AUTONOMIC NERVOUS SYSTEM

Question 1

where is the control center of the ANS

Answer 1

-no true pinpoint of control center but hypothalamus is heavily involved
-hypothalamic neurons project into brainstem down spinal cord to synapse with autonomic neurons

Question 2

where are parasympathetic neurons located

Answer 2

travel through cranial/vagus nerves out through brainstem to innervate organs

Question 3

where are sympathetic neurons located

Answer 3

-travel through thoracic nerves + some lumbar nerves to innervate same organs + kidney
-some cause adrenal gland (on top of L/R kidney) to release epinephrine into bloodstream which will travel to organs (hormone)

Question 4

sympathetic/parasympathetic innervates the kidney

Answer 4

sympathetic only

Question 5

sympathetic neurotransmitter

Answer 5

norepinephrine
-epinephrine as the sympathetic hormone

Question 6

parasympathetic neurotransmitter

Answer 6

ACh

Question 7

name of receptors for nor/epi

Answer 7

adrenergic receptors
-for sympathetic

Question 8

name of receptors for ACh

Answer 8

muscarinic cholinergic receptors
-for parasympathetic

Question 9

general pathway of hypothalamic neurons to ANS neurons

Answer 9

neurons in limbic system (emotional center, gray matter) synapse with hypothalamic neurons ->
hypothalamic neurons synapse with sympathetic/parasympathetic neurons

Question 10

metabotropic

Answer 10

initiate a G-protein pathway

Question 11

muscarinic cholinergic receptors initiate what pathway

Answer 11

G-protein pathway (metabotropic)

-when ACh binds, initates G-protein pathway that will illicit parasympathetic response

Question 12

adrenergic receptors initiate what pathway

Answer 12

G-protein pathway (metabotropic)

-when epi/nor binds, initiate G-protein pathway that will illicit sympathetic response

Question 13

how do nicotinic cholinergic receptors work

Answer 13

-ionotropic- open up for ions to travel through
-these are the ACh receptors at NMJ -> located on fibers, allow sodium to enter + depolarize to generate AP

Question 14

can muscarinic + adrenergic receptors be both cAMP + IP3/DAG pathways

Answer 14

yes- just not on the same organ

-this is so that we can produce different responses from those organs

Question 15

cAMP pathway

Answer 15

neurotransmitter binds to receptor ->

alpha swaps out GDP for GTP + disassociates away from beta/gamma ->

alpha activates adenylate cyclase, which converts ATP to cAMP ->

cAMP activates kinases which phosphorylates things

Question 16

IP3/DAG (PIP2) pathway

Answer 16

-neurotransmitter binds to receptor -> alpha swaps out GDP for GTP + disassociates away from beta/gamma -> alpha activates phospholipase C, which converts PIP2 into IP3 + DAG

-IP3 opens SR channels so calcium can spill out + cause contraction of SMOOTH MUSCLE (not an actin/myosin interaction)

-DAG activates protein kinases, which phosphorylate things

Question 17

classes of adrenergic receptors

Answer 17

Alpha
* Alpha 1: IP3/DAG
* Alpha 2: cAMP

Beta
* Beta 1: cAMP
* Beta 2: cAMP
* Beta 3: cAMP

Question 18

adrenergic receptor on smooth muscle lining of blood vessels

Answer 18

alpha 1

Question 19

describe alpha 1 receptor pathway on blood vessels

Answer 19

-nor/epi binds to adrenergic receptor -> IP3/DAG pathway occurs -> IP3 goes to SR + releases calcium, causing smooth muscle to contract -> blood vessels narrow

-blood vessels narrow in response to sympathetic nervous system -> important so that blood can be shunted to areas needing it

Question 20

adrenergic receptor on smooth muscle lining of lungs

Answer 20

beta 2

Question 21

describe beta 2 receptor pathway on lungs

Answer 21

-nor/epi binds to adrenergic receptor -> cAMP pathway occurs -> increase in cAMP activates protein kinases, which inhibit smooth muscle contraction

-smooth muscle relaxation causes lungs to dilate + diameter of bronchioles will increase so more air can come in/out

-sympathetic nervous system does this to oxygenate blood + blow out CO2 during exercise