Why we need a lymphatic system | Lymphatic system physiology | NCLEX-RN | Khan Academy

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The cardiovascular system pumps blood to deliver oxygen and nutrients, with the lymphatic system collecting leaked fluid to maintain balance by returning it to blood circulation. High pressure in blood vessels forces fluid out, with some returning to the vessels while the rest is collected by lymphatic vessels and reintroduced into the bloodstream.

Insights

  • The cardiovascular system, composed of the heart, blood vessels, and capillary beds, plays a crucial role in delivering oxygen and nutrients to cells throughout the body.
  • The lymphatic system acts as a vital counterpart to the cardiovascular system, collecting leaked fluid from blood vessels and ensuring a sustainable balance by returning it to the blood circulation.

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Recent questions

  • What is the cardiovascular system?

    It consists of the heart, blood vessels, and capillary beds, circulating blood.

  • How do blood vessels in capillary beds function?

    They have increased surface area for efficient nutrient exchange.

  • What is the role of the lymphatic system?

    It collects leaked fluid and returns it to circulation.

  • Why does fluid leak out of capillaries?

    High pressure forces fluid out, passing between cells.

  • How do lymph vessels function?

    They collect lymph and reintroduce it into circulation.

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Summary

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Cardiovascular and Lymphatic Systems: Fluid Balance

  • The cardiovascular system consists of the heart, blood vessels, and capillary beds, with the heart pumping blood throughout the body to deliver oxygen and nutrients to cells.
  • Blood vessels in capillary beds have increased surface area for efficient exchange of oxygen and nutrients with cells, turning blue as they lose oxygen and return to the heart.
  • High pressure in the heart and blood vessels forces fluid, mainly plasma, out of the blood vessels, leading to a potential buildup of fluid outside the capillaries.
  • The lymphatic system addresses this issue by collecting the leaked fluid through lymphatic vessels and returning it to the blood circulation, ensuring a sustainable balance.
  • Fluid is forced out of capillaries due to high pressure, passing between cells, with smaller proteins and water leaking out while red blood cells and larger proteins remain inside.
  • The concentration of solutes and pressure differences along the capillary lead to some fluid being pulled back into the blood vessel, but more fluid is pushed out, resulting in lymph formation.
  • Lymph vessels, distinct from blood vessels, collect lymph from various parts of the body, starting small like capillaries and merging into larger vessels that eventually reintroduce the lymph into the blood circulation.
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