Organ System
Organ System Definition An organ system is a group of organs that work together to perform a certain function in an organism’s body. Most animals and plants have organs, which are self-contained groups…
Organ
Organ Definition An organ is a self-contained group of tissues that performs a specific function in the body. The heart, liver, and stomach are examples of organs in humans. The word organ comes from…
Muscle Tissue and Motion
Muscle tissue is characterized by properties that allow movement. Muscle cells are excitable; they respond to a stimulus. They are contractile, meaning they can shorten and generate a pulling force.…
Classification Of Epithelial Tissues
Epithelial tissues are classified according to the shape of the cells and number of the cell layers formed . Cell shapes can be squamous (flattened and thin), cuboidal (boxy, as…
Epithelial Tissue
Most epithelial tissues are essentially large sheets of cells covering all the surfaces of the body exposed to the outside world and lining the outside of organs. Epithelium also forms…
What is Human Body Tissue? – Definition, Types & Examples
What is Human Body Tissue If you were to try to explain to someone what your body is made of, you might say two arms, two legs, feet and hands,…
How many cells are in the human body?
Have you ever wondered how many cells your body is made up of? You are not alone. Scientists are still debating the exact number, which currently remains a conundrum. The short answer…
What is a cell?
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food,…
Reconstruction Methods
As discussed earlier, SPECT combines conventional nuclear medicine image techniques and methods for image reconstruction from projections. Aside from radiopharmaceuticals and instrumentation, image reconstruction methods are another important engineering and…
Special Collimator Designs for SPECT Systems
Similar to conventional nuclear medicine imaging, parallel-hole collimators (Figure 13.10a) are commonly used in camera-based SPECT systems. As described earlier, the tradeoff between detection efficiency and spatial resolution of parallel-hole…
