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  • Introduction to Cells, Tissues,

    Organs and Systems

    304-7 Explain structural and functional relationships

    between and among cells, tissues, organs and

    systems in the human body

    110-2 Compare the early idea that living organisms

    were made of air, fire and water with the modern cell


  • In previous grades when you have studied living things, you have not broken them down into their smallest units, cells. However, this year, you get to learn about the cell in great detail.

    We will explore how the cell is important to life and we will explore the human body to see how cells make tissues, tissues make organs, organs make systems and the systems make the body.

  • A long time ago

    A couple thousand years ago, people

    could not study Biology like we do today.

    They did not have the technology that we

    have, but they were smart for their time.

    Aristotle (born in 384 B.C.), a philosopher

    and scientist of the ancient times thought

    that all substances were compounds of

    four elements: earth, water, air and fire.

  • Aristotle

  • \

  • He thought for instance that humans were

    made of earth, which gave material

    strength and weight; fire, which provided

    warmth; water, which accounted for blood

    and other bodily fluids; and air, which filled

    the lungs and provided the breath of life.

    Of course, some people were more

    earthly, fiery, airy, or watery than others.

  • This is a neat idea and we can see why he

    may have thought these things.

    What do you think we are made of?

  • Now with the technology that we have, we

    can break matter down smaller than in the

    ancient times and we now know that living

    things are made of cells.

    This is called Cell Theory the idea that

    cells are the basic unit of structure of

    every living thing.

  • Cells

    Red Blood Cells

    Sperm Cell

    White Blood Cells

    Nerve Cells Generalized Cell

  • Cells

    Cells are the smallest independent units of

    life, and all life depends on the many

    activities of that cells perform.

    Some basic functions of cells include:

    growth, metabolism, and reproduction.

    Cells range from 5 micrometers (sperm) to

    more than a meter (some nerve cells).

  • In the cell

    The cell is like its own little body that has mini-organs that keep it alive. These include:

    Cytosol water, proteins, nutrients, waste products, glycogen granules and lipid droplets

    Ribosomes RNA and proteins

    Mitochondria proteins and lipids

    * These are only some examples

  • Tissues

    Tissues are made up of many similar cells

    that perform a specific function. Tissues

    are divided into four groups: epithelial

    (skin, linings, protective), connective

    (bones and tendons, connects and

    supports body), muscle (skeletal, smooth

    and cardiac, produces movement) and

    nervous (brain, spinal cord and nerves,

    responds to stimuli and transmits signals).

  • Organs

    Organs are a collection of two or more kinds of

    tissues that work together to perform a certain


    Example: Stomach

    Epithelial tissue lines the stomach to protect it

    Smooth muscle tissue churns food

    Nervous tissue transmits nerve impulses that

    coordinate muscle contractions

    Connective tissue holds all other tissues together

  • Systems

    A group of organs that work together to

    perform a major function.

    Example: The respiratory system contains several organs that provide a mechanism

    for exchange of oxygen and carbon dioxide between

    the outside the body and the blood inside

  • Systems

    Cardiovascular (heart, blood, blood vessels)

  • Endocrine (ductless glands)

  • Nervous (brain, spinal cord,

    peripheral nerves, sensory organs)

  • Muscular (skeletal, smooth,


  • Integumentary (skin, hair, nails,

    sweat and oil glands)

  • Skeletal (bones and cartilage)

  • Respiratory (airways, lungs)

  • Digestive (stomach, intestines,

    other digestive structures)

  • Excretory (kidneys, ureters,

    urinary bladder, urethra)

  • Reproductive (ovaries, testes, reproductive

    cells, accessory glands and ducts)

  • Lymphatic (glands, lymph nodes,

    lymph, lymphatic vessels)

  • Introductory Questions

    What are the common structures that make up

    all living things?


    What do you think are the basic materials

    involved in the metabolism of all cells?

    Food, Oxygen, Carbon Dioxide and Water

  • What do you think happens when cells use up their food and oxygen before there is time to replenish it?

    The cells can not function death.

    Blood Cell

    Plant cell

    Cancer cell

  • The "strongest" human muscle

    Since three factors affect muscular strength simultaneously and muscles

    never work individually, it is misleading to compare strength in individual

    muscles, and state that one is the "strongest".

    1. lifting a weight - the jaw muscle is the strongest.

    2. If "strength" refers to the force exerted by the muscle itself - the

    quadriceps femoris or the gluteus maximus.

    3. A shorter muscle will be stronger "pound for pound" (i.e., by weight) than

    a longer muscle - during childbirth, the uterus exerts 100 to 400 N (25 to

    100 lbf) of downward force with each contraction.

    4. The external muscles of the eye are large and strong in relation to the

    small size and weight of the eyeball. It is frequently said that they are "the

    strongest muscles for the job they have to do" and are sometimes claimed

    to be "100 times stronger than they need to be."

    The statement that "the tongue is the strongest muscle in the body"

    appears frequently in lists of surprising facts, but it is difficult to find any

    definition of "strength" that would make this statement true. Note that the

    tongue consists of eight muscles, not one.

    5. The heart has a claim to being the muscle that performs the largest

    quantity of physical work in the course of a lifetime.