Anatomy and Physiology

    Electricity
    A person, holding to the edge of the bath, steps out onto an exposed wire in a frayed electrical cord attached to a domestic (240 V) radiant heater on the floor. Consequently a fatal current of 100 mA flows between their hand and foot. What must be the electrical resistance between these two points?
    Using Ohm’s law: V = I × R, so R = V ÷ I and realising that 100 mA = 0.1A, putting in the numbers gives: R = 240 × 0.1 = 2400 ohms
    Author: rikazzz Comment
    Respiratory System
    The volume of air which moves in and out of the lungs during a normal quiet respiratory cycle is called the:
    Tidal volume is the volume of air that is inhaled and exhaled while “at rest”.
    Author: rikazzz Comment
    Body Temperature, Energy and Heat Loss
    Which of the following is a biological mechanism of preventing heat loss?
    Vasoconstricting blood vessel close to the body surface will withdraw blood from the surface and allow the skin temperature to cool.
    Author: rikazzz Comment
    Nervous System
    Which of the following is true of anaxonic neurons?
    Choice B would be true of unipolar neurons. Choice C would be true of multipolar neurons. Choice D is true, but A is a better answer as it is more specific.
    Author: rikazzz Comment
    Renal System
    What molecule catalyses the formation of angiotensin I?
    Renin is an enzyme that catalyses the reaction that forms angiotensin I from angiotensinogen.
    Author: rikazzz Comment
    Nervous System
    Which of the following auditory structures are filled with fluid?
    The cochlea and the three semi-circular canals of the inner ear are filled with fluid.
    Author: rikazzz Comment
    Cells and Tissues
    Which of the following enables ions such as sodium to cross a plasma membrane?
    One function of integral protein in the PM is to form channels to allow for the passage of ions.
    Author: rikazzz Comment
    Chemistry for Physiology
    A solution that is isotonic to blood plasma is one which:
    The concept of tonicity involves reference to a membrane (in this case the plasma membrane of a RBC). Osmolarity is a property of the solution (and of how much solute is dissolved in it) and exists whether a semipermeable membrane is present or not.
    Author: rikazzz Comment
    Integument
    Which is the deepest layer of the integument?
    The dermis includes the papillary layer and the deeper reticular layer.
    Author: rikazzz Comment
    Ionising Radiation
    Which one of the following sources contributes to the background radiation?
    Background radiation is that radiation that is impossible to avoid as it is part of our natural environment. Potassium 40 and carbon 14 are two naturally occurring radionuclides that form part of the background radiation.
    Author: rikazzz Comment