)

a longitudinal system of tubules that is associated with the myofibrils and that stores calcium for muscle action

satellite cells

immature cells that can develop into mature cell types, such as myoblasts

single-fiber contractile velocity

the rate at which an individual muscle cell can shorten and develop tension

size principle

principle asserting that the size of the motor neuron dictates the order of motor unit recruitment, with small-sized motor neurons being recruited first

sliding filament theory

a theory explaining muscle action: a myosin cross-bridge attaches to an actin filament, and then the power stroke drags the two filaments past one another

static (isometric) muscle contraction

action in which the muscle contracts without moving, generating force while its length remains static (unchanged)

summation

the summing of all individual changes in a neuron’s membrane potential

tetanus

highest tension developed by a muscle in response to stimulation of increasing frequency

titin

a protein that positions the myosin filament to maintain equal spacing between actin filaments

transverse tubules (T-tubules)

extensions of the sarcolemma that pass laterally through the muscle fiber, allowing nutrients to be transported and nerve impulses to be transmitted rapidly to individual myofibrils

tropomyosin

a tube-shaped protein that twists around actin strands, fitting into the groove between them

troponin

a complex protein attached at regular intervals to actin strands and tropomyosin

twitch

the smallest contractile response of a muscle fiber or a motor unit to a single electrical stimulus

type I fiber

a type of muscle fiber that has a high oxidative and a low glycolytic capacity, associated with endurance-type activities

type II fiber

a type of muscle fiber with a low oxidative and a high glycolytic capacity, associated with speed or power activities

acetyl coenzyme A (acetyl CoA)

the compound that forms the common entry point into the Krebs cycle for the oxidation of carbohydrate and fat

activation energy

the initial energy required to start a chemical reaction or chain of reactions

adenosine diphosphate (ADP)

a high-energy phosphate compound from which ATP is formed

aerobic metabolism

a process occurring in the mitochondria that uses oxygen to produce energy (ATP); aka cellular respiration

anaerobic metabolism

the production of energy (ATP) in the absence of oxygen

ATP-PCr system

the short-term anaerobic energy system that maintains ATP levels; breakdown of phosphocreatine frees Pi, which then combines with ADP to form ATP

beta-oxidation

the first step in fatty acid oxidation, in which fatty acids are broken into two separate carbon units of acetic acid, each of which is then converted to acetyl coA

bioenergetics

term given to the study of metabolic processes that yield or consume energy

carbohydrate

an organic compound formed from carbon, hydrogen, and oxygen; includes starches, sugars, and cellulose

catabolism

the tearing down of body tissue; the destructive phase of metabolism

creatine kinase

the enzyme that facilitates the breakdown of PCr to creatine and Pi

crossover concept

the exercise intensity at which fat and carbohydrate utilization intersect as the energy derived from fat decreases and the energy from carbohydrate increases

cytochrome

a series of iron-containing proteins that facilitate the transport of electrons within the electron transport chain

electron transport chain

a series of chemical reactions that convert the hydrogen ion generated by glycolysis and the Krebs cycle into water and produce energy for oxidative phosphorylation

enzyme

protein molecules that speed up reactions by lowering their energy of activation

free fatty acids (FFAs)

the components of fat that are used by the body for metabolism

glucogenolysis

the conversion of glycogen to glucose

glycolysis

the breakdown of glucose to pyretic acid

kilocalories (kcal)

the equivalent of 1,000 calories

Krebs cycle

a series of chemical reactions that involve the complete oxidation of acetyl CoA and produce 2 mol of ATP (energy) along with hydrogen and carbon, which combine with oxygen to form H2O and CO2

lipogenesis

the process of converting protein into fatty acids

lipolysis

the process of breaking down triglyceride to its basic units to be used for energy

metabolism

all energy-producing and energy-using processes within the body