Sensation, Perception, & Cognition Flashcards
Sense Organs
* Eyes
* Ears
* Nose
* Tongue
* Skin
* Sense of body & space
We have to sense & respond to sensory input
The Senses
Our senses provide us with information about our internal & external environments
Our senses enable people to experience the world
Allows body to respond to changing situations & maintain homeostasis
Sensory experience involves 4 components in the nervous system;
- Stimulus
- Reception
- Perception
- Arousal mechanism
A ___ is a trigger that stimulates a receptor
The meaning depends on reception & processing
i.e. seeing/touching something
stimulus
___ is the process of receiving the stimuli from the nerve endings
Reception
Reception occurs through receptors, such as;
thermoreceptors
proprioceptors, &
photoreceptors
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Located in the skin, muscles, tendons, ligaments, joint capsules
Nerve endings in skin or body
Coordinate input to enable us to sense the position of our body in space
proprioceptors
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In the skin and detect variations in temperature
thermoreceptors
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In retina of the eyes; are what detect visible light & allow us to see and interpret that stimuli
photoreceptors
Components of the Sensory System: ___
___ is the ability to interpret sensory impulses
- Ability to give meaning to impulses
Affected by:
- location of receptor
- # of receptors activated
- frequency of action potentials
- any changes to the above
Perception
99% of stimuli is discarded by the brain
Components of the Sensory System: ___
___ is composed of consciousness and alertness
Mediated by the ___ (___)
Affected by environment, medications
Arousal
reticular activating system (RAS)
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Located in the brainstem and controls our consciousness and alertness
Neurons make connections between spinal cord, cerebellum, thalamus, & cerebral cortex
Relays visual, auditory, & other stimuli to help keep us awake, attentive, & observant
Without this stimuli, CNS becomes lethargic
reticular activating system (RAS)
Components of the Sensory System: Response
Factors affecting response:
Intensity of stimulus (excites more receptors; i.e. bright vs dim light)
Contrasting stimuli (from cold outside going into garage then into home)
Adaptation to stimuli (nurses accustomed to things in the environment)
Previous experience
This requires people to be alert and receptive to stimulation
What Affects Sensory Function?
Age/Stage of life
Culture (nature, type, & amt of interaction & stimulation; ppl are comfortable w/; preferences in space, eye contact, & touch)
Illness
- i.e. MS slows transmission of nerve impulses
- issues w/circulation like peripheral arterial disease that might impair function of sensory receptors in the brain; can alter our perception & response
- i.e. diabetes ⇒ diabetic retinopathy
- HTN also damages retina of eyes
Medication (aspirin & furosemide that are ototoxic)
Stress
Personality
Lifestyle
Sensory Alterations
Impaired Vision
Impaired Hearing / Smell (anosmia)
Impaired Taste / Kinesthetic Sense / Tactile Perception
Impaired Vision
Affects ALL aspects of daily living
macular degeneration loss of visual field > CVA
orbital trauma
Age-related changes; refractive errors; cataracts; glaucoma; diabetic/hypertensive retinopathy
Signs of Sensory Deprivation
(the state of the RAS depression that is caused by a lack of meaningful stimuli)
- Irritability / confusion / reduced attention span
- Decreased problem-solving ability / drowsiness / depression
- Preoccupation w/Somatic complaints / delusions
High Risk Groups
- Disabled/homebound elders
- Children in orphanages
- Prisoners
- People dealing w/language issues and are unable to interpret in foreign areas
Nursing Interventions: Sensory Deprivation
Focus is on prevention (keep that we are experiencing through our senses the environment around us)
Support the senses (glasses, hearing aids)
Orientation
> Calendar w/current date; view of environment
Provide Stimuli
> Regular contact, touch
> Television, radio
> Pet therapy
> Smells/aromatherapy
Sensory Overload (complex sensory environment [i.e. hospital setting] that contributes to our sensory overload)
Irritability
Confusion
Reduced attention span
Decreased problem-solving ability
Drowsiness
* 1st (5) are same as sensory deprivation
Muscle tension
Anxiety
Inability to concentrate
Decreased ability to perform tasks
Restlessness
Disorientation
Nursing Interventions: Sensory Overload
* Minimize stimuli
> Less light, less noise
> Less television, less bluelight
> Calm tone
> Reduce noxious odors
* Provide rest
* Teach stress reduction strategies
Common Vision Deficits
- Myopia
- Hyperopia
- Presbyopia
- Astigmatism
- Cataracts
- Glaucoma
- Macular degeneration
- Strabismus
?
Irregular curvature of the lens or cornea, causing blurred vision
Astigmatism
?
farsightedness
Hyperopia
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clouding of the lens of the eye
cataracts
?
crossed eyes; can lead to permanent vision loss
strabismus
?
nearsightedness
myopia
?
vision loss caused by increased pressure in the eye
glaucoma
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change associated with aging, lens is less elastic and less able to accomodate to near objects
presbyopia
?
loss of central vision d/t damage to the macula lutea
leading cause of visual impairment in adults over the age of 50; slow, progressive loss of central and near vision
macular degeneration
Visual Changes in the Older Adult
* The vitreous humor becomes thinner, and floaters appear in the visual field
* Presbyopia occurs
* Ciliary body contracts and the lens thickens
* Peripheral vision decreases
* Tear production decreases (e.g., dry eyes)
* Loss of visual acuity
* Decreased ability to accomodate to distance vision
* Sudden changes in illumination
* Decrease in night vision
Nursing Interventions: Visual Deficits
Ensure client has proper glasses available
Provide sufficient light
Protect eyes in sunlight
Provide a magnifying lens or large-print materials
Evaluate
> Client’s ability to perform ADL’s
> Client’s ability to remain safe in the environment
> Any needs for assistance
* Keep in mind increased risk for falls
Common Hearing Deficits: Hearing Loss
Hearing loss may result from injury or disease in structures of the ear, the nerves, or brain
Inability to hear impairs the ability to communicate, and hinders social interactions
Changes in the older adult
> i.e. drier cerumen
> ear scarring
> presbycusis (gradual loss of hearing in both ears)
Common Hearing Deficits
Conduction deafness / nerve deafness
Presbycusis / central deafness
Tinnitus / impacted cerumen
Otosclerosis / otitis media
?
Is progressive, sensorineural hearing loss
presbycusis
?
Middle ear infection
otitis media
?
Ringing in the ear; inner ear damage
Tinnitus
?
Damage to cranial nerve VIII or cochlear receptors
Nerve deafness
?
Hardening of bones in middle ear that leads to poor sound transmission; genetic
otosclerosis
?
Occurs from damage to auditory areas in the temporal lobes; from tumors, CVA, meningitis
Central deafness
Nursing Interventions: Hearing Deficits
* Hearing aids and care
* Closed-caption TV
* Masks to see mouth
* Regular inspection of ear canals
* Teach techniques to improve communication
* Promote safety
* Assess for social isolation
A few more sensory changes in the Older Adult…
Taste
* Taste buds atrophy and decrease in #, so there is less ability to perceive tastes
* Dry mouth may alter sense of taste
* Risk for nutritional deficiency
Smell
* Atrophy and loss of olfactory neurons decreases the ability to perceive smell, which may alter the sense of taste
Touch
* Loss of sensory nerve fibers and changes in the cerebral cortex decreases the ability to perceive light touch, pain, and temp variations
Changes of the Older Adult: Kinesthesia (how we view our bodies in space)
* Changes include a decrease in muscle fibers and a diminished conduction speed of nerve fibers
* This results in slowed reaction times, decreased speed and power of muscle contractions, and impaired balance
Think SAFETY
Level of Consciousness
* Indicator of cerebral function
* Most common assessment tool: Glascow Coma Scale (GCS)
* Document objective, specific facts in the nursing notes
* Max score of 15
Components of the Nursing Assessment
* Client history
* Physical examination
* Risk factors for impaired sensory perception
* Mental status
* LOC
* Environment
* Support network
Nursing Interventions: Altered Level of Consciousness
* Continue orientation to reality
* Safety measures
* Attend to body systems
> Eye care
> Range of motion
> Skin & oral care
> Urinary drainage
> Bowel management
> Nutrition
Nursing Interventions: The Confused Client
* Reorient frequently
> Your name, day, date, time
> Provide clocks, calendars
> Use as many belongings as possible
* Maintain a safe environment
* Communicate clearly & slowly
> Use gestures
* Limit choices
* Promote feelings of security
* Use alternative therapies
* Provide care continuity
* Differentiate between delirium (that’s acute & reversible) & dementia *
Seizures
Abrupt onset of disturbance of electrical activity in the brain
Generally last few sec to 5 min; about 3 min
?
Is a common type; widespread electrical activity; tonic-clonic
generalized
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Begin w/electrical discharge from one side in a limited area of the brain
i.e. aka focal seizure
Missed in children; no physical movements happen
partial seizures
Nursing Interventions: Clients at Risk for Seizures
* Pad the head, foot, & siderails of bed
* Suction and O2 should be at the head of the bed, readily avail for use
* Do not attempt to open the mouth during a seizure, or try to insert a tongue blade
* Maintain a safe environment for the client
* Turn to side-lying position to avoid aspiration
* Sleep deprivation lowers the threshold for seizures
* Aura stage
* Tonic stage
* Clonic stage
* Postictal stage
