Lecture 17- the autonomic nervous system Flashcards
what is the purpose of the autonomic nervous sytem?
innervates organs whose functions are not usually under voluntary control
where does the sensory info get processed?
hypothalamus, limbic system, spinal cord, medulla
reflexes are important for autonomic control, what can they evoke changes in?
autonomic output (negative feedback or feedforward)
what is the autonomic system?
actions involving involuntary control
what are examples of conscious control?
pee
heart rate can be controlled through meditation
what do visceral effectors do?
they adjust their activity to match the bodys needs to maintain homeostasis
they don’t need the ANS in order to function
what is the general autonomic nerve pathway?
CNS –> preganglionic fiber –> autonomic ganglion –> postganglionic fiber –> effector organ
what is a ganglion?
a mass or group of neuronal cell bodies. knot of cell bodies
in post ganglions do we have synapses?
we have networks of synapses (SOOO MANY)
what does the autonomic nervous system divide into?
sympathetic nervous system
parasympathetic nervous system
in the sympathetic nervous system where do the cell bodies and axons of preganglioinics originate?
thoracic (T1) and lumbar (L2) regions of the spine
what can be said about sympathetic nervous system preganglionic and postganglionic fibers?
preganglionic fibers are short
postganglionic fibers are long
what makes the sympathetic nervous system diverse?
there are many routes and many places for a preganglion to synapse
what are the 3 routes of axons after they exit spinal cord?
- make a synapse in a sympathetic chain ganglion
- pass through SCG and synapse in the adrenal medulla
- pass through SCG and synapse in a collateral ganglion
what neurotransmitters do most preganglionic fibres and postganglionic fibers release in the sympathetic nervous system?
preganglionic fibres release ACh
postganglionic fibres release norepinephrine