Introduction to Health Physics: Fourth Edition - Ruang Baca FMIPA UB

BIOLOGICAL BASIS FOR R ADIATION SAFETY 289
tract as one of the constituents of feces, by way of the skin as perspiration, and via
the lungs as exhaled water vapor.
Organ Systems
The body is an integrated assembly of organ systems whose structures are in accord
with their functions. These organ systems include the following:
the circulatory system,
the respiratory system,
the digestive system,
the skeletal system,
the muscular system,
the integumentary system (skin),
the urinary system,
the nervous system,
the endocrine system,
the reproductive system, and
sensory organs and tissues.
The organ systems are made up of several different types of tissues, and each tissue
comprises specialized cells that perform specific functions. The principal types of
tissues include:
Epithelial tissue, which forms the surface of many organs and the outside surface
of the body. Epithelial tissues are characterized by a basement membrane that
lies beneath the lowest layer of cells. The cells in the basement membrane are
the critical cells for radiation damage.
Connective tissue, which forms the bones, cartilage, ligaments (which join two
bones together), and tendons (which connect muscles to bones).
Muscle.
Nervous tissue.
The Circulatory System
The circulatory system (Fig. 7-4), which consists of a network of tubes called blood
vessels, through which blood is pumped by the heart, serves several different purposes,
including the
transport of oxygen and carbon dioxide,
transport of nutrient and metabolites from the GI tract to the various organs,
transport of hormones and antibodies,
transport of metabolic waste products to the kidneys for elimination, and also
serving as a water reservoir to maintain fluid balance in the several fluid compartments
and constant temperature within the body.
All these functions are carried out by the blood. As a result of pressure due to the
pumping action of the heart, blood flows through the blood vessels, called arteries,
veins, and capillaries, which carry blood to and from organs. The capillaries, a very
fine network of vessels, are dispersed throughout the organs and are the functional