A and J represent the gracile fasciculus, while B and I represent the cuneate fasciculus. Together they make up the dorsal column-medial lemniscal tract, responsible for pinpoint perception, proprioception, vibration, and pressure. Input is ipsilateral.
C and H make up the lateral corticospinal tract (also called the lateral cerebrospinal fasciculus), responsible for motor command of ipsilateral limbs.
D and G represent the lateral spinothalamic tract. It is responsible for pain and temperature conduction. The input arises in a limb (left lower extremity in this case), enters through the dorsal root (pictured between J and H), decussates and ascends at the anterior commissure (just behind E and F), and finally synapses on the second order neuron in the lateral spinothalamic tract. So the spinothalamic tract is responsible for contralateral pain and temperature sensation. Because our patient has lost sensation on the left, the lesion is in the right.
E and F are the anterior corticospinal tract. It is involved in motor control of proximal muscles, typically of the trunk.
A very similar question I have seen in Qbanks will ask why a patient with right heart failure does not develop edema and the answer is increased lymphatic drainage. I got this question wrong originally because I answered along this line of reasoning but I think in this case it all has to do with WHERE the extra pressure is coming from. In this question the pt has diastolic hypertension so you can think about the pressure as coming "forward" so constricting precapillary sphincters can prevent an increase in pressure in the capillary bed. However for right heart failure this extra fluid is coming from the OPPOSITE direction (backwards from the right heart) and constricting precapillary sphincters can do nothing (on opposite side of capillary bed) - the only way to prevent edema is to increase lymphatic drainage.
Coloboma is an eye abnormality that occurs before birth. They're missing pieces of tissue in structures that form the eye.
Colobomas affecting the iris, which result in a "keyhole" appearance of the pupil, generally do not lead to vision loss.
Colobomas involving the retina result in vision loss in specific parts of the visual field.
Large retinal colobomas or those affecting the optic nerve can cause low vision, which means vision loss that cannot be completely corrected with glasses or contact lenses.
Was it just me, or did "age at onset in years" appear RIGHT above the number of patients, rather than the mean. Which confused me for a good 3 minutes.
Alcoholic = pancreatic insufficiency. Linoleic, oleic, and palmitic acid can be absorbed without pancreatic lipases since they're just free fatty acids. Triglycerides need to be broken down by lipases before absorption.
Bile acids are the main method for eliminating cholesterol, not pancreatic enzymes
What a terrible picture. They they covered up part of it with lines. WTF
you need to know diff bt negative pressure ventilation (which is normal ventilation) and positive presssure ventilation (which is mechanical ventilation). In negative pressrue ventilation the diaphragm contracts making a - intrapleural pressure which allows alveoli to expand. in positive ventilation (the pt diaphragm is not contracting thus not expanding chest cavitiy and not creating the - pressure) the machine is creating positive pressure inside alveoli so so alveoli expands. :)
Maintenance dose formula is (CssCltau)/F where Css is steady-state target plasma conc. of drug, Cl is clearance, tau is dosage interval & F is bioavailability.
Neither dosage interval nor bioavailability is given, so ignoring those & plugging in the numbers (careful to convert units to mg/kg/day): (12 ug/mL * 1 mg/1000 ug) * (0.09 L/hr/kg * 1000 mL/1 L * 24 hr/1 day) = 25.92 mg/kg/day
...which isn't any of the answer choices listed. They must have rounded 0.09 L/hr/kg to 0.1 L/hr/kg, and doing so gives exactly 28.8 mg/kg/day (choice C)
Critical points for this question: 5 year old boy, immunosuppressed because of chemotherapy, 2 day history of fever, cough, shortness of breath, febrile (101.8 F), respirations 46/min, with cyanosis and generalized vesicular rash. Extensive nodular infiltration.
Of the options listed only measles and VZV give a rash. A rash from measles usually starts rostrally and descends caudally, and is flat and erythematous. By contrast, VZV (chickenpox) presents with generalized rash that quickly transitions from macular to papular then to vesicular.
The best I can understand, they're describing endometrial hyperplasia, a result of excess estrogen, a steroid hormone that translocates to the nucleus and binds its transcription factor.
So for Candida we can use
Azoles (fluconazole) (inhibit CYP450 demethylation)
Amphotercin B (pore formation in fungal cell membrane)
Caspofungin (prevent crosslinking of beta glucans in cell wall)
or Nysatin for oral or esophageal cases (pore formation)
This question is saying that she is taking an ORAL drug to treat candida vaginitis.
Amphotercin is IV
Caspofungin is also IV
so we're left with azoles
Azoles inhibit synthesis of ergosterol by inhibiting CYP 450 that converts lanosterol to ergosterol.
This is a type II Renal Tubular Acidosis. My Medical School Never taught this to me. Did you also go to poverty med school? I'm surprised they even gave us toilet paper.
Malaria can impair hepatic gluconeogenesis and can also consume glucose for its own metabolic demands.
He has fecal incontinence so his external sphincter is damaged, which is innervated by the pudendal n. (S2-S4). The pelvic splanchnic nerves, which mediate the erection process, are also S2-S4.
Attributable risk = incidence in exposed – incidence in unexposed
= 30/1,000 (smokers)
- 30/3,000 (nonsmokers)
= 0.03 - 0.01
= 0.02 (so the attributable risk is about 2%)
Applying it to a population of 10,000:
= 0.02 * 10,000
Did anyone else go down the: she's hypotensive so maybe she'll get waterhouse friderichsen syndrome because nothing else is making sense to me at this point??? route -
Turns out, severe malaria can cause cardiovascular collapse and hypotension.
surprisingly, I actually learned this from the Magic School Bus when I was a kid. That's the only reason I got this right. Thanks Ms. Frizzle! :D
She just completed the course of rituximab, which targets CD20 receptors. B-cell deficiency can predispose to bacterial infections.
b) BM failure is not associated with rituximab c) wrong d) wrong e) this occurs w/in 7-10 days of starting treatment, and would not occur after completing a 4-month course of rituximab.
Marfanoid habitus + Mucosal neuromas + Neck mass = MEN 2B (PMM) Pheo, Medullary thyroid CA (Calcitonin secreting), mucosal neuromas
The patient has a prior history of hysterectomy with bilateral salpingo-oophorectomy, and received external beam radiation to the pelvis. The patient now displays hydronephrosis and hydroureter, with distal ureteral narrowing bilaterally. The likeliest option is that we are seeing adhesions from previous surgery constrict the ureters, causing this.
E) Urothelial carcinoma (also called transitional cell carcinoma) is also a possibility. What makes this unlikely is the location: bilateral. The prior hysterectomy and bilateral salpingo-oophorectomy would leave scar tissue on both sides of the body, but the odds of urothelial carcinoma arising bilaterally are very slim.
A) The patient had a hysterectomy, so the odds of recurrent cervical carcinoma are also incredibly low. C) and D) Urethral condyloma and urethral transitional cell papilloma are in the wrong location to account for bilateral urethral narrowing with hydroureter.