Anatomy and Physiology

    Renal System
    Glomerular filtration rate can be altered by all of the following EXCEPT one. Which one?
    Macula densa does not constrict the tubule. A decrease in plasma protein would increase the osmotic pressure opposing glomerular filtration.
    Author: rikazzz Comment
    Chemistry for Physiology
    If a red blood cell (RBC) is placed in a solution that has a greater concentration than that inside the RBC, what will happen?
    Water will flow by osmosis from the RBC into the surrounding solution. If the difference in concentration is large enough, the outflow of water will be large, and the RBC will also shrivel (crenate) as a result of this outflow.
    Author: rikazzz Comment
    Cardiovascular System
    Exchange between the blood and the interstitial fluid occurs most readily through which type of capillary?
    Sinusoids have the largest gaps (intercellular clefts) between cells.
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    Ionising Radiation
    Consider the “inverse square law”. Compared to being 1 m from a point x-ray source, what will be the photon flux at a distance of 4 m from the source?
    “Inverse square” means at double distance, the flux will be one half squared of the original flux (½)2 = ¼. At 4x the distance, the flux will be (¼)2 = 1/16.
    Author: rikazzz Comment
    Ionising Radiation
    Which of the following imaging modalities uses x-rays?
    CT machines generate x-rays. The others are all nuclear medicine procedures.
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    Renal System
    How does the composition of the filtrate change as it travels through the loop of Henle?
    The descending limb is permeable to water, so water flows out of the tubule decreasing filtrate volume. The ascending limb is impermeable to water, so its volume does not change; however, sodium, potassium and chloride ions are reabsorbed which decreases the concentration of the filtrate.
    Author: rikazzz Comment
    Chemistry for Physiology
    Which of the following refers to the concentration of a solution?
    Although “pressure” appears in this term, it refers to the solution concentration when expressed in units of pressure. Choice D also refers to a concentration but of only one of the dissolved species.
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    Renal System
    Which of the statements about the capillaries of the glomerulus is NOT true?
    Capillary walls are made of endothelial cells; there is no smooth muscle.
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    Cells and Tissues
    Which of the following cell types denote an immature cell?
    The suffix “-blast” indicates that the cell is immature.
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    The Physics of Waves: Light Waves, Sound Waves and Ultrasound
    Which of the statements about sound and light is INCORRECT?
    In fact both ultrasound and ultraviolet light have frequencies GREATER than infrasound and infrared light, respectively.
    Author: rikazzz Comment