Flashcards in Autonomic Nervous System Deck (15):
Compare the structural and functional differences between the somatic efferent and the autonomic portions of the nervus system
-Autonomic nervous system= involves a preganglionic and postganglionic neuron to visceral-smooth muscle cardiac glamds
Identify the principal structural features of the autonomic nervous system
- preganglionic neuron begins CNS to ganglion- myelinated
- postganglionic begins at ganglion to effector- unmyolinated
Name three types of collateral or prevertebral autonomic ganglia in the sympathetic division
-These are sympathetic ganglia and the Celiac ganglion (solar plex) sends postganglionic fibers to upper abdominal structures such as stomach & liver
-the Superior Mesenteric ganglion sends postganglionic fibers to middle abdominal structures such as the small intestine
-the Inferior Mesenteric ganglion sends postganglionic fibers to lower abdominal/pelvic structures such as large intestine.
Define white ramus communicans and gray ramus communicans
- white ramus is the branching of the preganglionic neuron from the spinal nerve (leaving)
-synaps happens and can rejoin with the postganglionic
-gray ramus is the branching of the post ganglionic neuron to rejoin the spinal nerve.
-preganglionic neuron can also travel up or down the sympathetic trunk and have a synapse at any level with the postganglionic neuron.
Define splanchnic nerve
-pertaining to vicera
Name the 2 divisions of the ANS, Generally how do their functions differ?
-Sympathetic- fight or flight
-parasympathetic- rest and digest
Describe the anatomy of the sympathetic division. What is the sympathetic trunk= sympathetic chain ganglia
- The preganglionic neuron exits the spinal cord between T1-L2.
-Preganglionic neurons short & postganglionic neurons are long.
-The sympathetic trunk is a chain of interconnected ganglia so that the sympathetic response is widespread and shows divergence. (less control, but occurs in abundance and all over)
-It allows the stimulation that may have begun at L2 to have an effect at the level of your head.
Describe the anatomy of the parasympathetic division
-The preganglionic neurons exit the spinal cord in the S2-S4 region as well as from the brainstem along Cr. nerves III, VII, IX and X.
- There is no interconnection between these spinal cord segments and the individual cranial nerve segments.
-Isolated responses are the norm for parasympathetic.
-The preganglionic neurons long and the postganglionic neurons are quite short.
What structure does not have a postganglionic neuron?
-adrenal medulla which is a part of the sympathetic Division (releases norepinephrine and epinephrine to exaggerate f or f)
Compare the length of axons in the sympathetic and parasympathetic divisions. which division has more divergence?
-Sympathetic has much more divergence. It is rare to have and isolated sympathetic response such as increased heart rate without other sympathetic responses.
- isolated parasympathetic responses such as only a decreased heart rate.
Define cholinergic and adrenergic. Classify autonomic nerve fibers in each division as cholinergic or adrenergic
-Cholinergic- releases acetylcholine- both preganglionic PNS/postganglionic SNS
-Adrenergic- releases norepinephrine (postganglionic only) =SNS
Describe the various autonomic receptors
-Muscarine- located on the effector in the PNS
-will block salavary glands in R&D
-blocked by atropine
-Nicotinic- located on the postganglionic neuron in PNS and SNS
-Blocked by Curare
Norepinephrine/epinephrine SNS ONLY
-alpha (1&2's, 1 more common)
-constricts muscle (why we are pale in F or F because of contraction of blood vessels)
-Beta 1 (cardiac only)
-Stimulatory effect (b1 blocker for cardiac arrest, decreasted need for o2)
-Beta 2 (airways)
- tend to be inhibitory
-Stimulation=relaxation= open airways
-responds only to epinephrine (epi pen in allergic reaction)
Explain the role of the hypothalamus and its relationship to the sympathetic and parasympathetic divisions
- control. produces response
The drug atropine causes what effects to the ANS?
-Atropine is antimuscarinic and thus blocks the PNS (like salivating gland)