© Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION UNIT I Levels of Organization © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION 1 © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION CHAPTER 1 Introduction to Human Anatomy and Physiology OUTLINE 10. Compare positive and negative feedback Anatomy and Physiology Overview mechanisms. Organization Levels of the Body Essentials for Life KEY TERMS Homeostasis Anatomists: Experts or students in the study of anatomy. Positive and Negative Feedback Anatomy: The study of body parts, forms, and structures. Organization of the Body Appendicular: Relating to the upper and lower limbs (the Body Cavities and Membranes arms and legs). Organ Systems Atoms: The smallest particles of an element that have the Anatomic Planes element’s properties. Directional Terms Axial: Relating to the head, neck, and trunk. Abdominal Regions Cell: The functional and structural unit of life. Body Regions Homeostasis: The maintenance of a relatively constant Summary internal environment in the body. Learning Goals Homeostatic mechanisms: Effectors, receptors, and Critical Thinking Questions the body’s set point, which act together to maintain Websites homeostasis. Review Questions Mediastinum: The organs and tissues of the thoracic cavity that form a septum between the lungs. OBJECTIVES Metabolism: The cellular chemical reactions that break After studying this chapter, readers should be able to: down and build up substances. 1. Defi ne anatomy and physiology. Molecules: Particles made up of two or more joined 2. Name the components that make up the atoms. organization levels of the body. Organ systems: Groups of organs coordinated to carry 3. Describe the major essentials of life. out specialized functions. 4. Defi nehomeostasis and describe its importance Organelles: Structures within cells that have specialized to survival. functions. 5. Describe the major body cavities. Organism: An individual living thing. 6. List the systems of the body and give the organs Organs: Structures consisting of groups of tissues with in each system. specialized functions. 7. Describe directions and planes of the body. Parietal: Relating to the wall of a cavity. 8. Discuss the membranes near the heart, lungs, Peritoneal membranes: Smooth, transparent membranes and abdominal cavity. that line the abdominal cavity and contain the internal 9. List the nine abdominal regions. organs of the abdomen. 3 © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION 4 CHAPTER 1 Introduction to Human Anatomy and Physiology KEY TERMS CONTINUED in diff erent ways. It is not easy to separate the topics Physiology: The study of body functions. of anatomy and physiology because the structures of Tissues: Groups of similar cells that perform body parts are so closely associated with their func- specialized functions. tions. Each part has its own unique substructures Viscera: Organs in the body cavities, especially in that allow it to perform its needed functions. the abdomen. e human body has been studied for hundreds Visceral: Relating to the membranous covering of of years. Even though its inner workings are well an organ. understood, new discoveries are still being made even today. As recently as 2003, the human genome e study of anatomy and physiology is vital for (instructions that allow the body to operate) was all health professionals. It involves many diff erent deciphered for the fi rst time. ere are more than areas of science to understand how the human body 20,000 genes in the human body, so this substantial works as well as how it is structured. e study of discovery took many years to complete. Researchers anatomy and physiology provides answers to many frequently discover new information about physi- questions about the functions of the body in both ology, particularly at the molecular level, but health and disease. As a result of this understand- basic human anatomy changes very slowly as time ing, it is possible to see what happens to the body progresses. when it is injured, stressed, or contracts a disease or infection. It is important that all allied health stu- dents become familiar with the terminology used Organization Levels of the Body in anatomy and physiology. In this chapter, the Every body structure is made up of smaller struc- focus is on a complete introduction to anatomy and tures, which are, likewise, made up of even smaller physiology. components. Chemicals compose every material found in the human body. ey contain micro- Anatomy and Physiology Overview scopic atoms combined into structures known as e structures and functions of the human body are molecules. Many molecules may be combined closely related. Anatomy is the study of the struc- into macromolecules. ese macromolecules, in ture of body parts and how they are organized. turn, form organelles, which help to complete the Physiology is the study of how body parts work. intended functions of a cell, the basic unit of both Every body part functions to assist the human body structure and function in the human body. Tissue Organelle Cell Organ Macromolecule Organism Molecule Organ System Atom FiGure 1–1 Organization levels of the body Source: Adapted from Shier, D. N., Butler, J. L., and Lewis, R. Hole's Essentials of Human Anatomy & Physiology, Tenth edition. McGraw Hill Higher Education, 2009. © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION Essentials for Life 5 Cells are actually microscopic structures that may Stimulus be quite diff erent in size, shape and function. Cells (from external environment) are grouped together to form tissues, which in turn, are grouped together to form organs. Groups of similarly functioning organs form organ systems, organism which then combine to form a living (see Receptors Figure 1–1). Body parts are organized into diff er- ent levels of complexity, including the atomic level, molecular level, and cellular level. Atoms are the most simple in structure, with complexity increas- Control center ing in molecules, organelles, tissues, and organs. (set point) ✓ CHECK YOUR KNOWLEDGE 1. What is an organism? Effectors 2. Explain the organization levels of (muscles or glands) the body. Essentials for Life Response (change is corrected) Humans and other animals share many similar traits. We require specifi c nutrients in order to remain healthy, and to grow and develop normally. Energy FiGure 1–2 Homeostatic mechanism is gained from the breakdown, digestion, absorp- tion, and assimilation of food. Absorbed nutrients move throughout the body’s circulation. Respiration the patient’s condition include refl exes, the pupils of brings in oxygen that works with nutrients to grow the eyes, and brain waves. and repair body parts. e unusable parts of these processes are then excreted as waste. e body’s Homeostasis metabolism controls all of these processes. Human beings need several substances for sur- e internal environment of the human body must vival: food, water, oxygen, pressure, and heat in stay relatively stable in order for the person to sur- specifi c quantities and with specifi c qualities. Food vive. Homeostasis is a term that describes a stable provides nutrients for energy, growth, and regula- internal body environment. It requires concentra- tion of the chemical reactions in the body. Some of tions of nutrients, oxygen, and water to be normal these chemicals are used as energy sources or sup- and balanced, and for heat and pressure to be regu- ply the raw materials needed for building new living lated at tolerable levels. Homeostatic mechanisms matter. Others help to regulate vital chemical reac- regulate the body, and include: tions. Water is required for metabolic processes and ■ Eff ectors (which cause responses that alter makes up most of the body’s actual structure, trans- conditions) porting substances and regulating temperature. ■ Receptors (which provide information about Oxygen is a gas that drives metabolic processes internal stimuli) by releasing energy from food that is consumed ■ Set point (which gives particular values for and bringing nutrients to cells throughout the specifi c functions [see Figure 1–2]). e set body. Pressure, specifi cally atmospheric pressure, is point for body temperature, for example, is essential for breathing. Blood pressure is a form of 98.6 degrees Fahrenheit (37 degrees Celsius). hydrostatic pressure that forces the blood through Another set point is the one for normal adult the veins and arteries. Heat is produced as energy blood pressure, which is ideally below 120 from metabolic reactions, infl uencing their speed. (systolic) over 80 (diastolic). Body heat is measured as temperature. Vital signs are observable measurements taken to ✓ CHECK YOUR KNOWLEDGE determine the condition of a patient. ey include temperature, blood pressure, pulse rate, and respira- 1. Why is homeostasis essential to survival? tion rate. Other measurements that are taken to verify 2. Describe two homeostatic mechanisms. © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION 6 CHAPTER 1 Introduction to Human Anatomy and Physiology Positive and Negative Feedback portion. e axial portion of the human body appen- e body utilizes positive and negative feedback sys- includes the head, neck, and trunk. e dicular tems to regulate various activities. A positive feed- portion of the human body includes the back mechanism is one that makes conditions move upper and lower limbs. e axial portion includes away from the normal state to stimulate further the brain