Week 4 Flashcards
1
Q
Aqueous humor is produced by what structure?
A
the ciliary epithelium
2
Q
Aqueous humor is able to drain from the eye when what is true about the ciliary muscle and trabecular meshwork?
A
the ciliary muscle is contracted and tension in the trabecular meshwork is high
3
Q
What anterior eye structures receive parasympathetic innervation?
A
the sphincter pupillae and ciliary muscles
4
Q
What anterior eye structure expresses alpha-adrenergic receptors?
A
the radial pupillae muscle
5
Q
What anterior eye structure expresses beta-adrenergic receptors?
A
the ciliary epithelium
6
Q
Sympathetics do what to pupil diameter?
A
dilating it
7
Q
Is the accomodated eye best for seeing near or far objects?
A
near
8
Q
Describe the accomodated eye.
A
- constricted pupil
- rounded lens
- contracted ciliary muscle
- relaxed zonular fibers
9
Q
When the ciliary muscle is contracted, what happens to the lens?
A
it becomes rounder
10
Q
Is a rounder lens better for seeing far or near objects?
A
near
11
Q
Aqueous humor drains faster in response to stimulation by what division of the ANS?
A
parasympathetic
12
Q
Describe all the changes in the anterior eye associated with parasympathetic stimulation.
A
- near vision
- accomodated eye
- round lens
- constricted pupil
- contracted ciliary muscle
- contracted sphincter pupillae muscle
13
Q
Describe all the changes in the anterior eye associated with parasympathetic stimulation.
A
- far vision
- unaccommodated eye
- flat lens
- dilated pupil
- relaxed ciliary muscle
- contracted radial pupillae muscle
14
Q
What division of the ANS stimulates lacrimation?
A
parasympathetic
15
Q
What is carbachol?
A
a direct muscarinic agonist
16
Q
What is physostigmine?
A
an indirect muscarinic antagonist (AChE inhibitor)
17
Q
How do opiates elicit a constricted pupil?
A
via a central mechanism that inhibits radial pupillae contraction
18
Q
What is tropicamide?
A
a muscarinic antagonist used to open the pupil for an opthalmic exam
19
Q
What is mydriasis?
A
dilated pupil
20
Q
What is miosis?
A
constricted pupil
21
Q
What is phenylephrine?
A
a direct alpha-adrenergic agonist
22
Q
What is timolol?
A
a beta-adrenergic antagnoist
23
Q
Cocaine has what effect on the ANS of the eye?
A
it is an indirect adrenergic agonist
24
Q
What medication can be used to treat open angle glaucoma?
A
timolol, a beta-adrenergic antagonist
25
How can we medically control derangements of pain conduction?
with anti-epileptics
26
Fast pain is carried via what class of sensory afferent fibers?
A(delta)
27
Fast pain is carried by what division of the spinothalamic tract?
neothalamic
28
In addition to the thalamus, the paleothalamic tract projects where?
- periaqueductal grey
- reticular formation
- limbic system
- hypothalamus
29
Visceral pain is conducted by what class of sensory afferent fibers?
C fibers
30
Abnormal pain can be due to what four derangements?
- sensitization
- conduction
- modulation
- perception
31
What is reflex sympathetic dystrophy?
a derangement of sensitization seen after periods of immbolization
32
What is trigeminal neuralgia?
a derangement of conduction in which focal demyelination leads to cross talk between bare axons
33
What is post-herpetic neuralgia?
a derangement of pain modulation in which there is too little non-pain input to the brain for gate-control theory
34
Describe the pathway for descending pain modulation.
- cortex
- periaqueductal grey matter (enkephalin neurons)
- nucleus raphe magnus in medulla (NE/5HT neurons)
- dorsal horn interneurons (enkephalin neurons)
- A(delta) and C fibers
35
What NTs mediate the descending pain modulation pathway.
- periaqueductal neurons are enkephalin-producing
- nucleus raphe magnus are NE/5HT-producing
- the interneurons in the dorsal horn are enkephalin-producing
36
What are four methods for decreasing peripheral sensitization of pain?
- early mobility
- capsacin
- NSAIDs
- steroids
37
What classes of medications improve descending modulation of pain?
- antidepressants (NE/5HT)
| - opiods
38
What are the components of the reticular activating system?
- the pontomesencephalic reticular formation
- the intralaminar and thalamic reticular nuclei
- the cortex
39
The reticular formation is divided into what three columns?
- raphe nuclei (midline)
- medial (magnocellular)
- lateral (parvocellular)
40
What defines alpha, beta, theta, and delta waves?
- beta 12 or more Hz
- alpha: 8-11 Hz
- theta: 5 to 7 Hz
- delta: less than 5 Hz
41
In what state is alpha activity present in the brain?
a relaxed wakefulness with eyes shut
42
In what parts of the brain are alpha waves seen?
the back of the brain
43
Why is the thalamic reticular nucleus important?
it is the pacemaker of the brain responsible for synchronicity
44
The thalamic reticular nucleus works by modulating what?
the dorsal thalamus and thalamocortical circuits
45
Thalamic reticular neurons utilize what NT?
GABA
46
The thalamic reticular nucleus is modulated by what input?
that from the reticular activating formation
47
What sort of brain activity is seen in stage 1 sleep?
theta waves replace alpha waves
48
What sort of brain activity is seen in stage 2 sleep?
sleep spindles and k-complexes
49
What is synchronized EEG activity?
high-amplitude, low-frequency waves
50
What physiologic changes throughout the body accompany slow-wave sleep?
- low metabolic rate
- diminished sympathetic output (BP and HR drop)
- minimal muscle tone and reflexivity
51
How is atonia achieved during REM sleep?
active inhibition of alpha motor neurons
52
What is the reticulo-spinal tract?
the descending tract responsible for inhibiting alpha motor neurons during REM sleep
53
Describe the involvement of the cholinergic system in sleep.
the basal forebrain is responsible for initiation of sleep
54
Describe the involvement of the noradrenergic system in sleep.
the locus ceruleus initiates wakefulness and REM sleep
55
Describe the involvement of the serotonergic system in sleep.
the median raphe of the reticular formation helps initiate slow wave sleep
56
Initiation of sleep, initiation of REM, and initiation of slow wave sleep are associated with which NT systems and structures, respectively?
- initiation: cholinergic, basal forebrain
- REM: noradrenergic, locus ceruleus
- slow-wave: serotonergic: median raphe
57
What is the suprachiasmatic nucleus?
a brain structure responsible for monitoring light/dark cycles and setting the circadian rhythm
58
What is melanopsin?
a photopigment expressed by some retinal ganglion cells that are light sensitive and project to the suprachiasmatic nucleus
59
How does the suprachiasmatic nucleus set the circadian rhythm?
by stimulating the pineal gland to secrete melatonin
60
What is the retinohypothalamic tract?
a tract formed by photosensitive retinal ganglion cells projecting to the suprachiasmatic nucleus
61
Congenital cataracts are associated with what?
rubella infection
62
Which genetic conditions are associated with cataract formation?
- Wilson's disease
| - Lowe syndrome
63
What medication can cause cataracts?
steroids
64
What is posterior capsular opacification?
the most common complication of cataract surgery in which bits of lens remain and proliferate on the posterior capsule
65
What are the signs and symptoms of closed-angle glaucoma?
- pain, blurred vision, seeing halos
- nausea/vomiting
- mid-dilated pupil with edematous cornea
- history of hyperopia
66
Glaucoma causes vision loss in what pattern?
peripheral to central
67
What are drusens?
yellow deposits under the retina that form in those with macular degeneration
68
What are AREDS vitamins?
those to treat and prevent instances of dry macular degeneration
69
What is the treatment for neovascularizing ocular problems?
anti-VEGF injections
70
What is panretinal photocoagulation?
ablation of the peripheral retina to limit the eye's oxygen requirements and slow diabetic proliferative retinopathy
71
What are the common causes of cherry red spot?
- Tay-Sachs
- Niemann Pick
- Sandhoff
72
What is exophthalmos?
a bulging of the eye due to any disease that increases the orbital contents
73
Exophthalmos is a common feature of what endocrine disorder?
Grave's disease
74
Sties are caused by what?
acute folliculitis of teh Meibomian or Zeis glands
75
The most common malignancy of the eyelid is what?
BCC
76
What is pink eye?
a bacterial conjunctivitis
77
What organisms are most likely to cause pink eye?
H. influenza and S. pneumoniae
78
What is epidemic keratoconjunctivitis?
a viral conjunctivitis caused by adenovirus
79
What is the leading cause of blindness worldwide?
chlamydia trachomitis
80
What is opthalmia neonatorum?
a gonococcal infection of the eye acquired by newborns as they pass through the birth canal
81
Yellow matting in the morning is a feature of what ocular disease?
pink eye
82
What is keratoconjunctivitis sicca?
dry eye
83
Dry eye is a feature of what syndrome?
Sjogren
84
What populations are most likely to be affected by idiopathic dry eye?
- post-menopausal women
| - young, pregnant women
85
What is pterygium?
a growth of vascularized conjunctival tissue over the iris
86
Blue sclera is a feature of what pathology?
osteogenesis imperfecta
87
How do corneal abrasions often present?
individual thinks they have something in their eye but can't get anything out
88
What is the "chinese character" sign?
a sign of herpes simplex corneal ulcers
89
What are corneal degenerations and corneal dystrophies?
- degenerations are non-familial
| - dystrophies are familial and bilateral
90
Senile cataracts is thought to be caused by what?
misfolding of lens fibers due to UV exposure
91
Optic nerve cupping is a feature of what disease?
glaucoma
92
What form of vasculitis principally affects the eyes?
Takayasu aortitis
93
What is retinopathy of prematurity?
a proliferative retinopathy induced by high oxygen tension in premature infants
94
What is toxocara spp.?
an organism contracted from dogs or cats and likely to cause retinitis in children
95
What are the two types of retinal detachment?
- rhegmatogenous: with a tear
| - non-rhegmatogenous: without an associated tear
96
Non-rhegmatogenous retinal detachments are most often caused by what?
choroiditis or melanoma
97
What is papilledema?
edema of the head of the optic nerve due to elevations of CSF pressure
98
Always check for papilledema before performing what other procedure?
spinal tap
99
Retinoblastomas are typically present in what age group?
infants, younger than two years old
100
Children diagnosed with a retinoblastoma are at risk for what other malignancy?
osteosarcoma
101
What features of the eye constitute the uvea?
the iris, choroid, and ciliary body
102
What is the first clinical sign of retinoblastoma?
no red reflex
103
What is the most common malignancy of the eye?
a metastasis that involves the uveal tract
104
Uveal tract melanomas typically metastasize to where?
the liver
105
What is panophthalmitis?
a term used to describe inflammation of the interior eye that extends into the uvea and sclera
106
What is endophthalmitis?
a term used to describe inflammation of the interior eye involving the vitreous
107
Autism is a neurodevelopmental disorder affecting what?
social abilities and communication
108
What is cerebral palsy?
a neurodevelopmental disorder affecting motor abilities
109
What is the definition of intellectual disability?
- intelligence below average that affects daily living
| - IQ below 70 with an onset before age 18
110
What are some causes of intellectual disability?
- down's
- fragile X
- Rett syndrome
- lead exposure
- neonatal injury
111
What are the diagnostic criteria for autism?
impaired socialization detected before age three
112
What is autism spectrum disorder?
includes people with more mild forms of autism that are detected after age three
113
What is the theory of the mind?
the ability of humans to understand the mental state of others
114
Why is early socialization normal even in autistic individuals?
because it is automatic and requires no consciousness
115
What are the four types of cerebral palsy? What sort of lesion causes each?
- spastic (upper motor neuron damage)
- ataxic (cerebellar damage)
- dyskinetic (basal ganglia damage)
- hypotonic
116
What is dyskinetic cerebral palsy?
that due to basal ganglia damage and characterized by rigidity and abnormal involuntary movements
117
What are the features of ataxic cerebral palsy?
severe appendicular and gait ataxia
118
What is the germinal matrix?
an area within the brain that populates the cerebral cortex with neurons during development
119
Why is the germinal matrix clinically important?
it has a very fragile capillary network and is prone to ischemic strokes and hemorrhage in babies born before 32 weeks gestation
120
Which infants are likely to suffer a germinal matrix hemorrhage?
those born before 32 weeks gestation when the GM involutes
121
Hypoperfusion is most likely to affect what brain regions in preterm infants?
watershed zones (periventricular)
122
What is periventricular leukomalacia?
ischemia in the watershed territory of preterm infants
123
Vascular insult to the brain in the perinatal period is most likely to result in ischemia where in the brain?
the periventricular region
124
A brain scan will reveal what in infants that suffered a periventricular leukomalacia?
diminished white matter
125
Why is diplegic cerebral palsy most common?
because it CP often results from a periventricular hemorrrhage or leukomalacia and those events affect the leg fibers first, and the arm fibers second due to anatomy
126
A vascular insult in a preterm infant is most likely to cause what kind of cerebral palsy?
a diplegic spastic cerebral palsy
127
A vascular insult in a term infant is most likely to cause what kind of cerebral palsy?
a hemiplegic spastic cerebral palsy
128
Intellectual disability is most likely to result from what sort of vascular insult?
a pure hypoxia affecting the cerebral cortex
129
Dyskinetic CP is most likely to result from what sort of vascular insult?
a pure hypoxia affecting the basal ganglia
130
Ataxic CP is most likely to result from what sort of vascular insult?
a pure hypoxia affecting the purkinje cells of the cerebellum
131
What is kernicterus?
a bilirubin-induced neurologic dysfunction
132
Kernicterus is likely to cause what developmental encephalopathy?
dyskinetic cerebral palsy
133
List the brain structures most sensitive to hypoxia?
- cerebral cortex
- basal ganglia
- cerebellum
134
Where are the watershed areas in the adult brain?
in the cortex
135
Problems with sleep initiation are often linked to what emotional disturbance?
anxiety
136
Problems staying asleep are often linked to what emotional disturbance?
depression
137
What is parasomnia?
abnormal behavior during sleep
138
What is sleep inertia?
problems transitioning from sleep to wakefulness
139
Failure of REM paralysis often precedes the onset of what disease?
Parkinson's
140
What are extrinsic circadian rhythm disorders?
those due to changes in the environment (e.g. time zone change)
141
What is non-24-hour sleep-wake syndrome?
a person that is unable to entrain their circadian rhythm to the environment (often due to blindness)
142
Excessive daytime sleepiness can be due to what four things?
- inadequate quantity
- inadequate quality
- narcolepsy
- idiopathic
143
What might cause poor quality of sleep and therefore excessive daytime sleepiness?
- parasomnia
| - sleep apnea
144
What are the features of narcolepsy?
- daytime sleepiness
- cataplexy
- sleep paralysis
- hypnagogic hallucinations
145
What is cataplexy?
abrupt and reversible loss of muscle tone elicited by strong emotion
146
What is abnormal about the sleep cycle of individuals with narcolepsy?
they often enter REM as they are falling asleep rather than going to stage 1
147
Narcolepsy is thought to arise from dysfunction regulating what process?
REM sleep
148
What are hypnagogic hallucinations?
an almost dream like hallucination that accompanies sleep paralysis
149
Convulsions are often associated with what other event?
syncope
150
What is a seizure?
a clinical manifestation of abnormal synchronous discharge of cerebral cortical neurons
151
How are seizures categorized?
focal (partial)
- with retained awareness (simple)
- with impaired awareness (complex)
- focal to bilateral (secondary generalized)
generalized (primary generalized)
- motor: tonic-clonic (grand mal) or myoclonic (brief jerk)
- nonmotor (absence)
152
What is epilepsy?
an intrinsic tendency of the brain to have seizures
153
What is the diagnostic criteria for epilepsy?
two or more unprovoked seizures
154
Focal epilepsies are usually due to ___ while generalized epilepsies are due to ___.
- focal: structural damage
| - generalized: genetic predisposition
