Unit 3: Parasympathetic NS vs. Sympathetic NS Flashcards
How does the parasympathetic NS maintain homeostasis?
Maintains homeostasis at rest, stores nutrients, and is energy conserving
How does the sympathetic NS maintain homeostasis?
Maintains homeostasis in case of emergency - exercise, stress, excitement
Parasympathetic effect on heart
Decrease heart rate
Parasympathetic effect on blood pressure.
Decrease blood pressure
Parasympathetic effect on pupils.
Constrict pupils
Parasympathetic effect on salivary glands.
Stimulation of increased saliva production
Parasympathetic effect on digestive system organs.
All organs are stimulated.
Increased gastric juice production
Increased peristalsis for better digestion and absorption of nutrients
Parasympathetic effect on bronchioles.
Bronchoconstriction; less air enters lungs, so less oxygen is delivered
Parasympathetic effect on blood vessels.
NONE! (with few exceptions)
Parasympathetic effect on sweat glands.
NONE!
Sympathetic effect on heart.
Increases heart rate
Sympathetic effect on blood pressure.
Increases blood pressure
Sympathetic effect on pupils.
Dilates pupils
Sympathetic effect on salivary glands.
Inhibits saliva production
Sympathetic effect on digestive system organs.
Inhibitory effect - decreased ability to digest and absorb
Sympathetic effect on bronchioles.
Bronchodilation - more air enters lung, more oxygen delivered to the body
Sympathetic effect on blood vessels.
Vasodilation - of heart and skeletal muscles
Other organs (skin, digestive organs) will see vasoconstriction, with decreased blood flow to those organs
Sympathetic effect on sweat glands.
Stimulates an increase in sweat secretion
What is the parasympathetic division also called?
Craniosacral division
Craniosacral division consists of what nerves?
Nuclei of CNs III, VII, VIII, IX
S2-S4
Where are ganglia located in parasympathetic divison?
Close to target organ, within the wall of target organ
What is the size of the parasympathetic preganglionic axon?
Long
Are there any collateral branches on the parasympathetic preganglionic axon?
Few
What is the size of the postganglionic axon in parasympathetic division?
Short
Is there neural divergence on parasympathetic axons?
Limited
Is the effect of the parasympathetic division local or systemic?
Local
What is the outflow to the target organs in parasympathetic division?
Outflow achieved via cranial nerves
What neurotransmitter is released by the postganglionic neruon of the parasympathetic division?
Primarily acetylcholine
What is the sympathetic division also called?
Thoracolumbar division
Thoracolumbar division consists of what nerves?
Preganglionic neuron found in lateral horn of T1-L2
Where are ganglia located in the sympathetic division?
Close to spinal cord, distant from target organ
Sympathetic chain ganglia - bilateral
Prevertebral ganglia - superior mesenteric, celiac, and inferior mesenteric ganglia
What is the size of the sympathetic preganglionic axon?
Short
Are there any collateral branches on the sympathetic preganglionic axon?
Branched axon
What is the size of the postganglionic axon in sympathetic division?
Long
Is there neural divergence on sympathetic axons?
Yes, extensive
Is the effect of the sympathetic division local or systemic?
Systemic bc it effects all organs simultaneously
This is due to neuronal divergence and presence of adrenal gland (which can effect other organs)
What is the outflow to the target organs in sympathetic division?
Outflow to target organs via:
- Spinal nerves (sweat glands, erector pili m., subcutaneous vessels)
- Sympathetic nerves (organs of thoracic cavity)
- Splanchnic nerves (abdominal organs)
- Adrenal medulla (systemic effect due to secretion of NT in to the blood stream)
What neurotransmitter is released by the postganglionic neuron of the sympathetic division?
Norepinephrine and acetylcholine
Also epinephrine from adrenal medulla
What are the two main receptors of the ANS?
Cholinergic receptors
Adrenergic receptors
There are two types of receptors are are cholinergic. What are they?
Nicotinic receptors and muscarinic receptors
Where in our bodies do we find nicotinic receptors?
Skeletal muscles
Ganglionic cells
Where in our bodies do we find muscarinic receptors?
All target membranes in the parasympathetic division
What NT do all cholinergic receptors receive?
Acetylcholine
There are many types of receptors that are adrenergic. List them all.
alpha 1 alpha 2 Beta 1 Beta 2 Beta 3
Which division of the ANS would we find adrenergic receptors?
Sympathetic NS
Alpha 1 receptors stimulate…
Vasoconstriction
Alpha 2 receptors stimulate…
Inhibition of insulin production
Where are Beta 1 receptors found?
On the heart (SA and AV nodes)
On kidney (to increase Renin production)
- Excitatory
Where are Beta 2 receptors found?
On smooth m. of bronchiole and GIT
- relaxes the muscles (inhibitory)
Where are Beta 3 receptors found?
Adipose tissue (leads to lipolysis)
How is NT activity terminated with cholinergic receptors?
Ach is broken down/degraded by acetylcholinesterase
How is NT activity terminated with adrenergic receptors?
Norepinephrine from postganglionic neurons is taken back up into nerve terminals (reputake)
Epinephrine goes through metabolic transformation in the liver
