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Peripheral Nervous System. 1. PNS. Sensory (afferent) - receives info from senses Motor (efferent) - carry signals to muscles & glands - 2 subdivisions - somatic & autonomic. 2. Somatic. Somatic -voluntary (except reflexes, shivering, body posture & balance)
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PNS Sensory (afferent) - receives info from senses Motor (efferent) - carry signals to muscles & glands - 2 subdivisions - somatic & autonomic 2
Somatic Somatic-voluntary (except reflexes, shivering, body posture & balance) - carries signals from CNS to skeletal muscles - 31 pairs of nerves
Let’s Test the Somatic System… • How quickly (but accurately) can you complete the quiz maze?
Autonomic System • 2 subdivisions - sympathetic & parasympathetic • always active and opposing • works with endocrine to maintain homeostasis on involuntary processes (digestion, circulation, reproductive, smooth muscles, “normal” breathing…) 5
Sympathetic division predominates under stress, excitement, or physical activity • Parasympathetic predominates during quiet, low stress situations; “maintenance”
Pain & Painkillers • Pain = brain interpretation • Substantia gelatinosa (SG) = cells in grey matter of spine; send signals to injury & to the brain • brain signals pituitary & hypothalamus to release endorphins & enkephalins = pain killers • they block pain receptor sites
Classwork • Question for Quiz review Pg 529 2, 3 Pg 536 2, 3,4, 5,7,8,9 Pg 541 1, 3, 4,5,6 13