Anatomy and Physiology

    Cardiovascular System
    During which part of the cardiac cycle does blood enter the coronary arteries?
    When the myocardium is relaxed (in diastole), and the aortic valve is shut, blood from the aorta flows into the coronary arteries.
    Author: rikazzz Comment
    Endocrine System
    Which of the following “controls” the endocrine system?
    The hypothalamus secretes releasing and inhibitory hormones that stimulate the anterior pituitary gland to secrete hormones which in turn control the activities of endocrine cells in the thyroid, cortex of adrenal glands and reproductive organs. The hypothalamus produces ADH and oxytocin which are stored and released into blood from post.pit. The hypothalamus exerts neural control over the adrenal medullae.
    Author: rikazzz Comment
    Ionising Radiation
    Which one of the statements about the penetrating ability of radiation is true?
    Gamma rays and x-rays are indistinguishable, once they have travelled away from their site of production. So a 140 keV gamma or x-ray is more penetrating than a lower energy one.
    Author: rikazzz Comment
    Nervous System
    The ossicles of the ear pass on sound vibrations to the fluid in the inner ear. In what structure is this fluid located?
    The cochlea contains the scala vestibuli and the scala tympani, both of which are filled with perilymph. It also contains the cochlear duct filled with endolymph.
    Author: rikazzz Comment
    Nervous System
    Which of the following roles is NOT performed by the hypothalamus?
    The thalamus relays visual and auditory information, not the hypothalamus.
    Author: rikazzz Comment
    Cardiovascular System
    What is the term applied to the balloon-like sac that develops when the weakened wall of a blood vessel bulges out?
    An aneurysm describes a blood vessel distended beyond normal and in danger of rupturing.
    Author: rikazzz Comment
    Nervous System
    Through which structure must sound pass in order to enter the middle ear?
    Sound travels from the air in the outer ear to the middle ear by vibrating the tympanic membrane (the ear drum). Sound enters the cochlea (inner ear) via the oval window.
    Author: rikazzz Comment
    Chemistry for Physiology
    Which of the following is the name of a subatomic particle?
    A neutron is one of the constituents of the atomic nucleus.
    Author: rikazzz Comment
    Cardiovascular System
    What can be said about the endothelium of fenestrated capillaries?
    Fenestrated capillaries have pores (windows/fenestrae) which penetrate the endothelial lining which facilitates the passage of material through them.
    Author: rikazzz Comment
    Cardiovascular System
    Due to an atheromatous plaque, a man’s coronary artery has narrowed to one third of its healthy diameter, all other things being equal, and his blood flow rate (ml/min) in that artery would:
    Poiseuille’s law states that volume flow rate is proportional to radius to the fourth power, so blood flow rate would be 1/3 ×1/3 ×1/3 ×1/3 = 1/81.
    Author: rikazzz Comment