Ascending pathway Thermal pain receptor in finger to brain Response Thermal pain receptor in finger Afferent pathway Efferent pathway Ascending pathway Components of a reflex arc Receptor Afferent pathway Integrating center Effector organs to brain Triceps (exensor) Biceps (flexor) (spinal cord) Effector organs Stimulus = Stimulates = Inhibits = Synapse = Excitatory interneuron = Inhibitory interneuron
Brain Stem Cervical Spinal Cord PS Sym A Lumbar Spinal Cord Sacral Spinal Cord Thoracic Spinal Cord
Sympathetic ganglion chain Terminal ganglion Cranisosacral parasympathetic nerves Effector organs: Cardiac muscle Smooth Most exocrine glands and some endocrine = Sympathetic system = Parasympathetic system = Cell body = Axon terminal Sympathetic ganglion chain Terminal ganglion Spinal cord Thoracolumbar Sympathetic ACh NE = Preganglionic fiber = Postganglionic fiber ACh = Acetylcholine NE = Norepinephrine E = Epinephrine E, NE Collateral Blood
Postganglionic neuron Reproductive system Urinary system Preganglionic neuron Postganglionic neuron Reproductive system Urinary system Sympathetic trunk Vasomotor fibers to lower extremity To peripheral blood vessels (vasomotor) Hair folicle muscle (pilomotor) Sweat glands (sudomotor Eye Blood vessels of head Glands associated with eye, nasal cavity and oral cavity Respiratory system Circulatory system Digestive system Celiac ganglion Descending autonomic pathways Hypothalamus Superior cervical ganglion Inferior mesenteric ganglion Superior Kidney Adrenal
S2 S3 S4 Descending autonomic pathways Accessory oculomotor Nucleus (Edinger-Westphal) Salivatory nuclei Superior Inferior Dorsal vagal nucleus Preganglionic neuron Postganglionic neuron Urinary system Reproductive system Digestive system Circulatory system Respiratory system Blood vessels and glands of head Eye and lacrimal gland Hypothalamus Ciliary ganglion Submandibular ganglion Otic ganglion S2 S3 S4
+ EXOCRINE GLANDS + SMOOTH MUSCLE OF G.I. TRACT – HEART RATE + SWEAT GLANDS – BLOOD VESSELS (Some) + HEART SMOOTH MUSCLE + SPLEEN OF: + BLOOD VESSELS – G.I. TRACT (Most) – LUNGS SKELETAL MUSCLE POSTGANGLIONIC NERVES: GANGLION: PREGANGLIONIC A U T O N O M I C N E R V O U S S Y S T E M PARASYMPATHETIC SYMPATHETIC SOMATIC CHOLINERGIC NERVES ADRENERGIC CHOLI- NERGIC ALL EFFECTOR ORGANS: Adrenal Medulla ACh NOREPI C E N T R A L N . S . EPI Via the Blood NERVES ACh ACh
Vm (mV)
Sympathetic preganglionic fiber postganglionic Acetylcholine Norepinephrine Epinephrine Spinal cord Adrenal medulla Blood Target organs fiber Target organs
inactive A-kinase regulatory subunit catalytic complex of cyclic AMP and regulatory subunits active catalytic cyclic AMP
cAMP protein kinase enzyme X products of 1 molecule of signaling ligand receptor protein each activated receptor protein activates many molecules of G protein, each of which in turn activates an adenylate cyclase molecule each activated adenylate cyclase molecule generates many cAMP molecules each cAMP molecule activates 1 molecule of protein kinase each kinase moleculle phosphorylates and thereby activates many copies of enzyme X each copy of enzyme X produces many molecules of product cAMP AMPLIFICATION G protein acivated adenylate cyclase protein kinase enzyme X products of
GTP
Phosphatidylinositol Polyphosphoinositides Ptdins Ptdlins4P Ptdins4,5P2 Ins 1,4,5P3 AGONIST Diacylglycerol d a c b
Classification of Noradrenergic Receptors Linked to Second-messenger Systems Type Second-messenger system Gene family Location β1 Linked to stimulation of adenylyl cyclase β2 Linked to stimulation of adenylyl cyclase α1 Linked to phospholipase C mobilization of intracellular Ca2+ α2 Linked to inhibiion of adenylyl cyclase Cerebral cortex, cerebellum Superfamily of G-protein Brain, blood vessels, spleen coupled receptors Presynaptic nerve terminals throughout the brain
MUSCARINIC ACETYLCHOLINE RECEPTORS Nomenclature M1 M2 M3 M4 M5 Predominant Effectors IP3/DG cAmp K+ channel
inactive phosphorylas kinase active inactive A-kinase active A-kinase cAMP GLYCOGEN GLUCOSE 1-PHOSPHATE GLYCOLYSIS