1. Peripheral Nervous System Sections 14 and 15 READ TONIGHT!!!

2. General Info of PNS All nerves that branch off the CNS and connect to other body parts. Cranial nerves – 12 pairs Spinal nerves – 31 pairs Functions: To receive stimulus input and send to CNS. To relay the response from the CNS to the appropriate effector organ.

3. Nerve Anatomy of the PNS

5. Cranial Nerves Of the 12 pairs, here are some important ones to know: #1 – Olfactory = smell afferent #2 – Optic = vision afferent #8 – Vestibulocochlear = hearing/balance afferent #10 – Vagus = parasympathetic regulation of heart, lungs, BV, digestive tract

6. Peripheral Nervous System PNS Sensory (Afferent) Somatic Skin and special senses Visceral Motor (Efferent) Somatic (Voluntary) Skeletal Muscles Autonomic (Involuntary) SympatheticParasympathetic

7. Motor: Somatic nervous system –All voluntary or conscious activities –Nerves connect to skeletal muscles –Thick myelination, fastest impulses –Pathways have one motor neuron to muscle cells. (no synapses with other neurons outside CNS) –Neurotransmitter: Acetylcholine

8. Autonomic nervous system -All involuntary or unconscious activities. -Maintains internal environment -Nerves connect to cardiac, smooth muscle or glands -Pathways have two neurons synapsing at a ganglia before effector. -1 st neuron is lightly myelinated; 2 nd neuron is unmyelinated. -Neurotransmitters: Acetylcholine or Norepinephrine -Two divisions counterbalance each other: Sympathetic and Parasympathetic

9. Sympathetic prepares for energy-expenditure, excitement or stressful situations "fight" or take "flight“. Nerve fibers originate from the thoracic and lumbar regions of spinal cord. Short Pre and Long postganglionic fibers

10. Parasympathetic Stimulated during calm and relaxing situations "rest" and "digest". Nerve fibers originate from the brain and sacral region. Long preganglionic fibers and short post

14. Which pathway is responsible here? Sympathetic or Parasympathetic

16. Division of the ANS are distinguished by: 1.Unique origin sites a. Sacrocranial vs. Thoracolumbar 2. Different lengths of their fibers a. Preganglionic (long – P, short – S) b. Postganglionic (long – S, short – P) 3.Location of their ganglia a. P – close to effector b. S – close to spinal cord