ANS

Question 1

What second messenger system is associated with the alpha-1 receptor?

Answer 1

Gq = Phosopholipase C = IP3/DAG

-other receptors that share this pathway are Histamine1 and Muscarinic 1, 3, 5
-Vasopressin 1

Question 2

What second messenger system is associated with the alpha 2 receptor? Name other receptors.

Answer 2

Gi = decreased AC = decreased cAMP

M2
DA2

Question 3

What second messenger system is associated with beta 1 and beta 2 receptor? Other receptors?

Answer 3

Gs = increased Ac = increased cAMP

DA-1
VA- 2 (renal)
Histamine 2

Question 4

Describe PSNS heart innervation

Answer 4

M2 decreased contractility and heart rate

Question 5

Describe the autonomic innervation of vasculature

Answer 5

v/c ARTERIES = a1 > a2
v/c VEINS = a2 > a1

myocardium, sk. muscle B2 vasodilation

renal & mesenteric DA vasodilation

Question 6

describe the autonomic innervation of the bronchial tree

Answer 6

B2 = bronchodilation respond to catechols in the systemic circulation b/c not innervated

M3 = bronchoconstriction

Question 7

Autonomic innervation of the kideny

Answer 7

renal tubules = a2 (diuresis)
renin release = b1

a1/a2 = vasoconstriction
b2/da1 = vasodilation

Question 8

describe autonomic innervation of the eye

Answer 8

SPHINCTER MUSCLE (IRIS) = M = contraction = miosis

RADIAL MUSCLE (IRIS) = A1 = contraction (mydriasis)

CILIARY MUSCLE =
B2 = relaxation (far vision)
Muscarinic = contraction (near vision)

Question 9

Describe autonomic innervation of pancreas

Answer 9

alpha 2 = decreased insulin release
beta 2 = increased insulin release

Question 10

Bladder autonomic innervation

Answer 10

sphincter = a1 contraction
detrusor = b2 relaxation

Question 11

List the steps of NE synthesis. What is the rate-limiting step?

Answer 11

Tyrosine
via Tyrosine hydroxylase –> L-dopa
via Dopa decarboxylase –> Dopamine
via Dopamine B-hydroxylase –> NE
via Phenylethanolamine N methytransferase in the adrenal medulla –> EPI

**rate limiting is tyrosine hydroxylase

Question 12

Three ways that NE can be removed from synaptic cleft?

Answer 12

1. Reuptake (80%)
2. Diffusion into bloodstream
3. Reuptake by extraneural tissue

Question 13

What enzymes metabolism NE and epi? Final metabolic byproduct?

Answer 13

MAO and COMT (monoamine oxidase and catechol-O-methyltransferase)
VMA (VANILLYLMANDELIC ACID = 2-4-methoxy-4hydroxymandelic acid)

Question 14

Describe synthesis of Ach

Answer 14

Choline is transferred into neuron.
Mitochondria produces Acetyl CoA.
ChAT converts Choline + Acetyl CoA into Ach

Question 15

Where is Ach released for SNS postganglionic

Answer 15

Sweat glands, piloerector muscles, some vessels

Question 16

Where is the origin of the efferent SNS pathways?

Answer 16

T1 - L3 (THORACOLUMBAR)
via intermediolateral region of the spinal cord and axons exit via ventral nerve roots.

22 paired sympathetic ganglia**

Question 17

What is ShyDrager

Answer 17

-Multiple system atrophy (aka)
-causes autonomic dysfunction and degeneration at the locus coeruleus, intermediolateral column of spinal cord, and peripheral autonomic nerves.

s/s reflect autonomic dysfunction - orthoHoTn, urinary retention, bowel dysfunction, cerebral hypoperfusion

HD instability!! use direct acting sympathomimetics

Question 18

What is the ratio of epi to NE from chromaffin cells?

Answer 18

80% and 20%

Question 19

Describe the HD management of a patient with pheochromocytoma?

Answer 19

ALPHA block before BETA (A before B)

alpha antagonist: phenoxybenzamine, phentolamine (non-selective) or doxazosin and prazosin (selective)

Question 20

Name four things that shift K+ intracellularly

Answer 20

alkalosis
beta 2 agonism
theophylline
insulin

Question 21

Name 4 things that shift K+ out

Answer 21

-acidosis
-cell lysis
-hyperosmolar
-sux

Question 22

What are the sensors in the baroreceptor reflex?

Answer 22

Carotid body = GPN
Aortic arch = Vagus N.

Question 23

Describe the reflex arc of Bainbridge

Answer 23

-Sensor = SA node, RV, pulmonary veins
-Afferent = Vagus
CONTROL = VASOMOTOR CENTER IN MEDULLA
-Efferent: Vagus
-Effector: SA node increases HR

*only reflex still present in denervated heart
*ex = autotransfusion during childbirth

Question 24

Describe the reflex arc of the Bezold-Jarisch reflex

Answer 24

sensor = cardiac mechanoreceptors and chemoreceptors
afferent = vagus
control center = vasomotor center in medulla
efferent = vagus
effector = SA node decreases HR and AV node decreases conduction velocity

Question 25

Describe the reflex arc of the OCR

Answer 25

afferent = long & short ciliary n. > ciliary ganglion > ophthalmic division V1 of CN 5 > gasserion ganglion control = vasomotor center in medulla efferent = vagus

Question 26

Primary concerns for glomus tumor removal

Answer 26

-VAE (grow close to carotid artery, aorta, middle ear) -Aspiration (d/t GPN involvement, vagus, hypoglossal) -Serotonin & Kallikrein release (bronchoconstriction, HTN, diarrhea) -Histamine & Bradykinin (Bronchoconstriction & hOTN)

Question 27

Low, Intermediate, High dose Epi

Answer 27

Low = 0.01 - 0.03 mcg/kg/m - B1 & B2 (increased CO, decreased SVR, increased pulse pressure) Intermediate = 0.03 - 0.15 mcg/kg/m - beta & alpha High dose = > 0.15 mcg/kg/m (alpha)

Question 28

Isoproteronol

Answer 28

Synthetic catecholamine that stimulates B1&B2 -may reduce CPP by reducing DBP -clinical indications: pacemaker, heart transplant, bronchoconstriction, cor pulmonale

Question 29

When should ephedrine NOT be used to treat hypotension

Answer 29

-Patient on MAOIs, cocaine -Denervated heart -Sepsis

Question 30

6 drugs selective for beta-1

Answer 30

Betaxolol Bisoprolol Atenolol Acebutolol Esmolol Metoprolol

Question 31

6 drugs non-selective for beta blockers

Answer 31

-Carvedilol -Labetalol (has ISA) -Nadolol -Pindolol -Propanolol (MSA) -Timolol

Question 32

What is the primary site of metabolism of the commonly used beta blockers?

Answer 32

-Liver -The two exceptions are atenolol (kidneys) and esmolol (nonspecific plasma esterases)

Question 33

Which beta blockers have local anesthetic properties? What is another name for this?

Answer 33

Membrane stabilizing properties (MSA) -Propanolol and Acebutolol

Question 34

What is intrinsic sympathomimetic activity? Which drugs exert this effect?

Answer 34

-BB that exert a partial agonist effect while simultaneously blocking other agnoistss that have a higher affinity for beta receptors -Labetalol -Pimolol -Acebutolol

Question 35

List 3 alpha antagonists. What is the MOA for each?

Answer 35

1. Phenoxybenzamine (noncompetitive) & Phentolamine (short acting) - alpha 1&2 2. Yohimbe - alpha 2 3. Prazosin - alpha 1