Anatomy and Physiology

    Skeleton and Joints
    In which of the following bone structures do osteocytes live?
    Lacunae are the spaces within the lamellae of an osteon which enclose a bone cell (osteocyte). These cells extend their processes into the canaliculi.
    Author: rikazzz Comment
    Nervous System
    What would happen if a neuron lost its myelin sheath?
    The myelin sheath prevents sodium ions from leaking back into the intracellular fluid; hence, they can travel with minimum diminution to the next node to trigger the opening of abundant voltage-gated sodium channels.
    Author: rikazzz Comment
    Nervous System
    The central sulcus separates gyri involved with which two major functions?
    Motor function resides in the precentral gyrus, while sensory function resides in the postcentral gyrus.
    Author: rikazzz Comment
    Muscles
    Which of the following muscle structures is the smallest?
    A sarcomere is a section of a myofibril. A muscle fibre (cell) is a bundle of myofibrils, while a fasciculus is a bundle of muscle fibres.
    Author: rikazzz Comment
    Skeleton and Joints
    Where is the xiphoid process?
    At the inferior end of the body of the sternum. The temporal bone has a mastoid and a styloid process.
    Author: rikazzz Comment
    Gastrointestinal System
    During which phase are our gastric secretions stimulated by the sight and smell of food?
    The cephalic phase refers to the thought and sight of food stimulating our secretions in preparation for food entering our stomach.
    Author: rikazzz Comment
    Nervous System
    What is an “action potential”? It is:
    The action potential is the name given to the change in voltage of the inside of the cell from −70 to +30 and back to −70 mV again. This voltage change propagates along the axon.
    Author: rikazzz Comment
    Cardiovascular System
    Which type of capillary is required to allow the liver to perform its function of producing plasma proteins?
    Plasma proteins are very large molecules, which are too big to pass out of (or into) capillaries. Sinusoidal capillaries have gaps between the endothelial cells of their walls which are large enough to allow proteins to enter the blood.
    Author: rikazzz Comment
    Respiratory System
    The respiratory centre in the brain is sensitive to:
    The CSF is not buffered so is very sensitive to changes in hydronium ion concentration.
    Author: rikazzz Comment
    Skeleton and Joints
    What is contained within the medullary canal of a long bone?
    Red (and/or yellow) marrow fills the medullary canal (or cavity).
    Author: rikazzz Comment