Information Report: The Skeletal System
"Humans are an intricate system that needs care." During the fifth graders' second unit, they inquired into the nature of the self and physical, emotional, and mental health. As students explored further on the human body systems, they chose a specific body system and gathered more information about it - its functions, its importance, how it is connected to the other systems of the human body, and how to care for it. As a summative assessment task, students wrote an information report demonstrating their understanding of their chosen body system. Have a look at what this student has learned about our body's framework - the skeletal system.
Skeletal System
by Sarah Davidson 戴安琪, 5th grade
Like the metal framework of skyscrapers, to the wooden substructure of a typical European house, bones support our body as long as we live. From the first squalling cry that we let out, to the last breath that we’ll ever take, bones always support our body. The human skeleton is composed of 207-300 bones at birth, but by adulthood, only 206 remain. This is because some of the smaller bones fuse together as our body slowly matures. Our skeletal system serves at least 5 important functions : support, movement, protection, production of blood cells, and storage of ions, or atoms with extra or missing electrons. However, the framework of bones may vary, depending on what kind of an animal we’re looking at.Some birds, for example, have many hollow bones with only criss-crossing struts for support. Usually, birds most likely to have many of these hollow bones are the types that prefer soaring, or gliding to get around. Of course penguins and ostriches don’t have any- the hollow bones are there to decrease weight, making it more easy for birds to fly.
Without bones, our bodies wouldn’t be able to move, and all our internal organs would just float around, with nothing to protect, or contain them. Bruise your body heavily, and your heart might just stop beating.(Of course, that would be rather difficult to do, seeing as now we can’t move at all). Since the list of things we can’t do without bones is rather lengthy, let me just compile a short list of what we can do without bones. -cry(have to do a lot of that without bones) -breath -live(?) Horrible as it may sound, there’s actually a disorder that leads to loss of all bone mineralization during childhood. (Luckily, there’s already a new drug that treats this horrible disease.)
There’s (at least) 2 skeletal types that living organisms benefit from: the exoskeleton, which is the hard outer shell of an organism( typically invertebrates) and the endoskeleton, which forms the support structure inside of the body.There’s also two forms of skeletons that organisms have: the hydroskeleton, which is a structure found in many soft bodied animals -such as earthworms- consisting of a fluid filled cavity, the coelom,and the cytoskeleton, which is used to preserve the form of cells; a complicated system (inside of human, fungal, animal, and plant cells) of interlocking thread-like structures and hollow tube-like body structures.
Exoskeletons are external, and protect soft tissues and vulnerable organs inside of the body. Some exoskeletons can shed their exoskeletons as they grow, like snakes, insects and (weirdly enough) crabs. The exoskeleton of insects and mollusks can also double as a surface for muscle attachment, watertight protection against drying and a sense organ-that mollusks don’t have- ( like our eyes, nose, mouth, etc.,etc.) to interact with the environment. Endoskeletons are the internal support for animals, and are found typically in vertebrates, and (as mentioned above) support, help the body to move, protect our vital organs, produce blood cells and store both calcium (40% more then the body needs-it’s like a warehouse) and atoms with extra or missing electrons.
Cytoskeletons preserve the form of the cell it’s contained in. It does much of the same things that the skeletal structure does for our body: it maintains the form of the cell, protects the cellular structure, and enables the cell to move. It extends throughout the cytoplasm, from the nucleus to the plasma membrane. The hydroskeletons is a semi- ridged, soft tissue structure filled with fluid and surrounded by muscles. The pressure of the liquid and action of the surrounding muscles are used to change the organisms shape and allow it to move extremely flexibly, as the bones aren’t hard and can be bent out of shape.
Bones are important in more ways then you might think. They help birds to fly, cheetahs (who are the only cats with dogs’ paws-it helps them run faster) to run, and earthworms to crawl. Basically, bones exist in almost every living organism (even if the size, shape, and structure vary)! Even your cells have cytoskeletons. And it’s not just living organisms- buildings rely on “bones” (framework) to stand up tall- without them, they would collapse in a heap of dust and rubble. Be thankful for your bones (some people are born without them) and don’t do idiot stunts that break them.( Unless, of course, you’re doing it to save the environment. Then it’s okay.)
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You are welcome to provide any feedback regarding the article. Please click the link below to visit the student's blog and key in your comments in the box found at the bottom of the blog page:
You may also read through the following students' information report on the other systems of the human body:
The Muscular System by Sophie Wu 吳苡瑄, 5th grade
The Nervous System by Enoch Yang 楊以諾, 5th grade
