Chapter 13/14 Spine and PNS
Functions of Spinal Cord Function1: Connects PNS to Brain Sensory nerves run toward the brain Motor nerves run toward the body Function 2: Coordination of spinal reflexes through interneurons Integration
Spinal nerves Spinal nerves are in pairs serving right and left sides of the body C1-C8 (8 pairs) T1-12 (12 pairs) L1-L5 (5 pairs) S 1-S5 (5 pairs) Coccyx See colored handout of spine See colored handout of Dermatome
Why are spinal nerves mixed nerves Sensory nerves enter the spine via the dorsal root Motor nerves leave the spine via the ventral root The dorsal and ventral roots are joined at the spinal nerve Therefore the spinal nerve is part sensory and part motor Away from the spine the nerve splits into dorsal and ventral Rami which mixed just like the spinal nerve Dorsal rami contain sensory neurons and motor neurons of the back Ventral rami contain sensory and motor neurons of the limbs and abdomen
What is a plexus? The rami of spinal nerves are associated into plexuses that innervate certain regions of the body. The Cervical Plexus: Head, Neck and Shoulders The Brachial Plexus: Shoulders, Arms, Hands The Thoracic Plexus: Chest, Abdomen, Thighs, Knees, Calves The Sacral Plexus: Pelvis, Buttocks, Thighs, Feet
Reflexes Crash Course PNS
Types of Sensory Receptors
Types of Sensory Receptors
Autonomic Nervous System Sympathetic vs Parasympathetic divisions Fight or Flight – Sympathetic Rapid and all at once Thoracolumbar Short preganglionic axons and long postganglionic axons Rest and Digest- As time permits not all at once Craniosacral Long preganglionic axons and short postganglionic axons
Sympathetic Division
Parasympathetic Division Rest and digest
Neurotransmitters of Autonomic NS
Neurotransmitters
Cholinergic vs Adrenergic Nicotinic and Muscarine Alpha and Beta
Plexus
Rami
Somatic vs Autonomic pathways
Key pages from Chapter13 Page 486 Classification of receptors by Stimulus type, by location Page 503 there are 31 spinal nerve pairs know numbers/section Page 505 Innervation of specific body regions Roots, Spinal nerve, Rami, plexus Page 512 Dermatome Page 515 Components of a Reflex arc Page 516-518 Stretch and tendon reflexes, Knee jerk reflex
Key pages for Chapter 14 Pages 528-529 ANS vs SNS figure 14.2 Page 530 Figure 14.3 Page 532 Parasympathetic division Page 536 Sympathetic division Pages 537-538 Visceral reflex arcs Page 539 Cholinergic vs Adrenergic Receptors & Neurotransmitters Page 540-541 Effects Parasympathetic Division vs Sympathetic Division Page 542 Role of hypothalamus and brain stem