Blood Vessels

The ________ is composed of circularly arranged layers of smooth muscle cells

• tunica interna
• tunica media
• tunica externa
• none of the above

In arteries, the thickest layer of the wall is the

• tunica interna
• tunica externa
• tunica media
• vasa vasorum

Gas, nutrient, and waste exchange occur between the __________ and the tissues of the body. 

• veins
• arteries
• capillaries
• legs

As an arterial pathway moves farther from the heart, the arteries

• get smaller
• get larger
• do not change in size
• have a party

As a venous pathway moves closer to the heart, the veins

• get smaller
• get larger
• do not change in size
• watch netflix

Precapillary sphincters will

• control blood flow into the true capillaries
• cause blood to flow directly from the metarteriole into the postcapillary venule
• open when the tissue needs nutrients
• All of the answers are correct

Valves in veins

• make the use of a skeletal muscle pump unnecessary for venous blood flow
• are the leading cause of high blood pressure.
• cause venous blood flow to go in only one direction
• are formed of the tunica media

Oxygen and carbon dioxide are transported between the blood and interstitial fluid by way of

• exocytosis and endocytosis by endothelial cells
• diffusion from areas of higher concentration to lower concentration
• pinocytosis using fluid-filled vesicles
• active transport (using ATP) by protein carriers of endothelial cells

Tags

NGSS.HS-LS2-3

Blood colloid osmotic pressure is largely due to

• the proteins in the blood, and it promotes reabsorption
• the high amount of water in the blood, and it promotes diffusion out of the capillaries
• the proteins in the blood, and it promotes filtration
• the high amount of water in the blood, and it promotes filtration from arterioles

Which statement is accurate? 

• Filtration dominates at the arterial end of a capillary bed, and is driven by osmotic pressure.
• Filtration dominates at the arterial end of a capillary bed, and is driven by hydrostatic pressure.
• Filtration dominates at the venous end of a capillary bed, and is driven by osmotic pressure.
  
  
• Filtration dominates at the venous end of a capillary bed, and is driven by hydrostatic pressure.