Week 5 (Test 2) Flashcards
How can damage to CN 7 cause hearing problems?
CN7 damage can cause malfunction of stapedius, and normal sounds can appear very loud, a problem called “hyperacusis”.
Similar to intracellular fluid, high in K+
endolymph
similar to extracellular fluid, high in Na+
perilymph
Which part of the basilar membrane is responsible for detection of low tones?
the apex
which part of the basilar membrane is responsible for detection of high tones?
the base
Which drug class can cause hair cell damage (ototoxicity)?
aminoglycosides
What’s the function of the trapezoid body?
it’s a set of fiber bundles that transmit auditory signals from side to side
What’s the ultimate destination for auditory info?
transverse temporal gyrus
Which Brodmann’s areas represent the primary auditory cortex?
41 & 42
List the auditory pathway (where the signal generated by sound travels to).
organ of Corti–> spiral ganglion –> cochlear nucleus (superior olivery nucleus)–> lateral lemniscus –> inferior colliculus –> brachium–> medial geniculate nucleus –> internal capsule, auditory radiation –> primary auditory cortex, transverse temporal gyrus
What role does the superior olivary nucleus play in hearing?
A structure that helps us to localize the source of a sound, i.e., from the left- or the right-side of the body.
What is the role of efferent cochlear bundles in hearing?
selective attention of sounds–>
In a noisy party we can usually pay attention to the voice of a certain person and ignore other noises
–Signals emitted from the sup. olivery nuc. are sent to the organ of Corti to suppress irrelevant auditory signals so we can focus on the interesting conversation with a certain person.
produce aqueous humor
ciliary processes
Does contracting the ciliary muscle make the lens fatten or become flat? How?
it makes the lens fatten; contracting the ciliary muscle relieves pressure on the zonular fibers (anchor the lens to the ciliary muscle) which allows the lens to fatten
What composes the outer nuclear layer of the retina?
nuclei of rods and cones
modified sweat glands that produce was in the external auditory meatus
ceruminous gland
responsible for sensing vertical movement
saccule
detects rotational movement
CRISTAE AMPULLARES
IN AMPULLAE OF SEMICIRCULAR DUCTS
responsible for sensing horizontal movement
utricle (U HOR)
What fluid is inside the semicircular canals?
endolymph
Hair cells in the utricle/saccule are activated by ______. This helps to detect linear acceleration.
otolith movement
Hair cells in the semicircular canal are activated by ____. This helps to detect angular acceleration.
endolymph movement
What is the vestibulo-ocular reflex test called when you perform it on a comatose patient?
oculocephalic reflex
Direction of nystagmus is defined by the ____.
fast phase
The way to memorize cold/warm water and direction of nystagmus is:
COWS: Cold Opposite, Warm Same
All NSAIDs inhibit ____.
cyclooxygenase
Prostaglandins cause:
vasodilation and inhibition of platelet aggregation
Thromboxane causes:
vasoconstriction and platelet aggregation
What makes aspirin unique amongst the NSAIDs?
it binds to COX irreversibly
What is ibuprofen good for at high dosage?
anti-inflammatory activity as effective as aspirin
What is ibuprofen good for at low dosage?
analgesic
Long half-life, 13 hr
Intermediate potency
Increased incidence of side effects (GI pain most common) compared to ibuprofen likely due to the need for increased dose
Naproxen
Drug of choice to close a patent ductus arteriosus (it was being kept open by PGE2)
Indomethacin
Can be administered orally or parenterally (i.m. or i.v.)
Used primarily for short-term management of pain
May be able to replace morphine in certain conditions but is often used with an opiate
Ketoralac
more selective for COX-2 than the others
Long half-life, 20 h;
Used for osteoarthritis and rheumatoid arthritis in adults
Meloxicam
a selective COX-2 inhibitor used to treat Rheumatoid arthritis, osteoarthritis, acute pain, dysmenorrhea
Celecoxib (Celebrix™)
Inhibits release of chemotactic and inflammatory mediators.
Highly Toxic, low therapeutic index – fatal at 2–5 x normal doses but is now approved for acute attacks of gout
Nausea, vomiting, diarrhea
Colchicine
What are the contraindications for aspirin use?
- Patients with renal disease, bleeding disorders, or hypersensitivity
- Patients with gout – inhibits uric acid excretion
- Young children during or following a viral infection - Reyes Syndrome
- Use with extreme caution during third trimester of pregnancy
used for prevention of gout; Inhibit renal tubular reabsorption of urate
Probenecid
How does allopurinol prevent gout?
converted to alloxanthine by xanthine oxidase to become a suicide inhibitor of xanthine oxidase – blocks urate synthesis
What’s the toxic dose of acetaminophen for kids?
150mg/kg
What’s the toxic dose of acetaminophen for adults?
10 grams
What’s the treatment for acetaminophen overdose? How does it work?
N-acetylcysteine (NAC); acts as a glutathione substitute (glutathione is necessary to take care of the toxic acetaminophen breakdown product, NAPQI)
What are some adverse effects of NAC?
- Vomiting, vomiting, vomiting
- Sulfur smell
- Anaphylaxis associated with IV dosing
What do you give a patient who presents within two hours of acetaminophen overdose ?
activated charcoal
How do local anesthetics work?
Bind to and inhibit the alpha subunit of sodium channel (the subunit through which the Na passes)
THEY PERFORM THE BLOCK FROM INSIDE OF THE CELL, NOT OUTSIDE
Small axonal diameter ____ sensitivity to local anesthetics
INCREASES; have less surface area that need to be blocked
Myelination of axons usually _____ sensitivity to local anesthetics.
DECREASES; an extra layer of padding that separates the nerve from the local anesthetic
What’s the graded sensitivity of spinal nerves to local anesthetics?
autonomic> sensory > motor
Local anesthetics have a lipid soluble group and a water soluble group. What’s the function of the lipid soluble group?
Lipid soluble fraction permeates cell membrane and enters the cell
Local anesthetics have a lipid soluble group and a water soluble group. What’s the function of the water soluble group?
Inside the cell, it is converted into the water soluble fraction which act on the Na+ channels
Of the amide local anesthetics, which has the most rapid onset?
lidocaine
What breaks down amide local anesthetics?
microsomal P450 in the liver
What breaks down ester local anesthetics?
pseudocholinesterase / serum cholinesterase
Which local anesthetics can cause Methhemoglobinemia
Prilocaine & Benzocaine
What does Methemoglobinemia cause?
converts Fe++ to Fe+++;
this causes a change in the way the blood is able to carry oxygen (puts patient in hypoxic shape)
How do you treat a patient suffering from methemoglobinemia?
give them methylene blue
Where do you see early signs of local anesthetic toxicity?
CNS
Effects of local anesthetic toxicity on the cardiovascular system can be seen late and are difficult to treat. What is the one treatment that can work?
intralipids given IV bolus
Pica for ice; specific for iron deficiency
pagophagia
In regards to eating disorders, enlarged salivary glands would indicate what?
bulimia nervosa
Consuming large amounts of food in discrete period of time with sense of lack of control without compensating by purging/exercising
Binge eating disorder
More prevalent than AN or BN
What does the female athletic triad consist of?
Disordered Eating
Amenorrhea
Osteoporosis
In which eating disorder can you see Refeeding syndrome?
anorexia nervosa
in which eating disorder would you see:
- Normal HR
- Arryhthmias secondary to electrolyte disturbances
Bulimia nervosa
In which eating disorder would you see:
- bradycardia and Low BP
- decreased left ventricular mass
anorexia nervosa
_______ in healthy young woman highly specific for BN.
marked hypokalemia
What causes Refeeding syndrome?
when glucose is infused or ingested, it causes a shift of phosphate from the extracellular to the intracellular; All the ATP the body needs is being depleted which causes cardiac problems and results in CHF
___ is very specific for migraines.
Aura
How do you make diagnosis of migraine?
- Lasts 4-72 hours
- Has at least 2 characteristics: unilateral, pulsating, moderate-severe intensity, aggravation by physical activity
- 1 assoc sx: nausea/vomiting, photophobia, phonophobia
- Physical Exam shows no organic disease
- If there is aura, they have one of the 6 types of aura
What are the characteristics of cluster headaches ?
- Pain is deep, excruciating, explosive
- Begins around the eye or temple, ALWAYS UNILATERAL
- May be associated with stabbing ice-pick like pain around the eye
- Most pts prefer to stay active
- Ipsilateral lacrimation, redness of eye, stuffy nose, rhinorrhea, sweating, Horner’s Syndrome
- Lasts 30 minutes to 3 hours
- occur for weeks to months at a time, followed by periods of remission
How do you treat someone who come in with cluster headaches?
hook them up to 100% oxygen
What’s the most common type of headache?
tension headache
What are the clinical manifestations of a tension headache?
- Pressure or tightness all around head
- No nausea/vomiting, phonophobia, photophobia, aura
- Usually occurs at the end of the day
What is a rebound headache?
Seen in patients that complain of daily headache
Seen in patients who overuse NSAIDs, Tylenol, narcotics
What do you see with a ruptured intracranial aneurysm ?
- Severe sudden onset of headache
- “worst headache of my life”
- Decreased level of consciousness and stiff neck are common
Specifically seen in people over 50.
Temporal Arteritis
What should you do if you suspect Temporal Arteritis ?
- Temporal artery biopsy is suggested for all pts suspected of having TA
- Steroids should be started once diagnosis is established
- You may start steroids if you have high suspicion before the TA biopsy but the biopsy should be urgent
Presence of one drug alters the serum concentrations of the 2nd drug
pharmacokinetic interactions
Presence of one drug alters concentration vs. effect relationships for a 2nd drug
–>Changes effect, not concentration
pharmacodynamic interactions
presence of one drug changes Solubility characteristics;
Ex. Add one drug to another and it suddenly precipitates
pharmaceutical interactions
List the common preop sedation combination.
benzodiazepines and opioids
Example: midazolam/propofol
Describe the 2nd gas effect seen with combinations of inhaled agents.
Pharmacokinetic additive interaction;
Uptake of 1st gas (N2O) reduces lung volume and increases concentration of 2nd gas – increases uptake of 2nd gas
What type of drugs are often used with muscle relaxants (neuromuscular blocking drug in particular) to increase the effects of the muscle relaxants?
inhaled agents
What is the combination therapy for PONV (Postoperative and postdischarge nausea and vomiting)?
5HT3 blockers and dopamine blockers [ex.) Ondansetron & droperidol]
But
5HT3 blockers and steroids is the MOST effective combination therapy for PONV
What do you see when damage is done to the efferent parasympathetic limb supplying the pupil?
dilated and unreactive pupil
What do you see when damage is done to the afferent parasympathetic limb supplying the pupil?
Marcus-Gunn pupil –> less reactivity with swinging light test
What do you see when damage is done to the efferent sympathetic limb supplying the eye?
Horner’s syndrome: ptosis, miosis, anhydrosis
What do you need to rule out when someone presents with Horner syndrome?
you need to rule out a tumor in the apex of the lung; T1/T2 nerves run across the apex so tumor present on the apex that is compressing these nerves could be what is causing the problems
A problem with the optic chiasm would lead to what visual defect?
bitemporal hemianopsia
A parietal lobe lesion would lead to what visual defect?
contralateral homonymous inferior quadrantoanopsia
A posterior cerebral artery occlusion would lead to what visual defect?
contralateral homonymous hemianopsia that is macular sparing (a small branch of the middle cerebral artery goes to the tip of the occipital lobe in some people and allows preservation of macular vision)
Why is Argyll-Robertson pupil referred to as “Prostitutes Pupil”?
It is caused by neurosyphilis and it “accommodates but doesn’t react”
That is, it will accommodate (pupil will constrict) when an object is brought near, but won’t react to light.
What causes sensorineural hearing losses? (In general, not specific examples)
Sensorineural hearing losses are due to pathology involving the cochlea or auditory nerve
What causes conductive hearing losses? (In general, not specific examples)
Conductive hearing losses are due to pathology involving the external auditory canal, tympanic membrane or ossicles.
What do you see when performing a Weber test with a patient who has sensorineural hearing loss in one ear?
the sound will be perceived as louder in the good ear
What do you see when performing a Weber test with a patient who has conductive hearing loss in one ear?
the sound will be perceived as louder in the bad ear because with conductive losses, air conduction is reduced but bone conduction is relatively enhanced
What do you see when performing a Rinne test with a patient who has sensorineural hearing loss in one ear?
Air conduction is greater than bone conduction normally and with sensorineural loss
What do you see when performing a Rinne test with a patient who has conduction hearing loss in one ear?
bone conduction will be greater than air conduction
What does the uncinate fasciculus connect ?
temporal to orbital gyri of frontal lobe
What does the arcuate fasciculus connect ?
superior temporal to middle and inferior frontal
What does the superior longitudinal fasciculus connect?
frontal with parietal and occipital
What does the inferior longitudinal fasciculus connect?
temporal with parietal and occipital
What does the cingulum connect?
frontal and parietal to parahippocampal and adjacent temporal
What commonly causes Alexia without Agraphia (inability to read without the inability to write)?
posterior cerebral artery stroke
