Transport in Organisms Don’t worry, urine good hands

What is transport? Transport – refers to all processes that move materials into and out of cells Materials must enter and exit cells via the plasma membrane Diffusion – material moving from high to low concentration, no energy required Osmosis – diffusion of water, no energy required Active transport – moves materials from low to high concentration, takes energy Water is very important to transport makes up most of cytoplasm in a cell Dissolves most materials to be transported Cells must have enough water but not too much Maintains homeostasis – internal balance of cells

How does transport in unicellular organisms work? What is a unicellular organism? Most of these organisms use diffusion Material moves through plasma membrane based on concentrations

How does transport work in multicellular organisms? All animals are multicellular Hydras and flatworms only have a few layers of cells (hydras only have 2 layers) None of their cells are far from the exterior environment These animals live in water where materials are mostly exchanged by diffusion Oxygen and carbon dioxide

What about larger multicellular organisms? Since most larger organisms cells are not in direct contact with the environment they have circulatory systems network of tubes or spaces that transport materials dissolved in a fluid to or away from the cells of an organism Purpose is to connect interior cells with exterior environment 2 types Closed circulatory system Open circulatory system

What does the circulatory system need? This system needs 3 things: Fluid for transporting material System of tubes and spaces for material to travel through Force that moves fluid through the body

What are closed circulatory systems? Closed circulatory systems – the fluids that transport materials never leave their network of tubes Most animals have blood as the fluid Blood transports glucose and oxygen while removing carbon dioxide Blood travels through hollow tubes called blood vessels Heart provides force to move blood in humans and most vertebrates 3 types of blood vessels Artery – carries blood away from heart Vein – carries blood to heart Capillaries – tiny vessels that allow gas exchange between cells and blood

Can invertebrates have closed circulatory systems? Earthworms, squid and octopi have closed circulatory systems heart animation

Assignment! Virtual Earthworm dissection Read the earthworm guide and use it to label the organism Call me over once you have labeled it and I’ll check you off Answer the journal questions on your own paper and turn it in http://www.mhhe.com/biosci/genbio/virtual_labs_2K8/labs/BL_17/i ndex.html

What are open circulatory systems? Open circulatory systems are not made of closed vessels Body cavity contains fluid that surrounds cells, tissues, and organs with nutrients and oxygen Fluid can’t be diverted to specific organs at specific times Common to mollusks (snails, oysters, clams) and arthropods (insects, spiders, crustaceans)

How do plants transport materials? Plants do not have circulatory systems or tubes but they do have tissues 2 types of plants Vascular plants (tracheophytes) Use vascular tissue to transport water and nutrients Includes some seedless plants like ferns, flowering and nonflowering plants Nonvascular plants (bryophytes) Do not have specialized tissue for transport 3 types Mosses Liverworts Hornworts Live in shady places to prevent drying out Usually small

How do organisms get rid of waste? Waste is generated through life processes and must be removed from the organism Simple organisms rid themselves of waste by diffusion Some cells store wastes in vacuoles until they can be removed Circulatory systems transport wastes to places they can be removed Urinary system – filters cellular wastes, toxins, and excess water from the body aka. Excretory system

How does the urinary system work? Kidneys are main organ of urinary system Blood enters kidney through renal (think kidney when you see renal) artery Blood is filtered to remove waste and excess water Clean blood returns to circulatory system through renal vein Waste leaves kidney as urine

Where does urine go once it leaves the kidney? Urine travels down the ureter to a saclike structure called urinary bladder Urine is stored in the urinary bladder until it leaves the body through the urethra excretory system

Does waste leave the body in other ways? Aside from the urinary and digestive systems, waste also leaves through skin and lungs Skin excretes water and salt as sweat or perspiration Maintains homeostasis (what is this again?) by cooling the body Lungs release carbon dioxide and water from cellular respiration

Assignment! Complete the excretory system worksheet packet All you need is the worksheet and something to write with