Nervous System

    Nervous System
    Which of the following statements about the action potential is FALSE?
    Anions (positive ions) crossing the membrane is the first part of the action potential, but this movement is triggered by a graded potential that is above threshold arriving at the start of the axon (the axon hillock). So choice D is false.
    Author: rikazzz Comment
    Nervous System
    What term may be applied to the shape of the lens of the eye?
    The surface of the eye’s lens bulges outwards anteriorly and posteriorly at its centre and is narrower at its edges where it joins to the ciliary fibres. This shape is convex “front and back” so is biconvex. If it bulged inwards, it would be biconcave.
    Author: rikazzz Comment
    Nervous System
    Which lobes make up each hemisphere of the cerebral cortex?
    The five lobes of each hemisphere are the frontal, parietal, occipital, temporal and insula. The insula is not visible on the surface of the brain.
    Author: rikazzz Comment
    Nervous System
    What part of the brain contains the autonomic control centre whose orders regulate food intake, water balance and body temperature?
    These homeostatic roles are performed by the hypothalamus.
    Author: rikazzz Comment
    Nervous System
    The following receptors for neurotransmitters may be stimulatory or inhibitory EXCEPT for one of them. Which one?
    Nicotinic acetylcholine receptors bind ACh and are always stimulatory.
    Author: rikazzz Comment
    Nervous System
    Which part of the ear contains the apparatus that we use to distinguish between different frequencies of sound?
    The cochlea contains the organ of Corti (the spiral organ) and its basilar membrane.
    Author: rikazzz Comment
    Nervous System
    What is meant by the term “accommodation” when referring to our vision? It refers to the ability of our eye to:
    Accommodation refers to the ability of our eye’s lens to alter its shape – its thickness or roundness or convexity – to enable it to bring light from objects at any distance to a focus on the retina.
    Author: rikazzz Comment
    Nervous System
    People over 45 years of age eventually require reading glasses. This condition (known as presbyopia) is the result of which of the following conditions?
    The elastic lens loses some of its elasticity with age so is not able to focus light from nearby objects such as books. Hence “reading” glasses – which have convex lenses – become necessary.
    Author: rikazzz Comment
    Nervous System
    Which choice correctly ends the following sentence? The parasympathetic division is part of the:
    The parasympathetic division is part of the autonomic nervous system.
    Author: rikazzz Comment
    Nervous System
    What part of the nervous system prepares the body for action during extreme situations?
    The sympathetic division (of the autonomic nervous system) “stirs you up”. It prepares for action, those body organs that will be required for rapid and vigorous activity.
    Author: rikazzz Comment