Entrance poll (Transport in mammals)

Which structural feature of veins helps maintain one-way flow of blood?

• Thick muscular walls to withstand high pressure

• Valves that prevent backflow

• C. Narrow lumen to slow blood flow

• 1. No endothelial lining

If a person’s blood has an abnormally low platelet count, which immediate effect is most likely?

• Significantly decreased oxygen transport

• Reduced ability to form blood clots

• Dramatic drop in blood pressure

• Impaired antibody production

Which statement best describes the primary function of capillaries?

• They only transport oxygenated blood.

• They link arteries and veins, allowing the exchange of substances with tissues.

• They maintain high blood pressure throughout the circulatory system.

• They store excess blood for later use.

If a patient’s red blood cell (RBC) count significantly decreases, which problem is most likely to occur first?

• Reduced ability to fight off infections

• Impaired blood-clotting mechanism

• Decreased transport of oxygen to tissues

• Low production of metabolic hormones

Which of the following pairs identifies the main blood vessels entering and leaving the kidney?

• Renal artery (in), renal vein (out)

• Renal vein (in), renal artery (out)

• Vena cava (in), hepatic portal vein (out)

• Pulmonary artery (in), pulmonary vein (out)