ANS function master

alpha 1 receptors

ADRENERGIC (EPI/NOREPI)

SMOOTH MUSCLE - CONTRACTION

Vasculature of organs

Eye - radial muscle MYDRIASIS

Sphincters - GI/GU

Seminal Vesicles - penis

Gq pathway -> inc IP3 and DAG -> act MLCK

Major Functions: ↑ Ca2+, causes contraction, secretion

alpha 2 receptors

ADRENERGIC (EPI/NOREPI)

Pre-Synaptic Neurons (Nerve Endings)

→ inhibit release of NE

Gi -> dec in cAMP -> inc in K+ efflux

Major Functions: ↓ Transmitter release (nerves), causes contraction (muscle)

beta 1 receptors

ADRENERGIC (EPI/NOREPI)

CONTRACTION/INCREASE

Cardiac cells -> inc HR and force (SA node and Ectopic Pacemakers)

Kidneys -> inc renin (juxtaglomerular apparatus)

Eye -> inc Aq humor from epithelial (25%)

Gs -> inc in cAMP

beta 2 receptors

ADRENERGIC (EPI/NOREPI)

SMOOTH MUSCLE - RELAXATION

Walls - GI/GU

Bronchi

Vasculature - Skeletal Muscle and Heart

Uterus

INCREASES

Liver - Gluconeogenesis/Glycogenolysis

Skeletal Muscle - Na/K Pump

Eye- aqueous humor production (75%)

Gs -> inc cAMP -> inhibit MLCK

muscarinic 1 receptors

CHOLINERGIC (ACH)

NEURONS (Nerve endings)

- Activates Myenteric Plexus

Gq -> inc IP3 and DAG

muscarinic 2 receptors

CHOLINERGIC (ACH)

NEURONS

SMOOTH MUSCLE

HEART DECREASE (atrial contractility and SA node)

- rate and force

Gi -> dec cAMP

muscarinic 3 receptors

CHOLINERGIC (ACH)

SMOOTH MUSCLE CONTRACTION

Eye - sphincter and ciliary - MIOSIS

Bronchi

Walls - GI/GU

Uterus

Gq -> IP3 + DAG

SMOOTH MUSCLE RELAXATION

Seminal - BV of penis

Sphincters - GI/GU

Gq -> NO release

SECRETION INCREASE

Glands - gastric

beta 3 receptors

CHOLINERGIC (ACH)

Adipose cells

- ↑ lipolysis

Gs → ↑ cAMP

dopamine 1 receptor

CHOLINERGIC (ACH)

Smooth Muscle

- Relax renal vascular smooth muscle (vasodilation)

Gs → ↑ cAMP

nicotinic N receptors

CHOLINERGIC (ACH)

Autonomic ganglion

- Na+-K+ ion channel

→ Depolarizes, evokes action potential

nicotinic M receptors

CHOLINERGIC (ACH)

Neuromuscular Junction

- Na+-K+ ion channel

→ Depolarizes, evokes action potential

Gs pathway

Gs →

adenylate cyclase →

↑ cAMP →

activated PKA →

↑ protein phosphorylation

Gs pathway in smooth muscle

NE binds B2R

→ Gs →

↑ adenylate cyclase →

↑ cAMP →

activated PKA →

→ phosphorylates MLCK

→ inactive MLCK

= RELAXATION

Gs pathway in the heart

NE binds B1R at the SA node →

Gs →

adenylate cyclase →

↑ cAMP →

activated PKA →

→ phosphorylates VG-Ca channels

→↑ intracellular Ca

→ phosphorylates RYR on sarcoplasmic reticulum

→↑ intracellular Ca

→ ↑ contraction, force, and rate

Gq pathway

Gq →

PLC →

cleaves lipid phosphoinositide bisphosphate (PIP2) →

↑ IP3 → ↑ Ca

↑ DAG → ↑ Protein kinase C

= increased protein phosphorylation/activation of calcium binding proteins

Gq pathway in SM contraction

binding of ACH to M3 OR NE to A1 →

Gq →

PLC →

cleaves lipid phosphoinositide bisphosphate (PIP2) →

↑ IP3 →

↑ Ca →

calmodulin →

activate MLCK →

MLCK phosphorylates myosin

= CONTRACTION

Gq pathway of SM relaxation

ACH binds M3R on intermediate cells→

↑ NO →

NO diffuses into muscle cells →

↑ GC →

↑ cGMP →

activates PKG →

1.

K+ channels opening →

↑ K+ efflux →

hyperpolarization

= RELAXATION

2.

activate MLCK- phosphatase →

MLCK dephosphorylated

= RELAXATION

Gi pathway

Gi →

↓ adenylate cyclase →

↓ cAMP →

↓ PKA →

↓ protein phosphorylation

Gi pathway in the heart

ACH binds M2 at the SA node→

G(beta-gamma) freed from Gi alpha →

Gby →

activates VG K+ channels →

↑ K+ efflux →

hyperpolarization (pacemaker cells (SA)) →

↓ membrane potential →

↓ SA pacemaker activity

= DECREASE rate/force

Gi pathway of autoregulation

NT binds pre-synaptic receptor (M2 or A2) →

Gi →

↓ adenylate cyclase →

↓ cAMP →

↓ PKA →

↓ Ca entry →

↓ in synaptic vesicle release of NT

what systems are dominated by parasympathetic innervation?

Heart, Lungs, GU, GI, Eye, secretions

- mucosal secretions, congestion, and bronchoconstriction

what systems are dominated by sympathetic innervation?

vasculature