The Eustachian tube is normally collapsed, i.e. closed, but opens upon positive pressure and swallowing. There are four muscles that are responsible for Eustachian tube functioning. The tensor and levator veli palatini muscles open the tube, by contracting the muscles of the soft palate.
Sickle Cell. These are the sickle-shaped blood cells of someone with sickle cell anemia, a genetic disease common among those of African descent. Sickle cell anemia is the result of a point mutation, a change in just one nucleotide in the gene for hemoglobin.This mutation causes the hemoglobin in red blood cells to distort to a sickle shape when deoxygenated. The sickle-shaped blood cells clog in the capillaries, cutting off circulation.ome well-known inherited genetic disorders include cystic fibrosis, sickle cell anemia, Tay-Sachs disease, phenylketonuria and color-blindness, among many others. All of these disorders are caused by the mutation of a single gene.
Sickle cell disease is caused by a genetic abnormality in the gene for hemoglobin, which results in the production of sickle hemoglobin. When oxygen is released from sickle hemoglobin, it sticks together and forms long rods, which damage and change the shape of the red blood cell.The sickle red blood cells causes the symptoms of sickle cell disease.Children are born with sickle cell disease; it is not contagious. It occurs when a child inherits two sickle hemoglobin genes, one from each parent. About 2,000 babies are born with sickle cell disease each year in the United States.hen oxygen is released from sickle hemoglobin, it sticks together and forms long rods, which damage and change the shape of the red blood cell. The sickle red blood cells causes the symptoms of sickle cell disease.