Lecture 4

Card Set Information

Lecture 4
2011-11-04 22:20:41
Anatomy Physiology ANS

Lecture 4: intro to autonomic pharmacology: Anatomy and physiology of the ANS
Show Answers:

  1. Sensory neurons
    afferent (into CNS)
  2. Motor Neurons
    efferent (instructions from CNS)
  3. Effects of Sympathetic Division
    "fight or flight"

    • increase HR
    • increase cardiac contractility
    • vasodilate skeletal muscle (increase blood flow)
    • vasoconstriction in viscera/skin (decrease blood flow)
    • Bronchodilation
    • Inhibit GI and urinary tracts
    • Sweating
    • Piloerection
    • Mydriasis (dilation)
    • Accomodation for far vision
  4. Effects of Parasympathetic Division
    "rest and digest"

    • -decrease HR
    • -decrease cardiac contractility
    • -bronchoconstriction
    • -Stimulation of GI and urinary tracts
    • -miosis (constriction)
    • -accomodation for near vision
  5. Systems only under Sympathetic control
    • -most blood vessels
    • -sweat glands
    • -pilomotor muscles
    • -adrenal medulla
  6. Systems predominantly controlled by Parasympathetic Division
    • -GI tract
    • -Urinary tract
    • -eye
  7. Adrenal Medulla
    • -secretes EPI and small amounts of NE into blood
    • -activated during 'fight or flight'
    • -innervated by thoracolumbar cord
  8. Termination of ANS NT actions
    • 1. Enzyme inactivation (ACh by AChE)
    • 2. Reuptake by presynaptic fiber (NE uptake by NET)
    • 3. Diffusion away from junction
    • 4. Uptake by extraneuronal sites
  9. Cholinergic Receptors
    • 1. Nicotinic (ligand gated ion channels)
    • -NN: on all ANS post-ganglionic neuron somas
    • -NM: on SKM

    • 2. Muscarinic (GPCR)
    • -M1 (Gq): on somas of postganglionic neurons in ANS ganglia
    • -M2 (Gi): on heart
    • -M3 (Gq): on smooth muscle and glands, on VSM (non innervated)
  10. Adrenergic Receptors
    • 1. alpha
    • -a1 (Gq): smooth muscle, eye, pilomotor, sphincters of GI and urinary tract
    • -a2 (Gi): a little on smooth muscle, in the CNS, on sympathetic and parasympathetic postganglionic fibers

    • 2. beta
    • -b1 (Gs): heart (SA, AV node, atria, ventricles), kidney (granular cells)
    • -b2 (Gs): smooth muscle (vascular, bronchial, GI, ciliary muscle)