Human body systems

​This is usually the final unit before I begin regents review with the students. It is meant to be an overview of how the human body systems work together to maintain homeostasis.  In discussing the body systems I am able to revisit some of our earlier topics such as diffusion, surface area, and energy usage.

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I start out asking students to brainstorm a list of body organs.  If they are able to assign groups of organs to particular systems, I have them do that.  I do make some mention of levels of organization and types of tissue.  I come back to this topic later in the unit.  ​

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​I begin with the digestive and excretory systems.  I provide students with some general information about digestive and accessory organs, as well as some information about how the body deals with solid, liquid, and gaseous waste.

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Additional instructional activities can be found here and labs can be found here.    To supplement instruction, a great informative and entertaining video series is Body Story (available both on YouTube and Amazon.)   Video worksheets for the series are available here.

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​It is in discussions of the circulatory and respiratory systems that I take the opportunity to talk with students about the different types of muscle tissue, especially smooth muscle.  I remind them about co- and incomplete dominance when I talk about blood type alleles.  I also remind them about surface area to volume ratios and how that relates to cell size.  I often show the Body Story video about the guy having a heart attack at this point.

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​Next we move onto the integumentary system:  The integumentary system serves as a barrier against infection/injury, helps regulate body temperature, assists in excretion, and provides protection against UV radiation.  I spend a few minutes discussing those items.  Since the integumentary system functions in excretion, I revisit the excretory system and talk about kidney function.

​When I talk about the lymphatic/immune system, I remind students that they previously learned about cell membranes having many different receptor molecules/surface markers that vary by shape and are often unique to the individual.  I discuss the terms pathogen, antigen, and antibody.  Some class time is also spent discussing immune system disorders, and vaccines.​

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​Next, I move on to control and coordination.  During instruction about the nervous system, I again revisit the theme of surface area when I discuss the sulci and gyri of the brain.

​The endocrine system also deals with control and coordination of the body.  Students learned a bit about the endocrine system during the reproduction unit.  However, in the Human Body Systems unit, I elaborate more on hormones and feedback mechanisms.  I provide students with information about specific hormones important in controlling blood glucose levels, body temperature, metabolism, lactation, uterine contractions, and blood clotting.  (These hormones have appeared on previous regents exams).  I also quickly review of male and female reproductive structures.

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​My overview of the skeletal and muscular systems is rather superficial due to time constraints and the reality that there are few detailed regents questions about these structures.  I focus on how the respiratory and circulatory systems work with the musculoskeletal system in terms of movement and the maintenance of homeostasis.  I then segue by encouraging students to brainstorm different body systems and how they work together to keep a dynamic equilibrium despite changes in the environment.  Exercise is a good environmental change to use an example of a condition which would prompt body systems to react.

​The unit wrap-up is also a wrap-up of the course.  I encourage students to name some common themes they've learned about in the course (surface area, support/protection, and shape of molecules are examples they might name.)  I also ask for comparisons between human body structures and cell parts.  The cell membrane is often compared to alveoli and nephrons because of its filtering function.  Lastly, I touch on disease and other disruptions to homeostasis.

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In the state lab:  Making Connections, students investigate scientific claims and describe how body systems work together under varying conditions.

The Presentation and Student Notes files are available here.