1. I. Types of Cells A. Branching Cells 1. nerve cells-helps communicate signals from the brain to the rest of the body B. Flat Cells 1. Join or overlap to cover a surface a. Ex. skin cells, line the mouth and stomach C. Round Cells 1. rounded discs with two dimples to help pick up oxygen/smooth shapes help it move easily through the blood a. Ex. red blood cells Ch 2 Lesson 2: How do cells work together?

2. D. Cilia 1. waving hair-like structure 2. sweep away dirt and germs out of the airway in the lungs

3. Cells Tissue Organs Organ Systems Organism Example: Nerve Tissue Skin Cells Skin Tissue Skin Muscle Tissue (Organ)

4. Ch 2 Lesson 3: How do organs work together? I. Organ Systems- group of organs working together A. Skeletal System- each bone is an organ 1. strong support system 2. protect internal organ B. Muscle System- each muscle is an organ *****Muscles only pull NEVER push**** 1. move your body

5. II. Organ Systems Work Together A. Muscle, Skeletal and Nervous System 1. Example: Triceps on the back of your arm bone/ Bicep connect to the front of your arm bone; Tricep pulls- arm straightens, Biceps pulls-arm curls; bone is the support system: Nerves tell the arm to move from the brain