Read the passage below. Then answer the questions that follow.
Epithelial tissue: Epithelial tissue lines most body surfaces, and it protects other tissues from dehydration and physical dam- age. An epithelial layer is usually no more than a few cells thick. The cells are typically flat and thin and have only a small amount of cytoplasm. Epithelial tissue is constantly being replaced as cells die.
Nervous tissue: The nervous system is made of nervous tissue. Nervous tissue consists of nerve cells and their supporting cells. Nerve cells carry information throughout the body.
Connective tissue: Various types of connective tissue support, protect, and insulate the body. Connective tissue includes fat, cartilage, bone, tendons, and blood. Some connective tissue cells, such as those in bone, are densely packed. Others, such as those found in blood, are farther apart from each other.
Muscle tissue: Three kinds of muscle tissue enable the movement of body structures by muscle contractions. The three kinds of muscle tissues are skeletal muscle, smooth muscle, and cardiac muscle.
Skeletal muscle is considered voluntary muscle because you can consciously control its contractions. Skeletal muscles move bones in the trunk and limbs.
Smooth muscle is called involuntary muscle because you cannot consciously control its slow, long-lasting contractions. Some smooth muscles, such as those lining the walls of blood vessels, contract only when stimulated by signal molecules. Other smooth muscles contract spontaneously.
Cardiac muscle is found in the heart. The powerful, rhythmic contractions of cardiac muscle pump blood to all body tissues. Cardiac muscle consists of interconnected cells. Groups of neighboring cells contract all at once, stimulating adjacent groups of cells to contract.