Compare and contrast epithelial and muscle. There are at least three primary functions that are performed by the epithelial tissue. Firstly it provides a great protective covering for all the tissues lying beneath it from radiation, toxins, physical trauma, desiccation and invasion of pathogens. Secondly it helps to regulate the exchange of chemicals between the body cavity and the tissues that lie underneath the epithelial tissues. It also helps in the secretion of the hormones in to the bloods. These are all major but primary functions of the epithelial tissues. From this we can easily understand the importance of the epithelial tissues.

Arock can be broken down into different kinds of substances by physical processes. no chemical reactions are needed to separate different parts of a rock into pure substances. this is because a rock is a(n)

Quickly! brainliest if two people answer! 1. the blood has red blood cells, white blood cells and platelets. red blood cells carry oxygen to other cells in the body. cells need oxygen to live. white blood cells destroy certain germs. they protect our bodies from disease. which question is answered in this paragraph? (a) what is the role of blood vessels? (b) what type of cells are attached to bones? (c) what type of blood cell to clot your blood? (d) what are the different types of blood cells? 2. which sentence from the section "stem cells" best explains the role of stem cells? (a) when one kind of cell stops working, stem cells can . (b) they can turn into that cell and take its place. (c) scientists are studying new ways to use stem cells. (d) these cells can people heal faster. 3. read the selection from the section "nerve cells." nerve cells send messages to the rest of our bodies. these messages move between the brain, spinal cord and various organs. nerve cells are also called neurons. fill in the blank. a "neuron" is a (a) cell that moves information from the brain to other parts of the body (b) stem cell that has both an axon and a dendrite (c) cell that controls the fingers of a body (d) cell that makes up the spinal cord 4. some muscles in our body move without us telling them to. these are called involuntary muscles. some examples are the cardiac muscle cells inside the heart. these cells the heart relax and fill with blood. what is the best definition of "involuntary" based on the context clues? (a) something that happens on its own (b) trying hard to do something (c) something moving back and forth (d) easily moved

Which element forms an ionic bond with flourine? 1) fluorine 2) carbon 3) potassium 4) oxygen