the first answer as blood needs to be oxygenated to be passes round the body then when its deoxgenated it will return to the heart to be pumped around the body again
Fissure because it's like a large gaping crack in the earth
Desmosomes
Desmosomes are cell junction that acts as anchors and distributes tension through a cellular sheet and reduces the chance of tearing when it is subjected to great mechanical stress.
Desmosomes are cell structure by which two adjacent cells are joined. Desmosomes are specialized for cell to cell contact and strong adhesion. The inactiveness of desmosomes can lead to diseases of the skin and heart. Desmosomes are found in tissue that undergo high mechanical stress, such as bladder tissue, epithelial, and cardiac muscle tissue.
Facilitated diffusion therefore allows polar and charged molecules, such as carbohydrates, amino acids, nucleosides, and ions, to cross the plasma membrane. Two classes of proteins that mediate facilitated diffusion are generally distinguished: carrier proteins and channel proteins.