How do cells work together? Ch. 2 L. 2 Notes (pg. 42 – 45)

Directions: Write one interesting fact or one question in a complete sentence for each slide.

Vocabulary Tissue - a group of the same kinds of cells working together doing the same job Organ – a group of different tissues combined together in one structure

Types of Cells Your body has about 200 types of cells A cell’s shape is specialized to fit its job Cells have special structures to help with their work Branching cells Nerve and brain cells Send signals quickly Can connect several parts of the body at once Flat cells Found in skin, stomach, and mouth Cover surfaces like shingles on a roof Round Cells Red blood cells Carry oxygen all over the body Shape helps move through vessels and pick up oxygen

Types of cells Hair-like structures Muscle fibers Many different jobs Vibrate in your ear sending nerve signals to brain Sweep dirt and germs out of airways and lungs Muscle fibers Made of protein Are like threads that move to make the cell shorter Work in bundles for strength

Cells form tissues Cells almost never work by themselves Many of the same kind of cells make a tissue Muscle cells make up muscle tissue Bone cells make up bone tissue Nerve cells make nerve tissue

Tissues form organs Organs are made up or many different tissues Tissues work together to do a job in the body Examples of organs: Heart, lungs, eyes, ears, stomach Skin is the largest organ of the body Plant organs are stems, roots, leaves, and flowers

Skin cell tissue Skin protects the inside of the body Keeps out germs and holds in water Made up of many layers of skin cells New cells are formed in bottom layers New cells push old cells away from blood supply By the time cells reach the surface they are dead and just fall off Other tissues in the skin Nerve cells for feeling Muscle for moving hairs and other parts Oil glands to keep skin soft

Skin cell tissue