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Purdue University Globle
NU551 Advanced Physiology and Pathophysiology Across the Lifespan
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NU551 Unit 3 Study Guide covers essential neuroanatomy, pain pathways, sensory function, and neurological disorders that nurses encounter in clinical practice. The central nervous system and peripheral nervous system work together to control movement, sensation, cognition, and vital body functions. Understanding conditions such as seizures, stroke, increased intracranial pressure (ICP), delirium, dementia, and pediatric neurological disorders helps nursing students recognize clinical deterioration, understand treatment priorities, and provide safer patient care.
This study guide explains the major structures of the nervous system, how pain is transmitted, and the assessment findings associated with common neurological conditions. It is designed to support nursing exam preparation, clinical learning, and review of important NU551 Unit 3 concepts.
The neurological system, also called the nervous system, is the body’s communication and control network. It receives information from the environment, processes sensory input, sends signals to muscles and organs, and regulates both conscious and automatic body functions. These activities support movement, memory, balance, learning, sensation, and homeostasis.
The nervous system is divided into two major components: the central nervous system (CNS) and the peripheral nervous system (PNS).
The central nervous system consists of the brain and spinal cord. It serves as the primary control center for the body, interpreting incoming information and coordinating responses.
The brain is responsible for higher cognitive functions, sensory interpretation, voluntary movement, and the regulation of many essential body processes. The spinal cord transmits signals between the brain and the rest of the body and also coordinates important reflexes.
The peripheral nervous system includes the cranial nerves, spinal nerves, and associated peripheral nerve structures. It connects the CNS to muscles, organs, skin, and sensory receptors.
The PNS carries sensory information toward the CNS and transmits motor commands away from the CNS. It also includes the autonomic nervous system, which regulates involuntary functions such as heart rate, digestion, and glandular activity.
The autonomic nervous system has two major divisions:
Together, the CNS and PNS allow the body to respond to internal and external stimuli while maintaining physiological balance.
The brain contains specialized structures that perform different functions. Recognizing the role of each region helps nurses understand neurological assessment findings and identify possible areas of injury.
The cerebrum is the largest part of the brain and controls many higher-level functions, including thinking, memory, language, voluntary movement, and sensory processing. It is divided into right and left cerebral hemispheres, which communicate through the corpus callosum.
Each cerebral hemisphere contains four major lobes.
The frontal lobe is associated with executive functions, personality, judgment, decision-making, voluntary motor activity, and speech production.
Damage to the frontal lobe may affect behavior, impulse control, motor function, or the ability to produce speech.
The temporal lobe processes auditory information and contributes to language comprehension, memory, and emotional processing.
Injury to this region may cause problems with hearing-related processing, memory, or understanding language.
The parietal lobe interprets sensory information from the body, including touch, pressure, temperature, and pain. It also contributes to spatial awareness and the ability to understand the position of the body in relation to its surroundings.
The occipital lobe is primarily responsible for processing visual information. Injury to this area can interfere with visual interpretation, even when the eyes themselves are functioning normally.
The cerebellum coordinates balance, posture, muscle tone, and the precision of voluntary movements. It helps the body perform smooth, controlled actions.
Damage to the cerebellum may cause:
The brainstem connects the brain to the spinal cord and contains pathways involved in communication between the brain and body. It also contains important centers that regulate vital functions, including breathing, heart rate, blood pressure, and consciousness.
Because of its role in life-sustaining functions, brainstem injury can be life-threatening and requires immediate assessment.
The spinal cord is the major communication pathway between the brain and the peripheral nervous system. It carries sensory information to the brain and motor commands from the brain to the body.
The spinal cord also coordinates reflex actions. Spinal cord injury may result in sensory loss, muscle weakness, paralysis, and impaired bowel or bladder function, depending on the location and severity of the injury.
Pain is an important protective response that alerts the body to actual or potential tissue damage. Understanding pain transmission helps nurses assess symptoms, recognize different pain types, and select appropriate interventions.
Pain begins when specialized sensory receptors called nociceptors detect potentially harmful stimuli, such as tissue injury, extreme temperature, or inflammation. These receptors transmit signals through peripheral nerves to the spinal cord.
Pain signals then travel through ascending pathways, including the spinothalamic tract, to areas of the brain involved in sensory processing and conscious pain perception.
Pain perception is influenced by more than tissue injury alone. Emotional state, previous experiences, attention, and the body’s pain-modulation systems can affect how an individual experiences pain.
Pain is commonly classified according to its origin and underlying mechanism.
Somatic pain originates in structures such as the skin, muscles, bones, joints, and connective tissues. It is often relatively well localized. For example, pain from a superficial cut or a musculoskeletal injury may be described as somatic pain.
Visceral pain arises from internal organs. It is often diffuse, poorly localized, or associated with referred pain. For example, discomfort from an internal organ may be felt in a different area of the body from the actual source.
Neuropathic pain results from injury or dysfunction of the nervous system. Patients may describe it as burning, shooting, tingling, or electric shock-like pain. Peripheral neuropathy and nerve injuries are common examples of conditions associated with neuropathic pain.
The Gate Control Theory of Pain explains how pain transmission can be modified within the spinal cord. According to the theory, non-painful sensory input can influence the transmission of pain signals, reducing the intensity of perceived pain in some situations.
For example, rubbing an injured area may stimulate touch receptors and temporarily reduce pain perception. This principle helps explain why some nonpharmacological interventions may provide pain relief.
Nursing interventions that may support pain management include:
These interventions do not replace necessary medical treatment, and their use should be based on the patient’s condition and clinical assessment.
Neurological disorders can affect the brain, spinal cord, or peripheral nerves. Nurses must recognize changes in neurological status, understand common symptoms, and respond promptly when a patient shows signs of deterioration.
A seizure is a sudden episode of abnormal electrical activity in the brain. Seizures can produce changes in movement, sensation, behavior, awareness, or consciousness. The clinical presentation depends on the brain regions involved.
A seizure is not always characterized by generalized shaking. Some seizures involve brief staring, unusual sensations, repetitive movements, or temporary changes in awareness.
Generalized tonic-clonic seizures involve both cerebral hemispheres and commonly cause loss of consciousness, muscle stiffening, and rhythmic jerking movements. The patient may experience confusion, fatigue, or drowsiness after the seizure.
Focal seizures begin in a specific area of the brain. They may occur with preserved awareness or with impaired awareness. Symptoms depend on the affected region and may include abnormal movements, sensory changes, emotional experiences, or altered responsiveness.
Absence seizures are brief episodes of impaired awareness, often presenting as staring spells. They are particularly associated with childhood epilepsy and may be mistaken for inattention.
During a seizure, the nurse’s priority is to protect the patient from injury, maintain safety, and assess breathing and neurological status.
Important nursing actions include:
Emergency assistance is required for prolonged seizures, repeated seizures without recovery, breathing difficulties, serious injury, or a first seizure when urgent evaluation is needed.
A cerebrovascular accident (CVA), commonly called a stroke, occurs when blood flow to part of the brain is interrupted or when a blood vessel in the brain ruptures. Brain cells can become damaged when they do not receive adequate oxygen and nutrients.
The two major types of stroke are ischemic and hemorrhagic.
Ischemic stroke occurs when a blood vessel supplying the brain becomes blocked, commonly by a thrombus or embolus. The blockage reduces blood flow to the affected brain tissue.
Hemorrhagic stroke occurs when a blood vessel ruptures and bleeding develops within or around the brain. The bleeding can increase pressure on brain tissue and cause neurological injury.
The FAST assessment helps identify common warning signs of stroke. If these symptoms occur suddenly, emergency medical care should be sought immediately.
Stroke treatment is time-sensitive. Rapid evaluation can help determine whether the patient is eligible for treatments such as thrombolysis or mechanical thrombectomy, depending on the type of stroke, timing, and clinical findings.
Increased intracranial pressure occurs when pressure inside the skull rises. The skull contains brain tissue, blood, and cerebrospinal fluid (CSF). An increase in one component without adequate compensation can raise intracranial pressure.
Common causes include:
Elevated ICP can reduce cerebral perfusion and impair blood flow to the brain. Severe, untreated pressure elevation may cause brain herniation, a life-threatening emergency.
Possible clinical findings include:
Cushing’s triad is a late and concerning sign of increased intracranial pressure. It consists of:
Cushing’s triad suggests significant neurological compromise and requires immediate medical attention. Nurses should not wait for all three findings to appear before reporting suspected increased ICP.
Nursing management focuses on maintaining adequate oxygenation, supporting cerebral perfusion, recognizing neurological deterioration, and following prescribed treatment.
The nurse should monitor neurological status, assess pupils and level of consciousness, observe vital signs, and report worsening findings promptly. Positioning, airway support, fluid management, and medications may be used according to the patient’s condition and treatment plan.
Delirium and dementia both affect cognition, but they differ in onset, progression, and underlying causes. Distinguishing between them is important because sudden confusion may indicate a reversible medical problem requiring urgent evaluation.
Delirium is an acute disturbance in attention and awareness that usually develops over a short period. Symptoms often fluctuate throughout the day and may be associated with infection, medication effects, metabolic disturbances, dehydration, or other acute illnesses.
Delirium may be reversible when the underlying cause is identified and treated.
Dementia is a general term for a decline in cognitive abilities that interferes with daily functioning. It typically develops gradually and may involve memory, language, judgment, reasoning, or other cognitive skills.
Many causes of dementia are progressive neurodegenerative diseases. However, not every cause of cognitive impairment is irreversible, so evaluation is important.
|
Feature |
Delirium |
Dementia |
|
Onset |
Usually sudden |
Usually gradual |
|
Course |
Often fluctuates |
Generally progressive in many common forms |
|
Duration |
Hours to days, sometimes longer |
Months to years |
|
Attention |
Markedly impaired |
May be relatively preserved early in some dementias |
|
Consciousness |
May fluctuate |
Usually clear until later stages, depending on cause |
|
Reversibility |
Often reversible when the cause is treated |
Depends on the underlying cause; many common forms are progressive |
|
Common causes |
Acute illness, infection, medications, metabolic problems |
Neurodegenerative disease and other chronic conditions |
A patient with a sudden change in mental status should be assessed for delirium and underlying medical causes rather than automatically being diagnosed with dementia.
Pediatric neurological disorders can affect movement, brain development, spinal cord function, and overall growth. Some conditions begin during fetal development, while others develop during infancy or childhood.
Early recognition and ongoing assessment are important because neurological impairment may affect mobility, communication, feeding, learning, and independence.
Cerebral palsy is a group of permanent disorders affecting movement and posture that result from disturbances in the developing fetal or infant brain. The underlying brain injury is non-progressive, although the child’s symptoms and functional needs may change over time.
Common manifestations include:
Management may include physical therapy, occupational therapy, speech therapy, assistive devices, and coordinated medical care.
Spina bifida is a neural tube defect that occurs when the spinal column does not close completely during embryonic development. The severity varies from mild forms with few symptoms to more significant conditions involving spinal cord and nerve impairment.
Children with more severe spina bifida may experience mobility limitations, lower-extremity weakness, and bowel or bladder dysfunction. Care may involve surgery, rehabilitation, mobility support, and long-term monitoring.
Adequate folic acid intake before conception and during early pregnancy helps reduce the risk of neural tube defects.
Hydrocephalus occurs when cerebrospinal fluid accumulates within the brain’s ventricles, causing ventricular enlargement and potentially increasing intracranial pressure.
In infants, possible signs include:
Older children may experience headache, nausea, vomiting, vision changes, or problems with balance.
Some children require surgical treatment, such as placement of a ventriculoperitoneal (VP) shunt, to divert excess CSF and reduce pressure. Children with hydrocephalus need ongoing assessment for neurological changes, developmental concerns, and possible shunt complications.
Neurological nursing care requires systematic assessment and early recognition of changes. A patient’s neurological status may deteriorate quickly, particularly in conditions such as stroke, seizures, traumatic brain injury, and increased ICP.
Important assessment areas include:
Level of consciousness: Assess alertness, responsiveness, orientation, and changes from baseline.
Pupil assessment: Observe pupil size, symmetry, and reaction to light when clinically appropriate.
Motor function: Evaluate muscle strength, movement, coordination, and signs of weakness.
Sensory function: Assess sensation, pain, numbness, tingling, and other sensory changes.
Speech and cognition: Observe speech clarity, comprehension, memory, and ability to follow commands.
Vital signs: Monitor blood pressure, heart rate, respiratory rate, oxygenation, and temperature as indicated.
Safety: Assess fall risk, seizure risk, swallowing ability, and the patient’s ability to protect the airway.
Nurses should promptly report new or worsening neurological findings and follow emergency protocols when a patient shows signs of stroke, seizure complications, increased ICP, or other acute neurological deterioration.
The nervous system controls communication, movement, sensation, cognition, and vital body functions. The CNS consists of the brain and spinal cord, while the PNS connects the CNS to the rest of the body through peripheral nerves.
The major brain regions have distinct functions. The cerebrum supports higher cognitive and sensory functions, the cerebellum coordinates movement and balance, the brainstem regulates vital functions, and the spinal cord transmits signals and coordinates reflexes.
Pain involves nociceptors, ascending pathways such as the spinothalamic tract, and the brain’s pain-processing systems. Somatic, visceral, and neuropathic pain differ in their origin and clinical presentation.
Seizures result from abnormal electrical activity in the brain. Stroke requires rapid recognition and emergency treatment. Increased ICP can reduce cerebral perfusion and cause life-threatening brain herniation. Delirium usually develops suddenly, while dementia generally develops gradually.
Pediatric conditions such as cerebral palsy, spina bifida, and hydrocephalus may require long-term monitoring and interdisciplinary care.
Strong neurological assessment skills help nurses recognize changes early, communicate concerns effectively, and support safe patient outcomes.
The nervous system consists of the central nervous system (CNS) and peripheral nervous system (PNS). The CNS includes the brain and spinal cord. The PNS includes the nerves that connect the CNS to the muscles, organs, and sensory receptors throughout the body.
The four major cerebral lobes are the frontal, temporal, parietal, and occipital lobes. The frontal lobe supports executive functions and voluntary movement, the temporal lobe processes hearing and contributes to memory, the parietal lobe interprets sensory information, and the occipital lobe processes vision.
The three common types of pain are somatic, visceral, and neuropathic pain. Somatic pain arises from skin, muscles, bones, or joints. Visceral pain originates from internal organs. Neuropathic pain results from injury or dysfunction of the nervous system.
The spinothalamic tract is an ascending pathway in the spinal cord that carries important sensory information, including pain and temperature, toward the brain for processing.
FAST stands for Face drooping, Arm weakness, Speech difficulty, and Time to seek emergency medical care. It is used to recognize common stroke warning signs and encourage rapid emergency response.
Increased intracranial pressure is elevated pressure within the skull. It may result from brain swelling, bleeding, tumors, or excess cerebrospinal fluid. Severe ICP elevation can impair cerebral perfusion and cause brain herniation.
Cushing’s triad includes hypertension with widened pulse pressure, bradycardia, and irregular respirations. It is a late warning sign of severe increased intracranial pressure.
Delirium usually develops suddenly, causes fluctuating attention and awareness, and is often reversible when the underlying cause is treated. Dementia generally develops gradually and causes progressive cognitive impairment in many common forms.
Common pediatric neurological conditions include cerebral palsy, spina bifida, and hydrocephalus. These disorders may affect movement, development, mobility, and neurological function and often require multidisciplinary care.
The main priorities are protecting the patient from injury, maintaining safety, observing seizure activity, assessing breathing and airway status, and monitoring recovery. The nurse should not restrain the patient or place objects in the mouth.
American Association of Neurological Surgeons. (n.d.). Hydrocephalus. https://www.aans.org/patients/conditions-treatments/hydrocephalus/
American Association of Neurological Surgeons. (n.d.). Spina bifida. https://www.aans.org/patients/conditions-treatments/spina-bifida/
Bickley, L. S. (2024). Bates’ guide to physical examination and history taking (14th ed.). Wolters Kluwer. https://shop.lww.com/Bates-Guide-to-Physical-Examination-and-History-Taking/p/9781975210878
Centers for Disease Control and Prevention. (n.d.). Signs and symptoms of stroke. https://www.cdc.gov/stroke/signs_symptoms/index.html
Centers for Disease Control and Prevention. (n.d.). About cerebral palsy. https://www.cdc.gov/cerebral-palsy/about/index.html
Hinkle, J. L., & Cheever, K. H. (2022). Brunner & Suddarth’s textbook of medical-surgical nursing (15th ed.). Wolters Kluwer. https://shop.lww.com/Brunner—Suddarth-s-Textbook-of-Medical-Surgical-Nursing/p/9781975161033
National Institute of Neurological Disorders and Stroke. (n.d.). Neurological disorders. National Institutes of Health. https://www.ninds.nih.gov/health-information/disorders
National Institute of Neurological Disorders and Stroke. (n.d.). Cerebral palsy. National Institutes of Health. https://www.ninds.nih.gov/health-information/disorders/cerebral-palsy
National Institute of Neurological Disorders and Stroke. (n.d.). Hydrocephalus. National Institutes of Health. https://www.ninds.nih.gov/health-information/disorders/hydrocephalus
National Institute of Neurological Disorders and Stroke. (n.d.). Spina bifida. National Institutes of Health. https://www.ninds.nih.gov/health-information/disorders/spina-bifida
National Institute on Aging. (n.d.). What is dementia? National Institutes of Health. https://www.nia.nih.gov/health/what-dementia
World Health Organization. (n.d.). Neurological disorders. https://www.who.int/health-topics/neurological-disorder
