PHIS 206 Lecture Notes - Lecture 6: Central Nervous System, Motor Neuron, Somatic Nervous System
2 May 2018
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Lecture 6: Intro to CNS
CNS Nutshell
• Check diagram on slide
Organization
• Central Nervous System - (CNS)
o Brain and Spinal Cord
• Peripheral Nervous System - (PNS)
o Nerve fibers that travel from the periphery to the CNS
▪ afferent division (carries information toward the brain)
• Sensory stimuli
• Visceral stimuli
o Nerve fibers that travel from the CNS to the periphery
▪ efferent division (carries information away from the brain)
• Somatic nervous system and autonomic nervous system
• Enteric Nervous System (ENS)
o Controls muscular activity and secretions of digestive organs
o Kinda like a brain in your gut?
Efferent Division Breakdown
• Somatic Nervous System
o Also known as somatic motor system → controls skeletal muscles movement
• Autonomic Nervous System - ANS
o Also known as visceral motor system → controls activity of smooth muscle of
organs, cardiac muscle of heart, and glands
o These are things that happen without us having to think about. Automatic, self
working, nervous system
ANS Breakdown
• Two divisions
o Sympathetic Nervous System → fight or flight
o Parasympathetic Nervous System → rest and digest (or feed and breed)
• ANS also has some overlying control of ENS
• They oppose each other
• Digestive system can survive on its own o:
Players
• Neuron - nerve cell - nerve fiber → somewhat synonymous
• Classes of Neurons
o Afferent → to CNS
o Efferent → from CNS
o Interneurons → within CNS
• Glia
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Players: glia, neuron - nerve cell - nerve fiber somewhat synonymous, classes of neurons, afferent to cns, efferent from cns. Interneurons within cns: glial cells (astrocytes, oligodendrocytes, schwann cells, microglia, ependymal cells) provide physical, metabolic, and functional support to neurons, support the nervous system, it is everything that"s not a nerve. Protection and nourishment: protective layers, cranium/vertebral column, meninges, cerebrospinal fluid (csf, blood-brain barrier (bbb) Meninges: three layers of membranes wrapping the brain and spinal cord (outside going in, dura mater, arachnoid mater, pia mater. Parts of brain: forebrain (diencephalon & cerebrum, diencephalon (thalamus & hypothalamus, cerebrum (cerebral cortex and basal nuclei) Overall functions: cerebral cortex, sensory perception, voluntary control of movement, language, personality traits, basal nuclei. Cerebral cortex: left/right hemispheres (connected by corpus callosum, outer gray matter (gray matter that does the thinking/processing) Inner white matter (because myelin is white, carries info back and forth)
