Test 2 Vocab Flashcards
1
Q
Amygdala
A
Part of the limbic system; in the temporal lobe; processes emotions for fear, anger,
and pleasure; controls storage of emotional memories
2
Q
Association fibers
A
Tracts that conduct impulses within a cerebral hemisphere
3
Q
Auditory
association area
A
In the temporal lobe; interpretation of sound
4
Q
Auditory cortex
A
Gray matter for sound perception; in temporal lobes
5
Q
Broca’s area
A
Speech center; controls motor movements for speech; usually in left frontal lobe
6
Q
Commissural fibers
A
Tracts in the corpus callosum and connects right and left cerebral hemispheres
7
Q
Frontal association
area
A
(Prefrontal area) Gray matter for thought processing; in frontal lobes
8
Q
Frontal eye field
A
Gray matter that controls voluntary eye movement; in frontal lobes
9
Q
Gustatory cortex
A
Gray matter for taste perception; in the insula
10
Q
Hippocampus
A
Part of the limbic system; controls conversion of short-term to long-term
memory, emotional responses to memories, and spatial memory (remembering
locations in space)
11
Q
Interventricular
foramen
A
(Foramen of Monro); passage for cerebrospinal fluid moving from the lateral
ventricles into the third ventricle
12
Q
Limbic system
A
Internal brain structures associated with emotions
13
Q
Longitudinal fissure
A
Groove in the sagittal plane that separates the cerebral hemispheres
14
Q
Motor cortex
A
Gray matter for voluntary muscle movement; in precentral gyrus of frontal lobe
15
Q
Motor speech area
A
(Broca’s area); gray matter for speech control; usually in lateral side of left frontal
lobe
16
Q
Nuclei
A
Gray matter in brain regions deep to the cortex
17
Q
Olfactory cortex
A
Gray matter for smell perception; in temporal lobes
18
Q
Optic chiasma
A
Beneath frontal lobes and anterior to pituitary gland; where the two optic nerves
unite
19
Q
Pons
A
Part of brain stem; relay center between medulla oblongata and higher brain
centers
20
Q
Postcentral gyrus
A
In parietal lobe immediately posterior to central
sulcus; contains somatosensory cortex
21
Q
Precentral gyrus
A
In frontal lobe immediately anterior to central sulcus; contains primary
motor cortex
22
Q
Prefrontal area
A
Gray matter for problem-solving, imagination, artistic skills; in frontal
lobes
23
Q
Premotor area
A
Gray matter for memory of reflexive motor skills; in frontal lobes
24
Q
Projection fibers
A
Tracts that connect the cerebrum to lower brain centers
25
Putamen
A basal nucleus; not well understood
26
Septum pellucidum
Membrane in sagittal plane and separates the lateral ventricles
27
Somatosensory association area
Gray matter for interpretation of somatosensory input; in parietal lobes
28
Somatosensory cortex
Gray matter for perception of touch, temperature, pressure; in
postcentral gyrus
29
Tracts
Bundles of white matter (neuron axons) in the CNS
30
Visual association area
Gray matter for interpretation of visual input; in occipital lobes
31
Visual cortex
Gray matter for light perception; in occipital lobes
32
Wernicke’s area
(Auditory association area); gray matter for interpreting speech; in left
temporal lobe
33
Anterior column
White matter between anterior horns
34
Anterior horns
Gray matter projections on anterior side of cord
35
Cauda equina
Nerve roots at inferior end of cord; resembles horse’s tail
36
Central canal
Small canal along entire length of cord
37
Lateral columns
White matter around lateral horns
38
Lateral horns
Lateral projections of gray matter in cord
39
Posterior columns
White matter between posterior horns
40
Posterior horns
Gray matter projections on posterior side of cord
41
Arachnoid mater
Immediately superficial to pia mater; resembles spider web
42
Dura mater
Most superficial meninx; tough and fibrous
43
Pia mater
Deepest meninx; thin membrane attached to surface of brain and spinal cord
44
Subarachnoid
space
Between arachnoid and pia mater
45
Subdural space
Between dura mater and arachnoid
46
potential difference
the voltage difference between 2 points due to separated electrical charges of opposite signs
47
membrane potential
the voltage difference between the inside and outside of a cell
48
equilibrium potential
the voltage difference across a membrane that produces a flux of a given ion species that is equal but opposite to the flux due to the concentration gradient of that same ion
49
resting membrane potential
the steady potential of an unstimulated cell
50
graded potential
a potential change of variable amplitude and duration that is conducted decrementally; has no threshold or refectory period
51
action potential
a brief all-or-none depolarization of the membrane, which reverses polarity in neurons; has a threshold and a refractory period and is conducted without decrement
52
synaptic potential
a graded potential change produced in the post synaptic neuron in response to the release of a neurotransmitter from a presynaptic terminal; may be depolarizing or hyperpolarizing
53
receptor potential
a graded potential produced at the peripheral endings of afferent neurons in response to a signal cell
53
pacemaker potential
a spontaneously occurring graded potential change that occurs in certain specialized cells
54
threshold potential
the membrane potential at which an action potential is initiated
55
ependymal cells
types of glial cells that line internal cavities of the brain and produce cerebrospinal fluid
56
astrocytes
helps regulate the composition of the extracellular fluid in the CNS by removing potassium ions and neurotransmitters around synapses
57
oligodendrocytes
Myelin forming cell in the CNS (glial cell)
58
microglia
a type of glial cell that acts as a macrophage
59
reflex arc
neural or hormonal components that mediate a reflex; usually includes receptor, afferent pathway, integrating center, efferent pathway, and effector
60
spinal cord
61
Gyri
62
sulci
deep grooves between gyri on the surface of the cerebral cortex
63
brain fissures
64
brainstem
brain subdivision consisting of medulla oblongata, pons, and midbrain and located between spinal cord and forebrain
65
medulla oblongata
part of the brainstem closest to the spinal cord; controls many vegetative functions such as breathing, heart rate, and others
66
pons
large area of the brainstem containing many neuron axons
67
midbrain
the most rostral section of the brainstem
68
cerebellum
brain subdivision lying behind forebrain and above brainstem; plays important role in skeletal muscle control
69
diencephalon
core of anterior part of brain; lies beneath cerebral hemispheres and contains thalamus and hypothalamus
70
cerebrum/cerebral cortex
Cerebrum: part of the brain that, with diencephalon forms the forebrain
Cerebral cortex: cellular layer covering the cerebrum
71
cerebrospinal fluid (CSF)
fluid that fills cerebral ventricles and the subarachnoid space surrounding brain and spinal cord
72
Meninges
protective membranes that cover brain and spinal cord
73
hemorrhage
74
hematoma
75
choroid plexus
highly vascular epithelial structure lining portions of cerebral ventricles; responsible for much cerebrospinal fluid formation
76
stroke
77
corpus callosum
78
amygdala
79
adaptation
decrease in action potential frequency in a neuron despite constant stimulus
80
adequate stimulus
the modality of stimulus to which a particular sensory receptor is most sensitive
81
chemoreceptors
afferent neuron endings (or cells associated with them) sensitive to concentrations of specific chemicals
82
mechanoreceptors
sensory neurons specialized to respond to mechanical stimuli such as touch receptors in the skin and stretch receptors in muscle
83
nociceptors
sensory receptors whose stimulation causes pain
84
perception
understanding of objects and events of external world that we acquire from neural processing of sensory information
85
photoreceptors
sensory cells specialized to respond to light; contain pigments that make them sensitive to different light wavelengths
86
rapidly adapting receptors
sensory receptors that fire for a brief period at the onset and/or offset of a stimulus
87
receptor potential
graded potential that arises in afferent neuron ending, or a specialized cell intimately associated with it, in response to stimulation
88
sensation
the mental perception of a stimulus
89
sensory information
information that originates in stimulated sensory receptors
90
sensory receptors
cells or portions of a cell that contain structures or chemical molecules sensitive to changes in an energy form in the outside world or internal environment; in response to activation by this energy, the sensory receptors initiate action potentials in those cells or adjacent ones
91
sensory system
part of nervous system that receives, conducts, or processes information that leads to perception of a stimulus
92
sensory transduction
neural process of changing a sensory stimulus into a change in neuronal function
93
slowly adapting receptors
sensory receptors that fire repeatedly as long as a stimulus is outgoing
94
stimulus
detectable change in internal or external environment
95
thermoreceptors
sensory receptors for temperature and temperature changes, particularly in low (cold receptor) or high (warm receptor) range
96
acuity
sharpness or keenness of perception
97
coding
process by which neural signals from sensory receptors are converted into action potentials in the CNS
98
lateral inhibition
method of refining sensory information in afferent neurons and ascending pathways whereby fibers inhibit each other, the most active fibers causing the greatest inhibition of adjacent fibers
99
modality
type of sensory stimulus
100
receptive field
area of body that, if stimulated, results in activity in that neuron
101
modality
type of sensory stimulus
102
receptive field
area of body that, if stimulated, results in activity in that neuron
103
recruitment
activation of additional cells in response to increased stimulus strength; increasing the number of active motor units in a muscle
104
sensory unit
afferent neuron plus receptors it innervates
105
ascending pathways
neural pathways that go to the brain; also called sensory pathways
106
auditory cortex
region of cerebral cortex that receives inputs form auditory pathways
107
gustatory cortex
region of cerebral cortex receiving primary sensory inputs from the taste buds
108
nonspecific ascending pathways
chains of synaptically connected neurons in CNS that are activated by sensory units of several different types; signal general information
109
olfactory cortex
region on the inferior and medial surface of the frontal lobe of the cerebral cortex where information about the sense of smell is processed
110
polymodal neurons
sensory neurons that respond to more than one type of stimulus
111
sensory pathways
ascending pathways
112
somatic receptors
neural receptors in the framework or outer wall of the body that respond to mechanical stimulation of skin or hairs and underlying tissues, rotation or bending of joints, temperature changes, or painful stimuli
113
somatosensory cortex
strip of cerebral cortex in parietal lobe in which neurons transmitting somatic sensory information synapse
114
specific ascending pathways
chains of synpatically connected neurons in CNS, all activated by sensory units of the same type
115
visual cortex
region of the occipital lobe of the cerebral cortex that receives ascending pathways from the eyes
116
cortical association areas
regions of cerebral cortex that receive input from various sensory types, memory stores, and so on, and perform further perceptual processing
117
anterolateral pathway
ascending neural pathway running in the anterolateral column of the spinal cord white matter; conveys information about pain and temperature
118
dorsal column pathway
ascending pathway for somatosensory information; runs through dorsal area of spinal white matter
119
itch
somatic sensation of skin irritation that evokes a desire to scratch
120
kinesthesia
sense of movement derived from movement at a joint
121
somatic sensation
feelings/perceptions coming from muscle, skin, and bones
122
transcutaneous electrical nerve stimulation (TENS)
123
transient receptor potential (TRP) proteins
family of ion channel proteins involved in sensing temperature
124
accommodation
adjustment of eye for viewing various distances by changing shape of lens
125
age-related macular degeneration (AMD)
126
amacrine cells
specialized type of neurons found in the retina of the eye that integrate information between local photoreceptor cells
127
aqueous humor
fluid filling the anterior chamber of the eye
128
astigmatism
129
binocular vision
visual perception of overlapping fields from the two eyes
130
bipolar cells
neurons that have one input branch and one output branch
131
cataract
132
cGMP-phosphodiesterase
an enzyme in cells that converts cGMP into GMP
133
choroid
pigmented layer of eye that lies next to retina
134
chromophore
retinal light-sensitive component of a photopigment
135
ciliary muscle
involved in movement and shape of the lens during accommodation
136
color blindless
137
cones
members of one or two retinal receptor types for photic energy; give rise to color vision
138
cornea
transparent structure covering front of eye; forms part of eye's optical system and helps focus an object's image on retina
139
dark adaptation
process by which photoreceptors in the retina adjust to darkness
140
discs
layers of membranes in outer segment of photoreceptor; contain photopigments
141
farsighted
142
fovea centralis
area near center of retina where cones are most concentrated; gives rise to most acute vision
143
frequency
number of times an event occurs per unit time
144
ganglion cells
retinal neurons that are postsynaptic to bipolar cells; axons of ganglion cells form optic nerves
145
glaucoma
146
guanylyl cyclase
enzyme that catalyzes transformation of GTP to cyclic GMP
147
horizontal cells
specialized neurons found in the retina of the eye that integrate information from local photoreceptor cells
148
hyperopic
149
inner segment
portion of photoreceptor that contains cell organelles; synapses with bipolar cells of retina
150
iris
ringlike structure surrounding and determining the diameter of the pupil of eye
151
lens
adjustable part of eye's optical system, which helps focus object's image on retina
152
light adaptation
process by which photoreceptors in the retina adjust to sudden bright light
153
macula lutea
a region at the center of the retina that is relatively free of blood vessels and that is specialized for highly acute vision
154
macular degeneration
155
melanopsin
opsin-like pigment in a subclass of retinal ganglion cells that relay information about day length to the hypothalamus
156
monocular vision
visual perception by a single eye
157
Muller cells
funnel-shaped glial cells that aid light transmission through the retina
158
myopic
159
nearsighted
160
ophthalmoscope
161
opponent color cells
ganglion cells in the retina that are inhibited by input from one type of cone receptor but activated by another type of cone photoreceptor
162
opsins
protein components of photopigment
163
optic chiasm
place at base of brain at which optic nerves meet; some neurons cross here to other side of brain
164
optic disc
region of the retina where neurons to the brain exit the eye; lack of photoreceptors here results in a "blind spot"
165
optic nerve
bundle of neurons connecting the eye to the optic chiasm
166
optic tracts
bundles of neurons connecting the optic chiasm to the lateral geniculate nucleus of the thalamus
167
outer segment
light-sensitive portion of the photoreceptor containing photopigments
168
photopigments
light-sensitive molecules altered by absorption of photic energy of certain wavelengths; consist of opsin bound to a chromophore
169
photoreceptors
sensory cells specialized to respond to light; contain pigments that make them sensitive to different wavelengths
170
pigment epithelium
dark, innermost layer of the retina; absorbs light that bypasses photopigments
171
presbyopia
172
pupil
opening in iris of eye through which light passes to reach retina
173
refraction
bending of light rays when passing between compartments of different density, as from air into the cornea of the eyes
174
retina
thin layer of neural tissue lining back of eyeball; contains receptors for vision
175
retinal
form of vitamin A that forms chromophore component of photopigment
176
rhodpsin
photopigment in rods
177
rods
members of one of two receptor types for photic energy; contain the photopigment rhodopsin
178
saccades
short, jerking eyeball movements
179
sclera
the tough, outermost tissue layer of the eyeball
180
suprachiasmatic nucleus
group of cells in the hypothalamus involved in production of circadian rhythyms
181
transducin
G protein in disc membranes of photoreceptor; initiates inactivation of cGMP
182
visible spectrum
wavelengths of electromagnetic radiation capable of stimulating photoreceptors of the eye
183
vitreous humor
jellylike fluid filling the posterior chamber of the eye
184
wavelength
distance between two successive wave peaks in oscillating medium
185
zonular fibers
fibers that connect the ciliary muscles with the lens of the eye
186
audition
sense of hearing
187
basilar membrane
membrane that separates cochlear duct and scala tympani in inner ear; supports organ of Corti
188
cochlea
inner ear; fluid-filled spiral-shaped compartment that contains cochlear duct
189
cochlear duct
fluid-filled membranous tube that extends length of inner ear, dividing it into compartments; contains organ of Corti
190
endolymph
extracellular fluid found in the cochlea and vestibular apparatus
191
eustachian tube
duct connecting the middle ear with the nasopharynx
192
external auditory canal
outer canal of the ear between the pinna and the tympanic membrane
193
hair cells
mechanoreceptor cells in organ of Corti and vestibular apparatus characterized by stereocilia on cell surface
194
helicotrema
outer point in the cochlea where the scala vestibuli and scala tympani meet
195
incus
one of three bones in the inner ear that transmit movements of the tympanic membrane to the inner ear
196
inner ear
cochlea; contains organ of Corti
197
inner hair cells
cells of the cochlea with stereocilia that transduce pressure waves into electrical signals
198
malleus
one of three bones in the inner ear that transmit movements of the tympanic membrane to the inner ear
199
middle ear
air-filled space in temporal bone; contains three ear bones that conduct sound waves from tympanic membrane to cochlea
200
organ of corti
structure in inner ear capable of transducing sound wave energy into action potentials
201
outer hair cells
cells of the cochlea with stereocilia that sharpen frequency tuning by modulating the movement of the tectorial membrane
202
oval window
membrane-covered opening between middle ear cavity and scala vestibule of inner ear
203
perilymph
fluid that fills the cochlear duct of the inner ear
204
round window
membrane-covered opening in the cochlea that responds to fluid movement in the scala tympani
205
scala tympani
fluid-filled inner-ear compartment that receives sound waves from basilar membrane and transmits them to round window
206
scala vestibuli
fluid-filled inner-ear compartment that receives sound waves from oval window and transmits them to basilar membrane and cochlear duct
207
stapedius
skeletal muscle that attaches to the stapes and protects the auditory apparatus by dampening the movement of the ear ossicles during persistent, loud sounds
208
stapes
one of three bones in the inner ear that transmit movements of the tympanic membrane to the inner ear
209
stereocilia
nonmotile cilia containing actin
210
tectorial membrane
structure in organ of Corti in contact with receptor cell hairs
211
tensor tympani muscle
skeletal muscle that attaches to the ear drum and protects the auditory apparatus from loud sounds by dampening the movement of the tympanu
212
tip links
small, extracellular fibers connecting adjacent stereocilia that activate ion channels when the cilia are bent
213
tympanic membrane
membrane stretched across end of ear canal; also called eardrum
214
vestibulocochlear nerve
eighth cranial nerve; transmits sensory information about sound and motion from the inner ear to the brain
215
ampulla
structure in the wall of the semicircular canals containing hair cells that respond to head movement
216
cupula
a gelatinous mass within the semicircular canals that contains stereocilia and responds to head movement
217
labyrinth
complicated bony structure that houses the cochlea and vestibular apparatus
218
otoliths
calcium carbonate crystals embedded in the mucous covering of the auditory hair cell
219
proprioception
sense of posture and position; sensory information dealing with the position of the body in space and its parts relative to one another
220
saccule
structure in the semicircular canals that responds to changes in linear movement of the head by mechanical forces on otoliths located on its surface
221
semicircular canals
passages in temporal bone; contain sense organs for equilibrium and movement
222
utricle
structure in the semicircular canals that responds to changes in linear movement of the head by mechanical forces on otoliths located on its surface
223
vestibular apparatus
sense of organ in temporal bone of skull; consists of three semicircular canals, a utricle, and a saccule; also called sense organ of balance
224
basal cells
cells found within taste buds that can divide and differentiate to replace worn-out taste receptor cells
225
gustation
the sense of taste
226
lingual papillae
taste buds located on the tongue
227
odorant
molecule received by the olfactory system that induces a sensation of smell
228
olfaction
sense of smell
229
olfactory bulbs
anterior protuberances of the brain containing cells that process odor inputs
230
olfactory epithelium
mucous membrane in upper part of nasal cavity containing receptors for sense of smell
231
taste buds
sense organs that contain chemoreceptors
232
A band
one of the transverse bands making up repeated striations of cardiac and skeletal muscle; region of aligned myosin-containing thick filaments
233
actin
protein that forms the thin filaments that contribute to muscle action
234
cross-bridges
in muscle, myosin projections extending from thick filaments and capable of exerting force on thin filaments, causing the filaments to slide past each other
235
heavy chains
pairs of large, coiled polypeptides that make up the rod and globular head of a myosin molecules
236
hypertrophy
enlargement of a tissue or organ due to increased cell size rather than increased cell number
237
H zone
one of transverse bands making up striated pattern of cardiac and skeletal muscle; light region that bisects A band
238
I band
one of transverse bands making up repeating striations of cardiac and skeletal muscle; located between A bands of adjacent sarcomeres and bisected by Z line
239
light chains
pairs of small polypeptides bound to each globular head of myosin molecule; function is to modulate contraction
240
M line
transverse stripe occurring at the center of the A band in cardiac and skeletal muscle; location of energy-generating enzymes and proteins connecting adjacent thick filaments
241
muscle
many muscle fibers bound together by connective tissue
242
muscle fiber
muscle cells
243
myoblasts
embryological cells that give rise to muscle fibers
244
myofibrils
bundles of thick and thin contractile filaments in cytoplasm of striated muscle; myofibrils exhibit a repeating sarcomere pattern along longitudinal axis of muscle
245
myosin
contractile protein that forms thick filaments in muscle fibers
246
myosin-ATPase
enzymatic site on globular head of myosin that catalyzes ATP breakdown to ADP and Pi, releasing the chemical energy used to produce force of muscle contraction
247
sarcolemma
the plasma membrane surrounding muscle cells
248
sarcomere
repeating structural unit of myofibril; composed of thick and thin filaments; extends between two adjacent Z lines
249
sarcoplasmic reticulum
endoplasmic reticulum in muscle fiber; site of storage and release of calcium ions
250
satellite cells
Undifferentiated cells found within skeletal muscle tissue that can fuse and develop into new muscle fiber following muscle injury
251
striated muscle
muscle having transverse banding pattern due to repeating sarcomere structure
252
tendons
collagen fiber bundles that connect skeletal muscle to bone and transmit muscle contraction force to the bone
253
terminal cisternae
expanded regions of sarcoplasmic reticulum, associated with T-tubules and involved in the storage and release of Ca2+ in skeletal muscle cells; also known as lateral sacs
254
thick filaments
myosin filaments in muscle cell
255
thin filaments
actin filaments in muscle cell
256
titin
protein that extends from the Z line to thick filaments and M line of skeletal muscle sarcomere
257
transverse tubule (T-tubule)
tubule extending from striated muscle plasma membrane into the fiber, passing between opposed sarcoplasmic reticulum segments; conducts muscle action potential into muscle fiber
258
tropomyosin
regulatory protein capable of reversibly covering binding sites on actin; associated with muscle thin filaments
259
troponin
regulatory protein bound to actin and tropomyosin of striated muscle thin filaments; site of calcium binding that initiates contractile activity
260
Z line
structure running across myofibril at each end of striated muscle sarcomere; anchors one end of think filaments and titin
261
acetylcholine (ACh)
a neurotransmitter released by pre- and postganglionic parasympathetic neurons, preganglionic sympathetic neurons, somatic neurons, and some CNS neurons
262
acetylcholinesterase
enzyme that breaks down acetylcholine into acetic acid and choline
263
alpha motor neurons
somatic efferent neurons, which innervate skeletal muscle
264
atropine
265
contraction
operation of the force-generating process in a muscle
266
cross-bridge cycle
sequence of events between binding of a cross-bridge to actin, its release, and reattachment during muscle contraction
267
curare
268
dihydropyridine (DHP) receptor
nonconducting calcium channels in the T-tubule membranes of skeletal muscle cells, which act as voltage sensors in excitation-contraction coupling
269
end-plate potential (EPP)
depolarization of motor end plate of skeletal muscle fiber in response to acetylcholine; initiates action potential in muscle plasma membrane
270
excitation-contraction coupling
in muscle fibers. mechanism linking plasma membrane stimulation with cross-bridge force generation
271
motor end plate
specialized region of muscle cell plasma membrane that lies directly under axon terminal of a motor neuron
272
motor unit
motor neuron plus the muscle fibers it innervates
273
neuromuscular junction
synapse-like junction between an axon terminal of an efferent neuron and a skeletal muscle fiber
274
power stroke
the step of a cross-bridge cycle involving physical rotation of the globular head
275
relaxation
return of muscle to a low force-generating state, caused detachment of cross-bridges
276
rigor mortis
stiffness of skeletal muscles after death due to failure of cross-bridges to dissociate from action because of the loss of ATP
277
ryanodine receptor
calcium-release channel found in the lateral sacs of the sarcoplasmic reticulum in striated muscle cells
278
sliding-filament mechanism
process of muscle contraction in which shortening occurs by thick and thin filaments sliding past each other
279
concentric contraction
muscle activity that involves shortening of muscle length
280
contraction time
time between beginning of force development and peak twitch tension by the muscle
281
eccentric contraction
muscle activity that is accompanied by lengthening of the muscle generally by an external load that exceeds muscle force
282
fast-twitch fibers
skeletal muscle fibers that contain myosin having high ATPase activity
283
fused tetanus
skeletal muscle activation in which actin potential frequency is sufficiently high to cause a smooth, sustained, maximal strength contraction
284
isometric contraction
contraction of muscle under conditions in which it develops tension but does not change length
285
isotonic contraction
contraction of muscle under conditions in which load on the muscle remains constant but muscle changes length
286
latent period
period lasting several milliseconds between action potential initiation in a muscle fiber and beginning of mechanical activity
287
load
external force acting on muscle
288
optimal length (L0)
sarcomere length at which muscle fiber develops maximal isometric tension
289
slow-twitch fibers
muscle fibers whose myosin has low ATPase activity
290
summation
increase in muscle tension or shortening in response to rapid, repetitive stimulation relative to single twitch
291
tension
in muscle physiology, the force exerted by a contracting muscle on object
292
tetanus
maintained mechanical response of muscle to high-frequency stimulation
293
twitch
mechanical response of muscle to single action potential
294
unfused tetanus
stimulation of skeletal muscle at a low-to-moderate action potential frequency that results in oscillating, submaximal force
295
central command fatigue
muscle fatigue due to failure of appropriate regions of cerebral cortex to excite motor neurons
296
creatine phosphate
molecule that transfers phosphate and energy to ADP to generate ATP
297
muscle fatigue
decrease in muscle tension with prolonged activity
298
oxygen debt
decrease in energy reserves during exercise that results in an increase in oxygen consumption and an increased production of ATP by oxidative phosphorylation following the exercise
299
fast-glycolytic fibers
skeletal muscle fibers that have high intrinsic contraction speed and abundant capacity for production of ATP by glycolysis
300
fast-oxidative-glycolytic fibers
skeletal muscle fibers that have high intrinsic contraction speed and abundant capacity for production of ATP by oxidative phosphorylation
301
glycolytic fibers
skeletal muscle fibers that have high concentration of glycolytic enzymes and large glycogen stores; white muscle fibers
302
myoglobin
muscle fiber protein that binds oxygen
303
oxidative fibers
muscle fibers that have numerous mitochondria and therefore a high capacity for oxidative phosphorylation; red muscle fibers
304
red muscle fibers
muscle fibers having high oxidative capacity and large amount of myoglobin
305
slow-oxidative fibers
skeletal muscle fibers that have slow intrinsic contraction speed but fatigue very slowly due to abundant capacity for production of ATP by oxidative phosphorylation
306
white muscle fibers
muscle fibers lacking appreciable amounts of myoglobin
307
antagonists
muscle whose action opposes intended movement
308
denervation atrophy
309
disuse atrophy
310
extension
straightening a joint
311
flexion
bending a joint
312
myostatin
a protein secreted from skeletal muscle cells as a negative regulator of muscle growth
313
recruitment
activation of additional cells in response to increased stimulus strength; increasing the number of active motor units in a muscle
314
costameres
clusters of structural proteins linking Z disks of sarcomeres to the sarcolemma of striated muscle cells
315
dystrophin
protein in muscle cells that links actin to proteins embedded in sarcolemma; stabilizes muscle cells during contraction
316
hypocalcemia
decreased blood calcium concentration
317
hypocalcemic tetany
318
dense bodies
cytoplasmic structures to which thin filaments of a smooth muscle fiber are anchored
319
smooth muscle
nonstriated muscle that surrounds hollow organs and tubes
320
latch state
contractile state of some smooth muscles in which force can be maintained for prolonged periods with very little energy use; cross-bridge cycling slows to the point where thick and thin filaments are effectively "latched" together
321
multiunit smooth muscles
smooth muscles that exhibit little, if any, propagation of electrical activity from fiber to fiber and whose contractile activity is closely coupled to their neural input
322
myosin light-chain kinase
smooth muscle protein kinase; when activated by Ca2+ calmodulin, phosphorylates myosin light chains
323
myosin light-chain phosphatase
enzyme that removes high-energy phosphate from myosin; important in the relaxation of smooth muscle cells
324
pacemaker potential
neurons that set rhythm of biological clocks independent of external cues; any neuron or muscle cell that has an inherent autorhythmicity and determines activity pattern of other cells
325
single-unit smooth muscles
smooth muscles that respond to stimulation as single units because gap junctions join muscle fibers, allowing electrical activity to pass from cell to cell
326
slow waves
slow, rhythmic oscillations of smooth muscle membrane potentials toward and away from threshold, due to regular fluctuations in ionic permeability
327
smooth muscle tone
smooth muscle tension due to low-level cross-bridge activity in absence of external stimuli
328
varicosities
swollen regions of axon; contain neurotransmitter-filled vesicles; analogous to presynaptic endings
329
cardiac muscle
heart muscle
330
intercalated disks
structures connecting adjacent cardiac myocytes, having components for tensile strength (desmosomes) and low-resistance electrical pathways (gap junctions)
331
L-type Ca2+ channels
voltage-gated ion channels permitting calcium entry into heart cells during the action potential; L denotes the long-lasting operon time that characterizes these channels
