Anatomy and Physiology

    Cardiovascular System
    What is the advantage of having a wide lumen in veins?
    The larger is the vessel diameter, the less will be the resistance to blood flow. The other choices are nonsense.
    Author: rikazzz Comment
    Skeleton and Joints
    What is the physical function(s) performed by synovial fluid?
    The lubricant action ensures a friction-free movement, while the relative incompressibility of the fluid allows, for example, the body weight to be distributed over the surface area of the knee joint (think about Pascal’s principle). Choice B is true but is a biological function.
    Author: rikazzz Comment
    Measurement, Errors, Data and Unit Conversion
    What is meant when a person’s mass is stated as 73.6 kg? That:
    Because the mass is stated to one decimal place, the absolute error is ±0.05.
    Author: rikazzz Comment
    Endocrine System
    Which of the following lists of organs and hormones involved in a control process that releases that hormone is WRONG?
    The thalamus is not involved in the chain of events that causes release of oxytocin from the posterior pituitary.
    Author: rikazzz Comment
    Endocrine System
    Which statement below about hormones is true?
    Hormones are circulating messengers that are transported in blood. A particular hormone does not necessarily affect every cell in the body. Some (but not all) hormones are released by neurones, for example, in the hypothalamus.
    Author: rikazzz Comment
    Organisation of the Body
    Which of the following correctly describes the two named body parts?
    Phalanges (finger bones) are indeed further from the trunk along the arm, than are the carpals (wrist bones).
    Author: rikazzz Comment
    Respiratory System
    The respiratory centre of the brain controls the respiratory muscles. Which of the following does NOT happen?
    Hydronium ions cannot cross the BBB. Carbon dioxide does and forms hydronium ions which go on to stimulate the central chemoreceptors as the CSF has no buffer to remove them.
    Author: rikazzz Comment
    Nervous System
    What determines the response of the postsynaptic cell to autonomic impulses?
    It is the type of receptor on the postsynaptic membrane (not the neurotransmitter molecule) that determines how the postsynaptic cell responds.
    Author: rikazzz Comment
    Respiratory System
    If the spinal cord is severed below C4, what will be the effect on breathing?
    The diaphragm is innervated by spinal nerves that leave the spinal cord between C3 and C5, so a break below C4 will leave some the nerves above C4 intact and some diaphragm movement is possible.
    Author: rikazzz Comment
    Chemistry for Physiology
    Given that deoxygenated blood in the pulmonary capillaries has an oxygen concentration of 40 mmHg and carbon dioxide concentration of 46 mmHg and alveolar air has an oxygen concentration of 104 mmHg and carbon dioxide concentration of 40 mmHg, in which directions will oxygen and carbon dioxide diffuse?
    Of course O2 diffuses from alveoli to blood, while CO2 diffuses from blood to alveoli. Or by considering movement down the concentration gradients: O2 from 104 to 40 mmHg and CO2 from 46 to 40 mmHg.
    Author: rikazzz Comment