KINE3440 Lecture 1: Neural Transmission PDF

Direct vs indirect control of movement - Direct is sensation = movement - Indirect is sensation = brain cognition = movement White matter vs grey matter Type White matter Grey matter ------------- ----------------------...

Direct vs indirect control of movement - Direct is sensation = movement - Indirect is sensation = brain cognition = movement White matter vs grey matter Type White matter Grey matter ------------- ------------------------------------------------------------------------ ------------------------------------------------------ Myelinated? Yes No In PNS Tract Nucelus In CNS Nerve Ganglion Function Communication between different brain regions and brain to spinal cord Processing info, sensory perception, decision-making Functional nerve divisions - Somatic - Spinal cord to body - Voluntary - Automatic - Spinal cord/brainstem to smooth muscles - Regulatory - Cranial - Brainstem to head/neck - Special senses - Voluntary PNS Concepts - Spinal nerves - Spinal roots origin (31 pairs) - Plexus - Mixed motor/sensory - Cranial nerves - Brainstem origin (12 pairs - Some sensory - Some motor - Some mixed CNS Concepts - Tract vs nucleus - Transmission vs control - Decussation - Crossing midline Brainstem - Medulla - Arousal, respiration - Pons - Posture, balance - Midbrain - Orienting Cerebellum - Motor function - Cognitive functions Cerebrum - 2 hemispheres - Grey and white structure Cortex - Brain lobes - Complex functions - Sensory, motor, etc Meninges - Surround CNS - Dura mater, pia mater, arachnoid mater Stem cells - Progenitor cells - Undifferentiated - Can grow to neurons if pushed Glial cells - Macroglia - Astrocytes - Oligodendroglia - Schwann cells - Microglia - Phagocytes (immune system) Local Potential - Where - Dendrites or soma - What - Excitatory- depolarize - Inhibitory- hyperpolarize - How - Ion channels open to allow either more Na (depolarize) or K/Cl (hyperpolarize) Integration of action potential - What - Triggered response - Action potential - Where - Voltage-gated channels (axon hillcock most important) - How - Opening/closing of ion channels Myelinated axons - Saltatory conduction - Fast, low energy cost - Process 1, under myelin - No voltage-gated ion channels - Passive current flow - Process 2, nodes of ranvier - Voltage-gated ion channels - Action potentials Demyelinated axons - Exposed axon - Acute - No voltage-gated channels - No insulation - Chronic - Voltage-gated channels develop - Becomes like unmyelinated Unmyelinated axons - One component - Voltage-gated ion channels - Action potentials along entire axons - High energy cost Pre-synaptic neurotransmitters - Synthesized in soma - Release - Voltage gate Ca channels - Action potentials - Diffusion to post synaptic membrane Post synaptic NT effects - Metabotropic receptors - G-protein activation - Can produce diverse effects Acetylcholine - Major role in PNS - Neuromuscular junction - Autonomic nervous system - Some role in CNS Glutamate - Primary excitatory NT in CNS - Plasticity - Excitotoxicity GABA - Primary inhibitor NT in CNS - Clinical features