Circulatory

• What are the three layers of the blood vessel wall?

  Tunica interna/intima, tunica media, tunica externa/adventitia
• What are the components of the tunica interna/intima?

  • Endothelium
  • Basement membrane
  • Internal elastic lamina
• What is the characteristic of the tunica media?

  It is the middle coat and the thickest layer of the blood vessel wall.
• What are the components of the tunica media?

  • Smooth muscles
  • Elastic fibers
• What is the function of the tunica externa/adventitia?

  It serves as the outer coat of the blood vessel wall.
• What are the components of the tunica externa/adventitia?

  • External elastic lamina
  • Collagen fibers
• What are the five types of blood vessels?

  Arteries, arterioles, capillaries, venules, veins
• What is the predominant layer in arteries?

  Tunica media
• What is the primary function of arteries?

  To carry blood away from the heart to other organs
• What are the two types of arteries?

  1. Elastic arteries
  2. Muscular arteries
• What are elastic arteries also known as?

  Conducting arteries
• What is a characteristic of elastic arteries?

  They have a greater amount of elastic tissue than smooth muscle.
• Name some examples of elastic arteries.

  • Aorta
  • Brachiocephalic
  • Common carotid
  • Subclavian
  • Vertebral
  • Pulmonary
  • Common iliac
• What are muscular arteries also known as?

  Distributing arteries
• What is a characteristic of muscular arteries?

  They have more smooth muscles than elastic fibers.
• Name some examples of muscular arteries.

  • Axillary
  • Brachial
  • Radial
  • Intercostal
  • Splenic
  • Mesenteric
  • Femoral
  • Popliteal
  • Tibial
• What are vasa vasorum?

  Small arteries that supply arteries and veins with a diameter greater than 1 mm.
• What are arterioles?

  Small, microscopic arteries that deliver blood to capillaries.
• What is the function of arterioles?

  To regulate blood flow into capillaries.
• What are capillaries?

  Microscopic vessels that connect arterioles to venules.
• What are the components of capillaries?

  • Endothelium
  • Basement membrane
• What is the function of capillaries?

  To exchange materials.
• What are the three types of capillaries?

  1. Continuous
  2. Fenestrated
  3. Sinusoids
• What are continuous capillaries?

  They are the most common type, with an uninterrupted ring around the capillary.
• What are fenestrated capillaries?

  They have many fenestrations (pores) in the plasma membrane.
• What are sinusoid capillaries?

  They contain spaces between endothelial cells and have an incomplete or absent basement membrane.
• What are venules?

  Small veins formed from the union of capillaries.
• What is the function of venules?

  To collect blood from capillaries and drain into veins.
• What is a characteristic of veins?

  They are distensible.
• What is the predominant layer in veins?

  Tunica adventitia
• What is the function of veins?

  To transport blood back to the heart.
• What are the two types of veins?

  1. Large veins
  2. Medium veins
• What is the function of large veins?

  To transport blood from medium veins into the heart.
• What is the function of medium veins?

  To collect blood from small veins and deliver them to large veins.
• What are venous valves?

  • Thin folds of tunica interna
  • Form flaplike cusps
  • Aid movement of blood back to the heart
  • Prevent backflow of blood
• What are the components of the Circle of Willis?

  1. ACA
  2. Anterior communicating artery
  3. ICA
  4. PCA
  5. Posterior communicating artery