Flashcards in Lab exam 3 Deck (46):
what system anazles sensory information, stores information and makes decisions?
an impulse from one nerve cell is communicated to another nerve cell via the ____
where are bipolar neurons commonly found?
in the retina of the eye
what affects the velocity and duration of muscle contraction?
load on the fiber
what is the most distinguishing characteristic of muscle tissue?
the ability to transform chemical energy into mechanical energy
where are ciliated CNS neuroglia that play an active role in moving the cerebrospial fluid called?
the period after an initial stimulus when a neuron is not sensitive to another stimulus is the ______
absolute refractory period
an anerobic metabolic pathway that results in the production of two net atps per glucose plus two pyruvic acid molecules is called
after nervous stimulation stops what prevents ACh in the synaptic cleft from continuing to stimulate contraction?
acetylcholinesterese destroying the ACh
what happens when an EPSP is being generated on the dendritic membrane?
a single type of channel will open, permitting simultaneous flow of sodium and potassium
a second nerve impulse cannot be generated until?
the membrane potential has been reestablished
what is true about ions moving across excitable living membranes
sodium gates in the membrane can open in response to electrical potential changes
are neruons mitotic?
collections of nerve cell bodies outside the central nervous system are called
fatigued muscle cells that recover rapidly are the products of
intense exercise of short duration
what does myoglobin store?
oxygen in muscle cells
neuroglia that control the chemical enviornment around neurons by buffering potassium and recapturing neurotransmitters are ___
what describes the excitatory postsynaptic potential?
short distance depolarization
what muscle is long and cylindrical with many nuceli?
straiated muscle cells
the strongest muscle contractions are normally achieved by
increasing the stimulation up to the maximal stimulues
the part of a neuron that conducts impulses away from its cell body are called
is innervation of skeletal muscle a function of the ANS?
excitation-contraction coupling requires which of the following substances?
Ca2+ and ATP
if a motor neuron in the body were stimulated by an electrode places about midpoint along the length of the axon
the impulse would spread bidirectionally
what does excess postexercise oxygen consumption represent?
the difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used
which of the following is not a function of astrocytes
provide the defense for CNS
The giant protein titin maintains the organization of the _________ assisting in muscle stretching
which muscle has one nucleus, no sarcomerese and rare gap junctions
multiunit smooth muscle
IPSP is associated with ___________-
in what way does the interior surface of a cell membrane of a resting neuron differ from the external enviornment. the interior is _______
negatively charged and contains less sodium
what is the role of tropomyosin
its a contraction inhibitor by blocking mysoin
in an isotonic contraction
the muscle changes in length and moves the 'load"
schwann cells are functionally similar to
the mechanism of contraction in smooth muscle is different from skeletal muscle in that
the site of calcium regulation differs
what is not a role of ionic calcium in muscle contraction?
activates epinepherine released from adrenal gland
the term central nervous system refers to the
brain and spinal cord
saltatory conduction is made possible by the
motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle and glands
What is the primary function of wave summation?
produce smooth, continuous muscle contraction
which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials
the sliding filament model of contraction involved
actin and myosin sliding past eachother and partially over lapping
the substance released at axon terminals to propogate a nervous impulse is called a
during vigorous exercise, there may be insufficient oxygen available to completely break down pyruvic acid for energy. as a result, the pyruvic acid is converted to
muscle tone is
a state of sustained partial contraction
smooth muscle is characterized by all of the following except
there are more thick filaments than thin filaments