NUR 252: Pathophysiology Exam Four Study
Guide
Differentiate sensation, perception, and sensory perception. - ANSWER - Sensation: ability to
perceive stimulation from sensory orgANSWER (internal: pain; external: pain, temperature, light)
- Perception: process by which we receive, organize, and interpret sensation
- Five senses: vision, hearing, sight, taste, touch
Which cranial nerves are involved with vision? - ANSWER Cranial Nerves II, III, IV, V, and VII
What does the iris, lens, and retina do? - ANSWER - Iris: regulates amount of light entering the eye
- Lens: bends light rays so they properly fall on the retina
- Retina: innermost area, transforms light impulses to electrical impulses that are sent to the optic
nerve which communicates to the brain to produce vision
Describe the causes and clinical manifestations of the following forms of visual dysfunction:
Glaucoma - ANSWER - Glaucoma: group of diseases resulting in an increase in intraocular pressure
(IOP); leads to slow, painless loss of vision due to too much production of aqueous humor or it does
not drain. It can lead to compression of retinal blood supply and damage to the retina and optic
nerve.
- Open-angle: Either too much aqueous humor or does not drain fast enough; no early symptoms or
warning signs; peripheral vision affected first
- Closed-angle/narrow-angle: treated as an emergency; outflow is stopped due to angle between iris
and cornea; dilated pupil unreactive to light, redness, pain, vomiting, blurred vision with halos; can
occur after administering dilating eyedrops
Describe the causes and clinical manifestations of the following forms of visual dysfunction: Macular
degeneration - ANSWER - Macular degeneration: macula, central part of the retina, degenerates
resulting in the loss of central vision
- Dry: most common, less severe, blurry or wavy central vision with normal peripheral vision
- Wet: severe, new blood vessels form growing around macula and cause bleeding, scarring, and
photoreceptor atrophy; damage is irreversible and occurs quickly
Describe the causes and clinical manifestations of the following forms of visual dysfunction: Diabetic
retinopathy - ANSWER - Retinopathy: any disorder leading to retina damage which is the nerve layer
lining the inside of the eye; damage results in vision loss in the corresponding field
,- Diabetic retinopathy: change in blood vessels overtime due to diabetes
- Nonproliferative: elevated blood glucose over a long period of time; walls of eye vessels weaken,
begin to leak fluid into the macula and space between nerves.
- Proliferative: next stage, tiny new vessels grow into vitreous humor clouding vision; can disrupt
aqueous humor outflow leading in neurovascular glaucoma
Describe the causes and clinical manifestations of the following forms of visual dysfunction:
Cataracts. - ANSWER - Cataracts: cloudy or opaque discoloration of an otherwise clear lens
- Symptoms gradual in onset, slow decrease in acuity, cloudy/blurring vision
- Risk factors: age, UV, light, congenital abnormalities, and pharmacologic triggers like medications
Describe the causes and clinical manifestations of the following forms of visual dysfunction: Retinal
detachment - ANSWER - Retinal detachment: retina separates from underlying structure; can occur
secondary to cataract surgery, proliferative diabetic retinopathy, and trauma
- Sudden onset of floaters, flashes of light, "veil" falling over vision
Which cranial nerve is required for hearing? - ANSWER Cranial Nerve VIII
Describe the causes and clinical manifestations of common hearing disorder exemplars: conductive
hearing loss - ANSWER - Impacts outer and middle ear structure-- sounds processed in the inner ear
are no longer as loud as they should be when they reach that area
- Cerumen impaction: wax blocks sound waves
- Otosclerosis: abnormal bone growth, fixation of stapes interferes with sound transmission
(genetics)
- Otitis media: infection
Describe the causes and clinical manifestations of common hearing disorder exemplars:
sensorineural hearing loss - ANSWER - Damage to the structures of the inner ear; frequency and
intensity of sound can no longer be accurately processed or transmitted to auditory cortex
- Presbycusis: loss due to aging
- Ototoxicity: certain medications can damage sensory cells of cochlea; aminoglycosides and
diuretics
Describe the causes and clinical manifestations of common hearing disorder exemplars: Causes of
mixed hearing loss - ANSWER Elements of both conductive and sensorineural are present
, What are the three major tracts of spinal cord injury? - ANSWER - Corticospinal: originates in the
brain-- crosses over in the brainstem and innervates on the opposite side of the body (motor)
- Spinothalamic: originates in the spinal cord, crosses over within 2 segments of entry into the cord,
and ascends to the thalamus in the brain (pain and temperature)
- Posterior column: posterior horn contains axons from the peripheral sensory neurons
(proprioception, light touch, and vibration)
Describe the loss of impulse conduction and inflammatory process for spinal cord injuries - ANSWER -
Secondary injury
- Loss of impulse conduction: after injury-- Ca++ influxes into the cells; inhibits impulse conduction;
increases ischemia (due to vasoconstriction and decrease of blood flow); increases lipid
peroxidation-- free fatty acids released from spinal cord-- increased vasospasm
- Inflammatory process: endothelial damage; increased vascular permeability; edema; and,
inflammatory cell migration
Contrast different levels of cord injury with complications present during varying phases of injury:
Paraplegia - ANSWER - Thoracic/lumbar paraplegic (altered function below level; altered DTR)
- S 1-2 (neurogenic/bladder/sexual/DTR function)
Contrast different levels of cord injury with complications present during varying phases of injury:
Quadriplegia - ANSWER - C 3-4 (altered phrenic nerve, neck, scapula)
- C 5-6 (altered deltoid/biceps/DTR function)
- C 6-7 (altered triceps/DTR function)
- C 8 - T1 (altered finger function)
Which spinal cord injury leads to death? - ANSWER C 1-2 (odontoid)
Contrast different levels of cord injury with complications present during varying phases of injury:
Spinal shock - ANSWER - Temporary loss of all or most spinal reflex activity below the level;
interruption of sympathetic outflow pathways and uninhibited parasympathetic impulses
- Leads to hypotension, decreased vascular resistance, vascular dilation, bradycardia, and blockage
of SNS outflow
Contrast different levels of cord injury with complications present during varying phases of injury:
Autonomic dysreflexia. - ANSWER - May occur after spinal shock resolves
Guide
Differentiate sensation, perception, and sensory perception. - ANSWER - Sensation: ability to
perceive stimulation from sensory orgANSWER (internal: pain; external: pain, temperature, light)
- Perception: process by which we receive, organize, and interpret sensation
- Five senses: vision, hearing, sight, taste, touch
Which cranial nerves are involved with vision? - ANSWER Cranial Nerves II, III, IV, V, and VII
What does the iris, lens, and retina do? - ANSWER - Iris: regulates amount of light entering the eye
- Lens: bends light rays so they properly fall on the retina
- Retina: innermost area, transforms light impulses to electrical impulses that are sent to the optic
nerve which communicates to the brain to produce vision
Describe the causes and clinical manifestations of the following forms of visual dysfunction:
Glaucoma - ANSWER - Glaucoma: group of diseases resulting in an increase in intraocular pressure
(IOP); leads to slow, painless loss of vision due to too much production of aqueous humor or it does
not drain. It can lead to compression of retinal blood supply and damage to the retina and optic
nerve.
- Open-angle: Either too much aqueous humor or does not drain fast enough; no early symptoms or
warning signs; peripheral vision affected first
- Closed-angle/narrow-angle: treated as an emergency; outflow is stopped due to angle between iris
and cornea; dilated pupil unreactive to light, redness, pain, vomiting, blurred vision with halos; can
occur after administering dilating eyedrops
Describe the causes and clinical manifestations of the following forms of visual dysfunction: Macular
degeneration - ANSWER - Macular degeneration: macula, central part of the retina, degenerates
resulting in the loss of central vision
- Dry: most common, less severe, blurry or wavy central vision with normal peripheral vision
- Wet: severe, new blood vessels form growing around macula and cause bleeding, scarring, and
photoreceptor atrophy; damage is irreversible and occurs quickly
Describe the causes and clinical manifestations of the following forms of visual dysfunction: Diabetic
retinopathy - ANSWER - Retinopathy: any disorder leading to retina damage which is the nerve layer
lining the inside of the eye; damage results in vision loss in the corresponding field
,- Diabetic retinopathy: change in blood vessels overtime due to diabetes
- Nonproliferative: elevated blood glucose over a long period of time; walls of eye vessels weaken,
begin to leak fluid into the macula and space between nerves.
- Proliferative: next stage, tiny new vessels grow into vitreous humor clouding vision; can disrupt
aqueous humor outflow leading in neurovascular glaucoma
Describe the causes and clinical manifestations of the following forms of visual dysfunction:
Cataracts. - ANSWER - Cataracts: cloudy or opaque discoloration of an otherwise clear lens
- Symptoms gradual in onset, slow decrease in acuity, cloudy/blurring vision
- Risk factors: age, UV, light, congenital abnormalities, and pharmacologic triggers like medications
Describe the causes and clinical manifestations of the following forms of visual dysfunction: Retinal
detachment - ANSWER - Retinal detachment: retina separates from underlying structure; can occur
secondary to cataract surgery, proliferative diabetic retinopathy, and trauma
- Sudden onset of floaters, flashes of light, "veil" falling over vision
Which cranial nerve is required for hearing? - ANSWER Cranial Nerve VIII
Describe the causes and clinical manifestations of common hearing disorder exemplars: conductive
hearing loss - ANSWER - Impacts outer and middle ear structure-- sounds processed in the inner ear
are no longer as loud as they should be when they reach that area
- Cerumen impaction: wax blocks sound waves
- Otosclerosis: abnormal bone growth, fixation of stapes interferes with sound transmission
(genetics)
- Otitis media: infection
Describe the causes and clinical manifestations of common hearing disorder exemplars:
sensorineural hearing loss - ANSWER - Damage to the structures of the inner ear; frequency and
intensity of sound can no longer be accurately processed or transmitted to auditory cortex
- Presbycusis: loss due to aging
- Ototoxicity: certain medications can damage sensory cells of cochlea; aminoglycosides and
diuretics
Describe the causes and clinical manifestations of common hearing disorder exemplars: Causes of
mixed hearing loss - ANSWER Elements of both conductive and sensorineural are present
, What are the three major tracts of spinal cord injury? - ANSWER - Corticospinal: originates in the
brain-- crosses over in the brainstem and innervates on the opposite side of the body (motor)
- Spinothalamic: originates in the spinal cord, crosses over within 2 segments of entry into the cord,
and ascends to the thalamus in the brain (pain and temperature)
- Posterior column: posterior horn contains axons from the peripheral sensory neurons
(proprioception, light touch, and vibration)
Describe the loss of impulse conduction and inflammatory process for spinal cord injuries - ANSWER -
Secondary injury
- Loss of impulse conduction: after injury-- Ca++ influxes into the cells; inhibits impulse conduction;
increases ischemia (due to vasoconstriction and decrease of blood flow); increases lipid
peroxidation-- free fatty acids released from spinal cord-- increased vasospasm
- Inflammatory process: endothelial damage; increased vascular permeability; edema; and,
inflammatory cell migration
Contrast different levels of cord injury with complications present during varying phases of injury:
Paraplegia - ANSWER - Thoracic/lumbar paraplegic (altered function below level; altered DTR)
- S 1-2 (neurogenic/bladder/sexual/DTR function)
Contrast different levels of cord injury with complications present during varying phases of injury:
Quadriplegia - ANSWER - C 3-4 (altered phrenic nerve, neck, scapula)
- C 5-6 (altered deltoid/biceps/DTR function)
- C 6-7 (altered triceps/DTR function)
- C 8 - T1 (altered finger function)
Which spinal cord injury leads to death? - ANSWER C 1-2 (odontoid)
Contrast different levels of cord injury with complications present during varying phases of injury:
Spinal shock - ANSWER - Temporary loss of all or most spinal reflex activity below the level;
interruption of sympathetic outflow pathways and uninhibited parasympathetic impulses
- Leads to hypotension, decreased vascular resistance, vascular dilation, bradycardia, and blockage
of SNS outflow
Contrast different levels of cord injury with complications present during varying phases of injury:
Autonomic dysreflexia. - ANSWER - May occur after spinal shock resolves
