Circulation and Gas Exchange

• True/False: Every organism must exchange materials with its environment
• For multicellular organisms ____ exchange is not possible. In these cases ______ like gills are required.

  Direct, specialed exchange systems
• In short every gas exchange system ____ diffuses from water into blood and _____ diffuses from blood into water

  O2, CO2
• Many animals like the axolotl have features that increase ___ ___ to maximize the total amount of diffusion

  surface area
• Diffusion is efficient for ___ distances and can be increased by ___ ___

  short, surface area
• In organisms where diffusion is not possible exchange happens through the ____ ____ that overcomes the slow rate of diffusion

  circulatory system
• The three components of a circulatory are

  1. A circulatory fluid
  2. Interconnecting vessels
  3. Pump(Heart)
• What are the two types of circulatory systems?

  Open and closed
• What is the fluid in an open circulatory system

  hemolymph
• In an open circulatory system, the hemolymph bathes the organs directly and isn't distinct from interstitial fluid
• In a closed circulatory system, blood is confined to ___ and is distinct from hemolymph

  vessels
• There are three main types of blood vessels

  arteries, veins, capillaries
• Arteries carry blood ____ from the heart and to capillaries. Then networks of capillaries called ____ ___ are sites of chemical ____ between blood and interstitial fluid. Viens then carry blood from these capillaries and to the ___.

  away, capillary beds, exchange, heart
• How are arteries and veins distinguished? 


  Direction of blood flow
• True/ False: Vertebrate hearts contain two or more chambers
• In the heart, blood enters through the ___ and exits through the ___

  atrium, ventricle
• ___ ___occurs in sharks/bony fishes (organisms with a two-chambered heart) and is where blood leaves the heart and passes through two capillary beds before returning.

  Single circulation
• In single circulation, oxygen-rich blood is found in the ____ while low-oxygen blood is found in the ____


  middle of the capillaries, artery
• True/ false:

  The problem with single circulation is that as the tract goes on the blood pressure gets low meaning that these aniaanimalsmls need to move a lot to get blood flowing
• ___ ___ occurs in amphibians, reptiles, and mammals.

  Double Circulation
• Double Circulation has oxygen-rich blood and oxygen-poor blood pumped ____ from different sides of the heart. Oxygen-poor blood flows through the ___ ____ and picks up oxygen at the ____. Oxygen-rich blood then delivers blood throughout the body through the ___ ___. 


  separately, pulmonary circuit, lungs, systematic circuit
• Which form of circulation has higher blood pressure

  double circulation
• In the mammalian circulation system, blood flow begins in the ____ventricle where blood is then pumped to the lungs by the _____ _____

  right, pulmonary arteries
• Once in the lungs blood loads ___ and unloads ____

  O2, CO2
• After unloading, oxygen-rich blood enters the heart through the ___ atrium by the ____ veins

  left, pulmonary
• After reaching the body the blood returns to the heart through the ____ ____ ____ and inferior vena cava. These flow into the ____ atrium

  Superior vena cava, right
• SRPLS--> the way to remember blood flow


  Right ventricle, lungs, left atrium, left ventricle, body systems, right atrium
• The layer that lines blood vessels is called the ___. They are smooth as to minimize resistance

  endothelium
• Which has thicker walls? Arteries, veins or capillaries 


  arteries
• Why do arteries have thicker walls?

  Accommodate the high pressure of blood pumped from the heart
• In veins how does blood reach the heart

  Primarily through muscle action
• True/False: Veins have thicker walls than arteries

  False
• Where is the velocity of blood the slowest and why?


  Blood is the slowest in the capillary beds because the exchange of materials happens here and that needs to be a slow process.
• Put in order the velocity of blood in different blood vessels

  Capillaries(3)

  Arteries(1)

  Veins(2)
• What is the lymphatic system responsible for? 


  Fluid return; some fluid leaks out from the capillary beds and is brought back via the lymphatic system
• Lymph means? 


  fluid lost by the capaillary beds
• Lymph ___ filter the lymph and play a role in ___


  nodes, defense
• How do you know when your body is fighting an infection 


  The lymph nodes are swollen and are tender
• Blood functions in three main things:

  exchange, transport, and defense
• In ___ circulation, fluid is continuous with the fluid surrounding the body cells(nondistinguishable)

  open