Term
| What are the three major components of the ANS central control? |
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Definition
1. Hypothalamus (part of limbic system) -Coordinates autonomic responses 2. Brain Stem Sympathetic & Parasympthetic 3. Spinal Cord |
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Term
| How are the peripheral nerves of the ANS organized? |
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Definition
Parasympathetic exit in the brain stem (CNs 3, 7, 9, 10) Sacral part of spine -Long preganglionic nerve, short postglanglionic Sympathetic Thorax and Lumbar sections of spine -short preganlionic fibers, LONG post ganglionic! |
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Term
| What are the difference in length of the pre and post ganglionic fibers for PS and sympathetic systems? |
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Definition
Parasympathetic system has LONG preganglionic fibers and SHORT postganglionic fibers Sympathetic system has SHORT preganglionic fibers and LONG postganglionic fibers. |
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Term
| What is the term used to describe the battle between sympathetic and PS |
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Definition
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Term
| How does the location of ganglia differ between the SNS and ANS? |
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Definition
SNS has ganglia within the CNS ANS has ganglia outside of CNS |
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Term
| Whats the difference between terminals in the SNS and those found in the ANS? |
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Definition
Terminals in the SNS are motor end plate (one nerve terminal per muscle fiber) ANS on the other hand has varicosities (spray terminals) |
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Term
(T/F) The ANS is completely depending on nerves in order to be activated |
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Definition
False There is spontaneous activity even in the absence of nerves i.e. the endocrine function of Epi from adrenal medulla. |
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Term
| What happens when you denervate the SNS and ANS? |
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Definition
Supersensitivity in both cases -Somatic nervous system USUALLY modulates reflex behavior. -Cut this out, hypersensitive reflexes |
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Term
| Explain why a heart attack can have referred pain on certain areas of the skin. |
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Definition
The visceral afferents from the heart synapse on the same neuron as somatic afferents from a certain area of skin. Nociceptor pain from the heart is then percieved as pain in the skin area. |
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Term
| With respect to general organization of neurotransmitters in the ANS (Ach for all PS and Ach and NE for Symp), what are the exceptions? |
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Definition
Sympathetic innervation of the sweat glands uses Ach for both pre and post ganglionic neurons. -They are muscarinic receptors Sympathetic innervation of blood vessels in skeletal muscles. Muscarinic receptor. |
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Term
How is the parasympathetic system down-regulated by the sympathetic system and vice-versa? |
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Definition
When the sympathetic system secretes NE, some of those molecules bind to alpha 2 receptors on Ach terminals restricting their secretions and thus downregulating the parasympathetic system. On the other hand, when the parasympathetic sytems secretes Ach, some of those molecules bind to a muscarinic receptor found on the NE terminal reducing NE output. This down regulates the sympathetic system. |
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Term
| Name a regulation of the ANS that occurs in the periphery. |
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Definition
| The regulation of sympathetic tone by alpha 2 receptors and muscarinic receptor binding. |
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Term
| What is the difference between alpha and beta adrenergic receptors? |
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Definition
Alpha have decreased sensitivity to isoproterol (a synthetic epinephrine) and are blocked by phentolamine. Beta's have a high sensitivity to isoproterenol and are blocked by by propranolol (Sir James Black) |
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Term
| What are the functions of atropine and pilocarpine? |
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Definition
Atropine BLOCKS muscarinic cholinergic receptors Pilocarpine STIMULATES muscarinic cholinergic receptors. |
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Term
| Explain the different types of adrenergic receptors. |
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Definition
Alpha 1. Target organ receptor. 2. on synaptic terminals releasing Ach. Beta 1. Equivalent response to NE and E. 2. Greater response to E than NE. -This means that B2's are going to respond much stronger to endocrine adrenaline (80% Epi)! |
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Term
| What part of the hypothalamus is activated for feeding behavior? |
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Definition
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Term
| What part of the hypothalamus is activated for the defense behavior? |
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Definition
The ventromedial nucleus. Vent anger in defense |
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Term
| Where is blood pressure fluctuations sensed? |
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Definition
In the baroreceptors of the carotid sinus Baroreceptors are stretch receptors -High BP causes more stretching |
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Term
| How is high blood pressure senses and what process occurs to correct the problem? |
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Definition
Baroreceptors in the carotid sinus sense the increase in blood pressure (stretched). They send a signal to neurons in the depressor center of the medulla. The medulla inhibits sympathetic nervous system which decreases force and contractility of the heart. The depressor center also activates the nucleus of the vagus, which decreases rate and contractility of the hear. There is also a reduced ammount of vasoconstriction in the arterial system. |
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Term
| What is a common trait of activation of either dorsalmedial nucleus OR ventromedial nucleus? |
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Definition
Increased blood pressure Dorsomedial (excess BP supplies gut) Ventromedial (high BP supplies skeletal muscles) |
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