Transcript ch 7 notes
The Human Body Table of Contents Body Organization System Interactions Homeostasis The Human Life Cycle Taking Care of Your Body 7.1 Body Organization • Each part of the body has a specific job to do and must work together so smoothly that you don’t even notice them. • The levels of organization in the human body consist of cells, tissues, organs, and organ systems. • cell→ tissue → organ → organ system Cells • Cell is the basic unit of structure and function in an organism. • The human body contains about 100 trillion tiny cells, most cannot be seen without a microscope. • 100,000,000,000,000 = 1014 Cell Structure • The cell membrane forms the outside border of a cell. • The nucleus directs the cell’s activities and holds information that controls cell function. • The cell is filled with a clear, jellylike substance called cytoplasm. Cell functions • Cells carry on the processes that keep organisms alive. • Inside cells, molecules from food release energy that cells use. • Cells also grow, reproduce, and get rid of waste. Body Organization Body Organization This diagram tracks the levels of organization in the body. What are the missing level names? Body Organization Tissues A tissue is a group of similar cells that perform the same function. Tissues • Tissue is a group of similar cells that performs the same function. –Muscle tissue: contract, or shorten, to make parts of your body move. –Nervous tissue: directs and controls the processes, and carries electrical messages back and forth between the brain and other parts of the body. –Connective tissue: provides support for your body and connects all its parts. –Epithelial tissue: covers surfaces, inside and out to protect the structures beneath it. Body Organization Organs The heart, like other organs, is made of different tissues. Which tissue matches each function? Body Organization Organization of an Organism Tissues are made from cells, organs are made from tissues that perform different functions. Organs • Organs are made of different types of tissue to perform a function, but the job of an organ is more complex that that of a tissue. • Each type of tissue contributes in a different way to the organ’s job. Body Organization Systems and Organisms Each organ in the body is part of an organ system. Starting with cells, the levels of organization in an organism become more and more complex. Systems •An organ system is a group of organs that work together, carrying out major functions. •On pgs 246-247, find the functions of the following systems: Skeletal Integumentary Muscular Circulatory Respiratory Digestive Excretory Nervous Endocrine Reproductive Body Organization Body Systems, Part 1 Body Organization Body Systems, Part 2 System Interactions Synesthesia Explore how your senses overlap. Look at the shapes. One of them is called kiki and the other bouba. Which name do you think matches each shape? 7.2 Vocabulary • • • • • • • • • Skeleton Skeletal muscle Joint Nutrient Absorption Gland Stimulus Response Hormone How do you move? • All movements happen as a result of the interactions between body systems. System Interactions Muscles Moving Bones Muscles and bones work together and make the body move. The nervous system tells your muscles when to act. •Muscles contract and relax. When a muscle contracts, it shortens and pulls on the bones to which it is attached. System Interactions •Your skeleton bends at its joints. Muscles make bones move at their joints. The nervous system controls when and who your muscles act on your bones. Bones and Joints A joint is a place in the body where two bones come together. Which systems move materials in your body? • The circulatory, respiratory, digestive, and excretory systems play key roles in moving materials in your body. Transporting Materials • The circulatory system includes the heart, blood vessels, and blood. • Blood flows through the blood vessels carrying water, oxygen, and food to every cell. • Carbon dioxide and cellular wastes also move through the blood. System Interactions The Body’s Highway The circulatory system is like a set of roadways that carry materials to and from cells. Use the word bank to identify the materials that move between cells and the blood. Breathing In, Breathing Out • Breathing is an automatically controlled by the nervous system, but also depends upon the muscles that expand and compress the chest. • Oxygen moves into the lungs and into the bloodstream. The respiratory and circulatory systems work together to deliver oxygen and remove carbon dioxide. Carbon dioxide is carried by the blood to the lungs and exhaled. System Interactions Breathing In, Breathing Out Without even realizing it, you breathe in and out more than 20,000 times in one day. System Interactions Something in the Air How would you fill in the blanks to describe the functions of the respiratory system? System Interactions Getting Food •The digestive system helps to break down foods into sugars and other nutrient molecules that the body can use. •The circulatory delivers the nutrients to all the cells in the body. System Interactions Moving Wastes •The respiratory, circulatory, and digestive systems all have roles in the excretory system, which eliminates wastes from the body. •Cellular wastes filter out of the blood by the kidneys through urine. •Solid wastes are eliminated through the digestive system through feces. Which systems control body functions? • To function properly, each part of your body must be able to communicate with other parts of your body. • Other messages are sent by chemical signals that are produced by the endocrine system which is made up of glands. • The nervous system and the endocrine system work together to control body functions. System Interactions Nervous System •All actions are controlled by the nervous system which is made up of brain, spinal cord, and nerves. •Signals in the environment cause a response from the body. Responses are directed by the nervous system but often involve other systems. The eyes, ears, skin, nose, and taste buds send information about the environment to the nervous system. System Interactions Stimulus and Response What is the correct order of the pictures to show stimulus and response? System Interactions Endocrine System •Hormones are transported through the body by the circulatory system and affect many body processes. •Hormones control amount of water and amount of sugar in the bloodstream. They also affect the reproductive systems. The chemical signals released by the endocrine system are called hormones. Homeostasis Stress and Catching a Cold In the 1980s, scientists began to gather evidence that stress can affect the immune system. 7.3 Vocabulary • Homeostasis • Stress How does your body stay in balance? • Regardless of external temperature, the body’s internal temperature is almost always 37°C. • Conditions inside the body, such as chemical makeup, water content, and body temperature, all stay the same. • All of your body systems working together maintain homeostasis and keep the body in balance. Maintaining Homeostasis • The nervous and endocrine systems control responses. Other systems also play roles. • Regulating temperature: When cold, nervous system causes shivering; when warm, endocrine system releases hormones to perspire. Homeostasis Homeostasis and Regulating Temperature Homeostasis keeps the body and its outside environment in balance. • Meeting energy needs: when lacking energy, hormones from endocrine system signals the nerves to feel hungry; when full, nerves signal to stop eating. • Maintaining water balance: when lacking water, nerves signals thirst; excess water leaves the body through the excretory system. • Keeping balance: structures in the inner ear sense the position of the head; when off balance, the brain sends messages to muscles to regain balance. Homeostasis Meeting Energy Needs What are the signals between the nervous system and the digestive system that control feelings of hunger? Homeostasis Relate Cause and Effect How would you complete the cause-and-effect table? Responding to Stress • When stressed or startled, the endocrine system pumps adrenaline to make the heart beat faster and increase breathing. • Some stress is normal, but ongoing stress can disrupt the body’s ability to fight disease, cause depression, headaches, digestion problems, heart problems. Fighting Disease • Bacteria and viruses can enter the body and cause illness. • The immune system creates specialized cells that can attack and destroy bacterial and viruses . • The body may fight infections by causing the body temperature to increase. • Fever takes extra energy and causes the body to feel tired. System Rap Fun Facts 7.4 Vocabulary • Adolescence • Puberty What changes occur from infancy to adulthood? • The changes that take place between infancy and adulthood include physical changes, such as an increase in size, as well as mental changes, such as ability to communicate. Infancy • During the first 2 years of life, or infancy, a baby’s shape and size change greatly. • At birth, a baby’s head is about one-fourth of its body length, but the body catches up over time. • A baby may double its birth weight within the first year. • At the end of infancy, babies learn to communicate, follow instructions, and feed themselves. Childhood • After 2 years, childhood brings increased height and weight, more coordination, and increased mental abilities. • Language skills improve rapidly, and most children show curiosity. • Children learn to read, play games, and solve problems. The Human Life Cycle How would you use the data table to complete a line graph? What would be a good title for the graph? Adolescence • Adolescents gradually become able to think like adults by thinking critically. • Their bodies undergo specific physical changes based on their gender. • Hormones are produced by the pituitary gland and by ovaries (in girls) or by testes (in boys). • Girls look like women while boys look like men. The Human Life Cycle What are three effects of entering adolescence? Adulthood • After puberty, mental, emotional, and physical growth continue into adulthood. • After 30, some signs of aging become visible such as wrinkled skin and decrease muscle strength. • Hormone levels begin to drop causing a decrease in the ability to reproduce. The Human Life Cycle Describe the changes that occur during each stage of a person’s life. Taking Care of Your Body Reading a Food Pyramid The width of each band of the pyramid shows the portion of that group to include in a healthy diet. In which group would you place the foods you ate yesterday? Taking Care of Your Body Carbon Monoxide in the Blood The more cigarettes a person smokes, the more carbon monoxide he or she inhales.