Anatomy and Physiology

    Renal System
    Complete the following sentence correctly. Atrial natriuretic peptide:
    ADH increases the permeability of the collecting duct to water. Angiotensin II stimulates the adrenal glands to release aldosterone and promotes peripheral vasoconstriction.
    Author: rikazzz Comment
    The Physics of Waves: Light Waves, Sound Waves and Ultrasound
    The wave equation may be written in symbols as v = fλ where f stands for frequency, v stands for velocity and λ stands for wavelength. If a wave has a speed of 2 × 108 m/s, what is its frequency and wavelength?
    Which combination of frequency and wavelength will give the speed 2 × 108 m/s? v = fλ = 5 × 1014 Hz × 4 × 10−7 m = 20 × 1014–7 = 20 × 107 = 2 × 108
    Author: rikazzz Comment
    Respiratory System
    In the control of respiration, which of the following is NOT true?
    Chemoreceptors in the central nervous system respond to changes in pH as there is no buffer in CSF. The presence of carbon dioxide in CSF generates hydronium ions which affect the central chemoreceptors.
    Author: rikazzz Comment
    Ionising Radiation
    To what energy can an x-ray tube that is operated at 110 kV accelerate electrons?
    An electron volt is the amount of energy gained by an electron when it is accelerated by a potential difference of 1 volt. 110 keV is the amount of energy gained by an electron when it is accelerated by a potential difference of 110 kilovolt.
    Author: rikazzz Comment
    Respiratory System
    Gas exchange occurs across the respiratory membrane. Which structures constitute the membrane?
    Gas must pass through two cells and their basement membrane to move from the alveoli into blood and vice versa. The hilum and pleura are not involved.
    Author: rikazzz Comment
    Electricity
    The effects on a human that result from an electric shock depend upon all of the following except one. Which one?
    Both AC and DC can electrocute a human, with DC requiring higher current, probably more than 300 mA.
    Author: rikazzz Comment
    Nervous System
    What is the likely result of an injury that severs the spinal cord between C5 and C6?
    Spinal nerves below the break cannot pass on impulses from the brain. So quadriplegia results because the spinal nerves that innervate the limbs leave the spinal cord below the level of the spinal cord break (except for some brachial nerves that leave at C5). Fortunately, the phrenic nerve, which innervates the diaphragm, leaves the spinal cord at C3, C4 and C5 so will still carry impulses from the brain. So breathing will continue.
    Author: rikazzz Comment
    Chemistry for Physiology
    One of the statements below about buffers is WRONG. Which one?
    The ability to produce hydronium ions with water defines an acid, not a buffer.
    Author: rikazzz Comment
    Integument
    Which statement below is correct?
    Keratin is the horny protein that gives the epidermis its protective qualities and is produced by keratinocytes.
    Author: rikazzz Comment
    Nervous System
    What is the function of the corpus callosum?
    Commissural fibres pass through the corpus callosum that connect corresponding areas in the two hemispheres.
    Author: rikazzz Comment