Anatomy and Physiology

    Biomechanics
    Why are the third-class lever systems of the human musculoskeletal system inefficient? Because:
    When the muscle insertion is closer to the joint than is the load, the effort arm is short. This means that the effort force must be large to provide the same torque exerted by the load acting on its longer load arm.
    Author: rikazzz Comment
    Muscles
    Which muscle is located on the front of the anatomical leg?
    The “leg” is between the knee and ankle – it contains the tibia and fibula. Anterior refers to the “front”, hence tibialis anterior. The other muscles are not on the leg. Rectus femoris is on the front of the “thigh”.
    Author: rikazzz Comment
    Cells and Tissues
    Which of the following is the smallest living structural unit of the body?
    The cell is smallest structural unit that is deemed to be alive.
    Author: rikazzz Comment
    The Physics of Waves: Light Waves, Sound Waves and Ultrasound
    A Doppler ultrasound device produces ultrasound of frequency 5 MHz, and the echo from red blood cells has a frequency of 5 002 500 Hz. The beat frequency produced will be:
    Beat frequency is the difference between the two frequencies. 5 000 000–5 002 500 = 2500 Hz. The frequency of the beats is within the audible range so we can hear them.
    Author: rikazzz Comment
    Nervous System
    Which cells of the retina are responsible for detecting light in scotopic (i.e. low light) conditions?
    Rods and cones are the light sensitive cells. Rods are used for viewing in low light (dim) or night-time conditions.
    Author: rikazzz Comment
    Body Temperature, Energy and Heat Loss
    Which mechanism of heat loss from the human body is minimised by wearing clothes?
    Clothes trap a layer of air close to the skin. This air is warmed to skin temperature and is prevented from blowing away by being contained within the clothing.
    Author: rikazzz Comment
    Cardiovascular System
    Cardiac muscle cells differ from skeletal muscle cells in that:
    Skeletal muscle is voluntary, while cardiac muscle is not under our conscious control. A skeletal muscle cell is a syncytium (composed from the amalgamation of many small cells (myoblasts)), while the myocardium behaves as a functional syncytium – the cells contract in unison.
    Author: rikazzz Comment
    Reproductive System
    From the list below, what do WOMEN have as part of their reproductive system that men do not?
    Bartholin’s glands (or greater vestibular glands) are possessed by women. The male homologue is Cowper’s gland (bulbourethral glands). The inguinal canal is present in women where it attaches to the round ligament of the uterus, as well as in men.
    Author: rikazzz Comment
    Cells and Tissues
    The diffusion of water through a membrane is referred to as:
    Osmosis is a word that is reserved for the movement of water through a membrane.
    Author: rikazzz Comment
    Ionising Radiation
    What advantage does brachytherapy as a form of radiation therapy have over external beam therapy (also called teletherapy)?
    In brachytherapy, the radioactive isotope is placed adjacent to or within the structure to be irradiated, so healthy tissue receives less dose.
    Author: rikazzz Comment