Module 3

2. Referring to the lungs or the respiratory system.
5. Referring to the membranes that surround the lungs and line the chest cavity.
6. Referring to the bicuspid valve in the heart that separates the left atrium from the left ventricle.
9. Referring to the part of the autonomic nervous system that mobilizes the body's resources in response to stress or danger.
10. A flexible rod of cells that runs along the length of the developing embryo and helps to shape the body.
13. The innermost of the three primary germ layers in an embryo, which gives rise to the lining of the digestive and respiratory systems.
15. The process by which new blood vessels form from precursor cells called angioblasts.
17. A cell that produces the pigment melanin, which gives color to hair, skin, and eyes.
19. A segmental unit in the development of arthropods and some other animals, consisting of half a segment from one segment fused with half a segment from the next segment.

1. A segmented block of embryonic tissue that develops into the vertebrae, muscles, and skin of the body.
2. An organ that develops in the uterus during pregnancy and provides nutrients and oxygen to the developing fetus.
3. The apical ectodermal ridge, a structure in the developing limb bud that regulates the growth and differentiation of the underlying tissues.
4. A patch of thickened ectoderm that develops into various sensory organs, such as the eyes and ears.
7. The process by which new blood vessels are formed from existing blood vessels.
8. A type of cell that develops into muscle tissue.
11. An exogenous agent that causes a non-heritable birth defect or leads to complications of pregnancy; such agents are sometimes used to disrupt embryogenesis in model systems as a tool to investigate the processes that they affect.
12. The surgical transfer of cells, tissues, or organs from one person to another to replace damaged or diseased tissue.
14. A group of cells in an embryo that gives rise to the vertebrae and ribs.
16. A type of pigment that gives hair and skin a reddish-yellow color.
18. A natural process of programmed cell death that occurs in multicellular organisms.