Transport in Animals

• What organ pumps blood in humans?

  The heart
• What do arteries do?

  Carry blood away from the heart
• What is the function of veins?

  Return blood back to the heart
• Where does material exchange occur in the circulatory system?

  In capillaries
• What is the role of capillaries?

  Site of exchange between blood and tissues
• How does blood flow from the heart to tissues?

  Through arteries to arterioles to capillaries
• What do tissues with high oxygen demand have?

  High capillary density
• What is tissue fluid composed of?

  Oxygen, water, glucose
• What happens to waste products in tissues?

  They diffuse back into capillaries
• What is the structure of arteries?

  Thick muscular walls and narrow lumen
• What is the term for the space inside a blood vessel?

  Lumen
• What is inner surface corrugation?

  Bumpy ridges inside arteries
• Why do veins have thin walls?

  They rely on surrounding muscles to push blood
• What is the shape of veins often like?

  Flattened due to muscle squeezing
• What prevents backflow in veins?

  Valves
• What is the aorta's function?

  Carry blood from the heart to the body
• What are coronary arteries responsible for?

  Supplying blood to the heart tissue
• What can block coronary arteries?

  Buildup of plaque
• What is coronary heart disease (CHD)?

  Blockage of coronary arteries
• What is a myocardial infarction?

  A heart attack due to blocked arteries
• What are some risk factors for CHD?

  Smoking, obesity, lack of exercise
• Why is it important to monitor heart health?

  To prevent blockages in coronary arteries
• What are the key features of arteries?

  • Thick muscular walls
  • Narrow lumen
  • Elastic and strong
  • Maintain high pressure
  • Inner surface corrugation
• What are the key features of veins?

  • Thin walls
  • Wide lumen
  • Relies on skeletal muscle for blood flow
  • Contains valves to prevent backflow
• What is the process of blood circulation in the body?

  1. Blood is pumped from the heart.
  2. Travels through arteries to arterioles.
  3. Enters capillaries for material exchange.
  4. Waste products diffuse back into capillaries.
  5. Blood returns to the heart via veins.
• What are the risk factors for coronary heart disease (CHD)?

  • Smoking
  • Obesity
  • Lack of exercise
  • High blood pressure
  • Poor diet
  • Age
• How does the structure of arteries relate to their function?

  • Thick walls withstand high pressure.
  • Narrow lumen maintains pressure.
  • Elastic fibers allow recoil after contraction.
• How does the structure of veins relate to their function?

  • Thin walls reduce resistance to blood flow.
  • Wide lumen accommodates low pressure.
  • Valves prevent backflow of blood.