Unit 2 - Human Body

The human body (and just about all other multi cellular organisms) are made up of cells. Cells - that have similar jobs - make up tissues, which (if they have similar functions) make up organs. Organs that have similar functions work as a specific system.

Cells are the smallest form of a living thing. It can function on its own but when working with other cells that have the same/close to the same jobs, they create tissues. Cells have organelles (a specialized subunit within a cell that has a specific function, and it is usually separately enclosed within its own lipid bilayer). These organelles include: mitochondria, nucleus, ATP, cytoplasm, endoplasmic reticulum, ribosomes, lysosome, cell wall, cell membrane, Golgi bodies, chloroplast (only in plant cells), vesicles, and vacuole. All of these organelles have different jobs they have to do for the cell to work right. The nucleus is the "brain" of the cell, it stores the information; the mitochondria is the power house of the cell, it converts the glucose into ATP/energy. The cytoplasm is the glue, it keeps everything together; the endoplasmic reticulum transports the needed material throughout the cell, it is the highway of the cell. The ribosomes are the proteins of the cell; the lysosomes remove wastes and clean up the cell, they are the clean up crew. The Golgi bodies package the needed material, they are the UPS stores of the cell; the cell membrane and cell wall both provide a level of defense for the cell, but the cell wall is more of the wall while the cell membrane is more like a body guard. the chloroplasts are only found in producers/plant cells, they do the act of photosynthesis; the vacuole  stores the water for the cell, they are the storage rooms.

There are different types of tissues: connective, muscular, and skeletal. Then you have the organs of the body. The three major body organs are: the heart, lungs, and the brain. Several different organs make up organ systems. There are the: circulatory, skeletal, Integumentary, reproductive, digestive, endocrine, lymphatic, urinary/excretory, muscular, nervous, and immune.

Purposes of the Systems:

• Circulatory: pumping and channeling blood and needed materials throughout the body using the heart, blood vessels, and blood.
• Integumentary: skin, hair, and nails; protective covering
• Skeletal: structural support and protection with bones, cartilage, ligaments, and tendons
• Reproductive: allows organisms to reproduce
• Digestive: digestion and processing food with salivary glands, esophagus, stomach, liver, gallbladder, pancreas, intestines, rectum, and anus
• Urinary: excretion of urine and balance of electrolytes using the kidneys, ureters, bladder, and urethra
• Respiratory: in charge of getting and exchanging oxygen for CO2 using the pharynx, larynx, bronchi, lungs, and diaphragm
• Endocrine:communication within the body using hormones made by the endocrine glands
• Lymphatic: structures involved in the transfer of lymph between tissues and the blood and includes the function of immune responses and development of antibodies
• Muscular: allows for manipulation of the environment, provides locomotion (movement), and produces heat (homeostasis)
• Nervous: collecting, transferring and processing information with the brain, spinal cord, and peripheral nervous system

All of the organ systems then make up an organism. These levels of organization go for all of the different multi cellular organisms, even in organisms as small as a fly. 

Website For Additional Information:

http://www.kidsbiology.com/human_biology/index.php