Nervous system

Nervous system

1. Autonomic nervous system

   • Sympathetic nervous system
     • Fight or flight
       • Mydriasis
       • Increased heart rate (chronotropic)
       • Increased force of myocardial contraction (inotropic)
       • Vasoconstriction (usually)
       • Bronchodilation
       • Decreased gastric motility
       • Increased urinary sphincter tone (less peeing)
       • Glycogenolysis and gluconeogenesis
     • Acetylcholine
       • Noradrenaline/adrenaline
         • G-protein coupled receptors
           • alpha-adrenoceptors
             • alpha-1
               • PLC
                 • DAG
                   • Protein kinase C
                     • opens Ca channels to let Ca inside cell
                 • IP3
                   • causes release of intracellular calcium
                     • Constriction
               • widely distributed
               • Gq
             • alpha-2
               • Gi, Go
               • Inhibit adenylyl cyclase
                 • Decreases cAMP
                   • Inhibits voltage-gated calcium channels
                   • Activates Ca-dependent K channels
                     • Constriction
           • beta-adrenoceptors
             • beta-1
               • Gs
               • Stimulates adenylyl cyclase
                 • Increases cAMP
                   • Increases protein kinase A
                     • Constriction
             • beta-2
               • Gs, Gi
               • Stimulate or inhibit cAMP
                 • VSM relaxation
                 • Bronchodilation
                 • decrease histamine release from mast cells
             • beta-3
             • beta-4
     • Diffuse innervation
   • Parasympathetic nervous system
     • Rest and digest
       • Decreased heart rate
       • Decreased force of contraction
       • Increased GI motility and secretion
       • Contraction of detrusor (peeing)
       • Miosis
       • Bronchoconstriction
       • Decreased bronchosecretion
     • Acetylcholine
       • Acetylcholine
         • Muscarinic receptors
           • G-protein coupled receptors
           • M1
             • Ganglia
               • Activate PLC -> IP3 + DAG
           • M2
             • Heart
               • Inhibit adenylyl cyclase -> opens K channels
           • M3
             • Smooth muscles and glandular tissue
               • Activate PLC
           • M4
             • CNS
               • Inhibit adenylyl cyclase
           • M5
             • Activate PLC
       • Nicotinic receptors
         • Ligand-gated ion channels
           • Increases permeability to Na and K
             • Na in, K out
         • Nn
           • ganglia
         • Nm
           • skeletal muscle (somatic efferent NS)

2. Somatic nervous system