2.5 structure & function of arteries, capillaries + veins

• What is the term used to describe the kidneys?

  Renal
• What does the pulmonary artery carry?

  Deoxygenated blood
• What are the main components of blood vessels?

  • Endothelium
  • Central lumen
  • Connective tissue
  • Elastic fibres
  • Smooth muscle
  • Valves
• What is the lumen of a blood vessel?

  Central channel through which blood flows
• What surrounds the endothelium in blood vessels?

  Layers of tissue
• What is the outer layer of arteries made of?

  Connective tissue
• What is the function of elastic walls in arteries?

  To stretch and recoil with blood flow
• What happens to arteries when the heart pumps blood?

  The walls expand
• What can smooth muscle in arteries do to control blood flow?

  Contract or relax
• What is the function of valves in veins?

  Prevent backflow of blood
• How do capillaries facilitate exchange of substances?

  Through their thin walls
• What is the thickness of some capillary walls?

  One cell thick
• Why do capillaries have a large surface area?

  To allow quick diffusion
• What is an arteriole?

  A small branch of an artery
• What is a venule?

  A very small vein
• What do vasoconstriction and vasodilation relate to?

  Controlling blood flow
• What happens to arterioles when you are too hot?

  They dilate
• What happens to arterioles when you are too cold?

  They constrict
• Why is blood supply important for exercising muscles?

  To provide nutrients and remove wastes
• What is the process of pressure filtration?

  • Plasma is squeezed out of capillaries
  • Occurs at high pressure in capillary beds
  • Supplies tissue fluid to surrounding cells
• What is tissue fluid?

  Liquid squeezed out of capillaries
• What does tissue fluid supply to cells?

  Glucose and oxygen
• How does much of the tissue fluid return to the blood?

  By osmosis and diffusion
• What happens to tissue fluid in lymphatic vessels?

  It becomes lymph
• What prevents backflow of lymph in lymphatic vessels?

  Valves
• What are the main components of blood?

  • Red blood cells
  • White blood cells
  • Platelets
  • Plasma
• What is the main component of plasma?

  Water
• What role does plasma play in the body?

  Exchange of materials between cells and blood
• What is the pressure of blood arriving at a capillary bed?

  High pressure
• What is the difference between tissue fluid and plasma?

  Tissue fluid lacks plasma proteins
• What is the function of the lymphatic system?

  • Returns tissue fluid to the bloodstream
  • Maintains blood volume
  • Prevents excess fluid accumulation in tissues
• What is the composition of tissue fluid compared to plasma?

  Similar, except lacks plasma proteins
• What happens to blood pressure as blood moves away from the heart?

  It decreases
• What does the renal artery do?

  Carries blood to the kidney
• What does the renal vein do?

  Carries blood away from the kidney