Body Systems Overview 1

1. cell membrane - the thin outer covering of a cell; holds the cell together 2. nucleus – the small central core in almost every cell; stores information and directs all the activities of the cell. 3. cytoplasm – the material between the cell membrane and the nucleus; made up of many parts that help the cell work 2

4. cell – is the basic unit of all living things 5. tissue – a group of cells that are alike and work together to do the same job. 6. organ – a body part made up of various tissues; does a certain job in the body. 7. body system – a group of organs that work together to do a certain job. 3

1. What are your cells? a. Everything in your body is made of cells b. Different cells have different shapes and do different jobs 4

c. Almost all have the same 3 parts i. Cell membrane – thin outer covering that holds the cell together, lets in water and everything else the cell needs, keeps out most things that could harm the cell ii. Nucleus – small center that stores information and directs all the activities of the cell, “brain”, sends messages iii. Cytoplasm – material that is between the nucleus and cell membrane. Made up of parts that help the cell work. 5

2. What are your tissues? a. Tissue – a group of cells, ex: muscles, blood, skin, hair, bone i. Each does a different job and are specially formed for the work they do - “function” ii. EX: bone cells are hard and cannot bend, skin cells are flat and thin and fit tightly together at the edges 6

3. What are your organs? a. Tissues work together to make up organs b. Each organ does a specific job to help you stay alive and healthy c. EX: heart is an organ that pumps the blood, eyes are organs that help you see 7

4. What are your body systems? d. some organs are part of more than one system e. systems work together to make sure that the body maintains homeostasis – is the condition in which the body’s internal conditions are at a stable state 8

Body Systems System Major Organ(s) Skeletal Bones, Cartilage, Ligaments Muscular Muscles & Tendons Digestive Stomach, Intestines, Liver Urinary Kidneys, Bladder Nervous Brain, Spinal Cord Circulatory Heart Respiratory Lungs Endocrine Glands & Hormones 9

How do body systems work together? Skeletal and Muscular Circulatory and Digestive Respiratory and Circulatory Example...when the kidneys (urinary) start to receive less oxygen, they produce a hormone (endocrine) that the blood (circulatory) carries to the bones (skeletal). There, the hormone stimulates the bone marrow to produce more red blood cells (circulatory). 10

Body Systems Worksheets 11

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Review What are the three main parts of a cell? What are the three jobs of a cell membrane? How do cells, tissues and organs work together in the body? How can a problem in one body system affect another body system? 13