Autonomic NS - General Info Flashcards
The ANS generally innervates…
smooth m, cardiac m, glands
control visceral functions necessary for life such as HR, BP, digestion, urination
The somatic sensory system transmits sensations of…
touch, pain, temp, position
The somatic motor system inn only…
skeletal mm (voluntary and reflexive movement)
ANS fibers travel on…
CN and artery pathways
ANS is controlled/modulated by fibers originating in…
the CNS
ANS motor unit has __ motor neurons while the somatic NS only has __.
ANS – 2 motor units (has pre and post synaptic neurons)
SNS – 1 motor unit (only post synaptic neuron)
Presynaptic neurons of the somatic motor system originate…
in the CNS, originating on the brain
Sympathetic cell bodies of the ANS lie in…
lateral horn of the spinal cord
The presynaptic axon synapses with the postsynaptic neuron in an…
autonomic ganglion (cell bodies of the postsynaptic neuron make up the ganglion)
What do autonomic ganglia have that are analogous to interneurons?
small neurons called intrinsic ganglionic cells
What are the purpose of intrinsic ganglion cells?
they modulate the activity of the ANS
turn off activity of postsynaptic neuron after it has fired
The ANS is split into what 2 systems?
symp and parasymp
What CN carry parasympathetics?
III, VII, IX, X
What are examples of symp NS stimulation?
pupil dilation, dilation of bronchioles, increased HR, overall vasoconstriction (localized vasodilation in heart and skeletal mm)
What are examples of parasymp NS stimulation?
digestion, HR drops, respiration rate drops, bronchioles constrict, pupils constrict
What anatomical regions of the CNS do the symp and parasymp systems arise from?
symp – thoracolumbar div (fibers from lateral horn of SC)
parasymp – craniosacral div (fibers from brain and sacral spinal cord)
Symp pathways have _______ presynaptic fibers and _______ postsynaptic fibers.
Parasymp pathways have _______ presynaptic fibers and _______ postsynaptic fibers.
symp – short presnaptic, long postsynaptic
parasymp – long presynaptic, short postsynaptic
Symp ganglia lie near the ______.
Parasymp ganglia lie near the _______.
symp ganglia – near the SC and vertebral column (short presynaptic)
parasymp ganglia – in or near the effector organ (long presynaptic)
True or false – Symp axons branch profusely but your parasympathetics do not.
True (so symp can mobilize a lot of organs at once for fight-or-flight)
carry info from sensory receptors of skin & other organs to CNS
afferent
carry motor infor away from CNS to the muscles & glands of the body
efferent
true/false:
ANS not considered as part of CNS
true
ANS is a motor system that acts ____ from the somatic nervous system (SNS)
independent
anything you can’t control on your own is controlled by the
ANS