which of the following most accurately describes the innervation of
skeletal muscles Correct Answer-motor neurons communicate with the
muscle fiber directly
the perimysium Correct Answer-is the connective tissue that surrounds
bundles (fascicles) of skeletal muscle cells
the function of calcium ions in skeletal muscle contraction is to Correct
Answer-bind to regulatory proteins leading to a change in shape so that
the myosin binding sites on the actin can be exposed
the contractile proteins within a muscle fiber (cell) are Correct Answer-
actin and myosin
individual muscle fibers are arranged in bundles called Correct Answer-
fascicles
each muscle fiber is divided or compartmentalized into repeating
segments of contraction called Correct Answer-sarcomeres
I Band Correct Answer-the ends of the sarcomere, where there are
ONLY thin filaments
thin filaments Correct Answer-actin, troponin, tropomyosin
,thick filament Correct Answer-myosin
aponeurosis Correct Answer-extension from a muscle that forms a broad
flat sheet
tendon Correct Answer-extension from a muscle that connects the
muscle to bone
motor unit recruitment Correct Answer-when the muscle fibers need to
get more help (increasing number of motor units in a contraction)
t-tubules Correct Answer-outpocketings of the plasma membrane
*** Correct Answer-nerve tissue in the brain and spinal cord appears
either white or gray. The white matter contains axons that are
myelinated.
*** Correct Answer-in a resting neuron, there are more potassium ions
inside the cell (intracellular) than outside the cell (extracellular)
*** Correct Answer-action potentials that occur in the axon of a neuron
operate according to an "all or none" principle
axon Correct Answer-during a nerve impulses, the action potential is
carried away from the nerve cell body by the ?
, multipolar Correct Answer-if classfied by their shape or structure, most
neurons in the brain and spinal cord are ______ neurons because they
have several dendrites and only one axon
graded potentials Correct Answer-the membrane potentials that can vary
in size, strength, or amplitude and are found on the dendrites and cell
bodies of neurons are called
axon hillock Correct Answer-the initial segment of the axon where it is
attached to the cell body and where the action potential begins
synaptic vessicles Correct Answer-tiny sacs found in the synaptic bulb
filled with chemical messengers called neurotransmitter
cell body Correct Answer-the central part of the neuron that contains the
nucleus and necessary organs
axon terminals Correct Answer-highly branched fine processes at the
end of an axon
synaptic end bulbs Correct Answer-flared swellings at the end of each
axon terminal
dendrites Correct Answer-short, highly branched extensions that receive
sensory information from receptors and other neurons