The duodenal lumen (and pancreatic proteases like CHYMOTRYPSIN) is the site where pancreatic enzymes (“endopeptidases”) cleave large polypeptides into smaller bits (=dipeptides,tripeptides). It is at the BRUSH BORDER where the smallest kinds of peptides (dipeptides,tripeptides) are broken down into their amino acids, which finally can be co-transported with Na+ into the intestinal cell.

I think about it this way:

• stomach acid denatures and “opens up” proteins (without specific cleavage);
• pancreatic enzymes then cleave denatured polypeptides into smaller bits;
• brush border enzymes finally break down tiniest peptides into absorbable amino acids.

this question makes me want to eat an e coli cookie and hope i bleed out

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.

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.

Urea Cycle Disorders > Isolated severe hyperammonemia (> 1000; i.e., no other severe metabolic disturbances

Ornithine transcarbamylase deficiency > (most common urea cycle dis.) orotic acidemia/aciduria, hyperammonemia

Organic Acidemias > Hyperammonemia, anion-gap acidosis, ketosis (from hypoglycemia)

Medium-chain acyl-CoA dehydrogenase deficiency > Hyperammonemia, hypoketotic hypoglycemia (seen in β-oxidation disorders, EXCEPT adrenoleukodystrophy)

Liver dysfunction > Hyperammonemia, LFTs messed up, older pt.

the majority of carbon dioxide molecules are carried as part of the bicarbonate buffer system. In this system, carbon dioxide diffuses into the RBCs. Carbonic anhydrase (CA) within RBCs quickly converts the carbon dioxide into carbonic acid (H2CO3). Carbonic acid is an unstable intermediate molecule that immediately dissociates into bicarbonate ions (HCO3-) and hydrogen (H+) ions.

The newly synthesized bicarbonate ion is transported out of the RBC into the plasma in exchange for a chloride ion (Cl−); this is called the chloride shift. When the blood reaches the lungs, the bicarbonate ion is transported back into the RBC in exchange for the chloride ion. The H+ ion dissociates from the hemoglobin and binds to the bicarbonate ion. This produces the carbonic acid intermediate, which is converted back into carbon dioxide through the enzymatic action of CA. The carbon dioxide produced is expelled through the lungs during exhalation.

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.

Which of the following reasons is why this question is bull?

1) Using the word "cyclic" instead of tricyclic for clarity

2) Knowing all of epidemiology of all drugs

3) having to reason out that anticholinergic effects are probably the worst over alpha1 or H1 effects to no certainty.

4) The crippling depression of studying for days-to-weeks on end to probably do average on the test.

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.