intro

Question 1

all nerves coming off of the spinal cord release what neurotransmitter? What receptor is stimulated?

Answer 1

1. Ach
2. Nicotinic

Question 2

where and when is epinephrine released

Answer 2

• adrenal medulla
• in flight/fight response

Question 3

list the sympathetic neurotransmitters and corresponding receptors

Answer 3

• Ach - M
• NE - a1, a2, B1
• D-D1

Question 4

what is adrenaline

Answer 4

epinephrine

Question 5

Which ANS system, once activated, can give discrete tissue regulation?

Answer 5

• parasympathetic
• sympathetics are all linked; don’t have sympathetic response in only one part of your body

Question 6

M1 and M3 receptors act through which G protein

Answer 6

• Gq -> formation of IP3 and DAG and increased intracellular calcium

Question 7

M2, a2 receptors act through which G protein

Answer 7

• Gi -> decrease cyclic AMP and dephosphorylate Ca2+ channels -> nerves are shut down

Question 8

Beta receptors act through which G protein

Answer 8

• Gs: stimulate adenylate cyclase and increase cAMP

Question 9

important shared location of M2 and a2 receptors

Answer 9

presynaptic

Question 10

Which receptor causes the iris circular muscle and ciliar muscle to contract? Response?

Answer 10

• M3
• miosis, and accomodation to near vision

Question 11

which adrenergic receptor causes the iris radial muscle to contract? Response?

which adrenergic receptor causes the ciliary muscle to relax? Response?

Answer 11

• iris radial muscle: a1 -> Mydriasis
• ciliary muscle: B -> decrease in IOP

Question 12

M2 receptor stimulation has what affect on the heart

Answer 12

• location: SA,AV, and atrial muscles
• response: decelerates SA node and decreases atrial contractility only -> main affect: decreased HR (not necessarily overall contractility)

Question 13

where are alpha receptors concentrated

Answer 13

• large veins > resistance arteries (e.g. skin, splanchnic vessels)

Question 14

Endothelium of blood vessels has what receptor? affect of stimulation?

Answer 14

• M3
• No innervation; but injection of acetylcholine can cause vasodilation through NO

Question 15

Which receptors are located on bronchiolar smooth muscle? Response of ativation of each?

Answer 15

• M3: bronchoconstriction
• B2: bronchodilation: only seen in epinephrine release

Question 16

which adrenergic receptors causes relaxation of GI smooth muscle walls? GI sphincters?

Answer 16

• GI smooth muscle walls: a2 and B2
• GI sphincters: a1

Question 17

Which receptor activation are responsible for erection and ejaculation

Answer 17

• erection: M
• ejaculation: a1

Question 18

which receptor activation is responsible for renin increase

Answer 18

• B1

Question 19

which receptor activation is responsible for lipolysis

Answer 19

B3

Question 20

which receptor activation is responsible for glycogenolysis and gluconeogenesis?

Answer 20

B2

Question 21

What is the only tissue with a predominant sympathetic tone??

Answer 21

• BV in skin, splanchnic vessels
• eye, heart, bronchiolar smooth muscle, GI and GU all have predominant parasympathetic tone!

Question 22

role of alpha 2 receptor activiation

Answer 22

• modulate NE release
  
  • activated a2 causes decreased NE release

Question 23

list the ways in which postsynaptic response can be regulated

Answer 23

1. up or down regulation of receptors
2. desensitization of receptors
3. moderate membrane potentials
   
   • inhibitory post synaptic potential: M2
   • excitatory post synaptic potential: peptides

Question 24

when will baroreceptors fire?

Answer 24

• they are simple stretch receptors
  
  • stretched more -> fire more
  • stretched less -> fire less

Question 25

explain the baroreceptor pathway

Answer 25

1. carotid sinus and/or aortic arch sense blood volume -\> fire of baroreceptor at a certain rate 2. sensory fibers reaches nucleus of tractus solitarius (NTS) in brainstem 3. inhibitory interneurons, originating on nucleus of tractus solitarius, act on vasomotor center (in medulla oblongata) 4. sympathetic response is changed accordingly

Question 26

any drug that causes a drop in BP will immediately result in

Answer 26

reflex tachycardia (immediate effect)

Question 27

any drug that causes a drop in BP will result in what long term effect

Answer 27

* increase in renin release -\> increase in Na+ and H20 retention

Question 28

explain the pathway of baroreceptor firing in parasympathetic response

Answer 28

* baroreceptors synapse directly onto the vagus nerve * vagus nerve innervates the SA and AV nodes and atrial muscle

Question 29

explain the baroreceptor pathway with increased arterial blood pressure

Answer 29

1. baroreceptors sense increased stretch in carotid sinus/aortic arch and fire more 2. baroreceptors synapse onto NTS and the inhibitory neurons act to _inhibit the vasomotor center_ 3. this causes decreased stimulation of the sympathetic nerves and decreased NE release -\> decrease arterial BP

Question 30

explain the baroreceptor pathway with decreased arterial blood pressure

Answer 30

1. baroreceptors sense decreased arterial BP in carotid sinus and aortic arch and fire less 2. less inhibitory action on the vasomotor center 3. vasomotor center will fire more frequently and cause increased NE release -\> increase in arterial BP