Overview: Tissues, Organs, and Systems (text pp 6-103)

In this unit, you will learn how understanding cells can help us understand how organisms function. Components of cells work together to perform all life functions. Examples of life functions include digesting what we eat, being able to breathe, and having a bone heal if it has been broken. Cellular processes enable all organisms to meet their basic needs. Two of an organism’s basic needs are growth and regeneration. Survival of the organism is dependent upon cell division in order to pass on the required hereditary materials.

By examining how animal cells work together in the human body, you will begin to appreciate that even though all cells begin alike (stem cells), they can differentiate into specialized cells that perform different functions and can group together as tissues to form the necessary organs for body functions. When the organ systems work together in the human body, important tasks such as respiration, circulation, and digestion maintain the homeostatic (even) balance required by all living organisms.

Exposure to technology, substances, and environmental factors can affect human health. You will examine some of the possible consequences of such exposure.

Unit 1.1 Why Are Cells Important?

Cellular components of both plant and animal cells work together to carry out life functions, and that their basic needs can be met through cellular processes such as diffusion and osmosis.

Unit 1.2 Why do Animal Cells Divide and What Happens When They Do?

Cells need to divide to survive. All hereditary material contained in the DNA molecule is passed on during cell division. Animal cells have a life cycle that includes both growth (interphase) and division (the phases of mitosis—prophase, metaphase, anaphase, and telophase—and cytokinesis, in which the cytoplasm and the organelles divide into two identical separate cells). All new animal cells are created during this controlled cell cycle. If division of animal cells becomes uncontrolled, it can result in cancer.

Unit 1.3 How do Cells Work Together in the Human Body?

All cells begin alike and differentiate into specialized cells. Specialized cells have different structures that allow them to perform unique functions. Groups of cells working together form tissues. Groups of tissues working together form organs, which work together in systems. This hierarchy of organization makes organ systems interdependent because of the interactions between them. For example, the oxygen necessary for the blood to nourish muscle cells is provided by the respiratory system.

Unit 1.4 How do Systems Work Together in the Human Body?

Systems work together in the human body. The text presents a number of different scenarios that describe various body systems. The respiratory system carries oxygen to the blood and removes carbon dioxide from the blood. The circulatory system transports dissolved gases and nutrients throughout the body. The digestive system breaks down food, absorbs nutrients, and eliminates solid waste. By considering these scenarios, you will learn about the important tasks that organ systems carry out together.

Unit 1.5 How do Technology, Substances, and Environmental Factors Affect Human Health?

Technology, substances, and environmental factors affect human health. Medical imaging technologies such as Xrays, CT scans, ultrasound, MRI scans, PET scans, endoscopy, and microscopy all allow individuals in the medical community to explore, diagnose, and treat the human body. Exposure to various technologies, substances, and environmental factors such as second hand smoke, pesticides, and cellphones can impair health. Technologies such as the i-Pill, regenerative medicine, and artificial blood will affect human health in new ways in the future. As new medical breakthroughs appear and are developed, our understanding, diagnosis, and treatment of the human body can be improved. Students will use their scientific investigative skills to research the ramifications of these medical developments.

Parts of a Microscope Quiz

Use page 380 of your text to learn the names of the parts of a microscope