Fundamentals Chapter 30 - Sensation, Perception, Cognition Flashcards

Vision
Hearing
Taste
Smell
Touch

To allow the body to respond to changing situations and maintain homeostasis.

Stimulus

Reception

Perception

Arousal Mechanism

It may be a sight, sound, taste, touch, pain, or anything that stimulates a nerve receptor. The brain must receive and process it to make it meaningful.

The process of receiving stimuli from nerve endings in the skin and inside the body. A receptor converts a stimulus to a nerve impulse and transmits the impulse along sensory neurons to the central nervous system (CNS). Some receptors remain activated for as long as the stimulus is applied. However, most receptors adapt to stimuli; that is, their response declines with time. Adaptation explains why, over time, you become unaware of an unpleasant smell or the persistent hum of an air conditioner.

Mechanoreceptors in the skin/hair follicles detect touch pressure and vibration

Hair cells are receptors for hearing, located in cochlea

Thermoreceptors in the skin detect temperature

Proporoceptors in the skin, muscles, tendons, ligaments, and joint capsules coordinate input to help us sense the position of our body in space

Photoreceptors located in retina detect visible light

Chemoreceptors for taste

Olfacory receptors a type of chemoreceptor for smell

The ability to interpret the impulses transmitted from the receptors and give meaning to the stimuli. The brain discards about 99% of all sensory info as irrelevant and unimportant.

• Location of the receptors and pathway activated
• Number of receptors activated
• Frequency of action potentials generated (which varies according to the intensity of the stimulus)
• Changes in location, number, and frequency

Located in the brainstem, controls consciousness and alertness.

The neurons of the RAS make connections between the spinal cord, cerebellum, thalamus, and cerebral cortex, relaying visual, auditory, and other stimuli that help keep us awake, attentive, and observant. Without such stimuli, the CNS becomes lethargic, and the person may lose consciousness. Anesthesia, sedatives, opioids, and some other drugs depress the RAS, as does a darkened, quiet environment.

• Intensity of stimulus: An intense stimulus excites more receptors, leading to a greater response.
• Contrasting stimuli: Contrast is also stimulating.
• Adaption to stimuli: Nurses become accustomed to the noise, lights, activity, and even alarms and are able to “tune them out.” These stimuli are new to many patients, so they notice them and may have difficulty resting.
• Previous experience: Prior experience with a stimulus affects ongoing responses to the same stimulus.

Correct answer: B

The stimuli gathered by proprioreceptors enable us to determine the position of our bodies in space.

People have differing sensory perceptual abilities at different stages of life.

Affects the nature, type, and amount of interaction and stimulation that people feel comfortable with. People of different cultural backgrounds tend to prefer differing amounts of eye contact, personal space, and physical touch.

Neurological disorders, such as multiple sclerosis, slow the transmission of nerve impulses. Diseases that affect circulation (e.g., atherosclerosis) may impair function of the sensory receptors and the brain, thereby altering perception and response. Some diseases affect specific sensory organs. For example, diabetic retinopathy is the leading cause of blindness among adults ages 20 to 74. Hypertension, too, can damage the retina of the eyes.

Aspirin and furosemide (Lasix) become ototoxic if taken for a long period of time and impair function of the auditory nerve. CNS depressants, such as opioid analgesics and sedatives, blunt reception and perception of stimuli.

Physical illness, pain, hospitalization, tests, and surgery are all stressors that can lead to sensory overload—more stimuli than the person can handle.

People vary in their personalities and lifestyles. Some people, by nature, like excitement, change, and stimulation; others prefer a more predictable and quiet life. Clients are at risk for sensory alterations if their previous level of stimuli does not match their current level. Health problems, a change of environment, or loss of a partner can each create changes in stimuli.

The vitreous humor becomes thinner, and "floaters"appear in the visual field.

Peripheral vision and tear production decrease

The lens becomes less flexible and/or discolored and opaque; the pupil becomes smaller allowing less light to reach the retina limiting vision.

Cerumen is drier and more solid creating hearing loss

Scarring occurs

Hearing changes commoly include presbycusis (hearing loss of high frequency tones) and decreased speech discrimination

Taste buds atrophy and decrease in number, so there is less ability to perceive tastes, especially sweetness. Dry mouth may also alter the taste.

Atrophy and loss of olfactory neurons decreases the ability to perceive smell, which may also alter the sense of taste.

Loss of sensory nerve fibers and changes in the cerebral cortex decrease the ability to perceive light touch, pain, and temperature variations.

Changes include decrease in muscle fibers and diminished conduction speed of nerve fibers, resulting in slowed reaction time, decreased speed and power of muscle contractions and impaired balance.

A state of RAS depression caused by a lack of meaningful stimuli. When environmental stimuli are deficient, the remaining stimuli, such as distant noises, minor pain, and cold extremities, can become overly noticeable or distorted, filling in the “sensory gap” and causing the patient a level of distress that is out of proportion to the intensity of the stimulus.

Develops when either environmental or internal stimuli or a combination of both exceed a higher level than the patient's sensory system can effectively process. For example, hospitalized patients often experience sensory overload due to a combination of physical discomfort, anxiety, separation from loved ones, and the unfamiliar hospital environment.

Irritability

Confusion

Reduced Attention Span

Decreased Problem Solving Ability

Drowsiness (due to insomnia for sensory overload)

Depression

Preoccupation with somatic complaints (eg, heart palpitations)

Delusions (misinterpretation of external stimuli)

Hallucinations (seeing hearing feeling tasting, or smelling something that is not there)

Muscle tension

Anxiety

Inability to concentrate

Decreased ability to perform tasks

Restlessness

Disorientation

May stem from impaired reception, perception or both. Of the 6 basic sensory deficits, impaired vision and hearing are the ones you're most likely to encounter in nursing practice.

Visual deficits may result from trauma or disease of the eye, microvascular problems, or CNS disorders. Common causes of visual deficits include age-related changes, refractive errors, orbital trauma, cataracts, glaucoma, diabetic or hypertensive retinopathy, macular degeneration, or loss of visual fields after a stroke. Changes in vision affect all aspects of daily living and may severely limit mobility
and interaction.

Hearing deficits may result from injury or disease in structures of the ear, the nerves, or the brain. Inability to hear decreases the ability to communicate and thus hampers social interaction. It may interfere with a patient’s ability to understand instructions from healthcare professionals and create a safety hazard due to inability to hear warnings.

Taste deficits may decrease the pleasure associated with eating; weight loss and malnutrition may result.

Excessively dry mouth...may be caused by meds, decreased saliva production, inadequate fluid intake, poor nutrition, or poor oral hygiene.

Muscle sense, a complex process involving proprioceptors that detect stretch in muscles to create a mental picture of how the body is positioned.

Parkinson's disease and other neurological disorders (tumors, stroke, meds) can impair kinesthesia.

Can be caused by a cerebrovascular accident (stroke), brain or spinal tumor or injury, or peripheral nerve damage caused by diabetes, Guillain-Barré syndrome, or chronic alcoholism.

When the sense of smell is lost (anosmia), food does not taste the same. Patients who are unable to smell food lose their appetite, and nutritional deficits may result. Permanent anosmia may develop after cranial nerve damage, a tumor, or atherosclerosis.

A change in vision associated with aging. The lens becomes less elastic and less able to accommodate to near objects. If you are older than 40, there's a good chance you may be experiencing this problem :-[

A clouding of the lens, resulting in blurred vision, sensitivity to glare, and image distortion.

A type of vision loss caused by increased pressure in the anterior cavity of the eyeball that distorts the shape of the cornea and shifts the position of the lens, resulting in loss of peripheral vision. It can eventually lead to blindness.

Crossed Eyes in which one eye deviates from a fixed image, can cause permanent vision loss.

Hearing deficit that results when one of the structures that transmits vibrations is affected. It may be a temporary or permanent condition caused by infection of the middle ear, a punctured tympanic membrane, or arthritis of the auditory bones. A hearing aid may be helpful.

Hearing deficit that is a progressive sensorineural loss associated with aging. It results from deterioration of the hair cells in the cochlea. Leads to diminished ability to hear high pitched sounds and to distinguish sounds in a noisy environment. Hearing aids may be of no value.

Hearing deficit that describes ringing in the ears. It mostly comes from damage to the microscopic endings of the nerve in the inner ear, for ex, trauma, turbulent blood flow, hypertension, ear infection, meds, otosclerosis, or arthritic changes of the bones of the ear.

A middle ear infection. It is a common childhood illness that may be caused by viruses or bacteria.

• Factors affecting sensory perception
• Mental status, mood, affect, cognition, and memory
• Level of consciousness (LOC)
• Use of sensory aids
• The patient's environment
• The support network
• Focused exam of vision, hearing, taste, smell, touch, balance, ability to respond to stimulation, muscle tone, coordination

Abrupt onset of reversible disturbances of consciousness, attention, cognition, and perception that develop over a short period of time.

Irreversible, long-standing, and or progressive deterioration of intellect and personality characterized by a decreased ability to interpret environmental stimuli and decreased capacity for intellectual thought processes and manifested by disturbances of memory orientation, and behavior

Inability to remember or recall bits of information or behavioral skills

Vulnerable to increased susceptibility to falling, which may cause physical harm and compromise health.

Orientation: provide a calendar or a view of the environment

Provide stimuli: regular contact, touch, television, radio, pet therapy, smells

Minimize the stimuli: less light or noise, less TV or radio, calm tone, reduce noxious odors, provide rest and teach stress reduction.

Correct answer: C

These measures would most directly decrease the client’s sensory overload.

Supply clean glasses, sufficient light, protect eyes from sunlight, provide a magnifying lens or large print books.

Evaluate their ability to perform ADLS, remain safe in environment, and need for assistance

Care of hearing aid, use closed captioned TV, Regular inspection of ear canal, teach techniques to improve communication, promote safety and assess for social isolation

Reorient frequently, state your name, day, date, time, provide clocks, calendars, visual clues to time, use personal belongings, maintain a safe environment, communicate clearly and slowly, limit choices, promote feeling of security, and use alternative therapies.

Continue to orient to reality

Safety measures: bed in low position and side rails up

Attend to body systems: eye care, ROM, skin and mouth care, urinary drainage, bowel management, nutrition

By promoting the body's natural ability to balance, regulate, heal, and maintain itself.

Relaxing
Treating wounds and burns
Skin Care
Asthma
Itching
Labor Pains
Colic
Dysmenorrhea

Headaches
Sinusitis
Vertigo
Muscle Aches
Asthma
Digestive Disorders: slow digestion, indigestion, nausea and gas

Promotes mental stimulation
Stimulates immune, circulatory, and digestive systems, muscle aches and tension

Antifungal oil: yeast infection, jock itch, athletes foot, and ringworm.

Insect bites, itching, migrane

boosts immune system

Answer:

3) Proprioceptors

Rationale:

Proprioceptors in the skin, muscles, tendons, ligaments, and joint capsules coordinate input to enable an individual to sense the position of the body in space. Photoreceptors located in the retina of the eyes detect visible light. Chemoreceptors are located in the taste buds and epithelium of the nasal cavity. They play a role in taste and smell. Thermoreceptors in the skin detect variations in temperature.

Answer:

3) Morphine sulfate

Rationale:

Central nervous system depressants, such as the opioid analgesic morphine, blunt the perception of stimuli. Furosemide, metoprolol, and metoclopramide do not affect the patient's perception of stimuli.

Answer:

2) Vitamin B₁₂
4) Zinc

Rationale:

Deficiencies in vitamin B₁₂ or zinc may cause diminished taste. Deficiencies in vitamin A and iron do not cause diminished taste.

Answer:

2) Astigmatism

Rationale:

Astigmatism is caused by irregular curvature of the cornea or lens that results from injury, infection, or an inherited trait. Astigmatism causes blurred and distorted vision.

Answer:

2) Acute Confusion

Rationale:

Acute Confusion is the abrupt onset of transient changes and disturbances in attention, cognition, psychomotor activity, level of consciousness, and the sleep-wake cycle. This diagnosis is used for those who exhibit signs of sleep deprivation. Chronic Confusion may be used for patients with Alzheimer's disease. Impaired Environmental Interpretation Syndrome is used when there is a lack of consistent orientation to person, place, time, or circumstances over more than 3 to 6 months. Impaired Memory is the inability to remember or recall bits of information.

Answer:

3) Provide aromatherapy for him.

Rationale:

Aromatherapy would stimulate the patient's sense of smell, which apparently is still intact. When one sense is impaired, it is important to stimulate others. This patient is at risk for sensory deprivation because he has no auditory stimuli, limited visual and tactile stimuli, and because of being confined to bed, limited social interaction. Nursing interventions should focus on providing appropriate stimuli. Although television can provide stimulation when used appropriately, it is meaningless when overused. In addition, this patient could not hear or see it. He would not be able to see artwork on the walls well enough for it to provide stimulation. Keeping the room dark and quiet would further reduce the limited stimuli from light that the patient is able to perceive. Furthermore, "quiet" would be irrelevant for a patient who is deaf.

Answer:

1) Protection from injury during seizures

Rationale:

The goal of seizure precautions is to protect the patient from injury during the seizure event. Seizure precautions are instituted for patients with a new diagnosis of a seizure disorder, any seizure activity within the past 12 months, frequent seizure activity, history of head trauma, and withdrawal from antiseizure medication. Although the nurse can attempt to prevent seizure activity possibly through the use of medications, the nurse can fully prevent seizures using nonpharmacological measures. Assessing a patient for an aura prior to a seizure is assessment (not a goal). Padding side rails, headboard, and footboard are nursing interventions—not nursing goals for care.

Answer:

1) Impaired kinesthesia

Rationale:

Patients with Parkinson's disease are at risk for impaired kinesthesia, placing them at risk for falling. Drooling, not excessive dry mouth (xerostomia) is common with Parkinson's disease. Seizures and macular degeneration are not associated with Parkinson's disease.

Answer:

1) Administering albuterol (a central nervous stimulate) every as needed

Rationale:

Medications that stimulate the central nervous system, such as albuterol, place the patient at risk for sensory overload. A tranquilizer and a quiet, darkened room may help the patient to relax, thus preventing sensory overload. If the patient's oxygen needs are met with oxygen at 6 L/min via nasal cannula, the patient should not experience sensory overload related to oxygen therapy alone. Oxygen deprivation can lead to air hunger and feelings of anxiety.

1

Correct!

Macular degeneration is the loss of central vision due to damage to the macula lutea, the central portion of the retina. Because the client lives alone and has a visual impairment, he would be at risk for falls.

4

Correct!

Impaired taste most commonly results from xerostomia (excessively dry mouth), which may be caused by medications, decreased saliva production, inadequate fluid intake, poor nutrition, or poor oral hygiene.

1

Correct!

Mechanoreceptors in the skin and hair follicles detect touch, pressure, and vibration.

1,4,5

Correct!

Feedback 1: For clients with severely limited vision, provide an uncluttered environment and do not rearrange furniture.

Feedback 2: For clients with a hearing deficit, not severely limited vision, provide closed-caption television.

Feedback 3: For clients with a hearing deficit, not severely limited vision, consider conversion to text-telephone service.

Feedback 4: For clients with severely limited vision, consider books on tape or in Braille.

Feedback 5: For clients with severely limited vision, avoid distracting the client's guide dog.

Feedback 6: For clients with severely limited vision, keep the bed in a low, not high, position.

3,4,5

Correct!

Feedback 1: Depression is a sign of sensory deprivation, not overload.

Feedback 2: Preoccupation with somatic complaints, such as heart palpitations, is a sign of sensory deprivation, not overload.

Feedback 3: Anxiety is a sign of sensory overload.

Feedback 4: Inability to concentrate is a sign of sensory overload.

Feedback 5: Restlessness is a sign of sensory overload.

Feedback 6: Delusions are a sign of sensory deprivation, not overload.

2

Correct!

Tinnitus is a term used to describe ringing in the ears. Most tinnitus comes from damage to the microscopic endings of the nerve in the inner ear, for example, trauma, turbulent blood flow, hypertension, ear infection, medications, otosclerosis, or arthritic changes of the bones of the ear.

3

Correct!

Often we take stimuli for granted. Recall your first clinical experience. Did you notice the noise and activity on the unit? Nurses become accustomed to the noise, lights, activity, and even alarms and are able to "tune them out." These stimuli are new to many patients, so they notice them and may have difficulty resting.

3

Correct!

Presbyopia is a change in vision associated with aging. The lens becomes less elastic and less able to accommodate to near objects. If you're older than age 40 years, there's a good chance you may be experiencing this problem.

1

Correct!

Some diseases affect specific sensory organs. For example, diabetic retinopathy is the leading cause of blindness among adults aged 20 to 74 years.

2,4,5

Correct!

Feedback 1: The Full Outline of Un-Responsiveness (FOUR) scale, not the Glasgow scale, assesses brainstem reflexes and respirations.

Feedback 2: The Glasgow Coma Scale is commonly used to assess LOC. It assesses eye, motor, and verbal responses.

Feedback 3: The Full Outline of Un-Responsiveness (FOUR) scale, not the Glasgow scale, assesses brainstem reflexes and respirations.

Feedback 4: The Glasgow Coma Scale is commonly used to assess LOC. It assesses eye, motor, and verbal responses.

Feedback 5: The Glasgow Coma Scale is commonly used to assess LOC. It assesses eye, motor, and verbal responses.

Feedback 6: The Glasgow Coma Scale does not assess for heart rate responses.

1,2,4,6

Correct!

Feedback 1: Impaired sensory reception (e.g., neurological injury, dementia, depression, sleep deprivation, sensory losses, and central nervous system depressant medications) is a risk factor for sensory deprivation.

Feedback 2: Inability to transmit or process stimuli as a result of a nerve or brain injury is a risk factor for sensory deprivation.

Feedback 3: Restricted mobility, not being physically active, is a risk factor for sensory deprivation.

Feedback 4: Sensory deficits (e.g., vision, hearing) are risk factors for sensory deprivation.

Feedback 5: A nonstimulating, monotonous environment is a risk factor for sensory deprivation. A busy airport would be a stimulating environment.

Feedback 6: Being from a different culture and unable to interpret received cues is a risk factor for sensory deprivation.

Correct!

The steps for performing otic irrigation on an adult client are as follows: 1. Warm the irrigating solution to body temperature. 2. Assist the patient into a sitting or lying position, with the head tilted slightly toward the affected ear. 3. Straighten the ear canal by pulling up and back on the pinna. 4. Instruct the patient to notify you if he experiences any pain or dizziness during the irrigation. 5. Place the tip of the nozzle (or syringe) into the entrance of the ear canal, and direct the stream of irrigating solution gently along the top of the ear canal toward the back of the client's head. 6. Continue irrigating until the canal is clean. 7. Perform an otoscopic examination. 8. Place a cotton ball loosely in the outer ear.

3

Correct!

An alert client will respond to auditory stimuli. If the client does not respond, progress to tactile and then painful stimuli.

1,2,4

Correct!

Feedback 1: For visual stimulation, put artwork on the walls, furnish colorful pajamas and robes, and place pictures or flowers where the patient can see them.

Feedback 2: For visual stimulation, help the patient with glasses to apply them whenever she is not sleeping. Make sure eyeglasses are clean and in good repair. This will allow the patient to receive available stimuli.

Feedback 3: Turning off the television reduces visual and auditory stimuli and is an appropriate intervention for a client with sensory overload, not for a client with sensory deprivation.

Feedback 4: To provide tactile stimulation, you may want to hold a patient's hand while talking or provide a back rub with morning and bedtime care.

Feedback 5: Dimming the lights in the room reduces visual stimuli and is an appropriate intervention for a client with sensory overload, not for a client with sensory deprivation.

Feedback 6: Removing fresh flowers or other heavily scented items from the room reduces olfactory stimuli and is an appropriate intervention for a client with sensory overload, not for a client with sensory deprivation.

3

Correct!

Proprioceptors in the skin, muscles, tendons, ligaments, and joint capsules coordinate input to enable us to sense the position of our body in space (proprioception).