Neurophysiology (3).pptx

Neurophysiology College of Pharmacy  1st Order Neurons of the lateral spinothalamic tract for pain transmission. C fibers use Substance P as the neurotransmitter at the dorsal horn synapse. A-delta fibers use glutamate as the neurotransmitter at the dorsal horn synapse....

Neurophysiology College of Pharmacy  1st Order Neurons of the lateral spinothalamic tract for pain transmission. C fibers use Substance P as the neurotransmitter at the dorsal horn synapse. A-delta fibers use glutamate as the neurotransmitter at the dorsal horn synapse. Prostaglandi n E2 (PGE2) Steroids (i.e., prednisone) Prevent phospholipase A2 From being cleaved off the Phospholipids in the cell Prostaglandins are Membrane. Hormone-like lipid molecules That promote Excitability/ NSAIDS prevent depolarization COX of peripheral Enzyme from nociceptors. converting Arachidonic Acid to Prostaglandins. Descending Pain Modulation Pain Transmission – Spinal Cord Opioid Action to suppress pain Presynaptic membrane inhibits Ca influx inhibiting glutamate release. Postsynaptic enhance Cl- influx and K+ efflux (hyperpolarizes neuron) Pain intensity from the frequency of action potentials. Opioid receptors bind at periaqueductal gray to enhance descending inhibition  Severed Carotid Artery and Jugular Vein Former army medic pinched off vessel until doctors stabilized wound. 11 fans fainted, 2 had MI, 3 players vomited on the ice. Special Sensory Vision Right half of both visual fields end up in the left visual cortex Cornea and Lens Avascular – blood vessels would impede function. Still have cells that receive nutrients from the aqueous humor Picture – corneal revascularization (a pathologic condition) Causes blindness secondary to optic nerve neuropathy/damage  Open and Cholinergic Agonist closed Angle Parasympathomimetic Agent Muscarinic Receptor Agonist Glaucoma Tx Pilocarpine – miosis and ciliary muscle contraction favors drainage (eye drops) Emergency Otherwise too many side effects (CNS, sweating, salivation)  Apraclonidine Open Angle Glaucoma Treatment Brimonidine (bruh mow nuh deen) Alpha 2 agonist Eye Drops Sympatholytic Properties Reduces intraocular pressure by reducing aqueous humor production Reduces NE release on beta 1 receptors (ciliary body) Reduce IOP 20 – 25%  Timolol Open Angle Glaucoma Treatment Beta Blocker; beta adrenergic antagonist (eye drops) Decrease aqueous humor production by blocking beta 1 receptor on ciliary epithelium Atropine Anticholinergic/Muscarinic Antagonist that induces mydriasis (see left) blocking Ach (oculomotor nerve, CN III) from binding to M3 receptors sphincter pupillae Tropicamide used for eye exams due to rapid onset and short duration.  Pupillary Light Reflex 1. Optic Nerve to pretectal nucleus (dorsal midbrain) 2. To both Edinger- Westphal Nuclei (parasympathetic preganglionic neurons in oculomotor nerve) 3. Ciliary Ganglion (post ganglionic neurons) to sphincter pupillae where Ach binds to M3 receptors  Why do Pupillary Light Reflex? Potential causes of Checks/Test damage Sensory nerve – Optic Nerve (II) Tumors Functionality of midbrain Infarction Motor nerve – Oculomotor Nerve (III) Aneurysm Brain dead - loss of brainstem Medications (Barbiturates) reflexes (nonreactive fixed and midpositon) Brainstem strokes Amoxicillin – otitis media Treatment for Parkinson’s Disease