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Autonomic N System
Autonomic Nervous System
Question | Answer |
---|---|
ANS function | Provides the ability to maintain homeostasis Functions at subconscious level, involved in regulating, adjusting, and coordinating vital visceral function-BP, temp, respirations, digestion, metabolism, elimination Strongly affected by emotional state |
ANS components | Sympathetic: fight or flight Parasympathetic: rest and digest |
Ganglia | Group of neurons that work together and are geographically close together |
Functions of Parasympathetic Nervous System | slowing heart rate, increase gastric secretion, emptying bladder and bowel, focus of eye for near vision, constriction of pupil, contraction of bronchial smooth muscle |
Functions of Sympathetic Nervous System | Regulation of cardiovascular system, regulation of body temp, implementing fight or flight response |
Preganglionic neurons and Postganglionic neurons in both PNS and SNS | Pre: neurons that go from the spinal cord to the ganglia Post: Neurons that go from the ganglia to the effector organs |
Adrenal medulla's function in SNS | Functional equivalent of a postganglionic neuron. Releases Epi which then produces effects much like those that occur in response to the stimulation of postganglionic sympathetic nerves. |
Somatic Motor System pathway | One neuron from spinal cord to muscles innervated by somatic motor nerves. They only have the neuromuscular junction (between somatic nerve and muscle). |
Adrenergic receptor function | Mediate responses to epinephrine (adrenaline) and norepinephrine transmitters |
Alpha 1 & beta 1 receptors | Produce excitation |
Alpha 2 & beta 2 receptors | Produce inhibition |
Eye response for muscarinic (parasympathetic) | Constriction for near vision |
Heart response for muscarinic (parasympathetic) | Decrease rate |
Lung response for muscarinic (parasympathetic) | Constriction of bronchi |
Bladder response for muscarinic (parasympathetic) | Relaxation |
GI tract response for muscarinic (parasympathetic) | Increase tone, peristalsis |
Glands response in parasympathetic | vasodilation |
Peripheral vessels response in parasympathetic | Dilate |
Adrenergic receptor subtypes | Alpha 1, Alpha 2, Beta 1, Beta 2 |
Nicotinic receptors | Occur on all dendrites and cell bodies of ANS postganglionic neurons, in the adrenal medulla, and at neuromuscular junctions (skeletal muscle) (excitatory) |
Cholinergic neurons release what | release acetylcholine from preganglionic neurons & from parasympathetic postganglionic neurons |
What are the two classes of receptors AcH binds to in cholinergic receptors | Nicotinic receptors and muscarinic receptors |
Alpha 1 activation: uses and side effects | Uses: Hemostasis (local bleed), nasal decongestion, adjunct to local anesthesia (vasoconst will keep anesthesia because it can’t diffuse away quickly), decreased BP, mydriasis (pupil dilation)SE: HTN, necrosis, bradycardia (baroreceptor reflex) |
Alpha 2 activation | central activation only, decreases symp outflow to heart and vessels Decrease symp outflow: decrease SNS even though you’re stimulating A2 |
Beta 1 activation: Uses and side effects | Uses: Cardiac arrest, heart failure, shock, AV heart block. You will increase heart rate, contraction, BP so it's good to use for these issues. SE: dysrhythmias, angina (if you inc work, you may not get enough blood) |
Beta 2 activation: uses and side effects | uses: delay preterm labor, asthma SE: Hyperglycemia: mobilized glucose stores-> inc blood glucose; tremor: albuterol for asthma |
Dual innervation | Most viscera receive nerve fibers from both parasyp. and symp. divisions (slowing/speeding heart rate) (produces saliva, from two different effectors) |
What cranial nerves does the parasympathetic innervate | 3, 7, 9 and 10 |
Muscarinic receptors | Occur on all gland, smooth/cardiac muscle cells that receives cholinergic innervation (excitatory or inhibitory) |