Body organization Coulter Body organization The levels of

Body organization Coulter

Body organization The levels of organization in the human body consist of cells tissues organ systems. Cell is the basic unit of structure and function in a living thing. The human body contains about 100 trillion cells.

Tissue is a group of similar cells that perform the same function. The human body contains four basic types of tissue Muscle tissue: can contract or shorten. Makes parts of your body move. Nervous tissue: carries electrical messages back and forth between the brain and other parts of the body. Connective tissue: provides support for the body and connects all its parts. Bone tissue and fat are connective tissue. Epithelial tissue: skin, protects delicate structures that lie beneath it.

Organs and organ systems Organ is a structure that is composed of different kinds of tissue. Organ performs a specific job which is more complex than the tissue. The heart pumps blood all throughout your body, over and over again. The heart contains all four kinds of tissue (muscle, nervous, connective and epithelial. Each tissue contributes to the organ’s overall job of pumping blood. Organs system is a group of organs that work together to perform a major function. Heart is part of the circulatory system, which carries oxygen and other materials throughout the body. Circulatory, digestive, nervous, skeletal, respiratory, excretory system, muscular, and endocrine.

Homeostasis is the process by which an organism’s internal environment is kept stable in spite of changes in the external environment. Your body has various ways of maintaining homeostasis. When you are too warm, you sweat. When you are cold, you shiver.

Stress and homeostasis Stress is the reaction of your body to potentially threatening, challenging, or disturbing events. Think about when you leave the starting line in a bike race. Your heart beats faster and your breathing increases. What is happening in your body? First, your endocrine system releases a chemical called adrenaline into your bloodstream. Adrenaline gives you a burst of energy and prepares your body to take action. Your muscles work harder and require more oxygen. Your heart beats even faster to move more blood to your muscles. Your body is experiencing stress. After you cross the finish line, you continue to breathe hard for the next few minutes. Soon, your breathing and heart rate return to normal. Homeostasis is restored after a few moments.

Skeletal system Skeleton is make up of all the bones in your body. The number of bones in your skeletal system depends on your age. Newborn has about 275 bones Adult has about 206 bones. Your skeleton has five major functions Shape and support Enables movement Protects organs Produces blood cells Stores minerals and other materials.

Shape and support Skeleton determines the shape of your body. The backbone, vertebral column, is the center of the skeleton. If your backbone were just one bone, you would not be able to bend or twist. Think of each individual vertebra as a bead on a string. These beads on a string allow you to move as you do.

Movement and protection Most of your body’s bones are associated with muscles. The muscles pull on the bones to make the body move. Production and storage of substances: some of your bones produce substances that your body needs. Long bones in your arms and legs that make certain blood cells. Bones also store minerals such as calcium and phosphorus. When the body is in need of these minerals the body releases a small amount.

Joints of the skeleton Joint is a place in the body where two bones come together. Joints allow the bones to move in different ways. There are two kinds of joints Moveable: allow the body to make a wide range of movements. These joints are held together by strong connective tissues called ligaments. Most have a second type of connective tissue, called cartilage, which is more flexible than bone. Cartilage covers ends of bone and keeps them from rubbing against each other. Immovable: some joints in the body connect bones in a way that allows little or no movement. Bones of the skull are held together by immovable joints.

Movable joints Hinge joints: allows forward or backward motion. Your knee is a hinge joint that allows you to bend and straiten you leg. Elbow is also hinge joint. Ball-and-socket joint: allow the greatest range of motion. Shoulder, allows you to swing your arm freely in a circle. Your hips also have ball-and-socket joints. Pivot joint: allows one bone to rotate around another. Pivot joint in the neck allows you to turn your head from side to side. Gliding joint: allows one bone to slide over another. In your wrist and ankle enables you to bend and flex as well as make limited side-to-side motions.

Bones structure Bones are complex living structures that undergo growth and development. Compact bone, hard and dense, but solid. Canals carry blood vessels and nerves from the bone’s surface to the living cells. Spongy bone, has many small spaces within it. Lightweight but strong. Found in the ends of bone Marrow, there are two types Red: produces blood cells. As a child, most of your bones contained red bone marrow. As a teen, only ends of femur, skull, hip, and sternum. Yellow: stores fat

Bone strength The structure of bone makes it both strong and lightweight. Bones are so strong that they can absorb more force without breaking than concrete or granite rock. Bones are hard because they contain minerals; phosphorus and calcium.

Bone Growth Bones are alive! They contain cells and tissues, such as blood and nerves. Bones also form new bone tissue as you grow. Even after you are grown bone tissue continues to form within your bones. Example: bones absorb force of your weight during sport activity and respond by making new bone tissue. New bone tissue can form after an accident; broken bones.

Types of bones Axial Skeleton: The skull, spine, ribs, vertebrae and sternum Appendicular Skeleton: bones of the upper and lower limbs and hips Types of bones: Long bones: humerous Short bones: wrist and ankle bones Irregular bones: facial bones Flat bones: ribs

Bone Development As an infant, much of your skeleton was cartilage (same as the end of your nose or ear). Over time most of the cartilage was replaced by hard bone. The replacement of cartilage with bone tissue is usually complete once you stop growing. Not all of the cartilage in your body is replaced by bone. Many joints contain cartilage that protects the ends of the bones.