Anatomy PDF

Chapter 13: Structure Architecture of X-Sectional View of the Spinal Column ○ The Posterior Root is the Dorsal Root Root contains Sensory neurons Spinal (Dorsal) Root Ganglion also has Sensory neurons ○ The Anterior Root is the Ventral Root...

Chapter 13: Structure Architecture of X-Sectional View of the Spinal Column ○ The Posterior Root is the Dorsal Root Root contains Sensory neurons Spinal (Dorsal) Root Ganglion also has Sensory neurons ○ The Anterior Root is the Ventral Root Root contains motor neurons ○ Motor Neurons Efferent signals that send out info to the CNS These neurons go down the spinal cord ○ Sensory Neurons Afferent signals that take in info from the CNS These neurons go up to the brain ○ Reflex Arc Sensory Receptor Sensory Neuron Ino Processing in CNS Motor Neuron Effector Chapter 16: PNS and SNS General architecture of the sympathetic and parasympathetic nervous systems The Sympathetic System has: The Parasympathetic System has: Origin is the Thoracolumbar T1-L2 Segments Origin is Craniosacral Pre-gang is short, myelinated Pre-gang is long, myelinated Post- gang is long, non-myelinated Post-gang is short, non-myelinated Sympathetic is increase and dilate Parasympathetic is decrease and constrict Pre-gang is cholinergic nicotinic Pre-gang is cholinergic nicotinic Post-gang is adrenergic Post-gang is cholinergic muscarinic The general plan of synaptic transmitters - THE MANTRA cholinergic ○ Releases Acetylcholine as neurotransmitter ○ Inhibits/Excites based on if nicotinic or muscarinic ○ Goes into all pregang neurons in both systems, and postgang in PNS nicotinic receptors Cholinergic receptor activated by ACh and Nicotine Present at pre-gang neurons in both systems Always excitatory muscarinic receptors Cholinergic receptor activated by ACh and Muscarine Found on target organs in PNS and SNS Can be excitatory/or inhibitory depending on organ and receptor type adrenergic ○ Releases Norepinephrine or Epinephrine as neurotransmitter ○ Usually exciting, but can inhibit based on alpha or beta receptors ○ Most post-gang Neurons of the SNS Pre-Gang neurons: Transmit ACh to receptor Nicotinic Post-Gang neurons (PNS): Transmit ACh to muscarinic receptors Adrenal Medulla (SNS): Releases Epi and Norepi into bloodstream AUTONOMIC TONE Autonomic motor neurons has resting level of activity w/o stimulation ○ Never increases or decreases activity since nerves maintain background level of activity. ○ Significant to dual innervation sites, more important where dual innervation doesn’t happen DUAL INNERVATION Autonomic plexuses are nerve networks in thoracic and abdominopelvic cavities ○ Formed by SNS Post-gang and PNS Pre-gang fibers ○ Travels along blood and lymphatic vessels that supply visceral organs Heart Receives Dual Innervation ○ ACh releases by PNS slows heart rate ○ NE released by SNS accelerates heart rate ○ SMALL AMTS are released continuously, producing Autonomic Tone ○ PNS dominates during rest. ○ During moments of crisis, SNS stimulates and PNS inhibits ANS 1 & 2: Feature Adrenergic Dopaminergic Serotonergic Neurotransmitter NE & E Dopamine Serotonin Receptors Alpha and Beta D1-D5 5-HT1 thru 5-HT7 Mechanism G-protein coupled cAMP, D1 & D5 GPCRs and ionotropic signaling, cAMP increase cAMP, D2,3,4 decrease cAMP Effects Excitatory or inhibitory Excitatory or inhibitory Excitatory or inhibitory Roles Stress response, Renal blood flow, Mood, gastrointestinal energy mobilization motor control motility EPINEPHRINE PATHWAY Tyrosine → Dihydroxyphenylalanine → Dopamine → Norepinephrine → Epinephrine Enzymes (in order of rxn): Tyrosine Hydroxylase → DOPA Decarboxylase → Dopamine-B-Hydroxylase → Phenylethanol-amine-N-methyl-transferase HISTAMINE PATHWAY Histidine → Histamine Enzymes (in order of rxn): Histidine Carboxylase SEROTONIN PATHWAY Tryptophan → 5-Hydroxytryptophan → Serotonin (5-Hydroxytryptamine) Enzymes (in order of rxn): Tryptophan-5-hydroxylase → Aromatic L-amino acid decarboxylase ACETYLCHOLINE PATHWAY Choline → AcetylCholine Enzymes (in order of rxn): Acetyl CoA MAJOR DRUGS Acetaminophen (Paracetamol) ○ Affects the CNS ○ Target: Prostaglandins, Anandamide ○ Site of Action: Brain and spinal cord Benzedrex ○ Affects the adrenergic and dopaminergic synapses ○ Target: NE and dopamine ○ Site of Action: Nasal mucosa and CNS at higher doses