An agent that is smaller than a virus causes scrapie. It is either a protein called a prion or it is another substance closely associated with the prion protein. Scientists still have a lot to learn about the scrapie agent and exactly how it works.
Tissue valves are made with tissues from porcine (pig) heart valves or bovine (cow) cardiac tissue because they function like human heart valves. Once the tissue is removed from the animal, it is chemically treated to preserve the tissue and prevent immulogic reactions once it is placed in a patient.
The muscles of our lungs, stomach, and intestines are made of smooth muscle tissue. Cardiac muscle tissue is the third type of muscle tissue. Cardiac muscle tissue makes our hearts. Organs are groups of tissues that work together to do a job.Our skin is made of hair tissue, oil and sweat gland tissues, nerve tissue, blood tissue, and many other tissues to make the organ called skin.Our eyes are made of nerve tissue, blood vessel tissue, muscle tissue, lens tissue, pupil tissue, and many more types of tissue to make the organ called eyes.LA.A.2.2.1.4.1) Cells, Tissues, and Organs Our bodies are made of cells, tissues, and organs. The cell is the smallest unit of life. All living things are made of cells. One kind of cell makes one kind of tissue. Only hair cells can make hair tissue. Only nerve cells can make nerve tissue.