CNS-Central Control stimulates and coordinates all other body systems Command center 1
PNS-Peripheral nervous system Nerves outside the brain and spinal cord ANS-Autonomic nervous system responsible for control of the bodily functions not consciously directed 2
Fundamental unit of nervous tissue is the neuron Neuron is a nerve cell that includes the dendrites and axons. Dendrite- fiber branches that receive impulses from other parts of the nervous system and bring it to the cell. Axons- transmit the impulses away from the cell body. COLOR BK PG 13 3
Myelin- fatty sheath surrounding the axon. Speeds up impulse conduction. Grey Matter is unmyelinated fiber, in the cerebral cortex and central spinal cord White matter is myelinated fiber within spinal cord and fiber systems. COLOR BK PG 13/77 Synapse- transmission of impulses from one neuron to another occurs at here. COLOR BK PG 70 4
Afferent neuron- sensory neuron takes the message from the skin to the brain. Or periphery to the CNS. COLOR BK PG 69 Efferent Neuron- motor neuron that takes the message from the brain to the muscle. Or CNS to the periphery. COLOR BK PG 69 5
-CNS Central is made up of the Brain and spinal cord. Brain is made up of the cerebrum, brainstem and cerebellum. Cerebrum is the largest and main portion of the brain, it is responsible for the highest level of function. It has four lobes. COLOR BK PG 73 6
The four lobes each have different functions. Thalamus is inside the cerebrum, this is where the nerve cells relay body sensations, where pain is perceived. COLOR BK PG 75 7
Cerebellum means little brain. The main function is to control muscle coordination, tone and posture. COLOR BK PG 76 Brainstem has three parts, the midbrain, pons, and medulla. COLOR BK PG 76 Midbrain is center for visual reflexes Medulla is the center for automatic control of respiration and heart rate. 8
Brain Protection Skull- bones with fused joints for greater strength of protection. COLOR BK PG 22 Brain Protection-three membranes-meninges Dura mater-outer thickest layer that means in latin COLOR BK PG 81 9
-Injuries Brain Protection-three membranes-meninges Arachnoid mater- middle layer Subarachnoid space- where the shock absorbing cerebrospinal fluid is located. Pia mater- carries blood vessels to the brain. COLOR BK PG 81 10
Spinal Cord is 17 inches long (approximate) Has the same 3 protective layers as the brain Outer dura mater Arachnoid memebrane Inner pia mater Cerebrospinal fluid flows between arachnoid layer and pia mater Spinal cord and spinal nerves COLOR BK PG 86 11
VERTEBRAE AND SPINAL CORD/NERVES Vertebrae Vertebral Foramen-passageway for the spinal cord. Intervertebral foramen- sides of the vertebral column, where the spinal nerve roots exit the vertebral canal COLOR BK PG 25 12
Peripheral The part of the nervous system outside of the vertebral column: Cranial Nerves Spinal Nerves Peripheral Cranial Nerves have origin in the brain. They are sensory nerves, motor nerves or mixed. Sensory- I, II, VIII, Motor- III, IV, VI, XI, XII Mixed V, VII, IX, X COLOR BK PG 83 13
Peripheral The cranial nerves are: 1.CN I - Olfactory Nerve 2.CN II - Optic Nerve 3.CN III - Oculomotor Nerve 4.CN IV - Trochlear Nerve 5.CN V - Trigeminal Nerve 6.CN VI - Abducens Nerve 7.CN VII - Facial Nerve 8.CN VIII - Vestibulocochlear Nerve 9.CN IX - Glossopharyngeal Nerve 10.CN X - Vagus Nerve 11.CN XI - Spinal Accessory Nerve 12.CN XII - Hypoglossal Nerve Oh Oh Oh To Touch And Feel Very Good Velvet Such Heaven 14
Spinal Nerves There are 31 pairs of spinal nerves. 8 cervical-exit above their vertebrae 12 thoracic-exit below their vertebrae 5 lumbar 5 sacral 1 coccygeal COLOR BK PG 86 15
Spinal Nerves Plexuses- network of nerves Root/Trunk/Cord/Peripheral nerves COLOR BK PG 87 Another Brachial Plexus Picture 16
Terminal Nerves Let s Build the Brachial Plexus 17
Spinal Nerves There are 3 plexuses Cervical Plexus- make up C1-C4 Brachial Plexus- make up C5-T1 Lumbosacral Plexus- make up L1-S5 COLOR BK PG 87 Spinal Nerves FUN FACT! Most muscles are inervated by at least 2 spinal nerves so loss of function will not occur, likely the muscle will weaken 18
Spinal Nerves FUN FACT! Significant levels C3- damage here or above would affect function of the diaphragm. Need assistance with breathing. C5- damage from here down would result in loss of upper extremity function. Spinal Nerves Dermatomes- COLOR BK PG 89 Area of skin supplied with the sensory fiber of a spinal nerve. Most areas have overlap, so total anesthesia will not occur unless 2 nerves lose function. 19
Spinal Nerves 20