The human body is complex. 17.1 The human body is complex. You can think of the body as having five levels of organization: cells, tissues, organs, organ systems, and the whole organism itself. The different systems of the human body work together to maintain homeostasis. tissue organ organ system Organism (human) Cells (cardiac muscle cells) Tissue (cardiac muscle) Organ (heart) Organ system (circulatory system) 1 2 3 4 5 homeostasis CHAPTER RESOURCES SIMULATION Explore the different systems in the human body. SECTION OUTLINE

17.1 homeostasis The human body is complex. tissue homeostasis organ A condition needed for health and functioning in which an organism or cell maintains a relatively stable internal environment. organ system homeostasis CHAPTER RESOURCES KEY CONCEPT SUMMARY

The skeletal system provides support and protection. 17.2 The skeletal system provides support and protection. Bones are living tissue. The skeleton is the body's framework and has two main divisions, the axial skeleton and the appendicular skeleton. skeletal system compact bone spongy bone Bones come together at joints. axial skeleton appendicular skeleton Angular Movement (elbow) CHAPTER RESOURCES SECTION OUTLINE

17.2 skeletal system Anatomy of a joint Types of joints Examples The skeletal system provides support and protection. skeletal system skeletal system compact bone spongy bone The framework of bones that supports the body, protects internal organs, and anchors all the body’s movement. Anatomy of a joint Types of joints Examples axial skeleton appendicular skeleton CHAPTER RESOURCES KEY CONCEPT SUMMARY

17.2 compact bone The skeletal system provides support and protection. The tough, hard outer layer of a bone. spongy bone axial skeleton appendicular skeleton CHAPTER RESOURCES KEY CONCEPT SUMMARY

17.2 spongy bone The skeletal system provides support and protection. compact bone spongy bone Strong, lightweight tissue inside a bone. axial skeleton appendicular skeleton CHAPTER RESOURCES KEY CONCEPT SUMMARY

17.2 The skeletal system provides support and protection. skeletal system axial skeleton compact bone spongy bone The central part of the skeleton, which includes the cranium, the spinal column, and the ribs. axial skeleton appendicular skeleton CHAPTER RESOURCES KEY CONCEPT SUMMARY

appendicular skeleton 17.2 The skeletal system provides support and protection. skeletal system appendicular skeleton compact bone spongy bone The bones of the skeleton that function to allow movement, such as arm and leg bones. axial skeleton appendicular skeleton CHAPTER RESOURCES KEY CONCEPT SUMMARY

The skull and crossbones flying from a pirate ship have long been a symbol of death. Therefore, you might think that bones are dead structures made of rocklike material. This isn't true. The bones in your body are very much alive! Bones are living structures with 5 functions: protect internal organs support the body make blood cells store minerals provide for muscle attachment A point where two or more bones connect is called a joint. There are two different types of joints in the body: Movable joints (like ball-and-socket, hinge, gliding and pivot joints) Immovable joints (like the bones of the skull and pelvis) which allow little or no movement

Skeletal system game Locate the bones Whack a bone Virtual knee surgery Another bone game

Muscular System

Major Muscles Because there are so many skeletal muscles in your body, we can't list them all here. But here are a few of the major ones: In each of your shoulders is a deltoid (say: del-toyd) muscle. Your deltoid muscles help you move your shoulders every which way — from swinging a softball bat to shrugging your shoulders when you're not sure of an answer. The pectoralis (say: pek-tuh-rah-lus) muscles are found on each side of your upper chest. These are usually called pectorals (say: pek-tuh-rulz), or pecs, for short. When many boys hit puberty, their pectoral muscles become larger. Many athletes and bodybuilders have large pecs, too. Below these pectorals, down under your rib cage, are your rectus abdominus (say: rek-tus ab-dahm-uh-nus) muscles, or abdominals (say: ab-dahm-uh-nulz). They are also sometimes called abs for short. When you make a muscle in your arm, you tense your biceps (say: bye-seps) muscle. When you contract your biceps muscle, you can actually see it push up under your skin. Your quadriceps (say: kwad-ruh-seps), or quads, are the muscles on the front of your thighs. Many people who run, bike, or play sports develop large, strong quads. And when it's time for you to take a seat? You'll be sitting on your gluteus maximus (say: gloot-ee-us mak-suh-mus), the muscle that's under the skin and fat in your behind!

The muscular system makes movement possible. 17.3 The muscular system makes movement possible. Types of muscle Function muscular system skeletal muscle skeletal muscle, voluntary moves bones, maintains posture, maintains body temperature voluntary muscle smooth muscle smooth muscle, involuntary moves internal organs, such as the intestines involuntary muscle cardiac muscle cardiac muscle, involuntary pumps blood throughout the body CHAPTER RESOURCES SECTION OUTLINE

The skeletal system provides support and protection. 17.2 The skeletal system provides support and protection. II. The skeletal system provides support and protection. skeletal system A. Bones are living tissue. compact bone 1. Two Types of Bone Tissue spongy bone 2. Marrow and Blood Cells axial skeleton B. The skeleton is the body’s framework. appendicular skeleton 1. The Axial Skeleton 2. The Appendicular Skeleton C. The skeleton changes as the body develops and ages. CHAPTER RESOURCES D. Joints connect parts of the skeletal system. KEY CONCEPT SUMMARY

The muscular system makes movement possible. 17.3 The muscular system makes movement possible. III. The muscular system makes movement possible. muscular system A. Muscles perform important functions. skeletal muscle 1. Movement 2. Maintaining Body Temperature voluntary muscle 3. Maintaining Posture smooth muscle B. Your body has different types of muscle. involuntary muscle 1. Skeletal Muscle cardiac muscle 2. Smooth Muscle 3. Cardiac Muscle C. Skeletal muscles and tendons allow bones to move. CHAPTER RESOURCES D. Muscles grow and heal. KEY CONCEPT SUMMARY

Image Gallery Click on the icons to see a larger image or animation. CHAPTER HOME Image Gallery Click on the icons to see a larger image or animation. SIMULATION Explore the different systems in the human body. SIMULATION Assemble a skeleton.

Image Gallery 1 5 2 3 4 CHAPTER HOME Cells (cardiac muscle cells) Organism (human) 2 3 4 Tissue (cardiac muscle) Organ (heart) Organ system (circulatory system) BACK TO IMAGE GALLERY