TESTED ANSWERS GRADED A+
⩥ cell body (soma).
Answer: action potential begins here, dictates the critical firing rate of
the action potential
⩥ dendrites.
Answer: neural branches that receive impulses and conduct them toward
the cell body
⩥ axon.
Answer: deliver action potentials to the motor endplate of the muscle.
larger ______ = faster conduction velocities
⩥ myelin sheath.
Answer: lipoprotein membrane that wraps around the axon, acts as an
electrical insulator
⩥ schwann cells.
Answer: create or deposit the myelin sheath
⩥ nodes of ranvier.
,Answer: interrupt the myelin sheath every 1-2 mm along the axon
⩥ salutatory conduction.
Answer: allows the action potential to jump from node to node
⩥ slower.
Answer: if no myelin were present, conduction velocities would be a lot
....
⩥ nerve terminal branches.
Answer: multiple extensions of the axon that innervate individual
muscle fibers
⩥ motor endplate / neuromuscular junction.
Answer: interface between the end of the axon @ the terminal branch
and the muscle fiber
⩥ multinucleated cylindrical cells (fibers).
Answer: skeletal muscles of the body are composed of ___________
_________ ______ (_______) which run parallel to each other. Force is
directed along the long axis
⩥ fiber length.
,Answer: can vary from a few mm in small muscles (eye) to approx. 30
cm in large muscles (leg)
⩥ connective tissue layers associated with skeletal muscle.
Answer: endomysium
perimysium
fasiculus
epimysium
tendons
periosteum
⩥ endomysium.
Answer: wraps each muscle fiber and separates it from others
⩥ perimysium.
Answer: bundle surrounding up to 150 fibers
⩥ fasiculus.
Answer: large bundle of fibers
⩥ epimysium.
Answer: surrounds the entire muscle
, ⩥ tendons.
Answer: extension of the epimysium at the ends of the muscle
connecting to bone
⩥ periosteum.
Answer: bones outermost covering; tendons connect the muscle to this
⩥ skeletal muscle structures.
Answer: sarcolemma
basement membrane
sarcoplasm
sarcoplasmic reticulum
⩥ sarcolemma.
Answer: muscle fiber membrane, thin elastic membrane that encloses
the fiber's cellular contents, true fiber boundary
⩥ basement membrane.
Answer: loose collection of glycoproteins and collagen, outside the
muscle fiber
⩥ sarcoplasm.