| What is the principle integrating center in the CNS? |
hypothalamus |
| What are the autonomic centers in the brain? |
medulla and spinal cord |
| Where do the medulla and spinal cord receive sensory inflow from? |
from the viscera |
| How do CNS centers respond to activation of visceral afferents? |
by activating efferent reflex impluses by the ANS |
| What is an example of the CNS response? |
baroreceptor reflex- rise a BP causes ANS reflex to lower it |
| What can modify the activity of the ANS? Example? |
emotions- example is neurogenic or psychogenic diarrhea where
excessive stimulation of the parasympathetic nervous system increases the
motility and secretion of mucus in the distal colon |
| What is not part of the ANS? |
afferent pathways |
| What is collectively known as the ANS? |
efferent pathways |
| Where are somatic division motor cell bodies located? |
in the CNS |
| Where are autonomic division motor cell bodies? |
in ganglia outside the CNS |
| A typical autonomic reflex chain contains how many synaptic junctions
between the CNS and the effector organ? |
1 |
| Where is the 1 synapse located? |
in the ganglia |
| Where can inhibition in the autonomic system occur? |
at either pre or postganglionic neurons |
| What type of inhibition is unique to the ANS? |
some postganglionic neurons directly inhibit the effector organ they
innervate |
| What are the two divisions of ANS outflow? |
sympathetic nervous system and parasympathetic nervous system |
| In the SNS, where do preganglionic neurons originate from? |
thoracic and upper lumbar segments (T1-T12) and (L1-L3) of the
intermediolateral cell column of the lateral horn of the spinal cord |
| Sympathetic ganglia are not embedded in? |
the effector organs |
| What is the SNS activated by? |
fear, trauma, hypoglycemia, etc. |
| How does the SNS discharge? |
as a unit- widespread |
| What does SNS activation cause? |
causes the release of NE from the postganglionic neuron directly onto
the effector organ |
| SNS activation also causes the release of what? |
causes the adrenal medulla to be stimulated and release a mix of
epinephrine and NE in to the blood (85:15 mix) |
| What does the mixture of E:NE do? |
these are now hormones and activate every effector organ they come
into contact with |
| Where do parasympathetic ganglions originate from? |
from cranial nuclei 3, 7, 9, 10 and sacral segments of the spinal cord
(S2-S4) |
| Where are ganglia in the ParaNS? |
usually embedded in the effector organ |
| What is the characeteristics of the postganglionic neuron? |
it's usually short |
| What is the purpose of the ParaNS? |
it balances the actions of the SNS |
| How does the PNS discharge? |
never as a whole system- activation is discrete |
| What are cholinergic neurons? |
nerves that release ACh |
| What are the typical cholinergic neurons? |
all somatic motor neurons, all PNS (both SNS and ParaNS) preganglionic
neurons, all autonomic paraNS postganglionic neurons supplying sweat
glands. certain blood vessels, and piloerector muscles |
| ACh is destoryed by what? |
cholinesterase in the synapse |
| What are nerves called that release NE and E? |
adrenergic neurons |
| What are the typical adrenergic neurons? |
majority of postgang. sympathetic neruons (some release ACh) |
| What are sympathetic postgang. neurons similar to? |
adrenal medullary cells |
| What does the adrenal medulla secrete more of? |
more E than NE |
| What are nerves termed that release dopamine? |
dopaminergic |
| What are some typical dopaminergic neurons in the ANS? |
fibers found in the kidney, small intensely flourescent (SIF) nerons
in the sympathetic ganglia |
| Nerves that release peptides are called? |
peptidergic |
| What are the two cholinergic receptors? |
muscarinic and nicotinic |
| What kind of receptor is the muscarinic? |
indirect- both inhibitor and excitatory |
| What kind os receptor is the nicotinic? |
direct |
| Where is the muscarinic receptor located? |
on all effector organs in the ParaNS and sweat glands, skeletal blood
vessel and piloerector mucles in the SymNS |
| Where is the nicotinic receptor located? |
located on the dendrites and soma of postgang. neurons in SymNS and
ParaNS, also in somatic motor system's skeletal muscles |
| What are the variations of adrenergic receptors? |
alpha and beta |
| Are the alpha and beta receptors direct or indirect? |
indirect- slow |
| Where are alpha and beta adrenergic receptors located? |
majority of effector organs in the SNS |
| Peptide receptors are direct or indirect? |
indirect ligand gated |
| Dopamine receptors are direct or indirect? |
indirect |
| Regulation of blood pressure by altering blood vessel diameter is
under what control? |
SymNS |
| There is a steady tonic SymNS firing to arterioles in all systemic
organs which causes what? |
a baseline vasoconstriction |
| What does the baseline vasoconstriction do? |
maintains BP |
