Cognitive & Sensory Alterations Study Guide for Exam 3

Cognitive and Sensory Alterations- Chapter 31



Sensation is a feeling within or outside the body of conditions resulting from stimulation of
sensory receptors.
Cognition is knowing influenced by awareness and judgement.
Perception is the way the brain perceives the information.
The area of the brain that controls alertness and attention is the Reticular Activating System
(RAS.)
Sensory Adaptation is the brains process of filtering impulses by priority during time of
alertness.
Tactile receptors (touch, pressure, temperature, pain) are in the dermis and subcutaneous
tissue.
oSmell: Chemoreceptors in the upper nasal passages
Anosmia is the complete loss of sense of smell.
oTaste: Chemoreceptors in the taste buds on the tongue, the roof of the mouth, and the
throat
oHearing: Occurs through the workings of the outer, middle, and inner ears
Age related hearing loss is presbycusis.
oEquilibrium: Receptors in the ear’s semicircular canal
oVision: Photoreceptors in the eye’s retina
Aging
◦ Number of neurons decrease
◦ Gradual decline in the ability to interpret sensory stimuli that reach the brain
◦ Response time is slower
◦ Does not affect judgment, language, or the ability to live independently
Cognitive alteration
Delirium
◦ Signs and symptoms: fluctuating awareness, impairment of memory, disorganized thinking,
hallucinations, and disturbances of sleep-wake cycles

, Depression
◦ Signs and symptoms: loss of interest, sadness for an extended period, decreased self-
esteem, sleeping too much or insomnia, and changes in eating patterns.

Cognitive alteration
Dementia is a permanent decline in mental function and has a subtle onset. Not reversable and
worsens over time.
Characterizations
Decline in reasoning
Decline in use of language
Memory loss
Computation (math)
Decline in judgement
Decline in learning
Alzheimer's disease is a progressive neurologic disorder that causes the brain to shrink
(atrophy) and brain cells to die. Alzheimer's disease is the most common cause of dementia — a
continuous decline in thinking, behavioral and social skills that affects a person's ability to
function independently.
Characterizations
Amyloid plaques
Neurofibrillary tangles
Chronic inflammation
Vascular contributions to Alzheimer's disease
Loss of neuronal connections and cell death

Brain injuries and illnesses
Cerebrovascular accident (CVA) occurs when an area of the brain is deprived of blood flow,
CVAs are also called strokes.