ANS

Question 1

Gq receptor

Answer 1

↑ Phospholipase C → ↑ IP3, DAG, Ca2+

• A1
• M1, M3, M5
• V1
• H1

Question 2

Gi receptor

Answer 2

↓ adenylate cyclase → ↓ cAMP

• A2
• M2, M4
• D2

Question 3

Gs receptor

Answer 3

↑ adenylate cyclase → ↑ cAMP

• B1, B2
• D1
• V2
• H2

Question 4

B1 receptor

Answer 4

• myocardium, conduction system → ↑ HR, contractility, conduction speed
• kidneys → renin release

Question 5

B2 receptor

Answer 5

Bronchial tree → bronchodilation

Myocardial and skeletal muscle vascular beds → vasodilation

Ciliary muscle relaxes (far vision)

Gallbladder and ducts relax

Pancreas islet beta cells release MORE insulin

Liver ↑ serum glucose

Uterus relaxes

Bladder: destrusor relaxes

Question 6

A1 receptor

Answer 6

Vasoconstriction (arteries > veins, but both)

EYES: radial muscle (iris) → contracts → MYDRIASIS

GI: sphincters contract

LIVER: serum glucose ↑

UTERUS: contracts

BLADDER: trigone + sphincter contract

Sweat glands ↑ secretion

Question 7

A2 receptor

Answer 7

• vasoconstriction (veins > arteries, but both)
• Kidney: renal tubules → ADH inhibition → DIURESIS
• pancreas: Islet beta cells ↓ insulin release → hyperglycemia
• Salivary glands: dries out
• antishivering
• promotes platelet aggregation

Question 8

SNS receptors in kidneys

Answer 8

A2 (renal tubules, diuresis via ADH inhibition)

B1 (↑ renin release)

Question 9

DA receptors

Answer 9

-renal and mesenteric vasodilation

Question 10

M2 receptors

Answer 10

-HEART: myocardium, conduction system: → ↓ HR, contractility

Question 11

M3 receptor

Answer 11

BRONCHIAL TREE → bronchoconstriction

Question 12

Phosphodiesterase III

Answer 12

• metabolizes cAMP to AMP which basically “turns off” a specific protein kinase, the cell is no longer instructed to perform that specific function.
• If you inhibit PDEIII, the “turn off” mechanism is inhibited and it indirectly ↑ cAMP, maintaining the protein kinases in the “turned on” state.

Question 13

Lusitropy

Answer 13

Increasing the rate of relaxation by speeding up the return of calcium to the SR

Question 14

Adrenal medulla

Answer 14

80% epi, 20% norepi

At rest secretes:

0. 2mcg/kg/min epi
1. 05mcg/kg/min norepi

Remember catecholamines in the bloodstream last 5-10X longer than they do in the synaptic cleft

Question 15

Baroreceptor reflex monitoring locations and innervation: AFFERENT

Answer 15

1. ) carotid sinus —> carotid sinus nerves (nerves of Hering) + CN IX (glossopharyngeal) converge to send afferent impulses to nucleus tractus solitarus in the medulla
2. ) Transverse aortic arch sends afferent signal via vagus nerve.

Question 16

Baroreceptor reflex location and innervation: EFFERENT

Answer 16

Vasomotor center in medulla and pons

Afferent traffic to nucleus tractus solitarus stimulates rostral ventrolateral medulla and intermediolateral nucleus.

SNS output is ↓ via inhibition of T1-T4 cardio accelerator nerves, neural network to vasculature, and at the same time a reciprocal rise in vagal tone. The net effect is ↓ HR, inotropy, and SVR.

Question 17

Clinical examples of baroreceptor reflex

Answer 17

CEA: carotid sinus may cause bradycardia

Mediastinoscopy: pressure from scope on transverse aortic arch may cause bradycardia

Phenylephrine!

Question 18

Drugs that preserve baroreceptor reflex

Answer 18

TPL, etomidate, hydralazine, SNP, NTG, norepi

Question 19

ANS receptors: eye

Answer 19

A1: contraction radial muscle → mydriasis
B2: relaxation ciliary muscle → far vision

Question 20

ANS receptors: pancreas

Answer 20

A2: ↓ insulin release
B2: ↑ insulin release

Question 21

ANS receptors: liver

Answer 21

A1: ↑ serum glucose
B2: ↑ serum glucose

Question 22

ANS receptors: uterus

Answer 22

A1: contraction
B2: relaxation

Question 23

ANS receptors: bladder

Answer 23

A1: trigone + sphincter contraction (facilitates urination)
B2: detrustor relaxation (facilitates retention/storage)

Question 24

Vasopressin receptors

Answer 24

V1: Gq
V2: Gs

Question 25

Histamine receptors

Answer 25

H1: Gq
H2: Gs

Question 26

How do preganglionic fibers get from spinal cord to SNS chain?

Answer 26

SNS preganglionic fibers exit SC via ventral nerve roots

Enter SNS chain via white rami

Question 27

Steps of norepi synthesis

Answer 27

Tyrosine —(tyrosine hydroxylase) → DOPA → Dopamine → Norepi → Epi

Tyrosine hydroxylase is the rate limiting step

Question 28

Where is the origin of efferent PNS pathways?

Answer 28

Craniosacral

• CN 3,7,9,10
• S2-S4

Question 29

What drugs can be given to augment HR in a patient who got a heart transplant?

Answer 29

Epi, isoprel, glucagon

Question 30

Glomus tumors

Answer 30

Originate from neural crest cells, tend to grow in neuroendocrine tissues that are near carotid, aorta, CN IX, and middle ear. Usually benign
→ release vasoactive substances HTN or hypo (NE, 5HT, histamine, bradykinin)
→ octreotide can be helpful for carcinoid-like sx
→ CN dysfunction (IX, X, XII) can ↑ aspiration risk, a/w obstruction
→ resection of a glomus that invaded IJ vein ↑ air embolism risk

Question 31

Low, medium, and high dose epi compare/contrast

Answer 31

Low dose (0.01-0.03mcg/kg/min) → non selective beta. B1 ↑ HR/contractility, B2 → skeletal muscle vasodilation ↑ CO ↓ SVR

Intermediate dose (0.03-0.15mcg/kg/min) → mixed alpha beta

High dose (>0.15) → alpha prevails, BP ↑, tachyarrythmias

Question 32

4 indications for isopreterenol

Answer 32

Chemical pacemaker if atropine not working
Heart transplant
Bronchoconstrition
Cor pulmonale

Question 33

B1 selective drugs

Answer 33

Atenolol, Esmolol, Metoprolol, Bisoprolol Betaxolol

Question 34

Non selective beta agonists

Answer 34

Propranolol, Labetolol, Carvedilol, Nadolol, Pindolol, Timolol

Question 35

Alpha antagonists

Answer 35

Phenoxybenzamine: long acting nonselective noncompetitive antagonist A1+A1
Phentolamine: short acting nonselective competitive antagonist A1+A2

Prazosin selective A1 antagonist