Organization of the Human Body On the cellular level, the structure of the human body is very complex and designed for efficiency. Every structure, from the different types of cells to the different organs, has a specific and unique function that all work together to maintain life. All of these functions are highly regulated and interactive to provide the processes and chemical products that are necessary to maintain life. The basic unit of structure and function of life. The cell is an organized system that is that made up of small structures, called organelles. Organelles are found within cells and allow cells to carry out their functions. Examples of organelles are: • Nucleus: Control center of the cell, the genes decide which proteins the cell makes. • Cell membrane: allows certain substances to pass through into the cell. • Mitochondria: carry out respiration and provide the cell with energy. • Cell wall: allows the cell to keep its shape • Vacuole: storage area for sugars and other minerals. • Chloroplasts: contain chlorophyll which converts sunlight into sugars for food. A group of cells of the same type, performing the same function Tissues Cells which all have a similar function are grouped together to form tissues. For example, muscles are made up of a group of muscle cells, all specialized to work hard. This group of cells forms muscle tissue. This muscle tissue is kept alive by the blood that supplies it. The blood is supplied through blood tissue. A group of tissues that work together to perform a function Organs An organ is made of a group of tissues all working together to perform a specific function. Examples of organs include the heart, the lungs, the liver, the stomach, and the brain. A group of organs working together to accomplish the same, or similar functions. The organ system is the highest level of internal organization for all organisms. An organ system is a group of organs that work together to perform a job. There are eleven systems in the human body. Example of a system: the mouth, esophagus, stomach and intestines are part of the digestive system. All of these organs all work to complete the common goal of nutrient extraction and absorption. Homeostasis, which is the body’s ability to maintain a stable internal environment, is dependent on all of the systems functioning properly and working together to create balance. There are certain factors that must be maintained for life to continue. These factors include temperature, blood glucose levels, blood pH, water balance, oxygen and carbon dioxide levels. The systems each functioning independently and normally, as well in conjunction with other systems creates an internal environment that is balanced, or in homeostasis. An example of systems working together to maintain homeostasis is the process of maintaining blood glucose levels. The digestive system is responsible for extracting glucose, which is a sugar, from food. The circulatory system then transports these sugar molecules to the cells, so that they can create cellular energy that can be used for the different types of cells to function. The respiratory system brings in the oxygen that is needed for cellular respiration and removes carbon dioxide as a waste product. If too much glucose is present, the endocrine system prompts the pancreas to release insulin to reduce the level. If too little glucose is present, the pancreas is stimulated to produce glucagon to release stored glucose from the liver and kidneys. All of this is ultimately regulated by the brain, which receives messages about internal and external stimuli from the nerves and neurons. Quick Review Complete the following activities and practices to review the concepts presented in this PowerPoint. Order the words below in the following pyramid. Have the smallest level on the bottom and work up to the largest. Organelle Organ Organism Cell Organ System Tissue Order the words below in the following pyramid. Have the smallest level on the bottom and work up to the largest. Organism Organ System Organ Tissue Cell Organelle Can you name any of the organ systems below? Can you name any of the organ systems below? Endocrine Respiratory Skeletal Muscular Digestive Circulatory Nervous Determine if the following statements are true or false. Tissues are made from only one type of cell. Lots of organ systems work together to make an organism. An organelle is bigger than an organ The circulatory system carries electrical messages around the body The spinal cord and brain are organs in the Nervous System Determine if the following statements are true or false. Tissues are made from only one type of cell. True Lots of organ systems work together to make an organism. True An organelle is bigger than an organ. False The circulatory system carries electrical messages around the body. False. The spinal cord and brain are organs in the Nervous System. True Review Questions 1. What are the functions of these organelles: a) Nucleus b) Chloroplast c) Mitochondria 2. What is the job of the digestive system? 3. What is the role of tissue? 4. What are the components of an organ system? 5. How is homeostasis maintained? Review Questions 1. What are the functions of these organelles: a) Nucleus- Control center of the cell b) Chloroplast- Contain chlorophyll which converts sunlight into sugars for food c) Mitochondria- Carry out cellular respiration and provide the cell with energy 2. What is the job of the digestive system? To extract nutrients from foods that we eat. 3. What is the role of tissue? Group of like cells that carry out a specific function. 4. What is an organ system? Group of organs and tissues that perform together to accomplish a specific function. 5. How is homeostasis maintained? By the different systems functioning properly independently and together as a group.