Midterm 1 Flashcards
(247 cards)
1
Q
acetylcholine (ACh) -
A
A neurotransmitter released from somatic motor neurons, pre-ganglionic sympathetic and parasympathetic motor neurons, and post-ganglionic parasympathetic motor neurons.
2
Q
action potential -
A
A short-lasting electrical event in which the membrane potential of a cell rapidly rises above the threshold of excitation, then falls. Occur in excitable cells such as neurons, muscle cells, and endocrine cells. Form of communication from one cell to another. In muscle cells, action potentials activate intracellular processes.
3
Q
adrenal cortex -
A
The outer layer of the adrenal gland that produces steroid hormones: cortisol, aldosterone, and androgen.
4
Q
adrenal gland -
A
Also known as suprarenal glands, these are endocrine glands that produce a variety of hormones, including epinephrine, norepinephrine, cortisol, aldosterone, and androgen.
5
Q
adrenal medulla -
A
The inner layer of the adrenal gland that produces catecholamines: epinephrine and norepinephrine.
6
Q
adrenaline -
A
The generic name for epinephrine, one of the catecholamines released from the adrenal medulla. Most of the adrenal medullas, secretion is this (epinephrine).
7
Q
adrenergic -
A
Refers to the effects of adrenaline (epinephrine) and noradrenaline (norepinephrine).
8
Q
afferent neuron -
A
A sensory neuron.
9
Q
all-or-none principle -
A
In regards to a neuron, if the stimulus reaches the threshold of excitation, an action potential will be propagated the length of the axon, otherwise there will be no response. In regards to skeletal muscle, single twitches of motor units will contract fully, or not at all.
10
Q
alpha motor neuron -
A
Also called a somatic motor neuron, this is a neuron that innervates skeletal muscle.
11
Q
alpha receptor -
A
An adrenergic receptor that binds with both epinephrine and norepinephrine to cause vasoconstriction.
12
Q
annulospiral sensory neurons -
A
One of the two types of sensory neurons that wrap around the center of both types of intrafusal fibers. Detect the rate of change in length of the muscle.
13
Q
antagonistic control -
A
The type of neural control of effector organs of the autonomic nervous system that have dual innervation by sympathetic (excitatory) and parasympathetic (inhibitory) motor neurons. The activity of the organ is a function of the net effect, or sum of excitatory and inhibitory stimulation.
14
Q
atrophy -
A
A decrease in the size of an organ. In skeletal muscle, a decrease in the cross-sectional area of the muscle.
15
Q
autonomic nervous system -
A
The part of the nervous system that controls smooth muscle, the heart, and glands. Most organs of this have dual innervation.
16
Q
axon hillock -
A
A part of the cell body that connects to the axon. Thought to be where an action potential originates from the sum of synaptic inputs to the dendrites of the cell body.
17
Q
beta receptor -
A
An adrenergic receptor that binds with both epinephrine and norepinephrine to cause various responses depending on the specific type of receptor.
18
Q
catecholamines -
A
A generic name for water-soluble organic compounds (epinephrine and norepinephrine) released from the adrenal medulla as part of the fight-or-flight response.
19
Q
central nervous system (CNS) -
A
From an organizational perspective, the central nervous system includes the brain and spinal cord.
20
Q
cholinergic -
A
Refers to the effects of acetylcholine.
21
Q
cholinergic receptor -
A
A receptor that binds with acetylcholine. These include nicotinic receptors and muscarinic receptors.
22
Q
contraction -
A
The development of tension resulting from the interaction of actin and myosin filaments in muscle cells.
23
Q
cytoplasm -
A
Composed of cytosol (the watery substance inside the cell membrane) and the organelles of the cell. This is the location of most cellular activities, such as glycolysis.
24
Q
dendrites -
A
Branched projections from the cell body of a neuron that receive electrical stimulation from other nerve cells and propagate the stimulation to the cell body.
25
depolarization -
The brief and rapid shift of a cell's internal electrical charge from its negative resting membrane potential to a positive charge.
26
dorsal root -
One of two roots that emerge from the spinal cord. location of sensory neuron entry into the spinal cord.
27
dorsal root ganglia -
A cluster of cell bodies of sensory neurons in the dorsal root of the spinal cord.
28
effector organ -
The target organ of motor neurons.
29
efferent neuron -
A motor neuron.
30
endocrine glands -
A gland of the endocrine system that secretes hormones directly into the blood.
31
epinephrine (EPI) -
One of the two catecholamines secreted by the adrenal medulla. Also known as adrenaline.
32
excitability -
A property of some cells, such as nerve and muscle cells, to depolarize.
33
excitatory postsynaptic potential (EPSP) -
A hypopolarizing graded potential that makes the postsynaptic membrane more likely to reach the threshold of excitation and to fire and action potential.
34
exocrine glands -
Glands that synthesize and secrete substances by way of a duct (rather than secreting the substance directly into the blood). Examples are sweat and salivary glands.
35
extrafusal fibers -
Skeletal muscle fibers surrounding the muscle spindle.
36
fight or flight -
An acute stress response of the autonomic nervous system to a perceived threat characterized by increased sympathetic activity that primes the body.
37
flower spray sensory neurons -
One of the two types of sensory neurons that wrap around the center of the nuclear chain intrafusal fibers. Detect the rate of change in length of the muscle.
38
gamma motor neuron -
A motor neuron that innervates the muscle spindle, causing it to contract (shorten) or relax (lengthen) to maintain proportionately the same length as the surrounding skeletal muscle fibers.
39
ganglia -
A cluster of cell bodies
40
glucagon -
A hormone produced by the alpha cells of the pancreas and released in response to low blood glucose levels to raise blood glucose levels by stimulating liver glycogenolysis. The actions are in opposition to the actions of insulin.
41
glucosuria -
The excretion of glucose into the urine. Ordinarily, urine contains no glucose. High blood glucose levels, such as in diabetes mellitus, results in glucose spilling over into the urine since the kidneys are unable to reclaim the filtered glucose back into the blood.
42
GLUT - 4
Glucose transporter that transports blood glucose across the skeletal muscle cell sarcolemma.
43
golgi tendon organ -
A proprioceptive sensory receptor located in the tendons of skeletal muscle that senses forces of contraction. Also called the inverse myotatic reflex, results in the inhibition of the antagonist muscle group.
44
graded potential -
Changes in the membrane potential that vary in size (as opposed to being all-or-none). Can be hypopolarizing or hyperpolarizing.
45
growth hormone -
Also known as *somatotropin * a peptide (made from amino acids) hormone synthesized and released from the anterior pituitary gland that stimulates growth and cell reproduction.
46
hormone -
Signaling molecules produced by a gland and transported in the blood to target organs throughout the body to regulate physiology.
47
hyperglycemia -
High blood glucose levels.
48
hyperpolarization -
A graded potential that moves in the negative direction, further away from the threshold of excitation.
49
inhibitory postsynaptic potential (IPSP) -
A change in the membrane potential (more negative away from the threshold of excitation) that makes it less likely that an action potential will occur. A hyperpolarization of the cell membrane.
50
insulin -
A hormone released from the beta cells of the pancreas in response to rising blood glucose levels. Promotes the absorption of glucose from the blood into skeletal muscle and fat tissue.
51
insulin-dependent diabetes mellitus (IDDM) -
Usually referred to as type 1 diabetes (T1D). Previously referred to as juvenile onset diabetes. A form of diabetes mellitus resulting from the autoimmune destruction of the beta cells of the pancreas, which leads to an increase in blood (and urine) glucose. Administration of insulin is essential.
52
interneuron -
A neuron that connects a sensory neuron to a motor neuron in the central nervous system.
53
intrafusal fibers -
Muscle fibers that serve as specialized sensory proprioceptors in the muscle spindle that detect the amount and rate of stretch of a muscle. There are two types: nuclear bag and nuclear chain fibers. The ends of the fibers are innervated by gamma motor neurons. The ends contract.
54
mitochondria -
An organelle found in most cells. Described as the powerhouse of the cell because most of the energy (i.e., ATP) is generated in the mitochondria. Compartments or regions of the include the intermembrane space, inner membrane, cristae, and matrix.
55
motor end-plate -
A region on the sarcolemma of a skeletal muscle fiber that includes invaginations, or folds, which increase the surface area of the membrane. This region contains cholinergic receptors to which acetylcholine released from the motor neuron will bind.
56
motor neuron -
One of the three categories of neurons (sensory, motor, interneuron). Transmit action potentials away from the central nervous system.
57
motor unit -
One somatic motor neuron and all of the muscle fibers that it innervates.
58
muscarinic receptor -
One of cholinergic receptors that bind with acetylcholine.
59
muscle spindle -
A proprioceptive receptor embedded in the belly of skeletal muscle (extrafusal fibers) that detects changes in length and the rate of change in length. Responsible for the stretch reflex, or the myotatic reflex.
60
myelin sheath -
A fatty substance that wraps around the axon of some neurons. Increases the rate of conduction of action potentials the length of the axon.
61
myotatic reflex -
The stretch reflex initiated by the muscle spindle.
62
nerve -
A bundle of nerve cells (i.e., neurons).
63
nerve impulse -
A short-lasting electrical event in which the membrane potential of a cell rapidly rises above the threshold of excitation, then falls. Action potentials are a form of communication from one cell to another. In muscle cells, action potentials activate intracellular processes. See also action potential.
64
neuroeffector junction -
A site where an autonomic motor neuron releases a neurotransmitter at the effector organ.
65
neuromuscular junction -
A chemical synapse between the terminal ends of a somatic motor neuron and the membrane of a skeletal muscle fiber.
66
neuron -
A nerve cell.
67
neurotransmitter -
A chemical messenger synthesized in a neuron and released from vesicles in its terminal ends. Binds to a matching receptor, causing a specific response.
68
nicotinic receptor -
One of the two cholinergic receptors that bind with acetylcholine.
69
nodes of ranvier -
One of the two cholinergic receptors that bind with acetylcholine.
70
norepinephrine (NE) -
One of the two catecholamines secreted by the adrenal medulla. Also known as nor-adrenaline.
71
nuclear bag fibers -
One of the two types of intrafusal fibers in the muscle spindle that stretch when the muscle is stretched.
72
nuclear chain fibers -
One of the two types of intrafusal fibers in the muscle spindle that stretch when the muscle is stretched.
73
parasympathetic nervous system -
One of the two divisions of the autonomic nervous system. Stimulates "rest and digest" activities in the body. Organs that are innervated by sympathetic and parasympathetic motor neurons have dual innervation and antagonistic control.
74
peripheral nervous system (PNS) -
Part of the nervous system that includes nerves and ganglia outside of the brain and spinal cord. Connects the central nervous system with the organs and extremities.
75
proprioception -
The sense of position of body parts (e.g., head and limbs) relative to other body parts and the amount of force applied.
76
receptor -
Any structure or molecule that when exposed to a specific stimulus, produces a response. Can bind with neurotransmitters and hormones or detect changes in temperature, oxygen and carbon dioxide levels, pressure, pH, and body position.
77
reciprocal inhibition -
The process of muscles on one side of the joint relaxing to accommodate contraction of the muscle on the other side of the joint. The stretch, or myotatic, reflex
78
resting membrane potential (RMP) -
The difference in the electrical potential between the interior and exterior of a cell in the resting state. Is negative, typically -70 to -80 mv in neurons and -90 in skeletal muscle cells.
79
saltatory conduction -
The conduction of an action potential the length of a myelinated axon from one node of Ranvier to the next, increasing the velocity of conduction.
80
sarcolemma -
The skeletal muscle cell membrane.
81
sensory neuron -
One of the three types of neurons (sensory, motor, interneurons). Transmit action potentials to the central nervous system.
82
size principle -
The principle that states that motor units are recruited in an orderly fashion based on the size of the motor neuron. Small motor neurons with lower thresholds of excitation are recruited prior to larger motor neurons with higher thresholds of excitation.
83
somatic motor neuron -
The motor neuron that innervates skeletal muscle cells and is responsible for initiating their contraction. Also known as an alpha motor neuron.
84
spatial summation -
Achieving an action potential by summing input from multiple presynaptic cells.
85
stretch reflex -
Also referred to as the myotatic reflex. A reflex that involves the muscle spindle and three motor responses: contraction of the agonist muscle, relaxation of the antagonist muscle, and activation of the gamma motor neuron.
86
sympathetic chain ganglia -
Ganglia of sympathetic motor neurons that lie adjacent to the spinal cord.
87
sympathetic nervous system -
One of the two divisions of the autonomic nervous system that controls smooth muscle, cardiac muscle, and glands. The sympathetic nervous system stimulates fight or flight activities in the body. Organs that are innervated by sympathetic and parasympathetic motor neurons have dual innervation and antagonistic control.
88
synapse -
A junction between the terminal ends of one neuron and the dendritic end of another neuron.
89
synaptic cleft -
The space between the terminal knobs of the motor neuron and the post synaptic membrane.
90
temporal summation -
A high frequency of stimulation resulting in the summation of postsynaptic potentials and an action potential.
91
terminal ends -
The branching end of an axon.
92
terminal knobs -
Knobs at the terminal ends of neurons that release a neurotransmitter from vesicles.
93
tetanic contractions -
Contractions of skeletal muscle motor units at a high frequency of stimulation. Produce more force than single twitches of motor units.
94
threshold of excitation -
A membrane potential at which voltage-gated sodium channels are activated, leading to an influx of sodium ions into the cell. As more sodium ions enter the cell, the cell rapidly depolarizes, causing an action potential.
95
tonic control -
A type of neural control of an effector organ of the autonomic nervous system that has single innervation.
96
twitch -
A single contraction and relaxation of a muscle fiber or motor unit initiated from a single action potential.
97
ventral root -
One of two roots that emerge from the spinal cord. Location of motor neuron cell bodies in the spinal cord.
98
a-band (anisotropic band) -
The dark band within the sarcomere that extends from the end of one myosin to the other end of the same myosin.
99
acetylcholine -
A neurotransmitter released from somatic motor neurons, preganglionic sympathetic and parasympathetic motor neurons, and postganglionic parasympathetic motor neurons.
100
actin -
One of the two contractile proteins in muscle tissue. Binds to myosin to form crossbridges during the excitation-contraction process to facilitate contraction.
101
actin filament -
Strands of actin intertwined with troponin and tropomyosin.
102
alpha actinin -
A protein that helps anchor the actin filament to the Z-line.
103
ATPase -
The enzyme that catalyzes the breakdown of ATP into ADP and a free phosphate.
104
central bare zone -
The central region of the myosin filament which has not heads protruding. Corresponds to the H-zone of the sarcomere in the resting state.
105
contractile force -
The force produced by the contraction of muscle tissue. In skeletal muscle, it is referred to a P0.
106
contractile protein(s) -
Proteins in muscle tissue that are responsible for forming crossbridges during the contractile process. Contractile proteins include actin and myosin.
107
contractility -
One of the four properties common to all three types of muscle. Refers to the ability to develop tension because of the interaction between actin and myosin filaments.
108
contraction -
The development of tension due to the interaction of actin and myosin filaments of muscle tissue.
109
cross-sectional area (CSA) -
The area of a perpendicular cross-sectional slice of an object (e.g., axon or muscle fiber) used to determine the size of the neuron or muscle fiber.
110
crossbridge -
The binding of myosin heads to the active sites on the actin filament, thereby forming a crossbridge between the two filaments.
111
crossbridge cycle -
The repeated four-step cycle of actin and myosin forming and releasing crossbridges during the contractile process of muscle. The cross-bridge cycle provides a molecular explanation of the sliding filament theory of muscle contraction.
112
cytoskeletal proteins -
Proteins in skeletal muscle that are responsible for creating a dynamic shape with structural integrity that can resist deformation.
113
desmin -
A cytoskeletal protein in muscle that binds the Z-discs of adjacent myofibrils together and the outmost myofibril to the sarcolemma.
114
elasticity -
One of the four properties common to all three types of muscle. Refers to the ability of the tissue to return to its normal resting length after it has been stretched.
115
endomysium -
One of three layers of connective tissue in skeletal muscle. The endomysium envelopes individual muscle fibers within the fasciculus.
116
epimysium -
One of three layers of connective tissue in skeletal muscle. The epimysium envelopes the entire muscle.
117
excitability -
One of the four properties common to all three types of muscle. Refers to the ability of the tissue to respond to neural or other stimuli.
118
excitation-contraction coupling -
The sequence of events beginning with the excitation (depolarization) of a somatic (alpha) motor neuron and ending with the contraction of skeletal muscle fibers. The sequence of events couples the neural excitation component with the contractile process in the muscle fiber and sarcomere.
119
extensibility -
One of the four properties common to all three types of muscle. Refers to the ability of the tissue to lengthen or stretch.
120
f-actin -
The filament structure of actin composed of may G-actin formed into a filament strand.
121
fasciculi -
A bundle of muscle fibers.
122
fiber typing -
Laboratory methods used to define individual skeletal muscle fibers as one of the pure muscle fiber types. Skeletal muscle fibers are typed using histochemical staining for myosin ATPase activity and immunohistochemical staining for myosin heavy chain type. Because the myosin heavy chain type is the primary determinant of ATPase activity, the two methods are physiologically related.
123
G-actin -
Individual globular-shaped actin molecules.
124
H-zone -
The area within a sarcomere defined as the distance from the inner end of one actin filament to the inner end of an adjacent actin filament in the same sarcomere. In the resting state, the H-zone corresponds to the central bare zone of the myosin filament.
125
I-band (isotropic band) -
The light-looking band within the sarcomere of striated muscle tissue that extends from the outer end of one myosin to the outer end of the adjacent myosin in the adjacent sarcomere.
126
light band -
The I-band within the sarcomere of striated muscle tissue.
127
longitudinal tubules -
Tubules of the sarcoplasmic reticulum responsible for the uptake of calcium during the contractile process of skeletal muscle.
128
M-line (myomesin) -
M-band proteins (myomesin) in the middle of the H-zone of the sarcomere that link together the myosin filaments.
129
motor proteins -
Proteins in muscle tissue responsible for movement. Motor proteins include actin and myosin.
130
muscle fiber -
One long cylindrical-shaped multinucleated skeletal muscle cell.
131
muscle fiber composition -
The distribution of the different muscle fiber types within a muscle, usually expressed as a percentage of muscle fibers (e.g., 60% Type I).
132
muscle fiber size -
The cross sectional area of the muscle fiber.
133
myofibrils -
The basic rod-like structure of a muscle cell (fiber). A muscle fiber is a bundle of myofibrils. Myofibrils are composed of contractile, regulatory, and cytoskeletal proteins arranged in is such a way to result in the appearance of light and dark bands.
134
myoglobin -
An oxygen-carrying molecule found within the muscle cell.
135
myosin -
One of the two contractile proteins of muscle tissue, composed of two intertwined myosin heavy chains with head, neck, and tail regions. Myosin have two motor movements: hinging of the neck region and tilting of the heads.
136
myosin ATPase -
The ATPase isoform used in the contractile process of skeletal muscle to generate energy necessary for the power stroke of myosin heads.
137
myosin filament -
Hundreds of myosin molecules arranged tail-to-tail to form a single myosin filament where the myosin heads protrude outward at specific locations. A central bare zone is void of myosin heads.
138
myosin heavy chain (MHC) -
Proteins composed of a head, neck, and tail region. Two myosin heavy chains form a single myosin.
139
nebulin -
An actin-binding cytoskeletal protein in muscle tissue. Because its length is proportional to the length of the actin filament, it is thought to be the molecular ruler of actin, meaning that it regulates thin filament length during assembly and repair of sarcomeres.
140
perimysium -
One of three layers of connective tissue in skeletal muscle. The perimysium is the middle layer of connective tissue that wraps around the fasciculi.
141
power stroke -
The motor movement of the myosin that includes the hinging of the neck region and tilting of the myosin heads. The motor movement of myosin heads slide the actin filament over the myosin filament. The power stroke is part of the four-step cross-bridge cycle.
142
regulatory protein(s) -
One of three categories of proteins responsible for regulating the contractile process of skeletal muscle. Regulatory proteins include troponin and tropomyosin.
143
resistance to fatigue -
One of the characteristics of skeletal muscle cells (fibers) used to describe metabolic characteristics of muscle fibers. Type I muscle fibers are highly oxidative and fatigue resistant whereas type II muscle fibers are highly glycolytic and fatigable.
144
ryanodine receptor -
Receptors located in the terminal cisternae of the sarcoplasmic reticulum that mediate the release of calcium from the sarcoplasmic reticulum, which is an essential step in the contractile process of muscle tissue. Ryanodine receptors are mechanically linked to voltage-dependent dihydropyridine receptors located in the T-tubules.
145
sarcolemma -
The cell membrane of a skeletal muscle cell (fiber).
146
sarcomere -
The smallest and most basic unit of skeletal muscle capable of contraction. Defined as the box-like structure from one Z-line to the next Z-line.
147
sarcoplasmic reticulum (SR) -
An organelle found within the muscle fiber that is responsible for the storage, release, and uptake of calcium.
148
SERCA pump -
Sarco/endoplasmic reticulum calcium ATPase pump. The SERCA pump resides in the sarcoplasmic reticulum of muscle cells and transfers calcium from the cytosol of the cell to the sarcoplasmic reticulum during the recovery from exercise (muscle relaxation).
149
sliding filament theory -
The theory originally conceived by Hugh Huxley in 1953. According to this theory, the actin filaments slide over the myosin filaments during muscle contraction. This theory was later clarified by the crossbridge cycle.
150
terminal cisternae -
A thick region of the sarcoplasmic reticulum located adjacent to the t-tubule. During the excitation-contraction process, the terminal cisternae releases calcium ions that initiate the contractile process.
151
triad -
One t-tubule and the two terminal cisternae adjacent to it.
152
type I muscle fiber type -
A slow twitch muscle fiber. Also referred to as slow oxidative (SO).
153
type IIa muscle fiber type -
One of the sub-classifications of fast twitch (type II) muscle fibers. Also referred to as fast oxidative glycolytic (FOG).
154
type IIx muscle fiber type -
One of the sub-classifications of fast twitch (type II) muscle fibers. The least prevalent muscle fiber type in human skeletal muscle. Also referred to as fast glycolytic (FG).
155
vmax (maximal shortening velocity) -
The maximal shortening velocity of a muscle fiber. Related to the ATPase isoform present in the cell.
156
Z-disc streaming -
The smearing of the Z-lines of muscle tissue due to mechanically induced microscopic damage.
157
capillary-to-fiber ratio -
The number of capillaries that surround a muscle cell (fiber). Increasing the number of capillaries supplying the muscle fiber decreases the velocity of blood flow and increases the transit time of blood.
158
composition of the muscle -
The distribution of type I, type IIa, type IIx, and hybrid muscle fibers in a muscle. For example, the muscle is composed of 40% type I, 30% type IIa, 1% from type IIx, and 29% coming from hybrids. The composition of muscle varies between muscles within a human and between the same muscles in two individuals.
159
concentric contractions -
Contraction of the whole muscle that results in a decrease in the joint angle because the force of contraction is greater than the force of resistance.
160
dynamic contractions -
Contraction of the whole muscle that results in movement of the joint. Dynamic contractions are either concentric or eccentric contractions.
161
eccentric contractions -
Contraction of the whole muscle that results in an increase in the joint angle because the force of resistance is greater than the force of contraction.
162
fast glycolytic (FG) -
A type IIx muscle fiber.
163
fast oxidative glycolytic (FOG) -
A type IIa muscle fiber.
164
fast-twitch (FT) -
A general category of muscle fiber type, based on twitch characteristics, that includes type IIa and IIx muscle fibers.
165
fatigability -
The ease at which a skeletal muscle fiber becomes fatigued during contraction. Fibers that are more oxidative are fatigue resistant. Fibers that are more glycolytic are more fatigable.
166
fatigue -
The inability to maintain a given intensity of exercise.
167
force of contraction -
The amount of force or tension generated by the contraction of skeletal muscle.
168
force-velocity relationship -
The relationship between the force of contraction and the velocity of shortening of a muscle fiber or muscle.
169
glycolytic capacity -
The capacity of the skeletal muscle fiber to resynthesize ATP anaerobically.
170
high-intensity interval training (HIT) -
An exercise routine designed to increase cardiovascular fitness level using repeated bouts of high intensity exercise alternating with lower intensity active rest periods.
171
hybrid fiber type -
A muscle fiber that has myosin heavy chain or ATPase characteristics that are between the pure fiber types on the fiber type continuum.
172
hyperplasia -
The enlargement of skeletal muscle cross-sectional area due to an increase number of muscle fibers.
173
hypertrophy -
The enlargement of skeletal muscle cross-sectional area due to an increase in the cross-sectional area of existing muscle fibers.
174
in vitro -
An artificial environment outside of the living body. For example, the study of skeletal muscle fibers after they have been removed from the muscle using biopsy techniques.
175
in vivo -
In the living body. For example, the study of the force characteristics of whole skeletal muscle in the lab using isokinetic machines and EMG techniques.
176
isoform -
Proteins that have different structures by similar functions.
177
isometric contraction -
A contraction of an isolated skeletal muscle fiber that does not result in a change in length of the muscle fiber during contraction.
178
isotonic-lengthening contraction -
A contraction of an isolated skeletal muscle fiber in which the force of resistance is greater than the force of contraction and there is a lengthening of the muscle fiber during contraction.
179
isotonic-shortening contraction -
A contraction of an isolated skeletal muscle fiber in which the force of contraction is greater than the force of resistance and there is a shortening of the muscle fiber during contraction.
180
length-tension relationship -
The relationship between the length of the muscle fiber (or muscle) and the amount of force or tension that it is able to generate during contraction.
181
mitochondrial density -
The fraction of the skeletal muscle fiber (cell) occupied by mitochondria. It is related to the number and size of mitochondria in a muscle fiber (cell).
182
motor unit recruitment -
The orderly recruitment of motor units is related to the size principle. As the intensity of exercise increases, more motor units of the same type, same size, different types, and different sizes are recruited to meet the force requirements of the exercise.
183
motor unit synchronization -
The synchronized recruitment of motor units. Improved motor unit synchronization is one of the adaptations to exercise training.
184
myoglobin -
An iron and oxygen binding protein in the muscle cell. The primary oxygen carrying pigment of muscle tissues. Myoglobin is different from hemoglobin (the iron and oxygen-binding protein in the blood) is that myoglobin binds with only one oxygen (rather than four).
185
number coding -
Increasing the force of contraction of whole muscle by increasing the number of motor units recruited.
186
optimal length (L0) -
The length of the muscle fiber (or sarcomere) that results in the greatest peak tension. The optimal length of the muscle fiber is when the sarcomeres are about 100-120 percent of their normal resting length.
187
oxidative capacity -
The capacity of the muscle fiber to resynthesize ATP aerobically. Related to mitochondrial density, myoglobin content, and the capillary-to-fiber ratio.
188
peak tension (P0) -
The peak amount of force produced during a single twitch of a muscle fiber or motor unit. Peak tension is related to the size of the muscle fiber or motor unit as well as the type of muscle fiber or motor unit.
189
plastic -
A tissue that is plastic is highly dynamic and changeable.
190
power -
The rate at which work is performed. The product of force x distance divided by time.
191
pure fiber type -
Type I, IIa, and IIx muscle fibers are pure fiber types.
192
rate coding -
Increasing the force of contraction in whole muscle by increasing the frequency of stimulation.
193
repeated bout effect -
The phenomenon that describes the muscle damage that results from subsequent bouts of high-intensity exercise days or weeks apart. After a muscle experiences microscopic muscle damage, a second bout of the same exercise several days and up to 6 weeks later, will result in a lesser amount of damage to the muscle.
194
shortening velocity -
The speed at which an unloaded muscle fiber can shorten.
195
slow oxidative (SO) -
Slow-twitch or type I muscle fiber
196
slow-twitch -
One of the two twitch categories of skeletal muscle (slow twitch and fast twitch). Slow-twitch muscle fibers are also referred to as type I or slow oxidative (SO) fibers.
197
specific tension -
Peak tension of a muscle fiber divided by the cross-sectional area of the muscle fiber. Specific tension can be used to compare the force of contraction of different fiber types based on an equal cross-sectional area.
198
static contractions -
Contraction of whole muscle during which there is no appreciable change in length of the muscle.
199
strength -
The amount of force a muscle can exert.
200
striation -
The appearance of light and dark bands in skeletal muscle and cardiac muscle. Striations appear due to the arrangement of actin and myosin in the muscle cell. Striations appear at the level of the myofibrils.
201
structural protein(s) -
Proteins found in skeletal muscle that provide structural integrity to the arrangement of proteins in the sarcomere. Structural, or cytoskeletal, proteins include, titin, desmin, nebulin, myosin-binding C proteins, and many others.
202
time-to-peak tension -
The time required for the muscle fiber to reach peak tension after it has been stimulated.
203
titin -
One of the structural proteins. Titin is a spring-like protein that attaches to the Z-line on one end and the M-line on the other and helps align myosin in the sarcomere. Titin contributes to the elasticity of the muscle fiber and passive tension when the muscle is relaxed.
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adaptation -
One of the eight principles of training. Refers to any alteration of structure or function of a cell, tissue, or organ resulting from an exercise-induced overload.
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body composition -
The absolute or relative amount of lean mass (muscle, bone, water) and fat mass. Typically expressed as percent body fat.
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body mass index (BMI) -
The ratio of body mass (kg) to height (m^2). An index of obesity.
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cardiometabolic risk -
A term used to describe the all-inclusive global risk of cardiovascular disease and diabetes. Includes risk associated with overweight/obesity, age, race, gender, insulin resistance, blood pressure, blood glucose levels, blood lipid profile (HDL, LDL, triglycerides), family history, smoking, physical inactivity, and unhealthy eating.
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cardiorespiratory fitness -
The ability of the heart, blood, and lungs to deliver oxygen to the working muscles and the ability of the skeletal muscle to use the oxygen to produce energy for muscular work. Often referred to as aerobic fitness or cardiovascular fitness (measured as VO2max).
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cool-down -
One of the eight principles of training. The period of time following exercise during which the body's physiological systems (e.g., cardiovascular, pulmonary, metabolism) return to a resting homeostasis.
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dose-response -
The relationship between different levels of exposure (dose) of a stressor (e.g., exercise) and its overall effect (response)—for example, the relationship between different levels of physical activity (the dose) and the risk of cardiovascular disease (the response).
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exercise -
A form of physical activity that is planned, structured, and performed with the intention of improving or maintaining one or more of the components of physical fitness.
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flexibility -
One of the five components of health-related physical fitness. The ability to move a joint through a functional range of motion.
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health-related physical fitness -
Those components of physical fitness affected by habitual physical activity and related to one's health status, including the reduction of risk of lifestyle related diseases. The components of health related physical fitness are cardiorespiratory fitness, muscular strength, muscular endurance, flexibility, and body composition. Adequate health-related physical fitness allows us to perform activities of daily living, recreation, and sport.
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high-intensity interval training (HIT) -
A form of aerobic training that includes alternating intercals of high intensity aerobic exercise and rest periods. Interval training is beneficial because it results in similar adaptations as low or moderate intensity continuous aerobic exercise for much longer periods of time.
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improvement phase -
The second phase of an exercise program designed to make significant improvements in one or more of the components of physical fitness.
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indirect calorimetry -
Indirect measurement of energy expenditure using a metabolic measurement system that measures oxygen consumption, which can then be used to calculate energy expenditure.
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individualization (or personalization) -
The first principle of training, which identifies personal objectives, goals, personal preferences, medical or physical limitations or restrictions, use of medications, injuries, healthy history, risk factors, physical activity history, etc., prior to starting an exercise program. This process assures that the exercise program is safe and appropriate for the individual.
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initial conditioning phase -
The first phase of an exercise program that is designed to familiarize the body with exercise and prepare the body to handle the conditioning phase. The work load in the beginning must be moderate. Progression is achieved by gradual, planned increases in frequency, intensity, and time.
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light-intensity physical activity -
Defined in terms of METs as 1.1 to 2.9 METs.
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maintenance -
One of the eight principles of training which states that once the desired level of physical fitness is achieved, it can be maintained with less effort.
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maintenance phase -
The third and usually the longest phase of an exercise program designed to maintain the desired level of physical fitness.
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maximal oxygen consumption (VO2max) -
The maximal amount of oxygen that can be consumed during high intensity aerobic exercise. Used as an indicator of cardiorespiratory fitness.
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MET-minutes -
The intensity of exercise in METs multiplied by the duration that it is maintained for. For example, if John exercises at intensity of exercise equivalent to five METs for 30 minutes, his amount of exercise is 150 MET-minutes.
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metabolic equivalent (MET) -
A term used to describe intensity of exercise in absolute terms. 1 MET = 3.5 mL/kg/min or 1.05 kcal/kg/hr.
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moderate-intensity physical activity -
Defined in terms of METs as 3.0-5.9 METs.
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MRFIT -
The five components of overload: mode, rest, frequency, intensity, and time.
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muscle edurance -
The ability of the skeletal muscle to sustain submaximal intensities of exercise for prolonged periods of time.
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muscular fitness -
A generic term used to describe the overall physical fitness of skeletal muscle, including muscle endurance and muscle strength.
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muscular strength -
The ability of skeletal muscle to exert maximal amount of force for short periods of time.
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obesity -
A BMI of greater than 30 kg/m^2 or a body composition of greater than 25% body fat (men) or 30% body fat (women).
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overload -
One of the eight principles of training that states that in order for an adaptation to occur, a sufficient overload that is above and beyond what the physiological system is normally accustomed to must be applied to the physiological system.
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paradigm shift -
A dramatic change in a paradigm (a pattern of thinking) of a scientific community. The paradigm shift from exercising in order to be physically fit to being physically active in order to be healthy occurred in the 1990s.
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performance (or sports)-related physical fitness -
Those components of physical fitness (i.e., speed, power, coordication, agility) affected by habitual exercise training that are related to performance in a particular sport.
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physical activity -
Any bodily movement produced by contraction of skeletal muscle that results in an increase in energy expenditure.
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physical fitness -
A general term used to describe the ability to carry out daily living activities or participate in recreational activities or sports.
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plateau -
A lack of improvement despite an increase in training volume.
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progression -
A principle of exercise training that states that in order for further adaptations to occur during an exercise program, the overload must also be manipulated. For example, as strength improves during a strength training program, the resistance or number of sets or reps must be increased to maintain the same overload and continue to adapt.
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range of motion -
The range of movement of a body part around its joint.
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rating or perceived exertion (RPE) -
A numeric scale with anchors (very light, light, moderate, hard, very hard) that is used to describe perceptions of how difficult the exercise is. RPE scales use a 1-10 scale or a 6-10 scale.
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resting energy expenditure (REE) -
The amount of energy expended at rest (kcal) as measured using a metabolic cart. VO2 is used to calculate energy expenditure. If REE cannot be measured using indirect calorimetry, then 1 MET can be used as an estimate of REE.
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reversal -
A principle of exercise training that states that if the exercise stimulus is removed, there will be a reversal of the adaptations that were achieved when exercise training.
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specific adaptations to imposed demands (SAID) -
A principle that states that adaptations resulting from exercise are specific to the demands placed on the body. The adaptations are specific to the mode of exercise, intensity of exercise, duration of exercise, etc.
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specificity -
A principle of training that states that an overload must be applied to specific physiological system to attain a specific type of adaptation. Strength training results in an increase in muscular strength whereas aerobic training results in an increase in cardiorespiratory fitness.
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strength training -
A form of training designed to improve muscular strength that uses all types of resistance (machines, free weights, body weight, and other forms of resistance).
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transfer -
A concept that adaptations resulting from one mode of exercise training (e.g., running) will carry over to another mode of training (e.g., cycling).
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vigorous aerobic exercise -
Defined in terms of METs as 6.0 METs or greater.
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warm-up -
One of the principles of exercise training that includes low intensity aerobic exercise, stretching, calisthenics, etc., to prepare the body for the exercise that will ensue.
