Classification of Living Things & Human Body Systems

Classification of living things To classify organisms, scientists examine the similarities and differences between organisms. To place an organism in a kingdom, the following characteristics are considered: Is the organism single celled or multicellular? Is the organism able to make its own food? Do the cell(s) have a nucleus?

Classification Organisms are placed into more & more specific categories: Kingdom Phylum Class Order Family Genus Species Remember: Ken poured coffee on Fred’s good shirt!

The 6 Kingdoms Archaebacteria Eubacteria Protists Fungi Plant Animal # of Cells Single Most are multi Multi Make own food Some can some cannot Some can some can’t Cannot Can Nucleus None none present

Binomial nomenclature- naming organisms Example: tiger Panthera tigris The Genus is always capitalized and is the first name of the organism. The species is lower case and is the second name of the organism.

Cell Organization In multicellular organisms, cells are organized to perform different jobs for the body: Cells  Tissues  Organs  Organ Systems

The organization of cells Tissue Organ Organ system Organism = + + + + = + = + =

Human Body Systems The human body is divided up into several systems to complete the metabolic tasks of the body.

SKELETAL SYSTEM Function- The bones of the skeletal system provide structure & support and protect the internal organs of the body. Main organs- 206 bones, ligaments, tendons.

Muscular System Function- Muscles are attached to the skeleton and allow the body to move. Muscles also line internal organs like the stomach, lungs and heart. Main organs- voluntary & involuntary muscles.

DIGESTIVE SYSTEM Function- Takes in and breaks down nutrients into particles small enough to be absorbed in the small intestine. These particles enter the blood stream and are transported by the circulatory system to all cells in the body. Main organs- mouth, esophagus, stomach, small intestines, large intestines.

RESPIRATORY SYSTEM Function- takes in O2 and releases CO2 . Main organs- mouth, nose, trachea, bronchi, lungs, alveoli. The alveoli (air sacs) release O2 into the blood and remove CO2 from the blood.

CIRCULATORY SYSTEM Function- Transports food and oxygen to body cells. Blood vessels carry food and O2 to all cells in the body and carry waste away from cells. Main organs- heart, arteries, veins, capillaries.

NERVOUS SYSTEM Function- The brain receives and interprets information from the nerves in the body. Maintains homeostasis in the body. Main organs- brain, spinal cord, nerves.

The respiratory system works with the circulatory system The trachea is the tube that takes air from the nose and mouth and passes it into the lungs. Respiratory takes in oxygen and passes it to circulatory. The circulatory carries oxygen where it passes by diffusion into the cells In the cells the oxygen is used by mitochondria to do cellular respiration (using oxygen to release the energy in food.

The digestive system works with the circulatory system The stomach is the part of the digestive system that breaks down food into small particles. The small particles are absorbed into the circulatory system in the small intestine. The food is then transported throughout the body to each cell to provide the glucose necessary for the mitochondria to carry out cellular respiration.