NR 405A Loretto Heights School of Nursing Regis University Neurologic System 1
Overview of the Nervous System • Central nervous system (CNS) • Brain and spinal cord • Peripheral nervous system (PNS) • Cranial nerves • Spinal nerves • Pathways • Afferent (ascending) • Efferent (descending)
Divisions of the Brain
Central Nervous System : Lobes of the Brain
Central Nervous System • Corpus callosum • Connects the two cerebral hemispheres. • Limbic system • Primitive behavioral responses, visceral reaction to emotion, feeding behaviors, biologic rhythms, and sense of smell • Expression of affect (emotional and behavioral states), mediated by the limbic system and prefrontal cortex • Consolidation of memory
Spinal Cord • Lies within the vertebral canal and is protected by the vertebral column • Connects the brain and the body • Conducts somatic and autonomic reflexes • Provides motor pattern control centers • Modulates sensory and motor function
Cerebrospinal Fluid Passes out an opening below the cerebellum Circulates around the brain and spinal cord in the subarachnoid space
Overview of the Nervous System • Peripheral nervous system (PNS) • Somatic nervous system • Motor and sensory pathways regulating voluntary motor control of skeletal muscle • Autonomic nervous system • Motor and sensory pathways regulating the body’s internal environment through involuntary control of organ systems • Sympathetic • Parasympathetic
Autonomic Nervous System • Sympathetic—fight or flight • Increase heart rate, blood pressure • Dilate pupils, bronchioles • Blood from the GI, skin to skeletal muscles, brain • Parasympathetic—rest or digest • Decrease heart rate, blood pressure • Constrict pupils • Blood to the GI tract, increased secretions
Cells of the Nervous System • Neuron • Primary information and communication cell • Variable size and structure throughout the nervous system • Cellular constituents • Some neurons, such as olfactory neurons, continue to divide; others die, if not needed
Neurons have three components. Cell body (soma) Located mainly in the CNS Dendrites Receive Stimuli Axons Pass stimuli to next cell Myelin Layer of lipid material Insulating substance Formed and maintained by the Schwann Cell
Geriatric Considerations The aging brain is accompanied by a change in structure, function, and metabolism. The volume and weight of the brain declines at a rate of approximately 5% per decade after age 40. Cognitive changes occur such as a decline in episodic memory. Increasing blood-brain barrier permeability. Results in an increased inflammatory response and structural damage The prevalence of pain increases with age.
Sensory & Somatosensory • Sensory • Vision • Hearing • Somatosensory • Provides awareness of pain, touch, temperature and position • 4 major modalities of sensation • Touch • Temperature • Proprioception • Nociception/Pain
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- Spring '19
- Neurology, Traumatic brain injury, Cerebrospinal fluid