Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Cell culture wikipedia , lookup
Homeostasis wikipedia , lookup
Cell theory wikipedia , lookup
Microbial cooperation wikipedia , lookup
Neuronal lineage marker wikipedia , lookup
Dictyostelium discoideum wikipedia , lookup
Stem-cell therapy wikipedia , lookup
Hematopoietic stem cell wikipedia , lookup
Chimera (genetics) wikipedia , lookup
Adoptive cell transfer wikipedia , lookup
Human embryogenesis wikipedia , lookup
Organization of the Human Body Say Thanks to the Authors Click http://www.ck12.org/saythanks (No sign in required) To access a customizable version of this book, as well as other interactive content, visit www.ck12.org CK-12 Foundation is a non-profit organization with a mission to reduce the cost of textbook materials for the K-12 market both in the U.S. and worldwide. Using an open-content, web-based collaborative model termed the FlexBook®, CK-12 intends to pioneer the generation and distribution of high-quality educational content that will serve both as core text as well as provide an adaptive environment for learning, powered through the FlexBook Platform®. Copyright © 2013 CK-12 Foundation, www.ck12.org The names “CK-12” and “CK12” and associated logos and the terms “FlexBook®” and “FlexBook Platform®” (collectively “CK-12 Marks”) are trademarks and service marks of CK-12 Foundation and are protected by federal, state, and international laws. Any form of reproduction of this book in any format or medium, in whole or in sections must include the referral attribution link http://www.ck12.org/saythanks (placed in a visible location) in addition to the following terms. Except as otherwise noted, all CK-12 Content (including CK-12 Curriculum Material) is made available to Users in accordance with the Creative Commons Attribution-Non-Commercial 3.0 Unported (CC BY-NC 3.0) License (http://creativecommons.org/ licenses/by-nc/3.0/), as amended and updated by Creative Commons from time to time (the “CC License”), which is incorporated herein by this reference. Complete terms can be found at http://www.ck12.org/terms. Printed: November 1, 2013 www.ck12.org C ONCEPT Concept 1. Organization of the Human Body 1 Organization of the Human Body • List the levels of organization in the human body. • Identify the four types of tissues that make up the body. Do cells work together? Cells, like these nerve cells, do not work in isolation. To send orders from your brain to your legs, for example, signals pass through many nerve cells. These cells work together to perform a similar function. Just as muscle cells work together, bone cells and many other cells do as well. A group of similar cells that work together is known as a tissue. 1 www.ck12.org Organization of Your Body: Cells, Tissues, Organs Cells are grouped together to carry out specific functions. A group of cells that work together form a tissue. Your body has four main types of tissues, as do the bodies of other animals. These tissues make up all structures and contents of your body. An example of each tissue type is pictured below (Figure 1.1). FIGURE 1.1 Your body has four main types of tissue: nervous tissue, epithelial tissue, connective tissue, and muscle tissue. They are found throughout your body. Groups of Tissues Form Organs A single tissue alone cannot do all the jobs that are needed to keep you alive and healthy. Two or more tissues working together can do a lot more. An organ is a structure made of two or more tissues that work together. The heart (Figure 1.2) is made up of the four types of tissues. Groups of Organs Form Organ Systems Your heart pumps blood around your body. But how does your heart get blood to and from every cell in your body? Your heart is connected to blood vessels such as veins and arteries. Organs that work together form an organ system. Together, your heart, blood, and blood vessels form your cardiovascular system. What other organ systems can you think of? 2 www.ck12.org Concept 1. Organization of the Human Body FIGURE 1.2 The four different tissue types work together in the heart as they do in the other organs. Organ Systems Work Together Your body’s 12 organ systems are shown below (Table 1.1). Your organ systems do not work alone in your body. They must all be able to work together. For example, one of the most important functions of organ systems is to provide cells with oxygen and nutrients and to remove toxic waste products such as carbon dioxide. A number of organ systems, including the cardiovascular and respiratory systems, all work together to do this. TABLE 1.1: Major Organ Systems of the Human Body Organ System Cardiovascular Major Tissues and Organs Heart; blood vessels; blood Lymphatic Lymph nodes; lymph vessels Digestive Esophagus; stomach; small intestine; large intestine Pituitary gland, hypothalamus; adrenal glands; ovaries; testes Skin, hair, nails Endocrine Integumentary Muscular Nervous Reproductive Cardiac (heart) muscle; skeletal muscle; smooth muscle; tendons Brain, spinal cord; nerves Female: uterus; vagina; fallopian tubes; ovaries Male: penis; testes; seminal vesicles Function Transports oxygen, hormones, and nutrients to the body cells. Moves wastes and carbon dioxide away from cells. Defend against infection and disease, moves lymph between tissues and the blood stream. Digests foods and absorbs nutrients, minerals, vitamins, and water. Produces hormones that communicate between cells. Provides protection from injury and water loss, physical defense against infection by microorganisms, and temperature control. Involved in movement and heat production. Collects, transfers, and processes information. Produces gametes (sex cells) and sex hormones. 3 www.ck12.org TABLE 1.1: (continued) Organ System Respiratory Major Tissues and Organs Trachea, larynx, pharynx, lungs Skeletal Bones, cartilage; ligaments Urinary Kidneys; urinary bladder Immune Bone marrow; spleen; white blood cells Function Brings air to sites where gas exchange can occur between the blood and cells (around body) or blood and air (lungs). Supports and protects soft tissues of body; produces blood cells; stores minerals. Removes extra water, salts, and waste products from blood and body; controls pH; controls water and salt balance. Defends against diseases. Vocabulary • cardiovascular system: Organ system made up of the heart, blood, and blood vessels. • cells: Basic unit of structure and function of a living organism; the basic unit of life. • connective tissue: Group of cells that are all involved in supporting and binding other tissues of the body; i.e. tendon, cartilage, bone, and blood. • epithelial tissue: Layers of tightly packed cells that line the surfaces of the body. • muscle tissue: Bands of cells that contract and allow movement. • nervous tissue: Group of nerve cells that sense stimuli and transmit signals; found in brain, spinal cord, and nerves. • organ: Structure made of two or more tissues that work together. • organ system: Organs that work together to serve a common purpose. • tissue: Group of similar cells working together. Summary • The levels of organization in the human body include: cells, tissues, organs, and organ systems. • There are four tissue types in the body: epithelial tissue, connective tissue, muscle tissue, and nervous tissue. Practice 1. 2. 3. 4. What kind of symmetry does the human body plan show? Explain fully what this means. How does this symmetry extend to our senses? How much of our body is made of muscle? What does this muscle allow us to do? How are oxygen and nutrients delivered to the cells of the body? Review 1. What are the four levels of organization in an organism? 2. List the four types of tissues that make up the human body. 4 www.ck12.org Concept 1. Organization of the Human Body References 1. Child: Image copyright igor kisselev, 2012; Tissue images: jessy731 (Flickr). . Child: Used under license from Shutterstock.com; Tissue images: CC-BY-NC 2.0 2. Patrick J. Lynch, medical illustrator; C. Carl Jaffe, MD, cardiologist. . CC-BY 2.5 5