Question Answer
12 pairs of cranial nerves Olfactory 1, Optic 2, Oculomotor 3, Trochlear 4, Trigeminal 5, Abducens 6, Facial 7, Vestibulocochlear 8, Glossopharyngeal 9, Vagus 10, Accessory 11, Hypoglossal 12.
Olfactory 1 Sensory Function: smell. Motor Function: none.
Optic 2 Sensory function: Sight. Motor function: none.
Oculomotor 3 Sensory function: none. Motor function: Ciliary muscle, pupil constriction, extrinsic eye muscles (not superior oblique or lateral rectus).
Trochlear 4 Sensory function: none. Motor function: Superior oblique.
Trigeminal 5 Sensory function: Face, teeth, tongue. Motor function: Mastication.
Abducens 6 Sensory function: none. Motor function: Lateral rectus.
Facial 7 Sensory function: Taste (anterior 2/3 of tongue). Motor function: Facial muscles, saliva, tears.
Vestibulocochlear 8 Sensory function: Hearing, balance. Motor function: none.
Glossopharyngeal 9 Sensory function: Taste (posterior 1/3 of tongue). Motor function: Swallowing and saliva.
Vagus 10 Sensory function: 70% of parasympathetic. Motor function: 70% of parasympathetic.
Accessory 11 Sensory function: none. Motor function: Sternocleidomastoid, trapezius.
Hypoglossal 12 Sensory function: none. Motor function: Tongue muscles.
Neruon Pathways and Spinal Nerves 31 pairs of spinal nerves. Made of sensory afferent (enter dorsal) & motor efferent neurons (exit ventral). SAME DAVE.
Dermatomes A specific segment of skin supplied by a single spinal nerve. Pattern caused by embryonic somites. All spinal nerves except C1 innervate segment of skin. Referred visceral pain used in ER. Which nerve injured?
Shingles Rash of scaly, painful blisters. Usually confined to one or a few adjacent dermatomes. Chicken pox dormant in posterior root ganglia of spinal cord.
Nerve Plexuses A network of interweaving spinal nerves. Split into "named" nerves that innervate body structures. Principal plexuses (L&R): Cervical, Brachial, Lumbar, Sacral.
Cervical Plexus Spinal nerves C1-C4. Innervate anterior neck and parts of head and shoulders. PHRENIC NERVE innervates the diaphragm.
Brachial Plexus Spinal nerves C5-T1. Innervate pectoral girdle & upper limbs.
Nerves of the Brachial Plexus Median: center of arm. Involved w/ carpal tunnel syndrome. Ulnar: pinky side. Radial: Below other 3. Musculocutaneous: travels through coracobrachialis.
Lumbar Plexus Spinal nerves L1-L4. Inneravtion of lower limb. Femoral Nerve innervates anterior muscles of thigh.
Sacral Plexus Spinal nerves L4-S4. Innervation of lower limb. Sciatic nerve-longest and largest nerve in body. Supplies all of lower limb except anterior & medial regions of the thigh. Divides into the tibial and common fibular (peroneal) nerve.
Reflexes Rapid, automatic, involuntary reactions of muscles or glands to a stimulus. A stimulus is required. A rapid response requires that few neurons be involved & synaptic delay minimal. An automatic response occurs the same way every time.
Components of a reflex arc 1. Stimulus activates receptor. 2. Travels through sensory afferent neuron from PNS to CNS. 3. Interneurons (only in complex reflexes). 4. Travels through motor efferent neuron from CNS to PNS. 5. Effector responds to nerve impulse.
Types of Reflexes Monosynaptic-simple. no interneurons. Ex. patellar (knee jerk). Polysynaptic-complex. Involve interneurons. More delay between stimulus and response. Be able to differentiate with pictures.
Motor Efferent: Somatic vs. Autonomic Somatic is voluntary. It has 1 somatic sensory neuron and 1 somatic motor neuron. Autonomic is involuntary. It has 1visceral sensory neuron and 2 autonomic motor neurons.
Autonomic Nervous System Structure Chain of two motor neurons: Preganglionic neuron: Cell body in spinal cord or brain. Axon synapses w/ postganglionic neuron in autonomic ganglion. Postganglionic neuron: Cell body in autonomic ganglion. Axon extends to visceral organs.
Parasympathetic Division AKA Cranial sacral division. Rest and digest response. Recovery. Preganglionic neuron is myelinated; postganglionic not. Long pre. Short post. No branches. Recognize picture.
Sympathetic Division Fight or flight response. Adrenaline rush. Preganglionic neuron is myelinated. Postganglionic not. Pre is short. Post is long. Branches in preganglionic neuron. Recognize picture.
Dual innervation Most organs innervated by sympathetic & parasympathetic axons. Usually oppose each other. Antagonistic effects on same organ. Ex. Pupils: Parasymp causes constriction; Symp causes dilations.
Sympathetic division thoracolumbar region
Parasympathetic division Cranial and sacral regions.